The Dodge Challenger Message Board

During heavy acceleration sometimes the clutch petal will stay down on the floor during a shift. I noticed in a recent post that this had happened on startup of a new engine but I believe this is a different situation.

The clutch is an aftermarket diaphrgm unit and seems to have plenty of hook up (does not slip). My spring down on the throwout fork seems a little weak and probably is not a stock piece. Does anyone have a spec for the clutch return spring? Size? Picture?

I also noticed the rear transmission mount needs to be replaced. The rubber has separated from the steel housing above. Does Chrysler still make this part? I dont want a poly unit due to the excess vibration transfer.

Thanks

Jon

I doubt you would feel any vibration from a poly trans mount as long as your engine mounts are rubber.

But I am sure Year One and the like do the original type if you insist.

It does sound like you just need a stronger spring on the clutch but as I have no real experience with Chrysler manual transmissions I will leave that one for others to comment on.

I had the very same problem with my car up until 2 weeks ago.
Clutch is a Centerforce, and the manufacturer says the overcenter spring muyst be removed.
It was still in place (that's the huge spring between the clutch pedal and the dashboard frame - inside the car). The pedal would stay down whenever i depressed it. And it would spring back up on its own after a few seconds. Not really useful.
I removed the overcenter spring (not easy, that thing is as tough as a hood spring) and the clutch pedal comes back up immediately now. It just requires a little bit more effort ( the overcenter spring helps depress the pedal, and keeps it down).

My return spring is also a weak-looking thing, but it looks just like the originals (I bought a spare at Columbus 3 weeks ago).

I would also get that rear mount replaced as that can also cause the linkage to bind up causing this problem.

John Mac

I picked up a new "universal" clutch return spring at Napa today. It is much stronger than the one I had been using and should do the trick.

I now remember that I changed out the original spring when using a Heavily sprung 3 finger racing clutch back in the day. Only wanted to keep the throwout bearing off the pressure plate when the clutch was not in use. The idea was to eliminate as much petal resistance as possible.

As for the rear cross member/transmission mount my local Dodge dealer has one that can be ordered from Chrysler for $50. A little pricy but the last one survived for 30 plus yearsand it should be original. We will see what arrives next week.

Thanks for your help guys

Jon

I picked up the rear transmission mount from my Dodge dealer which appears exactly the same as the original unit. Includes the metal brackets with the rubber bushing fused to it. No Chyrsler stamping or part numbers though, just "made in Korea" on the bushing.

After a test drive we seem to have a new vibration at about 60 mph. My guess is the old mount had allowed the trans to sit lower due to the collapsed material. That angle may have been correct as the rear springs have an added leaf and have been re-arched in order to get the stance I want. (About 1-1/2' higher). Can anyone suggest which way I need to go with a tapered leaf shim to line things up? Moving the pinion upward seems logical as the transmission tail shaft is now higher. Also, how much does a degree or two make in the angle of the differential.


Thanks

Check out this post;

http://challenger.mpoli.fi/forum/viewto ... 0062#10062

Basically you want to get the axle pinion and the trans at the same angle to the floor so that they are parallel to each other.

But you also want only around 3 degrees from horizontal in each of them.

Drag racers talk about putting the pinion "nose down" slightly. But they often think this means physically pointing down to the floor when in fact it should only be down slightly from where it is in this diagram and it should still be physically pointing "up" from horizontal.