C5 Trans.

[Gordys74]

Has anyone ever heard of a C5 Auto Trans, and will one fit in my EB without alterations? My mechanic keeps telling me thats what I need in the Bronc, but I have never heard of a C5.

 

[ORVP]

Why yes that should work.

C5 was produced in 1982 thru 1987 the only diference is a slight modification to the valve body and the addition of a centrifugal lock-up converter clutch.

The same ATSG (Automatic Transmission Service Group) manual for both C4 and C5 slushboxs. Differences are in above discription.

 

[Gordys74]

Thanks, ORVP! Now I'm wondering how a C5 would work with a 302 and 4:11s and 235 tires. Should help gas milage. I may have to get more serious about this swap.

 

[ORVP]

Should work just fine.

Gearing is the same as C4. Is yours allready a auto?

 

[Gordys74]

Yes, mine already has a C4, but as I understand it, a C5 has a locking torque converter clutch that acts as an overdrive. Am I misunderstanding this? As I read it, what I'm actually looking for is an E2 casting number trans., not a C4 or C5 casting number. My interpretation is that most EB's came out with a C5 as they are pan fill. I think the E2's were exactly the same dimensions as the C4/C5 but acted like 4 speeds.

 

[67ster]

The E-2 case does have improved oiling to the rear thrust surface and the cooler lines . The cent. lock up is a pos and no longer serviced . Some C-4 sites say it is a better case to use in a build up but you have to use the short EB output shaft .

 

[broncnaz]

Yes, mine already has a C4, but as I understand it, a C5 has a locking torque converter clutch that acts as an overdrive. Am I misunderstanding this? As I read it, what I'm actually looking for is an E2 casting number trans., not a C4 or C5 casting number. My interpretation is that most EB's came out with a C5 as they are pan fill. I think the E2's were exactly the same dimensions as the C4/C5 but acted like 4 speeds.

The lock up torque converter doesnt act as a overdrive. It does slightly lower the rpms due to the fact the torque converter is no longer slipping but I doubt you'll really see any benifit from it. Your best bet is to get a actual OD tranny Eb's didnt come with a C-5 the pan fin is not the differance between C-4 and C-5's as sometime around 1970 C-4's went to the pan fill style

 

[Broncobowsher]

Some more research also shows that not all C5s were lock up converters. that lock up is centrifical so it will only show up at higher RPM, if it even does anything. In reality it was a bandaid that somehow made it to production and wasn't very good leaving a scar.

As for an overdrive, forget it. that converter isn't going to get you anything. maybe a 100 RPM drop if everything was optimized and you could get into the converter and tune it. If you see anymore then that then you are starting with a bad converter as a reference.

Pan fill does not mean it is a C5. Broncos are originally a C4 with a pan fill. Also Broncos have a deep pan, C5's don't have a deep pan. The case vs. pan fill is just a junkyard way of telling what the transmission probably is, not for sure.

Gearing in all C4 and C5 is the same unless you spent the bucks at Art-Carr on an aftermarket gearset.

There is no logical reason to replace a C4 with a C5 other then to help your mechanic make his boat payment. If you need to replace your transmission, either get your C4 rebuilt or if you really want an overdrive put in an overdrive transmission.

Note that there are no simple drop in overdrives. Every single one will require modification in order to install. Some more then others, but there is no way to get that 4th gear without doing custom work.

As for saving gas, you can buy an awaful lot of gas for the cost of an overdrive. Aerodynamics play a much larger roll. A small change in tire size from P235 to a 31" is probably the cheapest overdrive you can do. Make sure to correct the speedometer (odometer) error or else you calculated fuel economy will show the wrong way. Going to a 31" tire with no lift shouldn't have a major affect on aerodynamics either.

 

[BwoncoHowie]

The only trucks that a C-5 was ever made for was a Bronco II and ranger, all the rest were passenger cars. All the Bronco II's came from the factory with a deleted lock up in the TC because the stall speed was too high in those units, which would tear-up a centrifugal lock-up mechanizm quite rapidly. C-5s were found in mostly 6-cyls Although they have some strong points, they are basically a light duty trans that needs to be modified with a lot of C-4 parts in order to make them strong. Most shops will sell it with a deleted lock up in the TC because they inherrantly shed metal and eventually stick the spool valves. Therefore they will be reluctant to stand behind the warranty if you insist on having a Lock-up TC. They also have restrictive cooler line fittings that slow down the lube flow in order to work with a design change in the stator support.

You are better off with a pan-fill C-4. Get it done by someone who puts pride in their work and you will be on the right track.

 

[Gordys74]

I kinda though something sounded fishy about this. If it were that easy to get an OD trans. everybody would be looking for one. Well, everyone who wants an auto trans that is. I'm stickin' with my C4 but may change the gears to 3:50s. I don't think I can go to taller tires as my EB is uncut and I'm reluctant to change that. I think part of my confusion is that Ford Motors referred to both the C5 and the E2 as a C5, but they were two different transmissions.

I'm also going to have to keep an eye on my mechanic after this. I think he has an E2 he'd like to pawn off.

Thanks Everyone! As usual, good wisdom found here.

 

[76 bronco J]

their are lots of deep C5 transmissions pans with a hump similar to the bronco, if fact some stores give a car pan filter as a replacement for early broncos that does not reach as far down as stock,some claim thats all thats available, the filter for most C5's is the depth of the stock bronco filter , there are way more C5's with humps in the pan similar to the C4 in the bronco than there are C4's in the first place-- people have mistaked a bronco C4 for a C5 more than once because a C5 with a hump in the pan is way more common than a C4 with one-------

 

[Gordys74]

This is my best reference to why there is so much confusion over the C4/5 trans. question:

C4/C5 Nomenclature
When I stumbled into the transmission business in 1979, one of the hottest sellers was the C5 transmission. I could get $25 for every one I could find. Now, I know what you are thinking if you entered the transmission industry in the eighties or nineties, "HOW in the world is that possible, especially since Ford did not start making the C5 until 1982?" Therein lies a story of the REAL C5, the one that became confusing for many in the industry once Ford added a converter clutch to the C4 and then called IT a "C5!" For us old-timers, this has been a source of confusion ever since.

The story starts in 1964 when Ford introduced the C4. Every visible casting number on its parts started with "C4AP." Naturally, it was a logical short step to naming the transmission as a "C4." This transmission had the dipstick in the case behind the bell, making this a case-fill transmission. The bell attached to the case by using the pump bolts. Everything was just hunky-dory. New transmission, new name, no confusion.

Then in 1965 Ford decided to beef up the C4 for use behind bigger motors, like the 351 Windsor. So, they beefed up the bell, case, and some of the internal parts to withstand the extra torque of these bigger engines. This design made the case heavier at the bell. To strengthen the transmission the bell was attached to the case using separate bolts, instead of the pump bolts. They added more bolts around the pump specifically to attach the bell to the case. This redesign also required moving the dipstick to another location. So, the dipstick was moved to the pan, creating a pan-fill transmission. In keeping with ancient Ford policy, this redesigning required new casting numbers on the redesigned parts, especially the bell and the case. The new numbers all started with "C5," which naturally led to this being called a "C5." Again, everything was hunky-dory. We now have a case-fill transmission called a "C4" and a pan-fill one called a "C5." No confusion, no problem.

Fast forward to 1979. This was the final year of manufacture for this C5 transmission, but the C4 continued for another four years until 1983. In 1982, Ford did another redesign by adding a converter clutch to the C4. This again required redesigning many parts and again required a new series of casting numbers. So, now we have casting numbers starting with "E2." No problem there. Then some wise-ass at Ford had to gum up everything by naming this transmission a "C5!" Nothing but confusion ever since!!!! Now WHY in the world wasn't this transmission named an "E2," the MOST logical name available, and the one which would NOT add confusion to the industry???

To sum up we have the following possibilities along with bell casting prefixes:

* 64-83 (now designated "C4" by Ford)
o Case fill {C4 to C9, D0 to D9, & E1SP)
o Pan fill {C5 to C9, D0 to D9}
* 82-86 (now designated "C5" by Ford)
o Case fill {E2AP only)
o Pan fill {E2TP only}

 

[SaddleUp]

I have no clue how accurate these links are but they apear to contain the details that would lend to their credibility.

http://en.wikipedia.org/wiki/Cruise-O-Matic

http://en.wikipedia.org/wiki/Ford_C4_transmission

 

[broncnaz]

Most of the confusion lies in your using the year date code part of the P/N's to ID the trans type. The C4 C5 P/N your talking about are just that P/N's indicating the year the case was manufactured. In 65 the tranny wasn't designed for bigger motors such as the 351W as the 351 W didnt appear for 4 more years and most if not all 351W's had smallblock C-6's attached to them the redesign was due to a change in bellhousing bolt patterns early 65 and prior year small block engines used a 5 bolt bellhousing than was smaller than the later 65's that changed to the 6 bolt pattern. Not real sure on all the C4 history but it may have been that it first came out in 64 and the C4 designation stuck with it. The C5 may use the orginal the 65 case design and since it was a improvement so to speak upon the C4 it was designated as C5 reguardless of actual P/N not real sure where the C3 fits in here but it came out in the late 70's or 80's and is basically also a C4 that was used behind small engines probalby why it was designated C3.
There is no way a C5 or 4 built in the 70's or 1980's would have a C5AP for a P/N it would have to be a E series number maybe the E2 you were refering to earlier. While it could be exactly the same case as the C5 P/N built in 1965
Ford P/N break down
C series = 1960's
D series = 1970's
E series = 1980's