Tranny differences

[terky]

So i might be able to score a fairly new tranny. Dude says its got 500 miles on it but it needs a new diesel governer. He said it revs too high so i think when whoever rebuilt it they rebuilt it for gas maybe. I dont know anything about trannys and was wondering where this governor is located on the thing and how much does a new one cost?

Also it might be off a 2 wheel drive. How hard is it to make it mate to my transfer case? Dont i just need to swap the output shafts? Like I said I dont know much.

thanks

 

[K5dreamer]

very first piece of necessary information...... what transmission????

some transmissions have a two piece design, with swappable tailshaft housings, others are a complete one piece design. The tailshaft housing is what bolts to the transfer case in 4x4 applications, and narrows down to the yoke on a 2wd application.

There are some transmissions that can be converted from one to the other with a tailshaft housing and output shaft swap. others cannot. you also will need to make sure you get the right spline count on the output shaft.

also, i have yet to hear of a govener on a transmission, those are mounted on engines, and limit the rpm to prevent damage. Transmissions have what is called a torque converter, that has a "stall speed" which is the max speed an engine will turn with the transmission in park, or being braked. This is a very easy swap, and purchasing a diesel torque converter and putting it on will solve the problem of the "gasoline" transmission rev range. the converter is the fluid coupling between the engine and transmission. it slides onto the input shaft on the front of the transmission, and bolts to the flywheel on the back of the engine.

diclaimer, i know some stuff, but im hardley a transmission guru. so take this with a grain of salt.

 

[terky]

thanks for the info. Its a 700r4.

So I would need to put a diesel torque converter on and the tranny would have to accept the correct tailshaft housing.

 

[K5dreamer]

again, just my guess here, but from what ive read.....

for the 700R4, you need the 4x4 tailshaft housing, and output shaft, they are different lengths i believe. Also, are you swapping 700R4 for 700R4, or doing an overdrive upgrade, say, replacing a th350 or th400 with the 700R4? in which case overal case length, and spline count on the output shaft become critical issues.

 

[fallout232]

There is a "Diesel Governor" and "Gas Governor" on a 700R4, It controls shift speed on the tranmission. I see the diesel ones go on Ebay for around 50.00.

 

[K5dreamer]

There is a "Diesel Governor" and "Gas Governor" on a 700R4, It controls shift speed on the tranmission. I see the diesel ones go on Ebay for around 50.00.

interesting, learn something knew every day.... is that like the vacuum modulator on a th400???

 

[fallout232]

From what little I know about the 400 yes it controls shift points. I think the vacuum modulator however is dual purpose and controls the line pressure as well as shift points where on a 700R4 the TV Cable controls line pressure and the governor sets shift points.

(Disclaimer: I am no auto tranny expert, just years of tinkering and troubleshooting my personal vehicles)

 

[desertrat67]

No. The governor is a gear located inside the tranny(accessable from a cover plate on the ouside) that controls gear shifts. THe gear is plastic and easy to swap out if you have a small diameter punch. THe 400 and 700 both have this.

This is what it looks like:

The green gear on the end is the gear and there is a shear pin(roll pin) that hold it onto the governor. Push out the shear pin pull off old gear put on new one install new pin.

This should be accessable via a bolt on plate on the side of the tranny. THe 400 has it on the left rear and is held on with 4 bolts. THe governor just pulls out. nothing holding it in but the cover plate.

Here is am article on hoe to replace the governor on a 700:

http://www.dragracingonline.com/technical/vi_9-bm-1.html

I am guessing that there is a diesel application to keep it shifting in the right range.

 

[kennyw]

If the transmission is off of a 2wd it will require a complete tear down to replace the output shaft. You would be better off rebuilding the correct 4x4 core. You also loose the K case on the 2wd version.

 

[terky]

Thanks for the info guys.

 

[kennyw]

The 700R4 is an easy transmission to learn on if you want to rebuild one yourself too. You can make the so called "special tools" needed to take it apart/put it together.