Whiteline RSFB Inserts Usable Life

[cbl117]

I was driving home and admiring the improved handling from the whiteline RSFB inserts and had a thought...

Will the stock RSFBs and whiteline inserts wear out quicker than if I left it stock? I'm guessing the inserts would improve the life of the bushings just based on the fact that there is less movement. Will the whiteline inserts eventually soften up and "wear out" so to speak?

[Solo_M_Tech]

Give it time. History shows that the positive effects of the inserts wear off after a few months. When that happens upgrade to full polly bushings, M3 bushings( my vote) or solid. Solid never wears out.

[ShocknAwe]

Hard to say if they soften up and wear out, or if the driver just habituates to it extremely quickly as it's not a big change and still leaves a fair amount of excessive movement in the rear subframe

[E82MSport]

As I've only have mine in for a short time I feel they have adequately improved the feel. My impression is, this is how the vehicle should have come from the factory and would complement the OE suspension well.

My further impressions are these are merely a stop-gap to installing real M3 or upgraded urethane replacements.

As for improving or extending the life of the OE bushings I would speculate it would but have no real proof. Because the bushings are made of X material and the inserts of Y, the rate of degradation is different. Now if the inserts were installed into a new vehicle that crossing point on a graph would be much different.

In the end, money spent satiated me for the time being. I will however be upgrading in the near future to M3 or aftermarket.

[cbl117]

Originally Posted by ApexResistance

Give it time. History shows that the positive effects of the inserts wear off after a few months. When that happens upgrade to full polly bushings, M3 bushings( my vote) or solid. Solid never wears out.

I thought that history was due to not replacing the sub frame bolts since they are recommended as one time use (per BMW tech). Anecdotal data says the bolts, if reused, loosen over time and required re-torque. I replaced my bolts with the install and haven't noticed a change in the feeling of the car over the 6 months I've had them installed. But I guess time will tell.

Originally Posted by ShocknAwe

Hard to say if they soften up and wear out, or if the driver just habituates to it extremely quickly as it's not a big change and still leaves a fair amount of excessive movement in the rear subframe

Yeah I don't think its likely that they will soften over time given the material used. I haven't noticed any change in feeling with them installed buts its only been 6 months.

[cbl117]

Originally Posted by E82MSport

As I've only have mine in for a short time I feel they have adequately improved the feel. My impression is, this is how the vehicle should have come from the factory and would complement the OE suspension well.

My further impressions are these are merely a stop-gap to installing real M3 or upgraded urethane replacements.

As for improving or extending the life of the OE bushings I would speculate it would but have no real proof. Because the bushings are made of X material and the inserts of Y, the rate of degradation is different. Now if the inserts were installed into a new vehicle that crossing point on a graph would be much different.

In the end, money spent satiated me for the time being. I will however be upgrading in the near future to M3 or aftermarket.

Good points.

[Iron Man]

Originally Posted by cbl117

I was driving home and admiring the improved handling from the whiteline RSFB inserts and had a thought...

Will the stock RSFBs and whiteline inserts wear out quicker than if I left it stock? I'm guessing the inserts would improve the life of the bushings just based on the fact that there is less movement. Will the whiteline inserts eventually soften up and "wear out" so to speak?

Seeing how you are placing a harder insert into a softer/"hollow" bushing, I agree and would think you are increasing the life of the overall bushing together. I don't think the inserts will wear out over time (or wear much less then the softer bushing would). It would be nice to have feedback from some high mileage (20-30,000+ mile) vehicles.

[Solo_M_Tech]

[QUOTE=cbl117;17859370]I thought that history was due to not replacing the sub frame bolts since they are recommended as one time use (per BMW tech). Anecdotal data says the bolts, if reused, loosen over time and required re-torque. I replaced my bolts with the install and haven't noticed a change in the feeling of the car over the 6 months I've had them installed. But I guess time will tell.
QUOTE]

The bolts do NOT have to be replaced and they are not one time use. They are 10.9 cert steel and can be reused. I had the M3 bushings installed at the dealer here in Schwandorf (Germany) and they reused my original bolts. I asked about the one time use thing, and they told me that is a myth. Nothing in the instructions says to replace the bolts.

[goonerstrike]

Little off topic, but is anyone else experiencing a lot of squeaking at low speeds with the whiteline inserts? I have had them installed for about two weeks and used all the grease included with the inserts.

[Ginger_Extract]

Inserts are poly, their lifetime will exceed your ownership of the car. Are far as the bushing that they are reinforcing, since movement is limited, the bushing should last about as long as a contemporary solid rubber bushing, which usually have a lifetime off 100k miles, where they usually wear out due to age and the rubber begins to crack.

[3002 tii]

Originally Posted by goonerstrike

Little off topic, but is anyone else experiencing a lot of squeaking at low speeds with the whiteline inserts? I have had them installed for about two weeks and used all the grease included with the inserts.

I had mine for a year before selling the car, no squeaks. Did you make sure the top and bottoms didn't get mixed up?

[ShocknAwe]

Originally Posted by goonerstrike

Little off topic, but is anyone else experiencing a lot of squeaking at low speeds with the whiteline inserts? I have had them installed for about two weeks and used all the grease included with the inserts.

If they are squeaking then you didn't get them seated properly. There are little thin pieces that run from peg to peg, they sometimes fold over and prevent the insert from seating fully into the bushing. This leaves space between the bushing and the insert to rub against each other.

[cbl117]

Originally Posted by Ginger_Extract

Inserts are poly, their lifetime will exceed your ownership of the car. Are far as the bushing that they are reinforcing, since movement is limited, the bushing should last about as long as a contemporary solid rubber bushing, which usually have a lifetime off 100k miles, where they usually wear out due to age and the rubber begins to crack.

Ginger, this is what I was thinking too and wanted confirmation. Thanks your post makes sense.

[cbl117]

Originally Posted by goonerstrike

Little off topic, but is anyone else experiencing a lot of squeaking at low speeds with the whiteline inserts? I have had them installed for about two weeks and used all the grease included with the inserts.

Gooner, no squeaks here. tii and shock have good recommendations. Maybe try reseating them if you haven't already.

[Fidiman]

I have my Powerflex Black inserts for almost one year and still no movement of rear subframe. I'm quite impressed by the quality but as soon as there will be something wrong, I will upgrade them for AKG, aluminium, Powerflex or Motorsport bushings.