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Popular Transmissions To Swap into an Early Bronco

DebosDave'72

Bronco Guru
Joined
Nov 8, 2005
Messages
1,020
Loc.
Bozeman, MT
This FAQ will help answer your question as to what transmissions are available to swap into my Early Bronco?

First we will look at Manual Transmissions:

NV3550
- This is a 5-speed overdrive transmission that provides a sporty feel. Needs to be adapted to the stock transfercase and the engine. Has a decently low but driveable first gear.

NV4500
- This is a 5-speed overdrive transmission that is very heavy duty. Needs to be adapted to the stock transfercase and the engine. Has granny low. Truck feel to the shifting, but bulletproof in Early Bronco applications.

Ford ZF
- This is a 5-speed, overdrive transmission that is very heavy duty. Needs to be adapted to the stock transfercase. Has granny low gear, and a truck like shiting feel. Bulletproof and a FORD product!

Borg Warner T-18
- This is a 4-speed heavy duty truck transmission. Needs to be adapted to the stock transfercase. Has a low first gear.

NP435
- This is a 4-speed heavy duty transmission. Needs to be adapted to the stock transfercase. Has a granny low first gear.

TopLoader
- This transmission was available with three different gear sets. It is 4-speed, but can have overdrive and granny low. Needs to be modified to bolt to the stock transfercase

T5
- This transmission is a 5-speed sports car transmission. Provides overdrive, but not heavy duty. Needs to be adapted to the transfercase.

For more information on Manual Transmission swaps into the Early Bronco follow this link:
Manual Transmission Swap Info

Next a look at popular Automatic Transmissions

AOD
- This transmission provides an overdrive. It is a 4-speed automatic. Needs to be adapted to the stock transfercase.

AODE/4R70W
- This transmission allows for overdrive. It is a 4-speed automatic. The difference between the two is the gear sets, with the 4R70W having a slightly lower gearing in the first two gears. Both need to be controlled by a computer. Needs to be adapted to the stock transfercase.

C6
- This transmission is a 3-speed. This is a very heavy duty transmission, considered bulletproof in Early Bronco applications. Needs to be adapted to the stock transfercase.

C4
- This transmission is a 3-speed automatic. It can be found in Early Broncos from the factory. They need to be adapted to the stock transfercase. If you can find one in an Early Bronco, make sure to get the adapter.

700R4
- This transmission is a 4-speed with overdrive. Needs to be adapted to the engine and the stock transfercase. Can be built very strong.

If you would like more information on Popular Automatic Transmission swaps please follow this link:
Automatic Transmission Swap Info

Gear Ratio Chart:
transratios.gif


Thanks for looking, I hope this helps a little!

If you can add anything to this FAQ, please respond below:
 
Last edited by a moderator:

pfairon

New Member
Joined
Aug 9, 2008
Messages
1
Thanks for info! Any referrals to a Orange County or LA, CA tranny shop? Have 1969 manual that i want to convert to auto with drive shaft shifter.

Thanks in advance
 

Nickrp

Jr. Member
Joined
Jul 30, 2010
Messages
63
Thanks for info! Any referrals to a Orange County or LA, CA tranny shop? Have 1969 manual that i want to convert to auto with drive shaft shifter.

Thanks in advance

Was this questions ever answered? As I am in the same boat but with a 67.
 

Deano

Bronco Guru
Joined
Jan 9, 2010
Messages
1,182
There is a Mazda 5speed out of F150s that doesn't drive like the ZF it has a smoother shifting much like a car.
 

nabes68

Full Member
Joined
Sep 6, 2010
Messages
160
Loc.
Yuba city
I am looking at a 4speed from a ford f250 60's with a divorced transfercase will it be a np435 or t18
 

bmbm

Sr. Member
Joined
Jun 16, 2007
Messages
575
mazda 5 speed

I think it is known as a M50 or something like that. This could be a reasonably low cost swap but it has a hydraulic clutch I think. Wrecking yards should have plenty of them.
Also the ax15 is a nv3550 replacement I have read about, they might be reasonable but needs adapter for ford bell and d20.
 

Johnnyreb

New Member
Joined
Sep 7, 2009
Messages
5
Loc.
West Virginia
If they are NOT the same length. What lenght difference is their? I,m thinking about going to a 5 speed. What year did Ford start putting 5 speeds in their pick-ups and broncos?
 

ahansen_1985

Bronco Guru
Joined
Nov 2, 2008
Messages
1,245
Loc.
amity, oregon
The Mazda unit is called the m5od-r2
Found in late 80? To 90's f150s

It has a lil taller 1st gear ratio than the zf.. But shifts super smooth and fast... Will hold up to a 350 hp 351 no prob... I run mine hard...
The difference as a bronco brother put it,
The zf is a truck feel trans, the m5od is a go cart on steroids

Clutch is internal hydraulic but very easy to install...


1966 bronco, almost nothing factory
 

ahansen_1985

Bronco Guru
Joined
Nov 2, 2008
Messages
1,245
Loc.
amity, oregon
Also on the m50d a np 205 tcase will fit with a little modification just notch the trans wedding ring to allow the 205 shift rails clearance...
ImageUploadedByTapatalk1364651712.840732.jpg


1966 bronco, almost nothing factory
 

Joker11

Sr. Member
Joined
Sep 11, 2008
Messages
840
Loc.
Yuma, Arizona
The ZF for the bronco swap uses a hydraulic throw out bearing. So, yes, you need it.

There is ZF used in diesels that has an external clutch cylinder. I supposed you could fabricate a lever for it somehow.

There is also a ZF used in big block fords. I am pretty sure that one uses an external as well.

Why would you NOT want a hydraulic clutch? so much nicer.
 

landshark99

Bronco Guru
Joined
Oct 13, 2011
Messages
1,401
The zf behind a 460 is indeed an external hydraulic clutch setup. You would have to fab up a pivot point for a small block zf and a bracket for the external slave.
 

jimc351

New Member
Joined
Jul 8, 2015
Messages
3
Transmissions

Your information is very helpful, thank you. Do you know of or where there might be information of the performance reviews of each transmission. I just bought my first Bronco restore project, I now have three motors 302, 5.0, and a 351. The trans in it is a three on tree. I am not a rock climber, I want good roadability, towing, and offroad use for fishing. Nothing mountainous. Would prefer 4 or 5 speed, but AOD is ok too.


Thanks

Jimc351
 

DavidDolezilek

New Member
Joined
Nov 25, 2015
Messages
1
Me too

Jimc

I am trying to do the same as you. I was curious if you received any information about auto transmissions to make a daily driver

Thanks

DavidDolezilek
 

Joe473

Sr. Member
Joined
Jul 16, 2012
Messages
950
The Mazda unit is called the m5od-r2
Found in late 80? To 90's f150s

It has a lil taller 1st gear ratio than the zf.. But shifts super smooth and fast... Will hold up to a 350 hp 351 no prob... I run mine hard...
The difference as a bronco brother put it,
The zf is a truck feel trans, the m5od is a go cart on steroids

Clutch is internal hydraulic but very easy to install...


1966 bronco, almost nothing factory
Anybody out there knowledgable enough on the M5R2 to modify original tech? Things like overall length as compared to 3 spd? Ratio's? Zf d20 adapter and crosmember compatibilty?
Best years for shifter locations? Does 4.2 v6 bellhousing match 402? Compatible master cylinder and clutch pedal mod? NP 205 compatibility and benefits.

These transmissions seem easier to find than 3550 and similar torque ratings from what I have read.
 

egom

New Member
Joined
Mar 7, 2011
Messages
27
Loc.
El Paso
zf swap info

yes but there was an article on how to install a ZF into a 302 using spud shaft form the zf and adapter from the D20 by welding them together wher can I find it appriciate any info. this article was had easy step by step instructions.
 
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