Trans. governor pressure help please

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spray

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I have my truck at a very recpecyable transmission shop and the can not get it to shift to 2nd at WOT since they rebuilt it. They are saying the governor pressure drops to around 50psi when you put it to the floor and that is keeping it from shifting. Has anyone ever had this problem??? Please help....
 
Come on with all the knowledge on here someone should have some advice.....
 
Scrambler1 said:
Only guess is the solenoid. Did you do the GM solenoid upgrade?
Click to expand...

Yep we have tried 2 different GM ones and now a stock one is back in there.
 
I second trying the cable. I recently did the adjustment out of curiousity and found that if I have it like 1mm to tight that it shifts nicely and holds gears longer. What the downside was is you could feel it downshift at every slow down and I knew that couldn't be good for the clutches. I also could tell something in the pressure feed wasn't right so I added the 1mm of slack back and all is good again. In other words the cable is better off being a hair loose than too tight as it opens the Throttle Valve in the transmission and that apparently has to do with line pressure.:dontknow:
 
At WOT in 1st gear, the computer should command the 1-2 shift by spiking the governor pressure through an 800 millisecond electrical pulse on the govenor solenoid. It can be measured by reading the electrical signal going to the solendoid or by having a fast reacting fluid pressure gauge screwed into the govenor solenoid port. If the spike is occuring but it is still not shifting, there likely is an issue with dirt (old tranny friction material) in the valvebody or a bad seal around the solenoid bracket area. There may also be an internal fluid leak somewhere that is preventing the govenor pressure from fully acting on the 1-2 shift valve when line pressure and detent pressure are maxxed out, or the valve body could be warped and not mating up properly to the transmission case.
 
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WOT said:
At WOT in 1st gear, the computer should command the 1-2 shift by spiking the governor pressure through an 800 millisecond electrical pulse on the govenor solenoid. It can be measured by reading the electrical signal going to the solendoid or by having a fast reacting fluid pressure gauge screwed into the govenor solenoid port. If the spike is occuring but it is still not shifting, there likely is an issue with dirt (old tranny friction material) in the valvebody or a bad seal around the solenoid bracket area. There may also be an internal fluid leak somewhere that is preventing the govenor pressure from fully acting on the 1-2 shift valve when line pressure and detent pressure are maxxed out, or the valve body could be warped and not mating up properly to the transmission case.
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It is not spiking, it is going down instead of up.
 
could my problem with 2nd gear be related to pressure as well. comes out of second gear at about 4000 rpms under wot (like you threw in neutral) dealership replaced trans under warranty still same problems?
 
Well PATC called me today after having my truck for over 3 weeks and told me they could not fix the shifting problem and did not know what is causing it. I took the truck down there shifting fine just wanting a shift kit and a GM solenoid installed and they said it need new cluthes so I told them to go ahead and rebuild it so they did and it would not shift at WOT so then they told me I needed a big daddy drum that uses bigger cluthes, they guaranteed that would fix my problem but it did. So My problem now is that I have paid almost 3k and my trans is not shifting at WOT, They are saying the computer is making it drop govenor pressure from 110psi to 56 psi. Does anyone have any advice or know of anyone that I could talk to.
 
call (954)916-1155 and ask to speak to Jason about a Ram SRT-10 transmission. tell him Roger told you to call and speak to him about the pressure issue...I guarantee he will have an idea, he built several SRT-10 tranny's here and 100's of diesel tranny's across the US (same tranny as the SRT-10) also building a Twin Turbo ram and did an auto tranny conversion in it.
ATFspeed.com
 
spray said:
It is not spiking, it is going down instead of up.
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It sounds like maybe the GM solenoid is somehow behaving backwards. I wonder if it is possible for the solenoid to over-rotate and bleed off fluid pressure when commanded to fully close.

When you say the pressure drops to 50 psi at WOT, does it drop to 50 and just hold there, or are you saying that at WOT it gradually climbs up to 100+ and then suddenly drops?

At WOT, the govenor pressure will be lower at say 30 MPH than it would at part throttle. This is how the computer prevents the tranny from shifting early at WOT (plus, there is detent pressure acting on the opposite side of the 1-2 shift valve).

The govenor pressure should read 0-3 psi in drive with the brakes applied (wheels not moving). It should then rise slowly at part throttle around 1 psi or so per mph, until it shifts into 2nd.
 
jtsdad13 said:
could my problem with 2nd gear be related to pressure as well. comes out of second gear at about 4000 rpms under wot (like you threw in neutral) dealership replaced trans under warranty still same problems?
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Doubt it. Sounds like your problem is a slipping front band. Did they really replace the whole tranny or do a rebuild?
 
spray said:
I took the truck down there shifting fine just wanting a shift kit and a GM solenoid installed and they said it need new cluthes so I told them to go ahead and rebuild it so they did and it would not shift at WOT so then they told me I needed a big daddy drum that uses bigger cluthes, they guaranteed that would fix my problem but it did. So My problem now is that I have paid almost 3k and my trans is not shifting at WOT, They are saying the computer is making it drop govenor pressure from 110psi to 56 psi. Does anyone have any advice or know of anyone that I could talk to.
Click to expand...

It could be something as simple as a warped valve body. See if they can swap it out for another one just to test. It only takes an hour or so to swap a valve body.
 
I would get ahold of Dusty Hawk,he is a master at the 48RE tranny,he knows his stuff and more then willing to talk to a guy and explain the whole tranny and his prices are very good too,I got my parts from him and several others on here :)
http://www.htstransmissions.com/


Excellent info there too Ron!;) Rotten Ronnie
 
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How would you all recommend me getting my money back from PATC?
 
small claims of course or just walk in there slam your fist on the desk and start screaming. :motz: :fight:
ORRR bang the owners daughter :date::D
 
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