Thunk/thud after replacing front struts. Help! (1 Viewer)

[mark71]

I replaced the factory front struts (2008 with 120k) yesterday with Bilsteins. I am now hearing and feeling a peculiar double thunk/thud when the front wheels hit a bump.

Removal and installation was as expected and all hardware that was loosened is tight.

Suspect that replacing the mushy, leaking struts stiffened things up enough to unmask a problem but not sure where to start looking.

Ideas?

 

[Yossarian]

Not to sound like a broken record, I just replied to another thread and my thoughts were the culprit could be the KDSS system. In your case though, it might be also, but for different reasons. Search in the 200 section, another member had a knocking or clunking that turned out to be something related to the KDSS. Good luck.

BTW, I have a set of the garden variety Bilsteins collecting dust ready to go on.

 

[NLScooby]

This may sound odd, but I had that happen on a shock - it was as if the first inch of travel of the shock wasn't dampened at all. After a few full cycles up and down of the shock, it started behaving normally. I can't explain why, but it worked.

 

[Markuson]

This may sound odd, but I had that happen on a shock - it was as if the first inch of travel of the shock wasn't dampened at all. After a few full cycles up and down of the shock, it started behaving normally. I can't explain why, but it worked.

Wow. That could be dangerous...if your first hard turn is hard enough. Great way to roll!

 

[Willy beamin]

check the top nut that holds the shock (s) onto the shock tower. See if that is tight. If so you can eliminate that off the check list

 

[mark71]

And the gold start goes to Willy beamin! Thanx bud.

I don't understand why, but even with the top shock nut fully tightened down to the end of the threads on the shock, there was 1/8" slack between the rubber bushing and the top of the shock tower once weight was back on the suspension. This was what caused the thunk.

Solution (for now) was two fender washers.

Either I really needed to replace the support subassembly and/or shock absorber cushion due to the rubber parts being too 'squished' or something else occurred.

BTW, to those of you wanting to replace your own shocks, I highly recommend getting a front end kit. I got the one made by OTC for less than $100 off Amazon. Worth it's weight in gold for breaking all the necessary ball joints. Also made use of a good pry bar: getting the lower control arm pushed down far enough to free the strut was a b!+@#.

 

[Markuson]

And the gold start goes to Willy beamin! Thanx bud.

I don't understand why, but even with the top shock nut fully tightened down to the end of the threads on the shock, there was 1/8" slack between the rubber bushing and the top of the shock tower once weight was back on the suspension. This was what caused the thunk.

Solution (for now) was two fender washers.

Either I really needed to replace the support subassembly and/or shock absorber cushion due to the rubber parts being too 'squished' or something else occurred.

BTW, to those of you wanting to replace your own shocks, I highly recommend getting a front end kit. I got the one made by OTC for less than $100 off Amazon. Worth it's weight in gold for breaking all the necessary ball joints. Also made use of a good pry bar: getting the lower control arm pushed down far enough to free the strut was a b!+@#.

Way to go Willy!

I wish I had more of that know-how in me melon...

 

[Willy beamin]

"the force is strong"

 

[TexAZ]

@mark71 to get the lower control arms to move more freely, use a sharpie to mark the position of the alignment cams on the lower arms. loosen the bolts on the adjusters enough that the arms can move without binding on the bushings. and disconnect the sway bar linkage. once done with shock / spacer install, use a jack to help align the swaybar, then make sure the adjusting cams didn't move from the marks, and retighten bolts to specified torque...
a little more work, but makes the job easier!

 

[mark71]

Thanx, TexAZ. That was actually what I was thinking to try next. Those bushings sure can take a lot of twisting force.

I'm really quite surprised that more people on this forum haven't discussed this job. It's quite a bit harder than the online manual would suggest.

 

[TexAZ]

Other than the KDSS, the suspension is the same as the Tundra. There are a boatload more lifted tundras out there, their forums have many ways of doing things, some better than others. One helpful technique was how to replace shocks without using a spring compressor.... talks about loosening the adjusting bolts for greater travel of the lower control arms during maintenance.