I bet some of you looked at this posting title and went .


Ok in order to further understand, I am posting a solid front motor mount mod for the 00+ bonnevilles.

harofreak00 wrote:

taken straight from the post... jack car up, put jack stand under the engine/tranny and set jack back down... slightly.. enought to take tension off the mount... take off 3 bols on the mount, and 1 on the bottom, and remove all together parts i picked up - pucks were $2.99 each and the bolt setup was $10 make a template to center your drill holes, however this is not really crucial mark... and drill put bolt thru make sure everything is just as thick as the old mount wrapped in electrical tape just for cosmetic attach bracket in reverse order leftovers that i can return to home depot... so about a $13 mod

OK you have all read that. This can be adapted to the Rivieras. I didn't take any pictures during the install because I wasn't sure it was going to work. but









You will need to get a 2000+ Bonneville or Lesabre front trans mount bracket. You will also have to drill a hole in the subframe. But I must admit the results are noticeable. The car pulls alot better.

Disclaimer :

I have not driven this enough to say it was a total sucess. I hope someone trys to do it but. At your own risk.

thats REALLY COOL!!!!!!!!!!!!!!!!

Looks like an improvement over the OEM gumband strip mounts. Thanks for the writeup.

Albertj

passenger side mounts are 3" x 3" also. I poured a casting of polyurethane 85 durometer into a capped off piece of 3" ID PVC pipe, coatd the insides with wax, and marked 3.5" up and poured it. Slipps out easily because fo the wax and it's hard enough to machine the hole for the bushing and bolt. I got the poly in blue so it should look good installed.

Here is an idea of how I casted my mounts.

Passsenger side mount


Passenger side mount apart... got to bend the tabs for the center to come out. Factory glued it in also so get your hammer ready


I used a generic tube for the bushing. Same length 4" as stock and same ID.


Make template... The hole is off center.




Make sure you coat your template with a release agent. Before you pour.


I used toilet wax to fill any holes or gaps. Dont forget to cover the hole in the side!!! My first pour just came out the hole and covered everything. Thankfully I had everything resting in a baking pan so it was contained for the most part.

Pour and wait. I let it set for a good day before I removed the template. Wash off the wax and your set! Here is a photo of the passenger side mount and front mount completed. (I reused the bushing for the front and rear mounts-easy to cut out). The rear was my first attempt and I did not come out pretty- have to redo that one. I have no idea how I am going to deal with the drivers side mount. Pix of that at the end.





Not the prettiest but they should work well. 80A hardness. I would imagine stock is somewhere between 45-50A.

Now for the driveres side mount...

Eric, would this be something the rest of us could do ourselves? Want to make a few more..? lol

It's actually fairly easy once you get the hang of it. I went through several batches of poly before I got it right. Stupid things that could have been avoided if I wasn't in such a rush. I tried using a clay block to hold the bushing and mount- failed miserably. Forgot to plug the hole in the passenger side mount- big mess when the poly leaked out. Bought the wrong type of poly- cost me lots of money but I have very nice 85B hardness mounts now (they're harder than steel but completely un-usable). Stuff like that... Take your time and they will come out OK- If I was anymore anal I would redo them because you can (barely) see the brush strokes from the release wax application.

You can get the material at www.mcmaster.com. Shore 60A is P/N 8644K24. It will be firmer than stock. The 80A hardness, would be 8644K11. The hardness of a hockey puck is shore 85A for comparison. McMaster has the easiest stuff to use. If you want to fine tune the hardness you can go to Freeman’s site.

Good stuff, Eric. Thanks for the write-up!

ewolfe those mounts look nice!!!! can u link me to the exact material u used at the mcmaster.com website pls!!!!

The 80A hardness, would be 8644K11. I bought the release wax from freeman but mcmaster would probably have a comparable release wax. McMaster product is very easy to use for the do-it-yourselfer. I got 4 1lb kits. One for each mount. They have a 10lb kit but it is much easier one at a time- trust me. Freemans site is for the professional- able to fine tune but don't expect the people there to address any questions you might have, they assume you know what you are doing. (more for commercial applications)

An afterthought... 85A is a pretty stiff mount especially a "solid" mount with no gaps in the rubber/poly. For those who do not like vibration they might want to go with 60A hardness. Still stiffer than stock. They do break in after a while- just wanted to warn you guys.

thats cool! let us know how they ride!

Another easier fix would be to do what some the W-Body people do with their mounts. It would work on the front and rear trans mount but probably not the side mounts. The trans mounts are square with a lot of gap between the rubber . Fill the gaps with poly (I have heard JB Weld will work also). You still have some flex with the rubber still being in place but it will firm up the mount. I think I saw a thread about it at 3800pro.com forum.

The three mounts are now in. P mount and front/rear transmission mounts. Paul at PRJPerformance was impressed with them especially for my first castings. Other than being a PITA to install (mostly rear trans mount) they fit very well. Once I have a chance to drive the car after the rest of my mods, I will let you know how they perform. He suggested that I start making them available for sale. I am strongly considering it... I have the process down now and If I can make a reusable templete it will be that much easier. I could do it in 80A or 60S hardness. Would anyone be interested? I dont spend too much in material (not including the mounts) so they wouldn't be too expensive and should be in line with some of the aftermarket mounts for other 3800 cars. After a chance to drive with them for a while I will start a poll...just keep it in mind.

I'd be interested in the 60A mounts.