Hi Experts in All Things FB.

I've got an 83 completely stock GSL with an LSD. I get clutch shudder on moderate speed launches and I was curious if you think these motor mounts look. In each shot I have the ebrake on, and I put it in first and then reverse. Shot 1 is the engine movement looking into the bay, shot 2 is the driver side motor mount looking from below, and shot 3 is the passenger side mount.

https://drive.google.com/file/d/0B-l...ew?usp=sharing

They look pretty tight to me, but do you think they'd make the car shudder on launch?

Thanks so much and happy 4th!

Tom

 

Shudder can sometimes be caused by oil being on the clutch facing. It gets one there when the
rear main seal leaks a bit with age. Will burn off after using the clutch a few times, so will appear
to disappear once enough shifts have been done.

What rpm is a moderate speed launch? From a stop?

 

Motor mounts can contribute but the trans mount is especially responsible. Yours is probably separated rubber from steel by now.

I prefer the competition trans mount because they are advertised as 40% stiffer than stock, but a new stock one will do the job and get rid of shudder just fine.

Racing Beat sells the competition mounts.

 

clutch shudder is the clutch. engine mounts being bad make the symptom worse, but aren't the cause.

typical failure for the mount is the rubber separated from the steel, so they almost need to come out to tell

 

The RPM is ~1800 to 2200 when it happens. Yes always from a stop. Could be my lousy technique though...

Thank you! I will see if can inspect the tranny mount. No lift here . Oh and I forgot to mention there's only 32K miles on it.

So I went out around the block a few times. Uphill, level, downhill launches. You guys are making me think about what's really going on...and I think I mispoke. It's not like the clutch is skipping and is more like the stick wobbles in hand. And it's not always consistent...if I don't feather the clutch so well, it starts the stick wobbling side to side, mildly increasing in strength then stabilizes. If I do feather the clutch release well enough, no wobble. Never any discernible slip.

Maybe it's some 32 year old rubber!

Tom

 

Have you checked you trans mounts? The trans and engine mounts are cheap and easy to replace.

 

I looked at the motor mounts and they seem tight, but I'm not sure what too loose looks like. Do they look OK to you? Here's a video of the engine bay, driver side and passenger side mounts in 1st and Reverse with the ebrake on:

https://drive.google.com/file/d/0B-l...ew?usp=sharing

Thanks!

 

That video showed way too much movement for me. I like to grab the alt and be able to rock the whole car, not just the engine.

 

Did you check the trans mount? It's really hard to check the engine mounts without removing them because they are sandwiched.

 

Thanks you guys. Sounds like checking the mounts is pretty much the same as replacing them. So I'll get that done...tranny and engine.

Happy 4th!

Tom

 

Update for the group: I got new engine and tranny mounts installed. Feels more solid and doesn't typically shudder/wobble. I can *make* it wobble on hill stops if I don't feather the clutch so well and don't apply enough RPMs. Otherwise it's good.

Thanks for the collective opinions folks!