steering rack bushings

[pagosa dsm]

Has anybody made or bought polyurethane bushings for a 1st g steering rack?

 

[stealthTT]

A friend replaced bad bushings with polys in an attempt to remove a squeak. Ultimately the squeak was found elsewhere, but he claimed the steering rack bushings did improve feel in the car. However, new stock bushings could have produced the same result as the old bushings were bad.

I'm interested in making some bushings as the relatively small kit for a Stealth is $1200. I've done some research and found people had the best luck with a 2-part polyurethane from McMaster Carr or similar. However, one company that makes the aftermarket poly bushings claims to use an autoclave for curing. Others impregnate the poly with graphite to reduce squeaking. After more research, I plan to buy some and experiment.

 

[underradar92]

So you are saying that they're available somewhere? I've had no luck finding them.

Or could that be one of the few interchangeable bits that 3S's and DSM's share?

Since my car is guarding some of my jackstand collection again, (transmission died )maybe I should swap those right now...

 

[stealthTT]

So you are saying that they're available somewhere? I've had no luck finding them.

Or could that be one of the few interchangeable bits that 3S's and DSM's share?

Since my car is guarding some of my jackstand collection again, (transmission died )maybe I should swap those right now...

I had no luck confirming their availability now. The guy I know that put them in, bought them as leftovers from an old Stedabani kit. I believe he had little luck finding them new. Maybe as more and more people start tracking these older cars with tired bushings, we need to approach a company to have a run made.

I was going to measure all my bushings and call around to see if I could get something that was close and trim if needed. It'd be great to order a $150 kit for a Camaro instead of a $1200 kit for a 3S. But if we can approach a company and set up a group buy on a full kit for the dsm, 3S, or both, I'd be quite happy.

 

[underradar92]

FWIW, I'd be ok with just the rack bushings, since I already plastic bushed or rod-ended almost everything that moves on this thing. I may look into making plastic rack bushings this off season.

Or not, it already feels responsive, to the point where if I sneeze, I change lanes. Seriously, it's happened.

Can't wait for hayfever season.

 

[stealthTT]

I'd aluminum bushing or rod-end everything but I'd get dinged for a bunch of points with NASA (for good reasons). Non-metallic is free, so that's what I'm exploring.

Hayfever....yeah I got it right now....and I'm all out of Claritin.

 

[Evan K.]

What's the possibility of removing the stock ones and having someone mill some Delrin replacements since the car is floating on jack stands?

 

[underradar92]

What's the possibility of removing the stock ones and having someone mill some Delrin replacements since the car is floating on jack stands?

Someone like me? What an evil, evil plan. Sometimes I forget why I became a darn machinist. I'd rather use UHMW though, as it is (slightly) more compliant/compressable.

Reality is, at this moment I'm sick of making crap for this thing. That'll be another winter project most likely, unless I get a sudden burst of motivation. Planning to make front subframe/ crossmember bushings at the same time.

 

[underradar92]

Well, curiosity got the best of me. Just looked at the rack bushings and really, the one that controls lateral movement is so thin, that actual deflection is probably negligable.

Of course harder mountings would increase feedback, versus worn rubber even more so, but thats for the off-season for me.

I may do delrin on the front sway this week however.

 

[pagosa dsm]

I ordered oem left and right bushings today. Lets see if they come in next week. If they are correct I will post the part #s

 

[pneumo]

Well, curiosity got the best of me. Just looked at the rack bushings and really, the one that controls lateral movement is so thin, that actual deflection is probably negligable.

I agree. I replaced the rack bushings on my Laser a few months ago and took a close look at it. Lateral play is held in check with very little rubber, about 3 to 5mm. Then again, how much movement does it take to cause steering vagueness?

I remember reading on the Talon Digest about someone modifying the bracket by bending the sides outward slightly so the bracket contacted the rack, metal on metal. Seems like a good way to do it.

 

[underradar92]

I'd aluminum bushing or rod-end everything but I'd get dinged for a bunch of points with NASA (for good reasons). Non-metallic is free, so that's what I'm exploring.

Hayfever....yeah I got it right now....and I'm all out of Claritin.

I forget, is delrin also free, points wise in NASA? If so, at least on some major points, like where the oem bushings are really thick, even poly may have too much movement. I am not familiar with 3s bits but on DSM's the front control arm bushings are really thick and seem to flex a lot on dyno runs, so I'd assume they also move a lot in a turn.

The rear trail arms also seem to be a soft spot. The local 3s guy here has described the rear steer mechanism as being similar in function to 1g trail arm bits, only with the rear rack, sort of like a GVR4. Delrin may bind in that spot though, since that moves in multiple planes.

I agree. I replaced the rack bushings on my Laser a few months ago and took a close look at it. Lateral play is held in check with very little rubber, about 3 to 5mm. Then again, how much movement does it take to cause steering vagueness?

There are so many other "soft spots" to look at, I believe the rack bushings, unless they are deteriorated, are one of the last things we need to focus on. That doesn't mean I won't be making plastic ones this winter however.

As described in my earlier post, even with my present stock, rubber bushed front subframe and rack, my steering can hardly be described as "vague". I'm sure it will improve some more with the last few rubber bits gone though.

 

[Auto RS T]

A couple of months ago I had to replace my rack bushings also. The rack was actually slapping around under the car inside the metal brackets!

The problem ended up being that my rack came with two of the same bushings that didn't seat right when I replaced it a few years back, and finally worked its way loose. Nowadays, I like to think that I pay more attention to details.

With my local Mitsu dealer shutting down I got "newer" bushings from a low mileage n/t out of the boneyard. They were in much better shape than the ones I had. The yard attendant actually let me have them for free.

I used the newer n/t bushings and slightly bent in the metal brackets to squeeze in on the rack tube and it is held in there very well now.

So between the harsher solid mounts and extremely worn out and incorrect rubber, I think the "low mileage" bushings are a inexpensive happy medium.

I would like to hear some feedback if anyone does decide to go ahead and make the solid mounts.

 

[stealthTT]

Delrin is free as well. Only metallic bushings are assessed points and then not as harshly as I first thought.

NO-POINTS MODIFICATIONS:
31) Non-metallic replacement suspension bushings


You're assessed 3 points for the whole car with two exceptions:

SUSPENSION/BRAKES/CHASSIS:
25) Metallic replacement suspension bushings (Heim joints/spherical joints) +3 (except for
pillow ball camber plate joints, sway bar end links already assessed points in 6) above, and upper contol arm spindle/knuckle joints already assessed points in 7) above)

6) Add, replace, remove, or modify anti-roll bars ("sway" bars—front, rear, or both—may have spherical joints on the end links) +2

7) Replace or modify control arms (other than plates, shims, slots, or eccentric bolts/bushings for simple camber/caster adjustment only)(may have upper arm spherical/metallic joint(s) for
connection to the spindle/knuckle) +4

So even if you keep the stock anti-roll bars and control arms, but replace their joints or bushings with metallic, you're assessed the full points.

Sounds fair to me. Now I just need to decide if using 3 points here is worth it to me.

 

[pagosa dsm]

The part # for the steering rack bushings are mb501119 and mb315228