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View Full Version : Thrust arm torque. Different approach. Good?



Gene in NC
03-06-2006, 03:05 AM
Copied over from thread "Torque thrust arm bolts. Jack stands, ramps, other?'

Different approach but if poster is right it seems only way to go. What is wrong with his report. This was on the e28 board "mye28.com". Front suspension design is about the same with lower control arms interchangeable, if memory serves.

I'm going to post this here and open a new thread with it, because if it's right it needs a full review.
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You will need to reset the Toe anyway. Just wait & tighten them while it's on the alignment rack. If the shop you go to won't let you do that, (or tighten them for you) don't go there. ;-)
(My method from last week)
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"Gene said: Dick, why, do I need a FE align? What changed? Certainly practical way to torque. "
I say: Any suspension work/component replacement will affect the alignment.
In my case the toe-in Increased by 0.17" or about 3x too much. 0.080-.090 is about right. Mine went to 0.250" w/ new thrust arms.
It's your tires.

genphreak
03-06-2006, 03:35 AM
It'd be fine if you can trust your shop to get the right torque specs on the bolts (and manage enough torque on them yourself so they don't fall out on the way there:D)

I would run it up the ramps and do them myself though, just so I don't have to ask or hope they got it right and didn't forget...

BigKriss
03-06-2006, 03:52 AM
ditto. I don't understand the difference between torquing the thrust arm bolts on ramps or on an alignment rack.

Gene in NC
03-06-2006, 04:39 AM
The question is whether the alignment changes with new thrust arms and if so does car need a new alignment anyway.

genphreak
03-06-2006, 04:56 AM
The question is whether the alignment changes with new thrust arms and if so does car need a new alignment anyway.It will as there is a level of fore/aft play at the pivot point (minimal), but there certainly would be if your old bushes were worn out when the car last had an alignment. Any slack in the bush would allow the thrust arm to move when loaded one way or the other; the aligner would still be able to set the alignment, but moving the car/going for a short drive and then coming back to re-measure the wheels would probaly show the settings are not holding very well. If this was postively not the case during your last alignment and you are certain your alignment has not gone out since (from hitting bumps & kerbs etc.) I'd guess you wouldn't need to reset the toe (that is all they can adjust in an alignment on an e34).

Basic answer is unless your bushes were really shot, you probably don't need an alignment. Perhaps see how it drives, but maybe prepared to get one anyway? :D