polyurethane motor mount experience, why check your mounts??

[wilholl]

Just to inform and not to slam any particular design.
Polyurethane mounts can be found practically everywhere and many accept them as better than original rubber
And they are sometimes installed because race car or the owner will feel less concerned about breaking things when driving spirited or hard.




installed 6 years ago


and a torn subframe



I dont't think I drive that hard!!
So glad I have a new reinforced subframe to install later.
Installed OEM rubber mounts for now


And back to business!!
Clean up on isle.....????

[ButtJuice]

Same thing happened to my friend's e28 trans mounts, lol they were the same color as well.

[Mr. Burns]

Pm sent. Those mounts look too familiar...

[ak-]

6 years ago. This I.E.?

[Exodus_2pt0]

How were your other mounts?

There's a reason no one uses poly for control arm bushings, or areas that are subject to actual movement. (The exception would be race cars that aren't used all the time, or people who don't know better.)

If these were subject to impact or excessive movement, then that's why this happened. Loose nut maybe? Once it had some free play, the constant bashing from the engine loading/unloading the mount would explain why it completely disintegrated.

[flyboyx]

looks to me like the plastic deteriorated and disintegrated. probably due to heat in the engine compartment.

what do you suggest someone use instead?

[Exodus_2pt0]

I'm all for poly drivetrain mounts, subframe bushings, just area that don't move.

They shouldn't have disintegrated like that in this application, but even still, 6 years isn't a bad life span.

[wilholl]

Same thing happened to my friend's e28 trans mounts, lol they were the same color as well.

Pm sent. Those mounts look too familiar...

PM replied

6 years ago. This I.E.?

I am not trying to slam anyone's product. Basically all polyurethane mounts are subject to the same issue.

How were your other mounts?
The other mounts are beginning to fail as well. This one is the worst.

There's a reason no one uses poly for control arm bushings, or areas that are subject to actual movement. (The exception would be race cars that aren't used all the time, or people who don't know better.)

If these were subject to impact or excessive movement, then that's why this happened. Loose nut maybe? Once it had some free play, the constant bashing from the engine loading/unloading the mount would explain why it completely disintegrated.

No loose nuts... just the driver!

looks to me like the plastic deteriorated and disintegrated. probably due to heat in the engine compartment.

what do you suggest someone use instead?

I'm all for poly drivetrain mounts, subframe bushings, just area that don't move.

They shouldn't have disintegrated like that in this application, but even still, 6 years isn't a bad life span.

This is the mount closest to the exhaust manifolds. The heat shield was installed and intact. This mount is also subject to the most torque from the motor pulling on it and I agree that once it began to fail, the up and down movement, when on and off throttle, would grind the mount into little pieces.

The idea of this thread was to let community know what can happen if you use these mounts and you don't periodically check and replace.
Can other mounts do a better job and or last longer?
Sure, nylon, delrin, solid, even OEM rubber might last longer.
For myself, I am wondering if stock rubber might not be so bad even in hard driving conditions as long as they are not worn out.

Also, don't forget!! Harder mounts=torn subframe, if not reinforced

[Exodus_2pt0]

Also I'm not seeing the damage to the subframe. The opening looks intended. Maybe I'm not looking in the right spot?

[Kershaw]

Yeah, I don't see any tearing. But it's been so long since I've seen a RWD front subframe I can't really be the one to say anything.

[TimeMachinE30]

There is daylight to the right of the LCA mount which goes through the subframe.

Was just pulling mine out today... still am.

[ak-]

I am not trying to slam anyone's product. Basically all polyurethane mounts are subject to the same issue.

Well reason I ask is because I have two friends who had the same issue on the same side with the same product.
IE said they've changed the design since, though, so just curious considering yours is 6 years old in the same timezone of when they were selling them.

Heck, one of my friends even worked for them at the time of his failure.

[djmossm42]

I'm sure although they may be more durable than rubber they aren't truly a lifetime product. Based on your experience what's the real world lifespan for a street/track car with poly bushings? Are there intermediate checks that can/should be done to get more out of them?

Sent from my MI 4LTE using Tapatalk

[wilholl]

Well reason I ask is because I have two friends who had the same issue on the same side with the same product.
IE said they've changed the design since, though, so just curious considering yours is 6 years old in the same timezone of when they were selling them.

Heck, one of my friends even worked for them at the time of his failure.

PM sent

[b*saint]

Ill never run those. There's a reason they are rubber from BMW!