When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
99 Camaro engine mount swap with UMI round poly style
Hey all,
It’s another post about the engine mounts in an LS1 F-Body. Nothing new here just wanted to share my experience and how I went about it. Mine weren’t busted or broke but they had the original rubber clamshell and the clock has 90k on it. It had some shake to it and I decided to go ahead and replace. I hate the original design and the fact I have to do extra work after getting the mounts out was out of the question. So I went with UMI’s 2329 round/poly mounts. I had never swapped these in an LS car before and went in on the driver side, as it seemed to be the hardest. (I have long tube headers BTW and done one side at a time)It took about 5 hours to swap the mount. I did loose the pedestal that mounts to the frame. The new ones bolted right in place and I didn’t have to pry and fight like I’ve heard with the original design. Just a little up and down with the floor Jack proved all I needed to push the big bolt through. Had some help from my sons small hand to thread the upper back bolt to engine, that was a bit difficult. The next morning I went at the passenger side and I’m glad I did this second. Removed the starter, swung the compressor on the sway bar, removed the compressor mount and unbolted the pedestal and mount. That whole process on the passenger side only took 3 hours and not rushing, taking my time. The new mounts are shorter giving more space and I don’t feel the poly introduced any noise. Just my two cents.
Thanks - I didn't know that style of mount existed.
I used the clamshell Prothane mounts when I started getting a lot of grinding noise at idle. Original rubber was shot. The poly mounts increased vibration a little for the first couple of months (daily driven). After that they settled in and it's been smooth sailing since.
Hey all,
It’s another post about the engine mounts in an LS1 F-Body. Nothing new here just wanted to share my experience and how I went about it. Mine weren’t busted or broke but they had the original rubber clamshell and the clock has 90k on it. It had some shake to it and I decided to go ahead and replace. I hate the original design and the fact I have to do extra work after getting the mounts out was out of the question. So I went with UMI’s 2329 round/poly mounts. I had never swapped these in an LS car before and went in on the driver side, as it seemed to be the hardest. (I have long tube headers BTW and done one side at a time)It took about 5 hours to swap the mount. I did loose the pedestal that mounts to the frame. The new ones bolted right in place and I didn’t have to pry and fight like I’ve heard with the original design. Just a little up and down with the floor Jack proved all I needed to push the big bolt through. Had some help from my sons small hand to thread the upper back bolt to engine, that was a bit difficult. The next morning I went at the passenger side and I’m glad I did this second. Removed the starter, swung the compressor on the sway bar, removed the compressor mount and unbolted the pedestal and mount. That whole process on the passenger side only took 3 hours and not rushing, taking my time. The new mounts are shorter giving more space and I don’t feel the poly introduced any noise. Just my two cents.
What's your long term assessment with the UMI motor mounts? Any vibration or issues since the install?
No issue since the install and as far as vibration is concerned, I didn't notice any change. For me, going to a poly transmission mount was the night and day difference in more vibration. Also worth noting I didn't use the supplied bolts as they seemed a bit longer than the stock hardware. I also wanted to keep the studs and use for factory mounting.
I've wondered about these mounts since the polyurethane material is a lot less and thinner compared to the factory clam shell with Prothane or Energy Suspension inside of it. I figured since there was less/thinner polyurethane in the UMI mounts to dampen engine vibrations that NVH would be worse but that does not appear to be the case.
are these smaller round poly mounts easier to swap in than the clamshell type are? My car currently had longtubes on it and I've been holding out because i heard what a nightmare it was to do mounts with headers installed. Hoping maybe this style make it easier?
10-23-2023, 02:09 PM
99 Camaro engine mount swap with UMI round poly style 
