I have a question I hope you guys can help with. First my tranny is a 700R4 and it has a shift kit of which type I do not know. When I have the Tranny in plain "D" or 3rd gear, whenever I decellerate to a stop I can hear a clunk underneath the car and actually fell the car kind of kick when it downshifts. When it does this you can kind of hear the RPM's kick up a little. If I drive the car in "OD" or 4th, when I come to s stop it doesn't do this. Does this have something to do with my driveshaft, rear end, or tranny? Would it do this because of my shift kit, and is this a problem I should get checked out soon? Also when it upshifts to any gear the RPM's actually jump up higher before it gets into gear and then drops. Slipping tranny?? Have the car stored right now so I'm not able to drive it right now. If you need any more info from me just ask, but this is about the best I can explain it.

 

I'm assuming what you mean is that you have a harsh shift, where it clunks into gear? If this is the case then your tranny is on it's way out.... sorry.

 

Yah, I guess you could say that. When it downshifts into 1st gear, but only when I'm in Drive. When I'm in Over Drive it doesn't do it...WHY???

 

sure that the trans mount is good?

 

check your tranny mount like said, also check fluid level in your tranny... if neither of those fix it, it sounds like it's in need of a rebuild. What you may want to try though is going on eBay and buying a corvette servo and installing that... it might help you out a bit.

 

I heard about a chronic problem like this related to our cars, but it had to do with the brakes...When you are almost to a stop there is a "clunking" sound...I don't remember what caused it though. Anyone else know what I'm talking about?

 

Thanks for the info...I thought about maybe the mount. It looks good but I haven't really checked it ya know? It almost feels like the car is breaking in half if that makes any sense...like the front is stopping/slowing down before the rear and then it clunks when it catches up. The fluid seems to be good, I have checked that many times. As for the rebuild, I was thinking of doing that, but if the mount fixes it, then it can wait. I've read a little about the Corvette servo. I'm not real knowledgeable on auto tranny's...what will the servo do?

 

Yah, that is when it does it. The reason I'm brining it up now is because I was on a Recaro TA site and the guy on there was having the exact same problem as me, but he didn't know what the problem was so I figure I'm not alone.

 

Im pretty sure i can answer this for you, The Trans go shift kit, does this. Its caused by the the shims that replace the accumulator springs. Mine does the exact same thing, only in drive though. You can fix this by talking to Pro Built Automatics, pm him and tell him your problem, im pretty sure thats what it is though. He sells stiffer accumulator springs, that still give a firm shift, but softer shift when your not on it.

Kevin

 

when i rebuilt my trans and installed a transgo shift kit mine to does it in drive that is why i leave it in overdrive.

 

ok, here is another question. If I drive the car around town in OD, all of the shifts are soft. When I drive it in "D" the shift into second is pretty hard, sometimes I can chirp the tires. Shouldn't all shifts be hard? Also, what about the jump in RPMs just before it shifts into gear? Even when I get on it and it downshifts it does the same thing...the RPM's jump up for a split second then go where they should be as if the car was in neutral and then the gears catch. Can too much fluid cause a problem like this? The car has a 3speed auto shifter even though the tranny is OD. I don't know if a 4speed auto shifter makes any difference as far as the notch position for each gear. Someone told me my shift linkage geometry might be off. I'm assuming the tranny cable from the shifter is stock. Would I have to get a new cable for a 4speed shifter since it has an extra gear worth of travel or can it be adjusted?

 

My car does the same thing, but I think my "clunk" is in my rearend...so I am going to tighten my pinion to specs, since I know its loose. If i drive in OD it downshifts nice and smooth


<--Also has an unknown shift kit

 

Hello,

I have the same problem on GTA 87, trans mount changed and OK, when I push the brake, in downshifting, at 5-10mph only in D, a little clunk noise and a sensation of déconnection( downshiffing 2-1 perhapds), in OD no problem.... If you have a feedback since 2004, thanks for your helpfull, bye