My shop installed Bilstein 5100 shocks on my 2011 SR5 today. Both front and rear were installed. I just picked up the vehicle and the manager told me that he has a concern regarding the rear shocks.

He said that where the OE shocks have two bushings seperated by a spacer, with one of the bushings encased in metal (at the threaded end), the Bilstein have only one rubber bushing and the bushing has a smaller diameter than the factory lower bushing. He said that because the diameter of the Bilstein bushing is smaller, it will tend to move around (not fully fill up the hole it's in) and will degrade and make knocking noises in 5 or 6 months. He wondered whether Toyota made an in-model change to the specs which Bilstein has not adapted to.

So, I really like the way my 4Runner is now level front to back and the stiffer shocks make the ride much better. However, I am a bit alarmed by the shop manager's concerns. I've read numerous posts/threads here and have not seen this issue mentioned.

The shop manager did say that he checked Bilsteins online site to ensure that I have the correct part numbers and he confirmed that I do.

Any input, suggestions, experience with this issue? Thanks!

this was the case with my 5125's. a thicker, bigger washer will do the trick.

I want to do this mod so more info on this issue (or feedback) would be great

I called Bilstein yesterday afternoon and spoke with their customer service dept., which had me call their technical support department. The person in tech. support with whom I spoke acknowledged the difference between the OE and Bilstein rear shocks but told me it was nothing to worry about. He stated that when properly installed, the Bilstein shock's non-metal encased bushings essentially compress and widen to make up for their decreased diameter.

I do not have have the technical/mechanical knowledge to know whether his explanation is reasonable.

I installed the rear 5100's myself so I know exactly what you're talking about. I just tightened them pretty good to squish the rubber bushings flat. It shouldn't move much but I can see over the course of thousands of miles possibly developing some play. I'm not too worried about it. If I ever hear a clunking noise from the rear I'll know what it is.. ;)

Should we only do the front to avoid this issue? Go with a different model # for the rear maybe???

Any updates?

I'm thinking about getting Bilstein's for all 4 corners and don't want this problem.