700R4 differences

[F-ingrob]

is there a difference between the diesel and gas 700R4
besides the torque converter
my buddy just pick up a 85 diesel K5 and the trans has no second and no overdrive so i was gonna give im mine out of my 85

 

[dyeager535]

Normally they shift a lot sooner being a diesel.

Every GM trans made was different based on what it was put behind. Strength of the internals, valving, shift timing, converter stall, etc. Greg is the trans expert, but I assume the governor is the main difference in the diesel vs. gas.

The comparison is the tag on the side of the trans, if there is one. The last letter is a relative strength rating. A being "weakest" Z being "strongest".

 

[sreidmx]

I don't know about that.. Besides the shift timing and the modulator and governor they should be the same. I have never heard a diesel trans being any stronger or weaker than a gas 700.. By all means post some references.. I'd like to see that if its true.

 

[F-ingrob]

i know its a K case for sure but it sounds like he may need to just get his rebuilt so there wont be any shifting problems

 

[dyeager535]

I don't have access to the parts manual in front of me, but should be available in the link in my signature.

It's possible the diesel and say, 350 700R4 used the same "quality" of build, but you'd have to look at the various parts listed to see if any are broken down by engine VIN. GM didn't do that with any of their other trans, shift timing, firmness, etc. were all varied based on the drivetrain/application.

 

[Blue85]

You should be able to swap the diesel governor and torque converter into the gas tranny and drop it in the diesel truck. There is no modulator, and as far as I know everything in the valve body is the same. If there is any significant difference, Ducato would know.

However, be very careful in contamination. If something has let go in that trans, there could be stuff caught in the torque converter. If the pan is really clean you might get by just dumping fresh fluid in a few times before the swap. If the pan is full of metal, you might pay a shop to power flush it or just buy a re-man converter.

 

[Fubeca]

I've swapped in a 700r4 from a gasser into a diesel with a new converter and swapping the governor. Worked fine for the whole time I had the truck.

 

[Greg Ducato]

You can leave the valve body alone and just swap out the governor in almost every instance to make the gas trans shift early enough for the 6.2. The only difference between the Diesel trans and gas trans in terms of parts are the valve body calibration and governor, and some early examples of the diesel trans had a pressure regulator spring that was about a pound stiffer, ( identified by it's pink color). Converters were the same except the clutch damper was much heavier duty on the diesel and it had six mounting lugs on the earlier examples. Later converters moved to three reinforced mounting pads. Diesel converters can also be identified externally by the number "4" stamped around the circumference of the bowl in between the lower set of fins. This denoted the diesel exclusive low stall speed.

 

[F-ingrob]

thanks for all the help great info