After searching all over the internet and talking to a few mechanics, I have not had any luck figuring out my cars issue. I hope someone here can point me in the right direction!

I was driving to work the other day, when I went to shift into third gear the car revved and kicked out of gear. I went to shift it again and all it did was grind. So I coasted to the nearest driveway shut it off and started it back up with the car in gear and it was fine. So then I went to let out on the clutch and all it does is grind in any gear. I can put it in gear but when clutch is released it just grinds. The clutch is a Spec 3 Twin disk and it has about 7,000 miles on it. The only thing I have noticed before this problem was if I push the clutch to the floor while sitting in Neutral or any gear it makes a grinding sound with the motor like something is rubbing together (Not a grinding gear sound), Also has seemed to have more of a chatter off the line in the last few weeks????? I'm taking the car to my buddies shop with a lift tomorrow, so I was hoping to get some info before he tears into it!

Thanks ahead of time and I hope I posted this in the right section (First Thread here)

 

I noticed this morning I posted this in the C5 section instead of the C6 section. However, I hope someone can still help me.

Also, I forgot to mention when I release the clutch while in gear the speedo jumps while its making the grinding noise....I dont know if that helps at all.

 

Ok, wait a minute. So the car will not move in any gear, correct?

 

Correct! I can put the car in gear then when I go to let out on the clutch it just grinds and the speedo jumps up!

 

Sounds like a broken output shaft in the differential to me.

 

Thanks for the response, I ve been searching all over with no luck

I was thinking clutch, but with the speedo jumping up I would think the clutch is grabbing??? So hopefully your right and this gives me direction to start.... I was wanting to replace with hardened shafts anyways.....any recommendations on which ones????

 

RPM transmissions is practically in your back yard. Give them a call directly.

 

I appreciate all your help....I think your right with the output shaft! I just went and picked up the car and as I was pushing it I can hear something turning and clunking so hopefully thats it!

 

Worst case is a mainshaft, but you won't know until it comes apart. Good luck.

 

When I broke the shaft in my differential there wasn't any noise from either the transmission or differential when I tried to drive it. Since the speedometer pickup is located in the differential, the fact it shows speed seems to indicate you have rotation through the transmission but just not through the differential. You could test it by putting in gear and trying to push the car. If it doesn't roll then it's a clutch problem.

 

The fact that your speedo is moving indicates that the diff carrier is spinning. This means the trans main shaft should be intact and one of the output shafts on the diff is broken.

 

Thanks for the help guys....I'm hoping its one of the output shafts so I can atleast feel like this repair is an upgrade at the same time. Is there anything else I should beef up while I have it torn apart. I do not plan on going to the track, just a few pulls here and there with the local guys.

 

I do not doubt Lucky or Rick's diagnosis for one fleeting second. However I am curious about something. If one of the output shafts were broken, wouldn't the clutches in the differential be locking up? Hence the car would still move forward albeit in a crippled state?

 

No - the differential posi will not be enough to make the car move with one broken stub shaft.
While you are replacing your stub shaft(s) with hardened 300m aftermarket shafts, plan to also replace the wave washers in the posi clutch pack. It's a good chance you will find both are broken.

 

If the OP decide to upgrade to better shafts, use the Drive Shaft Shop's new shafts. I have seen too many "twisted" 300M shafts.