Thought this would happen in my truck before it happened to the Camaro...

I was sitting at a red light today and decided to open it up when the light turned green. The car launched fine, but when it went to shift into 2nd, the RPMs revved and I felt a clunk underneath. I immediately let off the gas and turned onto a side road thinking it would loop me back to the main road. After about 1/2 mile, I noticed the road went nowhere, so I shifted into reverse, backed into a driveway, and shifted back into drive, and nothing. I have no forward gears at all. When the car is put into 1st, I get a slight clunk, similar to going into reverse, but no forward movement. I only have reverse right now.

I'm under the assumption that I need a rebuild on the tranny, but what happened? I want to make sure that I get it fixed correctly. I also would like to know any recommendations for improving the tranny while keeping the original case. Thanks for any input.

 

Sounds kinda like the sun shell.

 

or forward sprag

you'll need the usual rebuild kit plus some hard parts like sprags and sunshell

you'll also be replacing the TC especially if the fluid got burnt

are you dropping it yourself? If so, for the bench rebuild, TC, 12 quarts fluid and 2 new u joints (you are replacing u joints while it's off aren't you) and new rear main seal (hey, the tranny's off, replace the rear seal) you are looking at less than $1,000 as long as you don't want a performance rebuild.

 

I will not be dropping it myself since I don't understand transmissions. Do I need to worry about the rear main seal if it was replaced in 2000? Also the u joints were replaced at the same time.

 

heck yeah!!! the transmission is off. The rear main seal is right there; replace it please.

I replace mine every time I drop a tranny unless it was less than a year.

dropping a tranny is just an exercise in getting the car up high enough and having a dolly or tranny jack. Or, you'll be paying at least $500 for the removal/reinstallation labor.

 

Update....

I got the car back from the shop tonight. I was told that I broke the head off the forward sprag. I have no clue what this part is or does, but since it was mentioned by torque_is_good, I thought I'd update. What is this part and what does it do? Is it a common occurrence? The above diagnosis is the only time I heard that mentioned with all of the shops I called. $1440 later, the rebuild has the Corvette servo, a shift kit, upgraded bands (??), a few other things, and synthetic fluid. I was not told which level of shift kit was put in as I was told there are a few levels. The shop left it very streetable, but wanted to be sure it didn't break again.

Now, here's a question. The car runs really different now. Before, from a dead stop, even the slightest acceleration lurched the car and all 1-2 shifts were hard. Under WOT, the car would run out of steam at about 4400 RPM, lag about 2 seconds and then launch 2nd with a tire chirp. The new tranny seemed to have no go when I gave it the normal gas. I gave it a little more and it started to move. The 1-2 shift was smooth and you could feel the slip, not a drop into 2nd. At WOT, the car launches hard and shifts hard into 2nd after reaching 5300 rpm. It's a totally new feel. The question is, was the original way the car shifted and drove normal or is the new way normal? Could I have had a bad tranny and got lucky that I even got 18k miles out of it? I've not driven another 87 IROC-Z with the 350 and low miles to compare it to. The onld tranny just felt very tight and the slightest acceleration from a stop would set you back. Just wondering. Oh, and the way the old tranny worked was how it worked from the day I got the car in 2000 with 6k miles on it.

 

I'll let the probuilt guy comment on the current feel. You may have had a shift kit in it previously. Did you replace the rear main seal on the engine? It was right there with the tranny off

anyway, the sprag "connects" for lack of a better word or "transfers" power to I believe the sunshell. Without it, you go nowhere. They will wear down or actually crack and break over time and also will fail more often when tranny fluid isn't changed regularly (note how this flies in the face of keeping the old tranny fluid fallacy)

There is also a reverse sprag.

when you let your foot off of the gas the sprag disengages and the transmission freewheels vs staying at higher rpm's

It is a vital "hard part" which does wear down and break and gets replaced with every tranny that I send for a bench rebuild.

When it does fail, the tranny needs to be completely torn down and rebuilt to eliminate any fragments which circulated. So, with rebuilds, it comes down to the pay me now or pay me later. That's why new sprags go in for me.

Oh, there are upgraded sprags for the 700r/4L and again, I'll let the probuilt guy jump in as I'm not sure if GM went to them in a certain year or if it's just an aftermarket thing.

 

My experience with lower miles healthy thirdgens with 700R4s is that they are pretty sharp. My 80k original mile GTA is really responsive off idle and it shifts firm and quick at WOT. I'd say 99% of the sogginess off idle is due to a looser torque converter than you had originally. Can't say much about the shift quality you're experiencing other than to say that the word slip is not ever a word i'd use to describe the shift quality of my GTA or my buddies lower mile 85 LB9 Z28. It sounds to me like what you had was correct and what you have now is not what you're looking for to retain the original feel of the car.

 

Well, I need to take the car back. I haven't had a chance to drive it much or check it out since I got it home. Tonight, I took it for a little spin around the neighborhood and when the car shifted from 1st to second at light throttle, there was a slight shudder. I stopped and tried to recreate the problem and was able to every time. The shudder was sometimes worse than other times, but it happened every time. Then while driving in 2nd at about 25mph, I floored it and the car sounded like it wanted to go, but no real acceleration or downshift. That was also able to be duplicated. Something ain't right!!! For $1500, I expected this to be done correctly. Why do I always seem to get the shaft on quality repairs? I have a 1 year warranty so I guess I better get this in tomorrow.

 

It's possible that they just didn't adjust the TV cable properly. If that's the case it's an easy fix... Which reminds me I need to readjust mine this weekend....

 

For a guy with 17 years of networking experience, this is my first youtube entry. Here is the issue I'm having. Sorry you need to hear the dork commentating.

 

does it shift under medium and light acceleration?

Anyway, you have a warranty so this will only cost you inconvenience

Anyone here who is over 21 has probably had something go bad when performing a repair or building something and that even includes a bad cut in block and one of the wires didn't punch through all the way

or, fat fingering and missing the "period" in between an octet or not setting the DNS server address or entering an incorrect VLAN id.

we are all human. It's what we do to remedy the problem which is a testament to our customer service

 

Ok. I adjusted the TV cable and the problem is still there. I took it back to the shop, showed the video and he wasn't impressed. I took him for a ride and showed the car not downshifting at WOT, caused the car to shudder at the 1-2 shift and drive horribly. Guess who has possession of the car right now?

 

By any chance, do you know what tranny fluid they put in? Do you know if they put in Dexron VI?

The reason why my GTA has a T56 in it right now is because the original tranny was dropped for a performance rebuild and we installed it and set the TV cable correctly, but we ran Dex 6. Your experience with the lack of power and the soft 1-2 shift is the same thing I experienced with the tranny I bought. For a performance rebuild you would expect the tranny with a shift kit and a vette servo to shift hard, especially 1-2. This trans, I hardly ever felt the 1-2 shift and the 3-4 shift was so soft it felt like I was driving one of those new CVT transmissions that the Nissan Maxima has.

Finally, about 100 miles later, 3rd and 4th went out, the tranny had less than 200 miles on it. Needless to say I was not happy. The tranny is still under warranty and I have to get it to the shop I bought it from, but the reason why I ask about the fluid is because shortly after my tranny died, I swapped in a T56 and dumped in 4 quarts of Dex VI since the T56 calls for Dex II/III and Dex VI is supposed to be backwards compatible. I noticed that the trans had some gear whine so I stopped driving it, went on LS1tech.com and found that GM had released a TSB on Dex VI stating that it should not be used on any manual transmission cars that call for ATF older than 2005 because the fluid is too thin for them and they have a possibility of eating away at the blocker rings. I immediately flushed out my T56 and put in the recommended GM manual trans fluid that the TSB instructed to run in place of the Dex VI. Gear whine disappeared and the trans shifts so much better now.

I wonder if it could be a problem with Dex VI? There seem to be a lot of transmission companies that are issuing warnings not to use this fluid in older transmissions.