Front shock shaft misalignment
#1
Front shock shaft misalignment
I haven't ever seen nor heard of this so I thought I would put this question out. This is on an NB miata, stock top hats, bilstein shock with DIY coilover/spring set up.
After my last track day I noticed my upper bushing and washer above the top hat were about 1/4" off center. I just took the tire off and those pieces (left phone at home, will get pics) and the shaft is actually wearing a hole horizontally into the upper mount. Tiny pic won't let me upload pics... but miata.net has pictures of a generic top had assembly.. somehow the shaft is moving horizontally.
I am having a hard time visualizing what would be causing this. I dont 'think' the shock itself is bent, I'm in the process of disassembly, but I'm curious if anyone has seen a shaft start moving and wearing off center of the top hat?
Thanks
After my last track day I noticed my upper bushing and washer above the top hat were about 1/4" off center. I just took the tire off and those pieces (left phone at home, will get pics) and the shaft is actually wearing a hole horizontally into the upper mount. Tiny pic won't let me upload pics... but miata.net has pictures of a generic top had assembly.. somehow the shaft is moving horizontally.
I am having a hard time visualizing what would be causing this. I dont 'think' the shock itself is bent, I'm in the process of disassembly, but I'm curious if anyone has seen a shaft start moving and wearing off center of the top hat?
Thanks
#3
Moderator
iTrader: (12)
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 21,052
Total Cats: 3,128
Two things come to mind. Maybe something is misaligned at the bottom mount but there is certainly an issue with retaining the top of the rod. The rod shouldn't move up and down in relation to the tophat but the tiniest of distances and should be protected from metal to metal contact by the bushings. The wear indicates an unrestrained sawing motion. The direction indicates a lot of force horizontally. Both issues may exist.
#4
I looked everything over, re assembled it in the right position, and drove it today...... it shifted horizontally again. Im quite lost. I keep staring at Flyin Miata's shock assembly drawings and even if I'm missing the bumpstop support, or the lower bushing, etc, I still can't fathom why the actual shock would go horizontally. I guess Ill have to try and take the entire thing out. Good thing I just installed the racing beat sway bar blocks, so the long bolt method won't work without taking it entirely apart.
#5
Update: Took entire thing apart, rebuilt it with new upper bushings and a new top hat. The shock itself was straight, however the lower shock bushing, the metal sleeve seemed to be slightly off center. I assume due to the age the bushing inside is starting to deteriorate slightly. I dont know if this can be pressed out and redone, or if a new shock should just be bought.
I am getting an alignment this morning and then a track day Thursday. I will see if there are any changes or if it stays centered with the new bushings.
I am getting an alignment this morning and then a track day Thursday. I will see if there are any changes or if it stays centered with the new bushings.