ClassicBroncos.com Tech Articles » Transmission

C4 Valve body service and modifications

BwoncoHowie — Fri, 21 Aug 2009 23:20:45 +0000

The purpose of this article is to explain and cover some basic info about do it yourself C-4 Valve body service. The actual valve body is from a 1974 Bronco, therefore the illustrations may differ slightly from what you may be working on. If you are inexperienced as a mechanic, perhaps you should get help when performing the steps shown below. It is recommended that you read the entire article first so you may prepare all the tools and materials as well as a clean work environment. After reading through the article first, you can then make notes on where your valve body may need attention. Some steps that are performed later may be mentioned early in the article in order to save time and computer space. VB is referring to Valve Body.

VB disassembly starts with the removal of these 2 bolts shown circled in green below.

Note: The 2 dots show where the Kick-down lever and the pin on the rooster comb must go to be properly indexed while installing the VB back into the Trans.

Next, remove the long main filter bolts and the 9 shorter VB bolts. Notice the correct location of the ID tag. This picture shows the throttle pressure limit valve and spring have not yet been removed. You should remove them at this time before taking the VB halves apart.

When the VB halves were first split apart the hockey puck was stuck to the separator plate indicated by the arrow. The circles show the proper locations of the viton shuttle ball and puck. Discarding the puck from the assembly will aid in firming up the shifts and will not hurt the transmission.

Next, remove the bolt holding the separator plate and gasket to the channel plate. Note proper locations of the 2 remaining Viton Check Balls. The one in the bathtub is mandatory; the other one can be removed for a firmer 3^rd gear shift. The channel plate is where a lot of sediment can collect and it is very important to clean it thoroughly. After cleaning with a suitable solvent, these components should be dried with compressed air in order to keep foreign particles like dirt and rag lint to a minimum. We refer to these channels that the hydraulic pressure travels through as “Worm Tracks”.

Drill separator in 2 locations as shown. Remember, these modifications are non reversible unless you have a spare unmodified separator plate. If you are unsure about having a firm shift, you can use the next two smaller drill bits 7/64” and 3/32” accordingly for a less aggressive modification that is near stock but slightly firmer. Caution: Do not drill any holes larger than 1/8” This is unnecessary and can cause valve body cross leakage and gasket damage. Drilling these holes larger than 1/8” is also rough on the rest of the Bronco drivetrain, Axles, U-Joints, Splines, Differentials, Transfer Cases, and Motor Mounts, etc. A high speed steel counter sink bit works very well for taking burrs off of holes that have been enlarged. (See last photo # 23)

This picture shows a 2 oz. ball peen hammer and a 3/8” steel ball bearing being used to knock down the sharp edges around the 2 holes on the separator plate where the shuttle balls need to travel. By doing this you will add longer life to the Viton Checkball. Do this to the plate in each of the 2 bathtub locations on the side of the plate that actually makes contact with the shuttle ball (Viton Checkball). Also prepare the 3^rd check ball location, it’s the larger hole that covers the single well used by the direct clutch feed passage. You don’t need to tap it very hard because all you are doing is dulling the sharp edge left by the factory hole punch and making a tapered seat for the ball to seal against. I’m using a machined flat piece of steel as a backing plate during this modification.

The next picture shows the valve components from left to right and top to bottom in that order. After cleaning, all valves must move freely in their perspective bores.

1. Shift valve retaining plate.

2. 1-2 Shift valve.

3. Manual 2^nd valve.

4. 1-2 Shift valve spring.

5. 2-3 Shift valve.

6. 2-3 Shift valve spring.

7. Throttle Modulator Valve.

8. Retaining plate for Transition and Cutback valves.

9. Transition valve spring, (outlined in red) which should be removed and discarded for Heavy Duty use

10. Transition valve.

11. 2-3 Back-out valve.

12. 2-3 Back-out valve spring

13. Cut-back valve, which uses no spring. For Heavy Duty and street versions, this valve can be blocked by inserting a spare viton checkball in the bore before inserting the valve and retaining plate, noted by the red dot.

This picture shows the shift valves installed after cleaning. They have been lubricated with a 50/50 mixture of Slick50 and Type-F transmission fluid. Note the spring tension is pushing the valves partially out of their bores. Install all valves and their retaining plates but when tightening the retaining plate bolts make sure the retaining plate will have plenty of clearance with the separator plate when the valve body halves are bolted together.

This picture shows the proper order of the servo accumulator valve.

By reversing the order of the spring to the outboard area of the valve will cause a firmer 2^nd gear shift. You may not want to perform this modification at first. Experimenting with the other milder mods first, may give you the desired results.

The main pressure regulator valve, and the Booster valve with its sleeve is shown removed for cleaning purposes. Note the spring retainer slips over the tail of the valve. And the smaller Booster spring rests inside the larger pressure regulator spring. Use a dab of Vaseline to hold the booster valve in its sleeve for easier assembly of the pressure regulator valve and springs. Vaseline has a low melting point and is perfectly compatible with all transmission fluids. The booster sleeve is retained by a small spring-clip, some models will use an (L)-pin in this location.

Pressure regulator components are shown from left to right in this order.

1. Retainer clip and booster valve sleeve.

2. Booster valve

3. Main pressure regulator spring.

4. Booster valve spring

5. Spring retainer

6. Main pressure regulator valve.

Check the operation of the kick-down valve by pushing the plunger shown in the first picture, make sure it moves freely and returns fully after the valve casting half has been cleaned with solvent and dried with compressed air. You may also move the other remaining valves with a pick/scribe to assure that they slide freely in their bores. If any of these valves are sticking or frozen, It is recommended that they be removed from their bores and the valve casting be cleaned carefully.

The picture shows a pick being used to move the valves against spring tension to see if they return to the home position.

After cleaning and assembling the valves, and cleaning and removing all traces of dirt and old gasket material, you will be ready to assemble the VB halves together. Start by selecting the proper gasket and with a few drops of trans oil, position the new gasket on the plate. Make sure the gasket is on the correct side between the separator plate and the lower VB channel plate. Position the gasket so all the holes are centered as much as possible. Some commercial Valve body modification service packages may ask you to delete this gasket. If your VB shows signs of having commercial aftermarket VB modifications installed, it may already have this gasket missing. If so, do not re-install a new gasket.

The next step is to turn the plate over and make sure no holes are blocked by a mis-aligned or wrong gasket.

The plate can then be placed over the channel plate. Make sure the necessary shuttle ball is in place and if desired, replace the 3^rd gear Kick-down check ball.

Here again shows the channel plate and check balls before the separator plate is placed into position.

Secure the separator plate with gasket to the channel plate with 1 of the short 10-24 bolts finger tight to make up the channel plate sub-assembly and set aside.

This picture shows the valve casting assembled, with the check ball and hockey puck already installed; ready for attachment to the channel plate and separator plate sub-assembly. Refer back to illustration No. 3 to see the proper location of the hockey puck and shuttle ball.

This picture shows the channel plate assembly with the valve body in position. Note the 2 quarter 20 bolts installed only finger tight at this point. A pair of tapered awls used in 2 specific locations for aligning the separator plate with the channel plate. At the time these awls were purchased I thought that MAC TOOLS made the best tools for this particular job. Tapered punches or dowels can also be used for this. These are the only 2 holes that should be used to align the plates before tightening the bolts.

120 inch pounds on the ¼-20 bolts.
46 inch pounds on the 10-24 bolts.

The following picture shows a well proven tightening sequence for these particular fasteners. The last bolt shown by the arrow, is installed loosely for alignment purposes during the assembly of the valve body. It will be removed and re-installed again after the valve body has been bolted-up to the transmission case. If you use a torque wrench, and have the ability to work in a clean environment, you are well on your way to putting together a quality piece of craftsmanship.

You should always try to include a filter gasket when doing work on the Bronco C-4 filter, even a used metal gasket is better than none at all. Be sure to install the throttle pressure limit valve and spring before installing the filter screen. NOTE; The Bronco specific sump pick-up pipe is missing from the filter in this illustration. It will be installed into the filter before the transmission pan is installed.

This picture shows the 2-3 shift valve and spring, and the throttle pressure limit valve and spring for size comparison. Notice the shift valve spring is slightly longer. The springs are very similar, don’t get them mixed-up.

This picture shows the filter being positioned, again using a tapered awl for alignment of the filter, and filter gasket with the bolt hole before tightening the filter bolts. Refer back to the tightening sequence to complete the filter installation. Don’t forget the 3 bolts on the other side need tightening, and it doesn’t hurt to double check the valve retaining plate bolts, if you leave them loose, you will get no upshift. With all the bolts properly torqued, this VB is ready for installation.

A little something regarding screens and filters:

With the C-4, always use them whenever possible, they will save you a lot of time and headaches. Ford engineers put them there for a good reason, clean and re-use them don’t leave them out! The C-5 uses the same screens and they are no longer available new. So if you need them try to get them from a used transmission where the last technician had enough sense to put them back where they belong.

On the left is the Governor screen, it is installed in the governor support distributor housing feed passage before installing the governor valve assembly. Service to the governor will not be included in this tech article, but I thought it was important enough to mention the need for this screen that is commonly deleted from the assembly during service. On the right is pictured the larger pump pressure port screen, which is installed in the case passage before the valve body is installed. There are 2 ports that are often confused that this screen will fit in. Correct installation is in the port closer to the shift lever. Both of these screens can help to save you from having sticky valves and damage due to particle contamination in the valve housings.

Here is a picture of my countersink drill bit I use it in the drill chuck with very light pressure to remove rough edges after drilling/enlarging holes in the separator plate.

I hope you enjoy reviewing this info as much as I enjoyed sharing it with you.

I also wish you success with your VB repairs and hope this article is helpful for those of you who want to improve the performance of your C-4 or just make the VB function correctly.

Tech article by BwoncoHowie

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Early Bronco Transmission Guide – Automatic Options

admin — Thu, 15 Jan 2009 05:01:59 +0000

Tech article by Jon Hanna (Admin)

This is the second article in a two part series on popular transmission swaps into your early Bronco. The first article focused on several manual choices for those who like to row their own gears. This second article is for you folks who prefer the ease and drivability of an automatic.The 3 speed manual or C4 automatic that came stock in the Bronco serve their purpose, but they’re not the best to be had. Some people want a stronger, more reliable transmission with ultra low gearing for those tough trails. For others, street performance is more important and a highway friendly overdrive becomes essential for those long commutes. And then there are some (all?) of us that want both!

This article is meant to give you some basic information to help you decide which transmission is best for your needs. There are several fine points to each conversion that aren’t covered here, such as TV cables, shifters, wiring, etc. Once you pick a tranny to go with you should research it thoroughly with the company providing the adapter.

Automatic transmissions are complicated and can be very daunting to the novice mechanic. It’s recommended that you have a competent shop do a rebuild since many of these units have weak points that a qualified rebuilder should be able to correct. Typically a new torque converter should also be installed, and you should research your choices here as well. The torque converter can have a significant impact on how your Bronco drives. As with most transmission swaps, headers can cause all sorts of grief. If you have headers, or plan on installing them, you should measure thoroughly so you aren’t surprised when you try to shoehorn that new tranny in.

This article assumes a small block Ford V8 engine is being used and the Dana 20 transfer case retained. The pricing shown is very approximate and conservative. Your prices may vary depending on your location and how friendly you are with you local salvage yards.

Use the following links for individual transmission pages:

Intro to Manual Transmissions

Intro to Automatic Transmissions

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700R4 4 speed automatic – Transmission Guide

admin — Thu, 15 Jan 2009 03:59:47 +0000

Tech article by Jon Hanna (Admin)

Automatic Trans Intro
• Gear Ratio Chart
• C4
• C6
• AOD
• AODE & 4R70W
• 700R4
See also Manual Trans

Transmission:
	700R4 Chevy 4 speed automatic with overdrive
Sources:
	1982-1993 Chevy 8 cyl cars and trucks. 1987 and newer models are preferred due to a redesign that corrected several problem areas.
Identification:
	Has a one-piece cast aluminum case and bell housing design. Look for a unique slope at the bottom of the bell housing. Case length of approximately 23.5″ and weighs 155-160 lbs.
Adapter required?
	Since the 700R4 is a Chevy transmission a bell housing adapter, new flex plate and torque converter adapter must be used to bolt up to Ford engines. Likewise an adapter kit is required to mate to the Dana 20 transfer case which should include 2 adapters, a new output (main) shaft and spud shaft.
Pros:
	The gear range is one of the best available in an automatic transmission. The low 1st gear combined with an overdrive makes it a great choice for street and trail rigs. The 700R4 is a reliable and well known with a large aftermarket following. They’re fairly easy and inexpensive to come by.
Cons:
	Well, it is a Chevy! Early versions (pre-1987) had some design problems, which gave the 700R4 a bad name, and some still prefer not to use them. However, these have been around long enough that it’s not hard to find shops to build them properly.
Cost: (Approximate)
	Transmission: $150-500 used and $800-1600 rebuilt Adapter to engine: $400 Adapter to transfer case: $500-550
Drive Shaft Mods:
	Total transmission is approximately 1.5″ longer requiring some drive shaft modifications
Bell housing:
	The 700R4 does not bolt up to Ford engines. An adapter kit is required.
Modifications needed:
	The transfer case is set back further requiring a larger hole in the floor and a new and/or modified cross member. An aftermarket transmission shifter or modification to your stock automatic shifter will be required. Transfer case to floor may be tight if you don’t have a body lift installed and the front drive shaft may be very close to the transmission pan depending on your lift. A smaller diameter front drive shaft or transmission pan modification may be required.

Manual Transmissions	1st	2nd	3rd	4th	5th
Bronco 3 spd (6 cyl)	3.41	1.86	1.00
Bronco 3 spd (8 cyl)	2.99	1.75	1.00
NP 435	6.69	3.34	1.79	1.00
T-18	6.32	3.09	1.69	1.00
Toploader (Close ratio)	2.32	1.69	1.29	1.00
Toploader (Wide ratio)	2.78	1.93	1.35	1.00
Toploader (Overdrive)	3.29	1.84	1.00	0.81
ZF	5.72	2.94	1.61	1.00	0.76
NV4500 (Dodge)	5.61	3.04	1.67	1.00	0.73
Automatic Transmissions	1st	2nd	3rd	4th	5th
Bronco C4	2.46	1.46	1.00
C6	2.46	1.46	1.00
AOD	2.40	1.47	1.00	.67
AOD w/ low gear set	2.84	1.55	1.00	.67
AODE/4R70W*	2.84	1.55	1.00	.67
700R4	3.06	1.62	1.00	.70

No related posts.

AODE & 4R70W 3 speed automatic – Transmission Guide

admin — Thu, 15 Jan 2009 03:58:42 +0000

Tech article by Jon Hanna (Admin)

Automatic Trans Intro
• Gear Ratio Chart
• C4
• C6
• AOD
• AODE & 4R70W
• 700R4
See also Manual Trans

Transmission:
	AODE & 4R70W (E = electronic, W = wide ratio) 4 speed automatic with overdrive
Sources:
	These were replacements to the older AOD. The AODE was available in 1992-1995 as a brief precursor to the 4R70W. The 4R70W started in 1993 in both Ford cars and trucks. 1996 and newer all have the “wide ratio” or low gear set. (F-series trucks started getting the “wide ratio” gears in 1994) Look for one out of a small block V8.
Identification:
	The AODE & 4R70W was Fords stronger, improved replacement for the earlier AOD. They are very similar to the AOD, but are electronically controlled and therefore have no kickdown lever. Look for an electrical plug on the rear, side of the housing (driver’s side) to differentiate it from an AOD. Like the AOD it also has a one-piece case and bellhousing design, but is 7/8″ longer. Look for two bolts (not three) for the starter to indicate it’s from a 5.0L not a 4.6L.
Adapter required?
	Use the same adapter as the AOD, with slight (and inexpensive) oil hole modifications.
Pros:
	This transmission features one of the lowest gears available for a Ford automatic. It’s also stronger than it’s AOD predecessor and the electronic controls provide more advanced, smoother shifting. Because they’re electronic, the shift points can be tuned specifically to your needs.
Cons:
	The electronic controls are a nice feature, but also require additional work and expense. First you’ll need a way to control the transmission. This can be done using a factory computer if you’ve swapped to a later model 5.0L or 5.8L engine. Or you can purchase an aftermarket controller made specifically for installing the AOD-E in older, non-computer controlled vehicles such as the “Baumanator” from Bauman Engineering. Expense is also a definite concern. The adapter kit and computer controller alone can cost almost $1000 in addition to the cost of the transmission.
Cost: (Approximate)
	Transmission: $300-500 used and $1000-2100 rebuilt Adapter kit: $550-620 Low gear set: $650-800 Computer controller: $400
Drive Shaft Mods:
	Total transmission is approximately 2.5″ longer requiring some drive shaft modifications.
Bell housing:
	The AODE came behind small block Ford engines and will bolt up to your 289-302-351 engines.
Modifications needed:
	The output shaft needs to be machined to install with the stock Dana 20 transfer case. The transfer case is set back further requiring a larger hole in the floor. An aftermarket transmission shifter or modification to your stock automatic shifter will be required. Transfer case to floor may be tight if you don’t have a body lift installed and the front drive shaft may be very close to the transmission pan depending on your lift. A smaller diameter front drive shaft or transmission pan modification may be required.

Manual Transmissions	1st	2nd	3rd	4th	5th
Bronco 3 spd (6 cyl)	3.41	1.86	1.00
Bronco 3 spd (8 cyl)	2.99	1.75	1.00
NP 435	6.69	3.34	1.79	1.00
T-18	6.32	3.09	1.69	1.00
Toploader (Close ratio)	2.32	1.69	1.29	1.00
Toploader (Wide ratio)	2.78	1.93	1.35	1.00
Toploader (Overdrive)	3.29	1.84	1.00	0.81
ZF	5.72	2.94	1.61	1.00	0.76
NV4500 (Dodge)	5.61	3.04	1.67	1.00	0.73
Automatic Transmissions	1st	2nd	3rd	4th	5th
Bronco C4	2.46	1.46	1.00
C6	2.46	1.46	1.00
AOD	2.40	1.47	1.00	.67
AOD w/ low gear set	2.84	1.55	1.00	.67
AODE/4R70W*	2.84	1.55	1.00	.67
700R4	3.06	1.62	1.00	.70

No related posts.

AOD 3 speed automatic – Transmission Guide

admin — Thu, 15 Jan 2009 03:57:34 +0000

Tech article by Jon Hanna (Admin)

Automatic Trans Intro
• Gear Ratio Chart
• C4
• C6
• AOD
• AODE & 4R70W
• 700R4
See also Manual Trans

Transmission:
	AOD 4 speed automatic with overdrive
Sources:
	1980 -1993 Ford cars and trucks with small block engines. In 1988 some design improvements were made making these newer models more desirable. A common swap is to take the 5.0L engine and AOD (or AODE or 4R70W depending on year) transmission out of a 1989 or newer Mustang. Look for one out of a small block V8.
Identification:
	As with most automatics the case and bellhousing are a one-piece design.
Adapter required?
	A tail housing adapter is required as well as a new spud shaft and new (or machined) output shaft.
Pros:
	The overdrive is one of the prime reasons people upgrade to the AOD. For those looking for lower gearing you can purchase a “low gear ratio” set. This will give you 2.84 first gear and 1.54 second gear.
Cons:
	The AOD transmission doesn’t have the best reputation in high abuse applications. However, several transmission shops specialize in correcting the factory weaknesses and beefing these up to handle real 4×4 duty.
Cost: (Approximate)
	Transmission: $200-500 used and $800-2000 rebuilt Adapter kit: $550-620
Drive Shaft Mods:
	Total transmission is approximately 1.5″ longer requiring some drive shaft modifications.
Bell housing:
	The AOD came behind small block Ford engines and will bolt up to your 289-302-351 engines.
Modifications needed:
	The cross member will need to be modified and relocated to make up for the 1.5″ longer AOD. The stock transfer case shifter also requires some modification and a larger hole needs to be cut in the floor. An aftermarket transmission shifter or modification to your stock automatic shifter will be required. Transfer case to floor may be tight if you don’t have a body lift installed and the front drive shaft may be very close to the transmission pan depending on your lift. A smaller diameter front drive shaft or transmission pan modification may be required.

Manual Transmissions	1st	2nd	3rd	4th	5th
Bronco 3 spd (6 cyl)	3.41	1.86	1.00
Bronco 3 spd (8 cyl)	2.99	1.75	1.00
NP 435	6.69	3.34	1.79	1.00
T-18	6.32	3.09	1.69	1.00
Toploader (Close ratio)	2.32	1.69	1.29	1.00
Toploader (Wide ratio)	2.78	1.93	1.35	1.00
Toploader (Overdrive)	3.29	1.84	1.00	0.81
ZF	5.72	2.94	1.61	1.00	0.76
NV4500 (Dodge)	5.61	3.04	1.67	1.00	0.73
Automatic Transmissions	1st	2nd	3rd	4th	5th
Bronco C4	2.46	1.46	1.00
C6	2.46	1.46	1.00
AOD	2.40	1.47	1.00	.67
AOD w/ low gear set	2.84	1.55	1.00	.67
AODE/4R70W*	2.84	1.55	1.00	.67
700R4	3.06	1.62	1.00	.70

No related posts.

C6 3 speed automatic – Transmission Guide

admin — Thu, 15 Jan 2009 03:56:27 +0000

Tech article by Jon Hanna (Admin)

Automatic Trans Intro
• Gear Ratio Chart
• C4
• C6
• AOD
• AODE & 4R70W
• 700R4
See also Manual Trans

Transmission:
	C6 3 speed automatic
Sources:
	1968-1979 Ford 4×4 trucks. You’ll need the 4×4 tail housing and 31 spline output shaft. Also be sure the donor vehicle has the same engine family you plan on using. (ie. Small block (289/302/351C/351W), big block (351M/400/429/460), or FE (331/352/360/390/391/427/428) )
Identification:
	The C6 case and bellhousing are a one-piece design. Also see the transmission pan image above for identification.
Adapter required?
	A tail housing adapter is required as well as a new spud shaft.
Pros:
	The C6 was originally put behind some of Fords most serious big block engines. It’s known as a practically bulletproof unit that can certainly handle any small block, especially if it’s built up a little. If you’re looking at swapping in a big block engine the C6 is one of the few choices because you can find one with the correct bell housing bolt pattern.
Cons:
	Expense, availability and size are the drawbacks to the C6. The small block C6 is fairly rare and may be costly. The C6 is quite a bit heavier than the C4 and hangs down causing possible clearance problems with the front drive shaft. The larger C6 also requires more horsepower to turn and has the same gearing limitations as the C4.
Cost: (Approximate)
	Transmission: $200-500 used and $800-1600 rebuilt Adapter kit: $650-700
Drive Shaft Mods:
	Total transmission length with adapter is approximately 2.5″ longer requiring some drive shaft modifications.
Bell housing:
	The C6 came behind small and big block engines. Because the bellhousing is part of the transmission you must get your C6 out of a vehicle with the same family engine you plan on using in your Bronco.
Modifications needed:
	An aftermarket transmission shifter or modification to your stock automatic shifter will be required. The front drive shaft may be very close to the transmission pan depending on your lift. A smaller diameter driveshaft may be required.

Manual Transmissions	1st	2nd	3rd	4th	5th
Bronco 3 spd (6 cyl)	3.41	1.86	1.00
Bronco 3 spd (8 cyl)	2.99	1.75	1.00
NP 435	6.69	3.34	1.79	1.00
T-18	6.32	3.09	1.69	1.00
Toploader (Close ratio)	2.32	1.69	1.29	1.00
Toploader (Wide ratio)	2.78	1.93	1.35	1.00
Toploader (Overdrive)	3.29	1.84	1.00	0.81
ZF	5.72	2.94	1.61	1.00	0.76
NV4500 (Dodge)	5.61	3.04	1.67	1.00	0.73
Automatic Transmissions	1st	2nd	3rd	4th	5th
Bronco C4	2.46	1.46	1.00
C6	2.46	1.46	1.00
AOD	2.40	1.47	1.00	.67
AOD w/ low gear set	2.84	1.55	1.00	.67
AODE/4R70W*	2.84	1.55	1.00	.67
700R4	3.06	1.62	1.00	.70

No related posts.

C4 3 speed automatic – Transmission Guide

admin — Thu, 15 Jan 2009 03:55:26 +0000

Tech article by Jon Hanna (Admin)

Automatic Trans Intro
• Gear Ratio Chart
• C4
• C6
• AOD
• AODE & 4R70W
• 700R4
See also Manual Trans

Transmission:
	C4 3 speed automatic
Sources:
	1973-1977 Broncos as well as several other Ford cars and trucks from 1964-1981
Identification:
	Unlike the other transmissions in this article, the C4 has a removable bell housing. Also see the transmission pan image above for identification.
Adapter required?
	Because the C4 was a stock option on Broncos an aftermarket adapter isn’t needed if you can find a stock unit. If not there are aftermarket adapters available.
Pros:
	This is the simplest, most straightforward and least expensive automatic transmission option because it was originally available on 1973-1977 Broncos. Find a donor Bronco with a C4 and transfer parts. Although the C4 was originally designed for smaller V8’s it has a strong aftermarket following and can take a lot of abuse if built properly.
Cons:
	The C4 has a fairly high first gear without the modern advantages of overdrive. In completely stock form the C4 can be a little weak for high output engines.
Cost: (Approximate)
	Transmission: $150-500 used and $500-1400 rebuilt (expect to pay near the upper end of this range if you are getting your C4 out of a 73-77 Bronco. Adapter kit: $500-550
Drive Shaft Mods:
	Total transmission is approximately 1.5″ longer requiring some drive shaft modifications.
Bell housing:
	The C4 came behind small block Ford engines and will bolt up to your 289-302-351 engine.
Modifications needed:
	Very few modifications are needed if using a C4 out of a Bronco.

Manual Transmissions	1st	2nd	3rd	4th	5th
Bronco 3 spd (6 cyl)	3.41	1.86	1.00
Bronco 3 spd (8 cyl)	2.99	1.75	1.00
NP 435	6.69	3.34	1.79	1.00
T-18	6.32	3.09	1.69	1.00
Toploader (Close ratio)	2.32	1.69	1.29	1.00
Toploader (Wide ratio)	2.78	1.93	1.35	1.00
Toploader (Overdrive)	3.29	1.84	1.00	0.81
ZF	5.72	2.94	1.61	1.00	0.76
NV4500 (Dodge)	5.61	3.04	1.67	1.00	0.73
Automatic Transmissions	1st	2nd	3rd	4th	5th
Bronco C4	2.46	1.46	1.00
C6	2.46	1.46	1.00
AOD	2.40	1.47	1.00	.67
AOD w/ low gear set	2.84	1.55	1.00	.67
AODE/4R70W*	2.84	1.55	1.00	.67
700R4	3.06	1.62	1.00	.70

No related posts.

NV4500 5 speed manual – Transmission Guide

admin — Thu, 15 Jan 2009 03:52:09 +0000

Tech article by Jon Hanna (Admin)

Manual Trans Intro
• Gear Ratio Chart
• NP435
• T18
• Toploader
• ZF
• NV4500

ZF 5 speed manual – Transmission Guide

admin — Thu, 15 Jan 2009 03:49:33 +0000

Tech article by Jon Hanna (Admin)

Manual Trans Intro
• Gear Ratio Chart
• NP435
• T18
• Toploader
• ZF
• NV4500

Toploader 4 speed manual – Transmission Guide

admin — Thu, 15 Jan 2009 03:46:33 +0000

Tech article by Jon Hanna (Admin)

Manual Trans Intro
• Gear Ratio Chart
• NP435
• T18
• Toploader
• ZF
• NV4500

Transmission:
	NV4500 (NV = New Venture) 5 speed manual with overdrive
Sources:
	1993 and later Dodge 4 wheel drive with gas engines (not diesel). GM also has a NV4500, but most adapter kits only support the Dodge version.
Identification:
	The NV4500 has a cast iron case with a single piece, aluminum, bolt-on top cover with shifter. This transmission has PTO cover plates on both the driver’s and passenger’s side. Weight is approximately 195 lbs.
Adapter required?
	This swap requires two adapters; one between the bell housing and transmission and another between the transmission and transfer case, as well as a new spud shaft.
Pros:
	The super low first and overdrive 5th gear make this one of the few transmissions that has the best of both worlds. The combination allows you to have comfortable highway speeds and still be geared to handle the tough trails. The NV4500 is a fully synchronized, smooth shifting, heavy duty transmission.
Cons:
	Expense and lack of availability seem to be the biggest drawbacks to the NV4500. Because they’re a popular swap for several other 4×4’s, finding one in a local salvage yard can be difficult. They are available new, but the $1900 price tag may be a little tough to stomach. Under dash air conditioning is very difficult because the shifter handle is so tight to the underside of the dash.
Cost: (Approximate)
	Transmission: $800 used and $1900 new Adapter (complete kit): $800 New drive shaft $150-200
Bell housing:
	An adapter is needed at the bell housing to make up for the Dodge bolt pattern and longer NV4500 input shaft.
Modifications needed:
	The swap requires a custom fabricated cross member and transfer case shifter brackets. Spline differences in the NV4500 input shaft require a new clutch disc. The overall length is 2″ longer than stock requiring a shorter drive shaft. Because of the top shifter a hole needs to be cut in the top of the transmission tunnel. A body lift isn’t required, but will ease installation.

Transmission:
	ZF 5 speed manual with overdrive
Sources:
	1988 or later Ford 4 wheel drive pick up with small block engine. The ZF S542 was used from 1988-1994 and the ZF S547 from 1995 on.
Identification:
	One of the easiest ways to spot a ZF is ribbed crisscross pattern on the sides. The transmission is aluminum and has an integral bell housing (one piece with the transmission) with a top mounted shift tower. Look for PTO cover plates on both the driver’s and passenger’s side. Weight is approximately 175 lbs.
Adapter required?
	The ZF integral bell housing will bolt directly to your stock 8 cyl engine, but requires an adapter between the transmission and transfer case, replacing your 8 cylinder intermediate housing. A new spud shaft for the transfer case is also required and is part of most adapter kits.
Pros:
	The super low first and overdrive 5th gear make this one of the few transmissions that has the best of both worlds. The combination allows you to have comfortable highway speeds and still be geared to handle the tough trails. The ZF originally came stock in ¾ ton and larger trucks making it a very heavy duty transmission. The fact that it’s a fully synchronized newer transmission also means it’s easier to find, shifts smoother and is more efficient.
Cons:
	Installation is fairly complicated, requiring some custom fabrication and may be out of the range of some shade tree mechanics. Under dash air conditioning is very difficult because the shifter handle is so tight to the underside of the dash.
Cost: (Approximate)
	Transmission: $800 used and $1000-1500 rebuilt Adapter (with spud shaft) $475-525 New drive shaft $150-200
Bell housing:
	Standard Ford. Will bolt up to small block (289-302-351) engines.
Modifications needed:
	The swap requires a custom fabricated cross member and transfer case shifter brackets. It also requires a hydraulic clutch due to the integral bell housing, although the stock Bronco clutch and flywheel are retained. The overall length is longer than stock requiring a shorter drive shaft. Because of the top shifter a hole needs to be cut in the top of the transmission tunnel.

Transmission:
	Toploader (also called “T&C” or “10 bolt top cover”) 4 speed manual
Sources:
	1967-1982 Ford cars and some trucks. Since it was used for so many years there are several different versions of this transmission. Tail shaft lengths will vary, but you won’t need the tail shaft anyway, just the case.
Identification:
	As the name implies, this transmission has a 10 bolt top cover to the case, rather than the more usual side cover plate. The case itself is 10.25″ with a side mounted, external style shifter. These came in both “close ratio” and the more common (and more desirable for Broncos) “wide ratio” versions. Look at the tooth count on second gear. A “close ratio” will have 28 teeth and a “wide ratio” will have 31 teeth.
Adapter required?
	The “adapter” needed in this case is an aftermarket output shaft, along with a shifter bracket and rod kit. The Toploader case takes the place of the stock Bronco transmission, so no adapters are needed to correct the bolt pattern. The stock Bronco 8 cylinder intermediate housing is retained, although modified (see below)
Pros:
	The Toploader is a fully synchronized, quick shifting and strong transmission. Because they came in so many vehicles they should be easy to find. However, they’re also a popular choice for several swaps including the Mustang and Jeep crowd, so demand may inflate pricing for both parts and transmissions.
Cons:
	Gearing is even higher than a stock 3 speed, which can be a pro or con, depending on how you drive. The high 1st gear is not typically ideal for the trail, especially rock crawling. However, if you spend most of your time on the highway the gearing may be exactly what you want. The closer shift points are also an improvement over the stock 3 speed. Since the shifter rods are on the side they can be vulnerable to getting jammed with mud and snow. An alternate top shifter came on some truck transmissions and replaces the top cover with one that has the shift forks built in.
Cost: (Approximate)
	Transmission: $400 used and $750-1000 rebuilt Adapter (output shaft): $250-350 Shifter $250
Bell housing:
	Standard Ford. The Toploader will bolt up to your existing bell housing on small block (289-302-351) engines. The existing Bronco clutch is also used.
Modifications needed:
	The entire assembly is 1″ longer than a stock 8 cyl Bronco transmission, so drive shaft modifications may be necessary depending on the amount of suspension lift you have. The stock Bronco 8 cylinder intermediate housing needs to be machined for the larger Toploader bearing and drilled to accept the shift rail. You’ll also need to cut a hole in the floor for the side shifter. A four speed floor shifter needs to be installed, requiring some floor board cutting.