So I get the c4 back in the car today after just having it rebuilt and guess what...... no reverse I have everything but reverse. luckily the guy who rebuilt it works next door, so I had him come look at it. we dropped the valve body to check things out and found that one of the ball valves was no longer in it. so we put a new ball valve in where it should have been. There are 4 total right? Got the valve body back in place assuming that we had found the cause of the problem. but no fix, still no reverse..... I'm kinda bummed. I scrambled all week to get the car ready for the car show this weekend and now I cant bring my car Any advice would be appreciated. I'm not sure what else could be wrong in there that would cause no reverse.
Have the shop who did it, put a pressure gage in the case and see if it has correct readings in all four gears. Sounds like a valve body problem but there are several other issues that could cause it. Band adj., servo seals, sealing rings and more, let them find it and fix it. All bands and servo's and clutch packs should have been bench tested after assy. for proper operation. When shift kits are installed in valve body, one check ball and sometimes two are removed. Should not affect reverse if you found one missing anyway. Let us know what you find out.
thank you. Doesnt first and reverse use the same band? and I do have first, so does that mean the band is not the problem? what a way to start the weekend Can pressure testing the gears be done with the trans in the car? (please say yes)
the band doesn't have to hold for 1st to work as long as the one way clutch in rear of tranny is holding you just won't have engine braking in 1st(let off the gas in 1st and it will freewheel).
Update: went for a drive today and not only do I not have reverse but I also do not have 3rd. could this mean something is wrong with the direct drive clutch? I'm really in the dark with this problem I'm going to pull the trans on monday and check it over with the guy that rebuilt it. anything in particular we should troubleshoot? I was thinking of going to the library and printing off some pages from the old mitchell manuals they have there.
I would suspect a direct clutch problem. What happens when it tries to shift to high gear? Does it feel like it goes to neutral, or does it not even try to shift at all? BTW low gear with the gear shifter in "drive" the rear band is not holding. The sprag is holding. In manual low, the rear band is on. When you take off in drive don't let it get fast enough to shift to 2nd gear and let up off the throttle. If it doesn't shift to 2nd gear you'll notice that the transmission freewheels. That is the one way (sprag) freewheeling, which makes the transmission operate smoother. Have your tranny guy take a real close look at the direct clutch pack. The clearance between the snap ring and the top pressure plate should be somewhere between .008"-.042". I like the direct pack to be on the loose side, .025" is the norm. Less drag in low and 2nd gear that way. Also, he needs to take a REAL good look at the valve body. inside that thing is a maze of fluid passages, all of which have high pressure oil in them most of the time....so ANY leaks between the upper half and lower half will cause big problems...and they're usually really weird problems (like the trans locking up between 2nd and 3rd gear, etc). That maze can be intimidating at first glance and it does play with your eyes at times....but it ain't hard if you know how to follow directions. also in the valve body are several valves (hence the name)...have him make sure they're all free. I like to take them all out, clean everything (needs to be spotless!), dry it, then reassemble in a clean environment. It don't take much to get one of those valves to stick...and stuck valves ain't exactly fun (neither is pulling the trans a couple times!)
It wont try to shift to 3rd at all I dont think. We had it on the highway today and it was in second at highway speeds. I will look into all these things you guys mentioned. I really appreciate the help.
Pulled the trans today......again. there were a few very small metal flakes in the pan, doesnt look good. I wont have any more info until the guy pulls it apart tommorow and checks to see if there is anything visibly wrong.
