Went to the track last night and raced against my friend in his '01 C5, I made it to the the end, he did'nt...transmission will not work in D or OD. But will shift into D and OD at about 20mph in 2nd. What could be the problem?

 

If the transmission does not "hold" 3rd or 4th gears, then you have most likely blown the 3-4 clutch pack.

 

When it happened, he said he heard a "Clunk" sound...yesterday he was driving and that same "Clunk" sound happened again. Then the car was normal!

WTF!!!

Can you explain what the clutch pack is? Is it a big deal?

I told him to get the auto. trans. fluid changed since he has 60+K miles on the car and it has never been changed.

Thanks for any help you can give!

 

Now it's back to only working in 1st and 2nd gear.

Any help?