I've had this problem for about a 1.5 years now, but I haven't been in a rush to fix it since I've noticed no further problems/noises at all and I've actually seen an increase in gas mileage. But...

My vette accelerates perfectly fine, very hard, no skips, noises or anything, just the way it did when there was no problem. However, it seems I have lost engine braking, like my torque converter disengages as soon as I take the shifter out of the OD position.

With the shifter in the OD position, the car climbs the gears, shifts as smooth as wet glass, and holds "compression", in the sense that it turns at the same speed as the engine (like when I am doing 38mph before the 41mph upshift to OD, it will hold the RPM's like it should)

HOWEVER, if I manually downshift (into any gear other than OD), instantly, it feels like the torgue converter releases and the RPM's drop down to idle RPM's (Around 600 RPMs) I can be going 60 mph, drop it into 1st on the shifter, and it just drops to 600 RPMs)

Now with that happening, I can hit the gas, the engine will rev up RPMs but feel like it's in Neutral. I will try to explain this next part as best I can...

Say I am traveling at 40mph in second gear (with the shifter in the 2 position, and I am on the gas) the RPM's are about 2500. If I take my foot off the gas, the RPM's drop to 600, and the car coasts. I can then rev the car to about 2500 RPMs and then by going higher, it feels like the transmission "catches" the engine and you can accelerate again.

The car has been doing this for some time now, the transmission fluid look very nice (still reddish) for 45,000 miles. No burning, no bangs, it shifts like wet glass...

I took it to a local transmission place and took a tech for a ride. He said it sounds like that is a built in saftey feature and doesn't seem to effect the performance of the car.

Any help will be greatly appreciated. Thank you in advance for the input. Take Care.

 

I know exactly what you are trying to splain. I forget what it was when mine did it too but it was a broken hard part in the tranny that caused my problem. I wouldn't take it back to that shop either because that explaination by the tech is retarded at best.
I broke mine downshifting to first at a tad bit too high of a speed.

 

I'm defenetly not a trans. expert, but isn't there a torque converter lock up solenoid on your 92? I wonder if that isn't malfunctioning. On my 92, it disengages when I hit the brakes on a long coast down...like a long exit ramp. The t/c stays locked up on coasting (no gas) but hit the brakes and the solenoid disengages the t/c.

 

My 92 works that same way

 

A stock TC/tranny will hold engine rpm/engine braking. If you aren't getting engine braking when you release the gas pedal you have trans issues. If you have engine braking in OD and not when the shifter is in 2nd gear it is safe to assume that the TC isn't the problem because the TC doesn't know what gear you are in.

"I'm defenetly not a trans. expert, but isn't there a torque converter lock up solenoid on your 92? On my 92, it disengages when I hit the brakes on a long coast down...like a long exit ramp. The t/c stays locked up on coasting (no gas) but hit the brakes and the solenoid disengages the t/c."

You are correct with this statement but this isn't his problem.

 

Have you had any work done to your trans? Sounds like it may be a valve-body related problem.

KC

 

If gummed up hydraulics aren't messing with your TCC, it sounds like a bad sprag unit.

RACE ON!!!

 

I do believe that was what was up with mine. Bad sprag.

 

Thank you everyone for responding...

The tranny has never had any work done on it, it's had 2 tranny flushes (at 40K and 80K) and the problem occured around 105,000 miles. It occured when I was downshifting from 3rd to 2nd at around 40. I am happy that it isn't my TC. But as for this sprag unit, how much is this going to cost, (am I looking at a rebuild)? Will the problem get worse if I leave it unattended?

Thank you again for your input. Take Care

 

The foward sprag element is approx $40. It is in the heart of the trans. You can replace it during the overhaul. There are a few other pieces that make up the foward sprag. They "usually" are good. The new element and a little sandpaper will make it as good as new. The overrun clutches will also be changed during the rebuild. Most quality shops will change the foward sprag and also the lo-roller clutch. The lo-roller clutch work the same way. It is located in the rear of the trans. That one is a few pennies cheaper. About $30. Even if the parts check good(which I doubt they will) they should be changed on a trans with more than 50K. In a performance application they should be changed every time the trans comes apart. Cheap insurance. Also stock, you have a 28 element sprag. Most performance stuff is 29 element. Not much difference but slightly more torque holding capability with the 29 .

 

sounds to me like the forward sprag is the issue here, not sure, but i reckon it might be....

 

while we are on the subject of the 4L60, or 4L60E in my case, i noticed 2 or 3 times before and again just 45 minutes ago on my way home, with my foot all the way to the floor in second, just as it is about to shift to third, the revs go up very quickly and sudenly. Im not sure if this is during the shift from 2nd to 3rd, or if it is just before it. The shifting seems fine at all other times, just at this full throttle 2nd to 3rd have i ever noticed this.

 

This is the 2-3 flare up. It is usually the beginning of the end. Non vettes usually do it for a bit longer than the vettes. The vette servo is bigger, for better apply.

 

so just incase it breaks, this is not the kind of speed i want the rear wheels locking up or anything like that, so IF it does, what can i expect to happen?

 

When it finally does give up the ghost, you usually just lose 3rd gear completely. Not a big deal. Safety wise anyway. Only the wallet will get hurt.

 

Just to let you know Pete K, you were dead right about the problem in my transmission mate. Its in getting rebuilt now, all clutches were burned, and flaking apart. Sprag element was also in a bad state. I upgraded to double row and extreme duty clutches. Thanks mate

 

Looks like I am a lucky guesser. Glad to hear it is getting fixed. The sprag "should" normally be repaced in a rebuild. Most do not do it. A 29 element sprag is available if you need it. Same money as the stock 28 element. I would buy it if possible. Also be sure to spend the $50 (us) and replace the reaction shell with an aftermarket replacement. It is known as the "beast". This is the #1 hard part that fails.

 

Keith, are you going to do any mods to your engine, because now is the time to seriously beef up the tranny. Here are some of the internals from my stock tranny.. after the 396 upgrade. Even if you don't plan on hot rodding it, you should drop the few bucks more for a top of the line sun gear shell (reaction shell) Here's an aftermarket 5 pinion planetery (stock is 4) clutchs and torque convertor

 

No worries mate, i went with all that, 29 element double row sprag, beast reaction shell, servere duty clutches, all except the 5 gear planetaries.Got a big cooler getting fitted in the morning too, and all brand new internal electronic parts as well.

 

so what kind of horsepower can i push through this transmission now that i have done all that??