New Tranny mount problem

**firemedic0135** · 06-15-2007, 05:13 PM

I just installed a new tranny mount from energy suspension seen here http://www.lmperformance.com/3118/8.html

I installed it today and now I think I may have gotten my pinion out of allignment.We had to jack up the tranny about 2" to get the crossmember back on due to the increased heighth of the new mount.I shutters a bit now when I go WOT and is really noticable between 60-100 mph never gone much further here on the local HWY
Should I just deal with it until I lower the car which may be sometime from now or just install a OEM model?
Thanks

**Wesman** · 06-15-2007, 07:31 PM

You basically put the pinion angle back to where its supposed to be at stock. The Poly mounts aren't supposed to be any larger than the stock mount, I know mine wasn't. If your old mount was that bad, then you may have damaged the pinion seal and pinion bearing, which will require taking the rear apart and replacing them.

Changing the pinion angle alone should not cause it to vibrate or shudder.

**firemedic0135** · 06-15-2007, 07:38 PM

yeah the old mount was shot ,and came out in two pieces.

how can I tell if the pinion is ruined now,or the seal?
I guess look for leaks huh?

**Y2KPewterSS** · 06-15-2007, 07:53 PM

Is your driveshaft possibly out of balance?

**Wesman** · 06-15-2007, 07:57 PM

Originally Posted by firemedic0135

yeah the old mount was shot ,and came out in two pieces.

how can I tell if the pinion is ruined now,or the seal?
I guess look for leaks huh?

Pretty much, you can also check for play in the pinion shaft by disconnecting the driveshaft at the rear and moving the pinion shaft itself to check for play.

If you can move it around at all, time for new bearings/seal.

**firemedic0135** · 06-15-2007, 08:16 PM

Originally Posted by Y2KPewterSS

Is your driveshaft possibly out of balance?

if the shaft were out of balance would there have been shutter before replacing the tranny mount?
another theory I have in mind is that since the mount was broken prolly since I bought the car was I just not feeling the shutter due to the connection between the tranny and crossmember being broken?
I dont know just thinking out loud.
I will take it to the shop and get it on a lift this week to try and figure this thing out if I cant do it here.
Thanks again and keep the ideas coming

**Y2KPewterSS** · 06-16-2007, 12:48 PM

Originally Posted by firemedic0135

if the shaft were out of balance would there have been shutter before replacing the tranny mount?
another theory I have in mind is that since the mount was broken prolly since I bought the car was I just not feeling the shutter due to the connection between the tranny and crossmember being broken?
I dont know just thinking out loud.
I will take it to the shop and get it on a lift this week to try and figure this thing out if I cant do it here.
Thanks again and keep the ideas coming

My driveshaft idea was just a guess. Most likely you would have felt the shutter prior to the tranny mount swap if it was the driveshaft. Wesman probably has you on the right track with his suggestions. If what Wesman suggested isn't the problem, I would consider having the DS balanced/checked out. Its fairly cheap to have done.

**fast enough Z28** · 06-16-2007, 01:39 PM

How bad is it shaking. cause I've never heard of one of those mounts not vibrating when installed, since it is a poly it doesn't give. Just normal effects!

**firemedic0135** · 06-16-2007, 01:41 PM

Originally Posted by fast enough Z28

How bad is it shaking. cause I've never heard of one of those mounts not vibrating when installed, since it is a poly it doesn't give. Just normal effects!

It is not a terrible shutter just noticable at heavy throttle.
I just want to be sure it is normal and not something else that needs attn.
Thanks

**fast enough Z28** · 06-16-2007, 01:45 PM

Originally Posted by firemedic0135

It is not a terrible shutter just noticable at heavy throttle.
I just want to be sure it is normal and not something else that needs attn.
Thanks

Mine does some but only at low speeds at heavy throttle. Your driveshaft is a one piece correct. If not switch to a one piece. Good Luck!

**mrr23** · 06-16-2007, 03:00 PM

it's the poly mount causing it. what you can do to reduce this is remove the steel plate it comes with. i didn't put mine in because of this.

**mrr23** · 06-16-2007, 03:01 PM

Originally Posted by Wesman

Changing the pinion angle alone should not cause it to vibrate or shudder.

it can. if the angle is far enough off, the u-joint will be binding.

**fast enough Z28** · 06-16-2007, 08:36 PM

Originally Posted by mrr23

it's the poly mount causing it. what you can do to reduce this is remove the steel plate it comes with. i didn't put mine in because of this.

You didn't put the steel plate in or the mount?

**mrr23** · 06-16-2007, 08:39 PM

Originally Posted by fast enough Z28

You didn't put the steel plate in or the mount?

no i did not put the steel plate that comes with the mount. it's called a preload plate. it makes the mount firmer by compressing it. this, in turn, will cause more transmittal of engine and trans vibrations throughout the car.

**fast enough Z28** · 06-16-2007, 08:41 PM

Originally Posted by mrr23

no i did not put the steel plate that comes with the mount. it's called a preload plate. it makes the mount firmer by compressing it. this, in turn, will cause more transmittal of engine and trans vibrations throughout the car.

Alright thanks!

**firemedic0135** · 06-16-2007, 08:43 PM

think I will try to remove that plate before going back OEM with another.
I put it on cause the instuctions said "IS NOT OPTIONAL" and I am just a sucker I guess LOL
Thats what I get for reading the instuctions HUH?

**Wesman** · 06-16-2007, 08:54 PM

Originally Posted by mrr23

it can. if the angle is far enough off, the u-joint will be binding.

That would be one hell of an oversized mount - i.e., the wrong one for the car.

Like I said, my Energy Suspension Poly mount fit in perfectly, just like stock. Maybe other brands don't fit as well though.