4r100 just rebuilt and will not move.

Thesk8nmidget · May 21, 2015

I'm a long time reader and follower of this forums but this is my first post.

I recently rebuilt my 4r100 4wd transmission and now it's
Complete and reinstalled it will not move.

I am a very experienced detail oriented mechanic by trade and took my time with this rebuild following my atsg repair manual and also the thread on this site.

A little history would be the transmission worked when removed but the forward gears were slipping, it would shift and drive fine and once I tore apart the transmission I found what I expected. A bad forward clutch pack. I still rebuilt the entire transmission with new discs and installed it all back into spec and also installed a brand new hd torque converter. Yes I put ATF in it before installing.

I did not tear into the valve bodies or front pump during the rebuild and when I reinstalled everything I used new seals and made positive all the rubber check balls were in the correct spot.

So back to the issue i'm having. Even with the rear tires jacked up off the ground the tires will not move in any gear at all. Although when I shift from park into a gear you can hear and see the rpms drop down a bit like there is a small load but nothing will budge. The t case is in gear and I just drained all the ATF to see if there was any signs of wear and there is not a piece of metal in the oil and it looks new still. No burning smell.

I'm now stumped and would like some advice on what to try next.

Thanks in advanced

NathannialD · May 21, 2015

have you checked line pressure?

Thesk8nmidget · May 21, 2015

Just double checked line pressures

Park and neutral
60psi

Reverse
90psi

1
100psi

Drive
60psi

All within spec with the manual

NathannialD · May 21, 2015

new cooler? new converter? needing more info to try and help what i can, im not very familiar with the 4r

Thesk8nmidget · May 21, 2015

Brand new converter, and the cooler was all flushed and cleaned.

Mark Kovalsky · May 21, 2015

Have you tried it in every position, including 1 and 2? How much fluid did you put in it?

Thesk8nmidget · May 21, 2015

Yes I have tried every gear. And the fluid is full. I have rebuilt trannies and am a mechanic by trade I have installed many auto trannies and have doubled checked everything on this specific one and still cannot figure it out

NathannialD · May 22, 2015

the part i cant get past is you rebuilt it but didnt open the pump or valve body? if clutches were smoked whos to say there isnt clutch material in either of them causing an issue?

not bashing its just curious.

Thesk8nmidget · May 22, 2015

I didn't have any seals for the pump so I didn't wanna separate that, I took the valve bodies apart because I bad the seals I just didn't take all the springs and such out of valve bodies.

JLDickmon · May 22, 2015

I'm with Nathannial. I think it's got some junk in the valve body or solenoids. Speaking one mechanic to another..

chicken-pecked from my iPad

Thesk8nmidget · May 22, 2015

I guess my next step would be pull the pans and valve bodies. Is there a specific one you would think that would cause all gears to not engage?

golfer · May 22, 2015

4WD?...transfer case happen to be in neutral?

Thesk8nmidget · May 22, 2015

Yes it's a 4wd and no it's not in neutral, I have tried every gear in my t case as well

Mark Kovalsky · May 22, 2015

The only stuck valve that will cause no engagement is the main pressure regulator. But if that were the problem you wouldn't have line pressure.

A common occurrence is that the linkage doesn't get attached to the manual valve. The shifter feels normal, but the manual valve never moves. Take the pan off and see if the manual valve moves.

Arisley · May 22, 2015

Awesome info right there. If it was me, I would have had the Frank (forum tranny) out of there and taken back apart looking for something I did wrong.

dieselmandustin · May 22, 2015

Did you make sure the low/reverse roller clutch was on the right way and working properly? I don't have my book but it needs to lock turning one way and spin freely the other. If it's on upside down or broken or just messed up it will keep it from moving in any gear.

gnxtc2 · May 23, 2015

Thesk8nmidget said:
cooler was all flushed and cleaned.

#1 killer of a new/rebuilt tranmission.

You can NOT clean/flush a stacked plate/honeycomb type cooler only a tube type cooler.

Billy T.
[email protected]

dieselmandustin · May 23, 2015

gnxtc2 said:
#1 killer of a new/rebuilt tranmission.

You can NOT clean/flush a stacked plate/honeycomb type cooler only a tube type cooler.

Billy T.
[email protected]

Agreed! Although it adds to the cost of the rebuild. It's easier to just buy a new cooler every time than chance getting shavings in a brand new trans and have to pull it back out. I learned this the hard way!