C4 Problem...

I just recently got my C4 back from a rebuild. Just a basic overhaul...new clutches, etc, and a manual valve body kit from TCI. I installed the trans with a new converter...and it won't move. No forward or reverse gears.

Fluid level is good, and shift cable adjustment appears to be correct.

When I first added fluid to the trans, it had a leak around the intermediate servo cover. I removed the cover and replaced the gasket, which stopped the leak. I didn't remove the servo itself...just the cover. Is there anything I could have done by removing and replacing the cover that would potentially cause the issues I'm having?

Anything I can check with the trans still in the car? I'm no transmission guy for sure...but If I can check anything with it still in the car, that would be great. It's a pain to get it into and out of the car!

Thanks for any assistance on this...

From speaking to some other racers...they think the issue may lie in the check balls within the valve body... does this sound plausible? I know it could be possible...but does anyone have any direct experience with this?

I don't want to chase anymore than I have to with this...and if that's a very good possibility...I can remove the valve body and have it checked without having to remove the trans, which would be great. I just don't want to jump on that possibility first because it looks appealing to me because it would be less work.

Would the pressures be off at the test port if this was the case? I can get a gauge and line tomorrow and check that first if it would show up.

Make absolutely sure the transmission is full - check it in Park with the engine idling.
Did you pressure test the operation of the clutches and bands when the valve body was off?
If not do that before you open the valve body up - TCI won't warranty it if it has been opened (if they even admit to a problem at all).

No forward or reverse gears sounds like the stator support sealing rings or low oil level.
Paul

Won't be checkballs whatever that means . Stick a pressure gauge on the test port you'll know . Nill pressure = pump issue, good pressure = valvebody issue

Gregaust wrote:Won't be checkballs whatever that means . Stick a pressure gauge on the test port you'll know . Nill pressure = pump issue, good pressure = valvebody issue

Most likely missed the manual lever when valve body was installed , busted front pump gears , wrong bell housing or converter , and converter pulled out of front pump.

whitefield wrote:

Gregaust wrote:Won't be checkballs whatever that means . Stick a pressure gauge on the test port you'll know . Nill pressure = pump issue, good pressure = valvebody issue

Most likely missed the manual lever when valve body was installed , busted front pump gears , wrong bell housing or converter , and converter pulled out of front pump.

Thanks, I think this is it (manual lever). I was able to get a pressure gauge on it yesterday and had 50 lbs idling. No change in pressure when shifted into gears. I drained the fluid to drop the valve body, but won't get a chance to check the lever until later.

I appreciate the responses guys...definitely helped point me in the right direction!

Hope it rises more than 50psi ...

Me too! lol. This is indicative of the arm not being aligned in the slot of the manual valve isn't it? I'm assuming this is why there is no pressure change...because the manual valve isn't being moved any to increase line pressures. Didn't get home in time last night to pull it...hoping to tonight.

Thanks!

Maxx Levell wrote:Me too! lol. This is indicative of the arm not being aligned in the slot of the manual valve isn't it? I'm assuming this is why there is no pressure change...because the manual valve isn't being moved any to increase line pressures. Didn't get home in time last night to pull it...hoping to tonight.

Thanks!

arm got nothing to do with regulating pressure on a C4, your thinking of the AOD.

richter69 wrote:

Maxx Levell wrote:Me too! lol. This is indicative of the arm not being aligned in the slot of the manual valve isn't it? I'm assuming this is why there is no pressure change...because the manual valve isn't being moved any to increase line pressures. Didn't get home in time last night to pull it...hoping to tonight.

Thanks!

arm got nothing to do with regulating pressure on a C4, your thinking of the AOD.

If manual lever isn't lined up or not connected at all it would effect fluid pressure. I am not saying that thats 100% whats wrong with it. I am just saying that the manual lever will have an effect on fluid pressure . Front pump sealing rings broke is another possibility or not installed on rebuild. I still think it is in the front pump and converter area.

Well...after checking a little farther...the trans appears to have good pressure. I was just moving the shifter into reverse and drive, and noting no pressure changes on the gauge. If I move the shifter all the way to low, or whatever gear the trans thinks it's in, the pressure goes up above 150. I will be taking the valve body back to the guy who installed the full manual kit and have him take another look at it. In the meantime, I ordered a full manual, reverse valve body yesterday. Also got the shifter gate to modify my shifter to reverse pattern.

I'm just wondering if the kit he installed changed it to a reverse pattern? it wasn't supposed to, we ordered one for the forward pattern...but it makes me wonder.

Oh well...hopefully this will take care of the issue, and I will have a spare on hand as well.

Well...new valvebody is installed, and Trans is working again! It isn't esactly a bolt in deal...but not too terrible.

A couple of thoughts on this:

* You have to grind/cut on the intermediate servo to clearance it for the increased pressure for the manual VB. This is not for the feint of heart lol. I called the TCI tech line more than once to make sure I was indeed reading the directions correctly. I reluctantly made the cuts, fully expecting to have to purchase a new intermediate servo for the trans to function.

* You also have to tap an existing hole...called the neutral hole...in the trans case, and install a pipe plug, which IS included with the VB. This has to be easier with the trans out of the car!

I tried...and succeeded in doing all of this with the trans in the car. If I had it to do again...I think I would just remove the trans and be done with it.

In the end...I'm happy it's working again...and can't wait to get it to the track. I was set to go Saturday...but strong storms in our area rained out racing at pretty much all of the tracks in the area, with the exception of Bowling Green, which was hosting the HotRod Reunion. Hoping to get a chance to go this weekend and see how it does.

Thanks for the advice everyone gave me. I appreciate the input, and it helped me pinpoint the issue without having to take the trans out and return it to the builder.