Dang! Knuckle replacement probs.

Yesterday I replaced the front left knuckle due to the backing plate bolts stripping out (and wheel almost comng off!). Before the replacement, my steering had been very tight. Now, with the replacement knuckle, I've got some road shimmy that I didn't have before.

Everything's certis peribus. No change in steering components, seals, and I even used the same kingpins, bearings, and shims from the oldie. Toe-in is just as good as before, but for some reason now I'm fearing for my life on the freeway.

What do you think my be going on? Thanks!
-Alan

 

Just back off on the spindle bolts and your ready to go! It worked earlier didn't it?

 

Hmmm. Maybe those bearings in the knuckle have some slop. Isn't there a shim pack that adjusts the bearing preload on the knuckle bearings? I'm not sure but I remember taking my old D25 apart and it had timken bearings top and bottom with shims under the caps. I'm sure someone else will have some input.

 

Actually Billy I think that at one point they changed to putting the shims on the top kingpin only.
But no Alan you cannot swap knuckles and use the same shim pack, bearings are made to alot tighter specs then the machined knuckles, so they are more than likely the culprit, you need to reshim them to the proper preload!!!

 

sounds like fewer shims are needed.

 

My method of checking the preload was rather primitive because I don't have a fish scale that reads over 6 lbs. So I just went by "feel" compared to when I did the same jobbie, successfully, last year. The knuckles are different, but the bearing, kingpins, and shims are the same.

Ahh, that's what I needed to hear. I wasn't sure of the affect of adding/subtracting shims would be. Hopefully I'll be able to pop the upper kingpin out, simply remove a shim, and replace, then test-drive. Thanks!

 

more shims=loose
fewer shims=more


fish scales are cheap investment.

 

Today I went back inside and removed a shim. Slapped the wheel back on and test drove. Still road-shimmy. Repeated above step, and this time removed all shims. Slapped wheel back on, and still no change. I get road wander w/ no shims as I did w/ 2 shims.

 

The only thing I did different was to remove shims from the top kingpin. Evidently it didn't work with everything else remaining installed (tie rod, seals, other kingpin). Would that be called "post-load?"

 

R) ok ok ok...Hi-ho, hi-ho, it's off to WalMart I go...

I know the procedure...just "cheating" a little. Didn't want to disassemble everything and get 140wt. all over creation if I didn't have to.

Theory: can't the bearing load be affected by adding or subtracting shims even after all else has been assembled?

 

yes. but to hve the proper setup, you need a shim pack, w/alot of different thicknesses of shims.

 

66cj5 I tested this simple theory ex post facto, and had no change in symptoms. I had plenty of shims available, and even removed them all with no change in symptoms.

So the answer must be "no", that bearing load cannot be affected after the tie rod and seals have been installed, presumably due to the other 2 variables--the installation of the tie-rod & seals. That doesn't make sense to me because the action of the kingpin-tightening on the bearing should still be very independent of the other variables.
Any research method buffs see any flaws in this? :?

 

after reading all this (and 2 beers and 2 brauts) back to basics here
tear her down again: lug nuts, wheel bearings, tie rod end, spindle bolts, correct pre-load, put her back together again
then go check the OTHER side for looseness..bingo