I have a Mav 302 C4, and i dont know what exactly is wrong with it. What happens is that my transmition has a hard time going into 3rd, i have to completly take my foot off the gas and let the rmps go down. And even then I have to kindof flutter the gass to get it into gear. I have read my shop manuals, changed the filter, which was not that dirty, hardly any fillings or shards, tightened some of the belts, and changed the oil in the transmition which was needed because it was as thick as honney. Does anybody have some suggestions. I would appreciate any help i could get.
The first thing I would try is changing the vaccum modulator. Sounds like its stuck in full vaccum mode. Also check your kick down linkage comming from your carb to see if it is stuck in the wide open throttle position. If that dosnt work let me know and I will try to explain how to clean your servo housings out. Don
While the modulator is a good bet for the problem, how did you change the fluid? Just dropping the pan only releases a fraction of the fluid. You still have a converter full of old fluid contaminating the new when you do it that way. The best way to completely change then fluid short of a full dissasembly is to take it to a place like Jiffy Lube and have the flush done. This process removes 100% of all the old fluid. It's worth the nearly $100 that it costs.
ok. i did just drop the pan. and put a new filter in. but i herd that the converter is a pain in the neck. and i just dont want to start somthing i cant finish properly and make more damage than there is now. Jiffy Lube, really .
i was about to say, a fraction of the fluid that makes sense. cause when i added fresh fluid it only took about 3 quarts at the most.
Ok today i talked to a guy who rebuild transmitions. He said that the worst thing that i could do was flush out the transmition for the fact that it is so old. He said that the detergents in the new fluid would ware off the protectants and seals on the old factory clutches and seals. I ask has he done this and he said that he quit doing it because that the transmitions went completely out and he was accused of making matters worse. PLEASE HELP,
My problems are that i can somtimes get into 3rd, and to get the C4 to get into Reverse is rare, i usualy have to persua it to get in to Reverse. PAIN IN THE NECK.
It sounds like you may still have air in the system. I would recheck the fluid level after it has settled for a while......only adding 3 quarts don't sound right
I know, that is because i didnt touch the tourq converter. and the other 6 quarts are still in there.
although i agree that new fluid can be hard on some old trannys, i would say the fluid you had was pretty degraded. having someone do the trans flush would be the way to go if your fluid is full. they disconnect the lines and run it until the fluid is all good. first check the level and modulator. also make sure the kickdown isnt adjusted to stay on like mentioned before. then if that doesnt cure it have the tranny flushed. if it doesnt get better, have them try to adjust the band tention on third. my trans had 150k on it when i bought it. had it flushed and drove it to 230k. i could have just replaced the front seal and kept driving it.
A C4 is a tuff trani, But is the modulator the silver box with wires coming out of it in the front of the engine compartment, I replaced that earlier in the year.
You are talking about the voltage regulator. The modulator is in the rear of the trans oil pan, and up on the case a bit, on the passenger side of the trans. Has a vacuum line, on some there may be two, coming from the rear of the engine to the modulator valve.
Check the hose going from the back of the engine, at the vacuum tree, and see if it is broken, cracked or missing. If so, that is the first thing to replace. If not, with the engine running, remove the hose and check the vacuum. If none, see if the tree is stopped up. If those are good, remove the hose from the modulator, and look inside the hose fitting for a screw. Turn it counterclockwise to try and bring the shift point down. If it is fine in the 1to2 shift, then the servo could be going out. Also, if the engine smokes a bit, check to see if there is any trans fluid coming from the fitting. If so, the diaphram is bad, and it needs to be replaced. Hope this helps.
