How-to Swap the Motor Mounts?

[VetteMed]

Originally Posted by Ccmano

Andrew,

Now that the mounts are in have you noticed any less engine/drive train noise inside the car? I've beed wanting to do this for a while on mine as I get an unusual amount of drivetrain noise inside the car. I'm thinking the mounts are collapsed and there is metal to metal contact somewhere.
Did the header to steering shaft clearance get any better?
H

Hans, I drove the car today, I can't say I noticed any appreciable difference in the sound or vibration inside the car - but admittedly it's been over a month since I drove it so I'm not sure if it helped. It did NOT help with my header clearance issue, so I'm rather frustrated about that. My #1 primary tube is still just a hair away from the steering shaft. Perhaps I need to try to shim up the motor mount with some large washers to gain some clearance.

-Andrew

[Ccmano]

Good to know, I went ahead and ordered a pair from RockAuto as well. Good price too, paid $89 delivered. I figure if nothing else it's time they get changed out on my 21yr old car!

Let us know how the shimming goes. I have the same issue as you, the steering shaft is like 1mm away from the header pipe. Everytime I turn right I can hear the engine touching the shaft.
H

[Dynomite]

A question regarding Motor Mounts came up and I refreshed an old thread with some additional information regarding Motor Mounts

Oreilly Auto 2902

Summit Racing 2902

Ecklers Motor Mounts

Originally Posted by VetteMed

Good to know -- looks like the same part as the Anchor unit, but who knows.

Anchor 2902, I ordered a private label and a regular inventory closeout, they were the same part but one had a made in india sticker, the other did not, but had INDIA stamped debossed on the rubber portion of the mount.

If buying from Rockauto , the Rockauto catalog is wrong - it lists the L98 mount as the right part for the 90-91 ZR-1, but you need to look up the PN for the LT1 or the later ZR-1 to find the right 2902 part.

Originally Posted by VetteMed

I pulled the headers off today, and removed the motor mounts. Here's what the original 20 year old mounts look like, next to the aftermarket new mounts. Anchor 2902. I ordered a private label and a regular inventory closeout, they were the same part but one had a made in india sticker, the other did not, but had INDIA stamped debossed on the rubber portion of the mount.



The OEM mounts are made in Japan, the aftermarket mounts are made in India. Quality seems OK, but on the mount I used for the passenger side, a little massaging with Mr. Angle Grinder was necessary for proper fit. The tube which slides into the bracket on the block, was a few mm too long, requiring some trimming.

[VetteMed]

Anchor 2902. I ordered a private label and a regular inventory closeout, they were the same part but one had a made in india sticker, the other did not, but had INDIA stamped debossed on the rubber portion of the mount.

[VetteMed]

Originally Posted by GOLDCYLON

hmm the one im trying to order is going up as a 2713 mount?

Yes, the rockauto catalog is wrong - it lists the L98 mount as the right part for the 90-91 ZR-1, but you need to look up the PN for the LT1 or the later ZR-1 to find the right 2902 part.

[VetteMed]

Hans, an update for you... today I unbolted the lower nuts from the motor mounts, and jacked up the driver's side of the motor. I slipped 2 body/alignment shims in around the stud (I chose 1/8 inch each, for a total of 1/4 inch), and lowered the motor back down, and tightened the nuts once again. I gained approximately 3/16 to 1/4 inch of clearance between the #1 primary and the steering shaft.

I'd like to find a shim with a larger surface area, but I suppose this has got to be better than the interference that was present before.

[VetteMed]

Update: After taking the car for a drive, the mount settled a little, leaving about 1/16" or so of clearance -- which was enough to make me notice just how much vibration was being transmitted through the car due to the interference. It's much quieter and smoother now.

[Ccmano]

Originally Posted by VetteMed

Update: After taking the car for a drive, the mount settled a little, leaving about 1/16" or so of clearance -- which was enough to make me notice just how much vibration was being transmitted through the car due to the interference. It's much quieter and smoother now.

Cool, my mounts are on their way... now I just need some time to install them.
H

[Ccmano]

BTW Andrew... did you have to remove or at least loosen the C-Beam?
H

[VetteMed]

Originally Posted by Ccmano

BTW Andrew... did you have to remove or at least loosen the C-Beam?
H

When I initially did the job, yes, I removed the headers, h-pipe, and the rest of the exhaust, and removed the c-beam so that I could have as much freedom as possible to jack up the motor. When I later shimmed the driver's side mount, I did not have to re-loosen the C-beam.