Front strut steering rotation question

[RABID_MP5]

I'm getting ready to change out the struts and a question appears. Basically, I used to think that front struts were anchored solid up top - i.e. no strut mount turntable - and the rod rotated in the strut housing bore. Then I learn about the mounts, with their bearings allowing the rotation, thus no rod movement (relative to the strut cylinder), right?

If so, then why when I mark the nuts on top in the engine bay and watch, they do not move at all when I move the steering wheel lock to lock? Where is the strut allowing the motion?

 

[MrGiggles]

I checked while changing my oil this evening, and mine don't turn either. The rod must turn inside the strut.

 

[pcb]

... The rod must turn inside the strut.

They do which is why they are s PITA to reinstall.

When you try to tighten the top nut the rod spins. The rears have a notch in the threads with a big notched washer to grab on to to keep the rod from spinning while tightening but not the fronts.

The guys had to reach in there with a vise grip to hold the rod and try to not damage it.

 

[RABID_MP5]

Oh OK, I understand now. yeah it seems odd from a seal wear perspective that they don't let the rod turn with the assembly. And I'm preparing to battle it for tightening the nuts. The do-or-not debate on using an impact gun is fierce. Gonna try the vice grips and manual tools first I think.

 

[katapaltes]

They do which is why they are s PITA to reinstall.

When you try to tighten the top nut the rod spins. The rears have a notch in the threads with a big notched washer to grab on to to keep the rod from spinning while tightening but not the fronts.

The guys had to reach in there with a vise grip to hold the rod and try to not damage it.

I just did all four corners a couple months ago. I'm pretty sure my front pistons did not spin at all as I tightened the piston (top) nut. I could swear there was a D-shaped (notched) opening in my front factory mounts similar to the notched washer in the back, and I thought that was what had kept the piston from spinning. Unfortunately, I had to remove one of the fronts soon after to replace the bump stop and the second time i installed the strut, it spun. It seemed like that D-shaped hole had rounded out (if it ever existed in the first place).

I couldn't tighten everything down fully, so I just drove carefully and tightened it again a couple days later, whereupon I made a little more progress perhaps because the suspension had settled?

I used an impact on one of the rears before seeing the instructions from KYB to never, ever do that. Oops. But their concern seems to be that you can weaken the top of the piston rod, not that you'll spin the piston within the strut.

The KYB instructions said not to use the original top nut as they provide a replacement nut with a nylon insert with each strut. I used the replacement nuts, but I'm guessing it would have been easier to use the original ones without the nylon inserts. I wonder if original nuts + locktite would be a possible solution to these strut-tightening difficulties. Dunno'.

 

[katapaltes]

I checked while changing my oil this evening, and mine don't turn either. The rod must turn inside the strut.

Now I'm wondering if the front strut mounts on our cars are just old and not spinning properly, and whether new mounts would do better. I know a lot of folks do change their mounts along with their struts, but I did not because mine seemed to be fine.

 

[RABID_MP5]

Well I got them on last weekend. Four hours but should have been 2. Used Autozone loaner compressors and did need them - about an inch of compression. Used KYB OEM type gas units. Old stuff including mounts seemed OK, tho I would have gotten entire drop-in units from Rock for not that much more if I did it again. Yeah the mounts have a D shaped cutout which stripped so now I'm trying to tighten the piston rods to the mounts. At least they give you a nylon thread locking type nut so they shouldn't fall off. Only the fronts needed it bad, so rears maybe later.

I screwed up at one point by not marking the position of the mount before I removed it. Luckily you can just look at the rust and dirt on the mount and get it back in the proper position.

The old ones allowed like 6 bounces if you pushed on the bumper a few times. Now you can hardly move it at all. The expected tightness over bumps and railroad tracks is great. What I wasn't ready for is how much the handling improved. The degeneration was so gradual I didn't notice them failing - no noises etc. Quarter million miles takes it toll though. Bottom line is I was looking for another car but 100 bucks in struts gives the P5 a new lease on life.