Transmission Front Servo 0 pressure
Transmission Front Servo 0 pressure
The transmission(46re) in my 01 ram 1500 5.9auto 4x4 on 35s finally crapped out after a long 150k miles.. I searched for used one for a few months but eventually gave up and rebuilt it myself. I am a mechanic and have experience with every other part on a vehicle, but this is my first time repairing a transmission.
As far as the rebuild itself goes, so far I have rebuilt the transmission with new metals and clutches, as well as a new front band and front drum as all of the friction material on the front band made its way to the bottom of the trans and grooved the drum in the process. My input shaft end play measurement were identical before and after rebuild so I feel pretty confident in that, However, when installing the new front servo gasket seal, it tore so I ended up just reusing the old seal. (I also should have air checked it, I know..) I know this could cause some issues but before I open it back up, I would like to know anyother possible causes, such as which ball valves in the valve-body control such flow.
Edit: Transmission also takes about 30 seconds to actually shift from Park to reverse or any drive range upon cold start.
I have also installed an aftermarket cooler, deleted the line check valve and installed an inline filter.
I pressure tested all of the ports and the readings were as follows: (basically everything was 100% to factory spec except for no measurements coming from the front servo port IN ANY GEAR OR REVERSE)
As far as the rebuild itself goes, so far I have rebuilt the transmission with new metals and clutches, as well as a new front band and front drum as all of the friction material on the front band made its way to the bottom of the trans and grooved the drum in the process. My input shaft end play measurement were identical before and after rebuild so I feel pretty confident in that, However, when installing the new front servo gasket seal, it tore so I ended up just reusing the old seal. (I also should have air checked it, I know..) I know this could cause some issues but before I open it back up, I would like to know anyother possible causes, such as which ball valves in the valve-body control such flow.
Edit: Transmission also takes about 30 seconds to actually shift from Park to reverse or any drive range upon cold start.
I have also installed an aftermarket cooler, deleted the line check valve and installed an inline filter.
I pressure tested all of the ports and the readings were as follows: (basically everything was 100% to factory spec except for no measurements coming from the front servo port IN ANY GEAR OR REVERSE)
Last edited by tehzohan44; Jan 31, 2016 at 12:53 PM.
Grand Champion
Joined: Feb 2015
Posts: 7,435
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I think you will have to drop the pan/vb and air test the front servo. At lest then you know the servo is working so the issue must be in the vb. You did check the shift linkage is adjusted correctly right?
Record Breaker
Joined: Sep 2007
Posts: 1,810
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From: PA
I'm no expert, but isn't the check valve that you deleted supposed to keep the fluid in place? If you took it out, the fluid would drain and you'd have to wait a bit to build up the pressure - hence your 30 second cold start delay?
I assume it works well after that?
I assume it works well after that?