What motor mounts?
What motor mounts? Should have done mine when doing headers but oh well. Everyone says use poly over the stock rubber but how much longer does the poly actually last than stock rubber? And if using poly what else do I need to modify to make these poly mounts work? Or are they ordered with EVERYTHING needed and direct fit/replacement?
Last edited by senicalj4579; May 23, 2011 at 10:13 AM.
I decided to let the chevy dealer replace them with the stock ones. I dont need the hassle of doing mounts right now. Ill replace them in a couple years with poly when I take my pacsetters out for stainless.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Polys are great....and cheap. They keep things in check. You pull the mount, cut some rivets off with a grinder, pry the rubber out, insert the poly insert, bolt the clamshells back together, put them back on the car.
Launching!
Joined: Jul 2009
Posts: 222
Likes: 0
From: Durham, NC
Should have done mine when doing headers but oh well. Everyone says use poly over the stock rubber but how much longer does the poly actually last than stock rubber? And if using poly what else do I need to modify to make these poly mounts work? Or are they ordered with EVERYTHING needed and direct fit/replacement?
Unlike rubber, polyurethane is not affected by salt and most other road contaminates, it is more resistant to heat as well. Due to the higher durometry or hardness reading, the poly mount will retain its shape longer than rubber with the probable answer or 6 to 8 times longer.
If you order a kit, you receive the poly mount insert and bolts, that's it. You will have to open up the "clam shell" and remove your old mount, put the poly into place, close up the clam shell and bolt it back together.
The most difficult part is getting everything to line up correctly.
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On The Tree
Joined: Oct 2009
Posts: 135
Likes: 0
From: Arizona
Take it easy man, your gonna freak some people out.
Poly Motor Mounts and Rubber GM Trans-Mount have done me good for almost 2 years now. Would do it again. Have a good 1
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I did mine with the Prothane replacements in a A4. They seem to be working great........ but what would I know?....... When I pulled the clamshell on the drivers side pedestal, the metal motor mount insert from the factory bushing fell out with the little remaining rubber attached to it & hit me in the head. I guess I should checked it a while back. Point is ANYTHING is better than what was on my car at the time.... LOL
Thanks for the help guys. Chevy dealer wants 219 for labor and 97 for each mount. I will be doing my headers again in the future so I will do polys then. Right now I just want the car done and they will do it in 2.5 hours. I will be happy if I dont have to work on the damn thing for a month lol
Launching!
Joined: Jul 2009
Posts: 222
Likes: 0
From: Durham, NC
Launching!
Joined: Jul 2009
Posts: 222
Likes: 0
From: Durham, NC
I think you have to define, what does "last" mean to you.
If you mean, do they still work (ie they do what motor mounts do, having a mechanical connection from motor to frame/k-member) then they'll work for over 200K miles.
If you mean, do they retain their factory shape, then, truthfully, I have no idea.
IMO, Rubber Motor Mounts typically retain their factory shape up to 25 to 30,000 miles or 3-5 years. Some will last longer, some less. There are different type of stresses associated with each type of motor and trans setup. A manual transmission will have more torque stress applied to the mounts due to simple reason that the stress is not absorbed inside the transmission much like an automatic.
I am only guessing at the number above, I've seen pics of rubber mounts that have 100K miles and they are thrashed. I removed my mounts at 57K miles and they did not have that that extreme amount of damage but they were not in their factory shape condition.
I don't think anyone has done an experiment which they removed these mounts at typical set points (say every 3K miles) to check on the mounts' condition and to see if the mounts retained their shape. If anyone has done this experiment, I commend them for acquiring some actual data. As far as I know there currently is not any data stating a failure point.
If you mean, do they still work (ie they do what motor mounts do, having a mechanical connection from motor to frame/k-member) then they'll work for over 200K miles.
If you mean, do they retain their factory shape, then, truthfully, I have no idea.
IMO, Rubber Motor Mounts typically retain their factory shape up to 25 to 30,000 miles or 3-5 years. Some will last longer, some less. There are different type of stresses associated with each type of motor and trans setup. A manual transmission will have more torque stress applied to the mounts due to simple reason that the stress is not absorbed inside the transmission much like an automatic.
I am only guessing at the number above, I've seen pics of rubber mounts that have 100K miles and they are thrashed. I removed my mounts at 57K miles and they did not have that that extreme amount of damage but they were not in their factory shape condition.
I don't think anyone has done an experiment which they removed these mounts at typical set points (say every 3K miles) to check on the mounts' condition and to see if the mounts retained their shape. If anyone has done this experiment, I commend them for acquiring some actual data. As far as I know there currently is not any data stating a failure point.
I think you have to define, what does "last" mean to you.
If you mean, do they still work (ie they do what motor mounts do, having a mechanical connection from motor to frame/k-member) then they'll work for over 200K miles.
If you mean, do they retain their factory shape, then, truthfully, I have no idea.
IMO, Rubber Motor Mounts typically retain their factory shape up to 25 to 30,000 miles or 3-5 years. Some will last longer, some less. There are different type of stresses associated with each type of motor and trans setup. A manual transmission will have more torque stress applied to the mounts due to simple reason that the stress is not absorbed inside the transmission much like an automatic.
I am only guessing at the number above, I've seen pics of rubber mounts that have 100K miles and they are thrashed. I removed my mounts at 57K miles and they did not have that that extreme amount of damage but they were not in their factory shape condition.
I don't think anyone has done an experiment which they removed these mounts at typical set points (say every 3K miles) to check on the mounts' condition and to see if the mounts retained their shape. If anyone has done this experiment, I commend them for acquiring some actual data. As far as I know there currently is not any data stating a failure point.
If you mean, do they still work (ie they do what motor mounts do, having a mechanical connection from motor to frame/k-member) then they'll work for over 200K miles.
If you mean, do they retain their factory shape, then, truthfully, I have no idea.
IMO, Rubber Motor Mounts typically retain their factory shape up to 25 to 30,000 miles or 3-5 years. Some will last longer, some less. There are different type of stresses associated with each type of motor and trans setup. A manual transmission will have more torque stress applied to the mounts due to simple reason that the stress is not absorbed inside the transmission much like an automatic.
I am only guessing at the number above, I've seen pics of rubber mounts that have 100K miles and they are thrashed. I removed my mounts at 57K miles and they did not have that that extreme amount of damage but they were not in their factory shape condition.
I don't think anyone has done an experiment which they removed these mounts at typical set points (say every 3K miles) to check on the mounts' condition and to see if the mounts retained their shape. If anyone has done this experiment, I commend them for acquiring some actual data. As far as I know there currently is not any data stating a failure point.
And if anyone has done this experiment then I would have to say they have been laid off longer than me
Im rethinking this and looking into this Prothane kit motor/trans mounts. I hear half people say poly trans along with poly engine mounts are not bad. Hmmm???
Launching!
Joined: Jul 2009
Posts: 222
Likes: 0
From: Durham, NC
Due to the motor mounts, you'll feel a little bit more vibration at idle, above idle, it will feel stock.
The Trans Mount is where some has issues with, as they feel vibrations at different speeds (typically above 80mph). If you have some vibrations, it's not due to the mount, something else is unbalanced.
I am not experiencing any of these speed/vibration issues. You will hear a little bit more of the transmission through the shifter.
I am currently using the Prothane Motor and Trans Mount kit.
Due to the motor mounts, you'll feel a little bit more vibration at idle, above idle, it will feel stock.
The Trans Mount is where some has issues with, as they feel vibrations at different speeds (typically above 80mph). If you have some vibrations, it's not due to the mount, something else is unbalanced.
I am not experiencing any of these speed/vibration issues. You will hear a little bit more of the transmission through the shifter.
Due to the motor mounts, you'll feel a little bit more vibration at idle, above idle, it will feel stock.
The Trans Mount is where some has issues with, as they feel vibrations at different speeds (typically above 80mph). If you have some vibrations, it's not due to the mount, something else is unbalanced.
I am not experiencing any of these speed/vibration issues. You will hear a little bit more of the transmission through the shifter.
Ill stick to rubber trans mount but should I do poly motor mounts?
Alright I gave in lol. I ordered the prothane engine mounts black. Ill have them for the dealer to install on thurs. I saved over 100 bucks buying these over the stockers also!
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Good choice, the reason why the poly trans mount cracked the tail was because they left stock rubber mounts in at the motor. Motor flexes, trans doesn't, tailshaft is what gives. With poly motor mounts your motor aint going nowhere so no need to worry about that.
