This particular incident happened Tuesday or Wednesday of last week. I was driving my car and was sitting at a red light waiting to get on to the highway. The light turned green and I proceeded to go WOT onto the highway. First gear was fine, shifted into second and that was fine. I'm in second (still WOT) and go to shift into third. It goes into gear but then there is a boom and then a grinding sound which i could feel through the shifter, and the motor proceeded to bounce off the rev limiter. I immediately pushed in the clutch, tried to put it into 5th, and was met by the grinding sound again. I was able to coast off the highway at the next exit and enter a near by parking lot.

As I'm in the parking lot and still coasting at around 15mph in neutral, I put the car into 1st. The car seemed to still have power to the rear end under idle but if I tried to accelerate, it felt as if the clutch "slipped" or the motor was turning faster and not in sync with the transmission. When this happened, the grinding sound occurred and sounded as if a shaft that was meant to have gears (assumption) had striped them all and was spinning freely. Note: The car still shifted into all gears, including reverse when the clutch was in. When shifting through all the gears, no grinding or abnormal sound occurred. If i recall correctly, I came to a complete stop and tried to go in reverse. I believe the car started to move slightly (less then 5mph) and then the grinding sound occurred and I lost power to the rear. The same thing happened when I tried to drive forward in 1st gear.

What I'm hoping is that someone has some advise as to what may have happened? Me being a "glass is half empty" type of guy, would assume that I've destroyed the trans and need to have it rebuilt. Someone at work mentioned that maybe the clutch went out but I have a feeling that it's bigger than that. A little side info, the car has 82k miles on it and i believe it is a factory clutch that seemed to be in great shape. I have previously done the test where you drive up to about 25-30mph and put the car in 6th and proceed to floor it. The clutch held up fine and never gave hint of wanting to slip during that test.

Any advise and help would be great. For what it's worth, I don't currently have the space to remove the transmission myself to check the carnage so my car would need to be hauled off to a friends place or even a shop. I'm hoping that I can get my issue narrowed down (or even pinpointed to a specific issue) so that I can cut out as many unnecessary steps as I can to get the car fixed.

Thanks!

 

Most likely that the trans is gone. Only way to be certain is to pull out the trans. Check the clutch and if it looks OK then time to tear down the trans. Good luck buddy. Been there before.

 

sounds exactly what happened to my z28 at around 80k miles. Stock clutch and i was banging gears on the highway....shifted to 4th and heard shitt scattering. pulled off the road and was able to shift into all gears. I could put it in gear and pull out with little throttle but if i gave it anymore than 1/4 throttle it would grind and wouldnt go anywhere. After tearing it apart i found that i broke the clutch disc dampening springs and it was spinning the disc around the hub. Either way you will more then likely be pulling your trans but it sounds like clutch to me. Hope this helps.

 

Drain the transmission fluid and see what it looks like. See if you have any teeth laying in the bottom of the trans.

 

Sound more like a broken clutch to me.

 

I doubt it is this, but make sure you check the driveshaft before you spend money buying parts. My ujoints broke on a WOT 2nd-3rd shift awhile back. Had it towed to the tranny shop where they replaced the driveshaft. Although that was the first thing I looked for, it was held up by the torque arm.

 

Thanks for the advise everyone! To the ones saying that it's probably the clutch, this gives me hope and makes my bank account sweat a little less.

LS1maro, when this happened to you, what clutch did you replace your stock one with?

318charger: Thanks and I'll check that, although I don't think that's the issue since I still had slight power at idle, and it was a grinding and not so much a clunking that I would expect.

 

hasn't happened to me yet (knock on wood) but I would recommend a Monster single disc clutch kit with Tick M/C and speed bleeder...go level 1 if you're gonna stay bolt-ons...level 2 if you plan on H/C

my level 2 is very smooth, much better than stock LS6, and is good for 550rwhp

 

at the time i didnt know any better and put a centerforce dual friction clutch and a spec billet fly wheel. This combo worked pretty well for a couple years on some nitrous hits although recently i went to an LS7 clutch kit and couldnt be more happy with engagement and driveability. The price is also big plus and it comes with a flywheel also.

 

Did you buy your LS7 clutch from a vendor or from a dealer?

 

Do you have any drive in 4th gear ?

4th just locks the input/mainshaft. SO no gears are involved

If you have no drive in 4th either the clutch is toast, or you've broken the input or output shaft.

If you have drive in 4th, then you've chewed all the teeth off the input shaft/laygear and clutch is likely fine.

 

Thanks for that advise! I'll check into that this weekend and report back.

 

Not true, the input and output shafts are still messed with gears to make 1:1 . My advice pull trans if the clutch is trashed up found the problem, Im betting on the trans is shot.

 

clutch all the way...ive had this happen twice on to different cars...and I have built a bunch of six speeds

 

Actually stevieturbo is right. There are no gears engaged when in 4th. Its simply locking the input and mainshaft together. All other gear are spinning but not engaged.