Passenger side steering rack loose
05-11-2013, 04:53 PM
#1
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Thread Starter
Passenger side steering rack loose
Hi all,
When rocking the pass side front wheel, I can see the rack moving up/down in it's cast housing.
I had this on my 81 too, and it is making my car drive horribly on uneven surfaces. Tramlining and changing directions by its own will.
I know a few of you have made delrin bushings to fit into the passenger side end of the steering rack assembly.
(It is not the bushings fixing the rack assembly to the cross member I'm talking about. )
I'm gonna call a machine shop to try to have one made. But what are the exact measurements? How tight should it be around the rack? Where do I drill for the set screw?
Please chime in with any experience you may have with this.
When rocking the pass side front wheel, I can see the rack moving up/down in it's cast housing.
I had this on my 81 too, and it is making my car drive horribly on uneven surfaces. Tramlining and changing directions by its own will.
I know a few of you have made delrin bushings to fit into the passenger side end of the steering rack assembly.
(It is not the bushings fixing the rack assembly to the cross member I'm talking about. )
I'm gonna call a machine shop to try to have one made. But what are the exact measurements? How tight should it be around the rack? Where do I drill for the set screw?
Please chime in with any experience you may have with this.
05-12-2013, 03:20 PM
#2
Under the Lift
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The OUTSIDE of this bushing will require some trial and error as I think the rack housing is cast and not perfectly machined inside that external part of the end. I'm not a machinist, metallurgist, so I can't give you the proper clearance between the bushing and the shaft. Maybe my machinist buddy who made these for me will chime in if he is still reading Rennlist (he sold his 928s). I drilled and tapped a small set screw hole in the side of the end snout. Used a drill and screw just long enough to go 1/4th of the way into the bushing. I have a picture of this and the bushing in-place, but I cannot locate it today.
The Delrin bushing we made is still doing fine after several years.
The Delrin bushing we made is still doing fine after several years.
05-12-2013, 03:26 PM
#3
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Oh, here, look at this thread. My pictures and discussion are in there. Also, it appears that we got a good fit on the OUTSIDE of the bushing w/o any fiddling after all. I remember now we did a fair amount of opening up the inner diameter until the shaft moved freely in the bushing, the opposite of what you might expect.
https://rennlist.com/forums/928-foru...dial-play.html
https://rennlist.com/forums/928-foru...dial-play.html
05-12-2013, 05:42 PM
#5
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Thread Starter
Quoted from jcorenman in the other thread:
"The steering tie-rod is not in line with the rack rod. So as the rack rod moves back and forth (i.e. at right angles to its axis), the tie rod end at the wheel moves in and out a bit, and changing what direction the tire is pointing. It does not seem like much but the steering arm is short, and a little movement has a big effect on toe. "
This effect of not being in line is stronger when the suspension is extended, and the tie rod almost aligns with the rack when the suspension is compressed; eliminating the unwanted toe looseness.
My car is more unstable under acceleration than under braking (good, thanks ). And on a couple of occasions I've been going fast over a series of crests, and the car has become almost dangerously unstable. This behavior sort of confirms the theory.
I'm gonna call a machine shop and get a bushing made ASAP
"The steering tie-rod is not in line with the rack rod. So as the rack rod moves back and forth (i.e. at right angles to its axis), the tie rod end at the wheel moves in and out a bit, and changing what direction the tire is pointing. It does not seem like much but the steering arm is short, and a little movement has a big effect on toe. "
This effect of not being in line is stronger when the suspension is extended, and the tie rod almost aligns with the rack when the suspension is compressed; eliminating the unwanted toe looseness.
My car is more unstable under acceleration than under braking (good, thanks ). And on a couple of occasions I've been going fast over a series of crests, and the car has become almost dangerously unstable. This behavior sort of confirms the theory.
I'm gonna call a machine shop and get a bushing made ASAP
05-12-2013, 07:49 PM
#6
Rennlist Member
Quoted from jcorenman in the other thread:
"The steering tie-rod is not in line with the rack rod. So as the rack rod moves back and forth (i.e. at right angles to its axis), the tie rod end at the wheel moves in and out a bit, and changing what direction the tire is pointing. It does not seem like much but the steering arm is short, and a little movement has a big effect on toe. "
This effect of not being in line is stronger when the suspension is extended, and the tie rod almost aligns with the rack when the suspension is compressed; eliminating the unwanted toe looseness.
My car is more unstable under acceleration than under braking (good, thanks ). And on a couple of occasions I've been going fast over a series of crests, and the car has become almost dangerously unstable. This behavior sort of confirms the theory.
I'm gonna call a machine shop and get a bushing made ASAP
"The steering tie-rod is not in line with the rack rod. So as the rack rod moves back and forth (i.e. at right angles to its axis), the tie rod end at the wheel moves in and out a bit, and changing what direction the tire is pointing. It does not seem like much but the steering arm is short, and a little movement has a big effect on toe. "
This effect of not being in line is stronger when the suspension is extended, and the tie rod almost aligns with the rack when the suspension is compressed; eliminating the unwanted toe looseness.
My car is more unstable under acceleration than under braking (good, thanks ). And on a couple of occasions I've been going fast over a series of crests, and the car has become almost dangerously unstable. This behavior sort of confirms the theory.
I'm gonna call a machine shop and get a bushing made ASAP
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05-13-2013, 12:30 AM
#8
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Do some measurements: depth of the end snout, inner diameter of the snout, diameter of the shaft. Start from there. Jim put a lip on the bushing - probably not needed. Be prepared to test fit the piece and to take it back for some opening up or you can just shoot for the "loose" side initially. Just about anything is better than the amount of movement I saw.