Darnedest steering problem - rack moving
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
Darnedest steering problem - rack moving
So I installed a rebuilt steering rack, replacing the bushings with polyurethane.
Now, there's enough slop at the driver side through bolt that the ENTIRE RACK is moving side to side when turning the wheel. I'm going to go back and re-torque, but it looks like the driver side bushing is moving inside of the rack itself. The passenger side donut bushing is doing jack squat to stop it.
Anybody run into this?
Now, there's enough slop at the driver side through bolt that the ENTIRE RACK is moving side to side when turning the wheel. I'm going to go back and re-torque, but it looks like the driver side bushing is moving inside of the rack itself. The passenger side donut bushing is doing jack squat to stop it.
Anybody run into this?
Last edited by PacerX; Jul 19, 2020 at 05:18 PM.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
No, but thank you. I probably didn't explain this well...
There's no problem with the rack, there's a problem with how it is interfacing with the body at the mountings.
The problem is that the entire rack is moving - housing and all. The pinion part is doing what it is supposed to do, but the housing is shifting on the mountings. The only thing I can figure at this point is that the driver's side bolt isn't tight enough, or the hole where the bushings go is too large, or the bushings are too small.
There's no problem with the rack, there's a problem with how it is interfacing with the body at the mountings.
The problem is that the entire rack is moving - housing and all. The pinion part is doing what it is supposed to do, but the housing is shifting on the mountings. The only thing I can figure at this point is that the driver's side bolt isn't tight enough, or the hole where the bushings go is too large, or the bushings are too small.
Last edited by PacerX; Jul 19, 2020 at 05:44 PM.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
No, it's there. Weird...
After some more investigating:
The bushing is moving around inside the hole in the rack. There's a little slop due to the fit between the insert and the bolt, but most of it is coming from the fit between the bushing and the rack.
So... either the bushing is wrong, or the rack is.
Neither of these options are particularly appealing.
After some more investigating:
The bushing is moving around inside the hole in the rack. There's a little slop due to the fit between the insert and the bolt, but most of it is coming from the fit between the bushing and the rack.
So... either the bushing is wrong, or the rack is.
Neither of these options are particularly appealing.
Last edited by PacerX; Jul 19, 2020 at 06:38 PM.
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Do you still have the old rack ? If so measure it. Of course to determine where the discrepancy is, you will need to measure the new(rebuilt) rack also. Then you will know if it is the rebuilt rack or the bushings.
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Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
Would not be shocked if either the rack or the bushings are wrong.
This suspension rebuild has reinforced what a clown show the aftermarket is... And I am using top shelf parts across the board.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
OK, tore it down yesterday, at least enough to pop the bushings and get a measurement.
The problem is the Detroit Axle steering rack.
A stock GM steering rack measures 29.8mm inner diameter at the driver's side bushing holes. This fits well with the stock GM bushings 29.9mm outer diameter and Prothane's bushings (same).
The Detroit Axle steering rack measures 31.8mm. That's a problem. Ballpark, there's 4mm of slop from side to side when you reverse directions with the steering wheel, which translates to a HUGE felt "dead zone".
I'm calling Detroit Axle today. If they can't get me a set of bushings I've got a new lawn ornament, or maybe their owner's car gets a new hood ornament... they're in Ferndale, Michigan - not quite so far from me.
Not happy. Not happy at all.
The problem is the Detroit Axle steering rack.
A stock GM steering rack measures 29.8mm inner diameter at the driver's side bushing holes. This fits well with the stock GM bushings 29.9mm outer diameter and Prothane's bushings (same).
The Detroit Axle steering rack measures 31.8mm. That's a problem. Ballpark, there's 4mm of slop from side to side when you reverse directions with the steering wheel, which translates to a HUGE felt "dead zone".
I'm calling Detroit Axle today. If they can't get me a set of bushings I've got a new lawn ornament, or maybe their owner's car gets a new hood ornament... they're in Ferndale, Michigan - not quite so far from me.
Not happy. Not happy at all.
Last edited by PacerX; Jul 22, 2020 at 08:18 AM.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
Well, on the bright side...
I'm now an expert at removing the steering rack!
EDIT: Detroit Axle is sending me new bushings. But fair warning to all: if you use Detroit Axle, polyurethane bushings are a no-go... unless you machine your own... which is a thought that just occurred to me... Hmmmm... Aluminum steering rack bushings...
I'm now an expert at removing the steering rack!
EDIT: Detroit Axle is sending me new bushings. But fair warning to all: if you use Detroit Axle, polyurethane bushings are a no-go... unless you machine your own... which is a thought that just occurred to me... Hmmmm... Aluminum steering rack bushings...
Last edited by PacerX; Jul 22, 2020 at 03:28 PM.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 986
Likes: 487
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
You can't argue with measurements.
Le Mans Master
Joined: Aug 2015
Posts: 6,144
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From: St. Charles MO
If they are sending you rubber bushings and you would prefer poly or harder, then at least one other option might be a reduction sleeve made of metal that would fit snugly in the holes for the rack, and then the Prothane bushings could fit inside the sleeves. But if you have access to a lathe, then you could machine your own either from aluminum or Delrin. I'm told that Delrin is a lot easier to machine than polyurethane because it's harder. Keep us updated - I'm sorry you have this problem (very frustrating because it's such a stupid issue for Detroit to have caused), but it's interesting to read about.
