Hey guys, I just put a C4 behind a 5.0 ho and the tranny will not go into reverse or shift from 1st to second or third, the fluid is good, linkage is correct and there is plenty of vacuum running to the modulator. The idle slows when it is engaged in reverse but it won't move. Any ideas on what might be causing this? Thanks in advance.
Supposedly it was rebuilt but that would probably do it, i'm not a tranny guy so I know very little about how these work. I know some basics, but not to advanced.
Does the car move at all? The way I read your first post it sounds like 1st gear works.
Have you tried to put the tranny in each position? (Park, Reverse, Neutral, Drive, 2, 1) What happens when the shifter is in each position?
I'm going to guess that there is a valve body issue if it will work in some gears but not others. You can pressure test the different circuits to verify that the different clutches and servos work correctly. There were a few videos on youtube covering this. I'll see if I can find them.
yea first gear is the only gear that works. Put the tranny in each position idle slows but doesn't move. In first it moves and when in drive it moves but won't shift out of first. Yea see if you can find those videos, that might give me a place to start. Thanks
Well, it sounds like at least the forward clutch and your pump works.
I'd take that valve body apart and make sure it is clean. Was the tranny rebuilt with a stock rebuild or did they do some valve body mods or anything? Also, how long did the tranny sit around before you attempted to use it? If you have a known good valve body it might be worth throwing it in to see what happens. I'd bet that the 1-2 shift valve in the valve body may be stuck.
These videos will test the different functions of the tranny to make sure each section works. To achieve the different gears, different combinations of the clutch packs and bands are applied.
Another cause could be is that when the valvebody was installed the missed the manual valve. Pull the pan off and move the shift lever and check to see if your manual valve is moving. If this the case then pull valvebody and line up linkage and manual valve and you should be good to go. Hope this helps
Park pawl would still work because it is part of the linkage set up and not part of the manual control. I always like to look at the stupid easy before getting into the hydraulic diagnosis. Most problems are usually the stupid easy steps that got overlooked in my experience :laughing: not that I would know :shaking: from my own learning experiences. hope this helps :grinpimp:
I had similar problems with my 75 bronco w/ the c4 except mine would still want to go forward in reverse and in park but would sometime go into park and reverse. I took it to my buddies shop and he tore it apart and the forward clutch was shot as well as the front pump. May need to be rebuilt..
Thanks for all the help guys, I'm gonna start tearing into it this week. Lots of things to look for, hopefully it's just a dirty valve body or something easy. Thanks again
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