Howdy folks,

My recently acquired TL Magna (ES model) has a loose driver's seat. No matter what position it is adjusted to, the seat moves back and forth a couple of millimetres. When you are accelerating and braking it's supremely annoying.

I'm curious if the thing can be disassembled and tightened up somehow, or if there is some well known backyard engineering fix for this.

EDIT: Apparently this happens on BMW Z3's as well - caused by a urethane bushing which wears out. Hmmm, sounds like something I could bodge up with stuff I keep in my garage..

Anyway, let me know if you've got any suggestions!

OK I found the source of the problem. It's where the seat mounts to the position adjustment thread (which is driven by the electric motor).

http://lh5.ggpht.com/_imVdZ49KUXA/TQAQ5eOzFOI/AAAAAAAAAHM/c6Jt5Kwe5-M/s800/P1020740.JPG

The bushings are too soft and have slop in them, and it also appears that the "nut" does not have a tight grip on the thread, so there is slop there too. I believe this is called a worm drive arrangement, yeah?

Both of these obviosuly need spacing out, but spacing out with what? How do I make the grip on the thread tighter? Spacing out the bushing can probably be done with some home made washers from an old coke can layered together until the desired thickness is achieved.

I've got a TL as well and found the same problem but mine went away after I played with the adjustments - maybe it was only sloppy in the exact same position as the previous owner had it in. (he owned it since new and was a big boy).
To fix or overcome the slop in the thread I would try fitting a reasonably strong spring to the nut and then attach the other end to the seat frame so that the spring always keeps tension on the nut...basically keeping tension between the nut and the threaded rod. Good Luck.

I've got a TL as well and found the same problem but mine went away after I played with the adjustments - maybe it was only sloppy in the exact same position as the previous owner had it in. (he owned it since new and was a big boy).
To fix or overcome the slop in the thread I would try fitting a reasonably strong spring to the nut and then attach the other end to the seat frame so that the spring always keeps tension on the nut...basically keeping tension between the nut and the threaded rod. Good Luck.

Yeah that seems like a valid solution. I wonder also if some heavier grease would provide enough resistance. Heck maybe that's all it needs?

Here's a video of the problem. It's a bit dark, sorry.


http://www.youtube.com/watch?v=XdiPlaMuEak&

Yeah that seems like a valid solution. I wonder also if some heavier grease would provide enough resistance. Heck maybe that's all it needs?

OK, grease didn't work. Didn't remove any of the slop - I think I'd need something of such high viscosity that it would just gum up the worm drive.

I've had similar problems with sloppy gear changes on a KE Laser - there were 3 or 4 bushes in the linkages made of hard yellow plastic that were virtually non-existent as they were totally exposed to the elements. Ford wanted over $30 for them so I looked for alternatives - found 13mm barbed black irrigation fittings used in home garden sprinkler/dripper systems were almost an exact fit with a shoulder the same thickness. There's always more than one way to skin a cat.

There's always more than one way to skin a cat.

Indeed. Backyard engineering is my speciality - just got to pick the right solution first and then find the bits to make it happen.

This is a known problem. I took mine back to a dealer and they said they'll add some washers to stop the movement. It is still evident to a degree afterwards however, I don't notice it anymore.

I did a write up on this a while ago.

Here you go - http://www.aussiemagna.com/forums/showthread.php?t=64042

I did a write up on this a while ago.

Here you go - http://www.aussiemagna.com/forums/showthread.php?t=64042

Dammit why did I not see that in my search? *Facepalm*

Dammit why did I not see that in my search? *Facepalm*

Don't worry, I didn't see it straight away, either. I found it by accident looking through an entirely different search index.

In hindsight mate, when I did mine, I wished I used slightly thicker washers as it started to move again after a few months. Only slightly, but yeah.

Good luck with it.

I can happily confirm the recommendations from Disciple solve the problem completely. Mind you, even though I had a zillion washers lying around, none of them had a hole large enough to fit the bolt so I had to widen it with my dremel! Before you take this job on, it might be worth dropping in to Bunnings to get some bigger than usual washers with at least a 12mm inner diameter.

A word of warning though. Even when being careful, I almost stripped one of the threads when tightening it up. Use caution and go slowly.