SC Steering Rack DIY Bearing Replace

[47silver]

The ball joints and a-arm bushings are 45 years old with 90000 miles and they needed replaced.
So i dropped the suspension and found.
Fuel lines needed replaced.

So i dropped the steering rack to get to them.

Luckily I did as i found that the luck nut that holds the steering shaft to the steering rack was loose. It was a blue lock nut so I do not think it was original. I am not sure that the steering shaft would have come off of the steering rack pinion but it would be catastrophic if it did. I am using a real lock nut and with blue or red loctite when i assemble it so the next owner may have to use heat to get it off.

I also noticed that the needle bearing that is in the smugglers box needed re-greased.

Since i had the rack off of the car I decided to clean and re-grease. Well you know how it goes you may as well replace the bearings, tie rod ends, etc.

I highly recommend inspecting the steering rack and fuel lines even if you do not redo the suspension.

[KTL]

I 'll take a look at the one rack I still have disassembled (for FAR too long) and see what the bearing depth appears to be. I don't recall it being all that critical but I could be mistaken.

In my limited experience the rotating of the puck doesn't work. The puck seems to find it's "happy place" again and it will rotate back to the worn slot/groove it created. The groove isn't super deep in the pucks that I have seen. So it shouldn't take a lot of sanding to flatten. Which means not a lot of shims are needed to bring back the lost puck thickness and reset the preload on it.

The four racks that I have done have all had very little grease left in them. If you see oil dripping out of the rack boots, it's a good sign the grease is mostly gone and needs to be refreshed. If you have the opportunity to turn the rack by hand without the additional leverage of the steering wheel, it's a good test for feeling the smoothness of the rack. If you can feel a lot of resistance to rotating the shaft/yoke by hand, you should take apart the rack and re-grease it. It should also feel smooth. If you can feel any roughness when rotating it by hand, you should re-grease it.

Also I have also seen the needle bearing frozen on a few of the upper steering shafts (the shaft that has the big rubber vibration isolator on it) on cars i've worked on and that's what prompted me to remove the racks in those cases. The most recent rack job I did was from my '86 Carrera that has only 78K miles. That bearing was missing altogether and only the molded rubber piece that is clamped to the body was supporting the shaft at that spot. No wonder the steering always made a slight rubber squeaking sound!

My '86 Carrera has not seen a lot of miles but it apparently had been exposed to weather prior to 1999 when my friend Mark bought it. We have had it in our family of cars since 1999 and very very rarely has it even been driven in the rain and never in the evil Chicagoland area snow. Yet the car still has plenty of surface rust underneath and some typical rust areas like the door sills, headlight buckets and forward area of rear wheel wells. Apparently it doesn't take a lot of weather exposure to seize the upper needle bearing on the external shaft.

Surprisingly that "smugglers box" area where the A/C box and the steering shaft reside get a significant amount of weathering, despite being protected by the steel belly pan. I think somebody chose to discard that bearing when they found it was seized on the shaft and just slap it back together instead of sourcing a replacement. They just pushed the steel bearing sleeve out of the rubber surround and put the surround back in place without the sleeve. I found some bearing needles sitting in the circular recess on top of the rack!.

I think the car was in a minor accident (maybe drove over a parking lot concrete block or a curb?) because I don't see any unibody damage, yet the fuel tank was replaced, the belly pan was dented quite a bit (not at all uncommon) and also a small piece of the front suspension aluminum crossmember (the slot where the torsion bar end cap adjusting screw passes through) was broken off. I mention this because I think the accident repair is probably what prompted the upper shaft needle bearing "fix" by somebody many years ago.

[KTL]

I missed the last post by 47silver when I replied. I'll take a picture of the original nut so you can see the type. Going by memory here at work, it's a flange lock nut that is the deformed type of thread. It's definitely not a blue nylon lock nut.

Funny you mention the loose nut on the pinion yoke, which is not funny at all. I say funny because I experienced something similar, but a bit worse, when I removed the rack from my racecar several years ago.

Here's what I first found. Somebody's wise idea to eliminate the rubber vibration isolator and replace with some steel tubing resulted in the shaft being wobbly.

https://www.youtube.com/watch?v=ioNS0GYmgXY

Then I looked closer and found this (caution, KTL drops the F bomb LOUDLY......... )

https://www.youtube.com/watch?v=atUyFyaBj80

[stownsen914]

That rubber donut is more than just a vibration damper ... the steering shaft needs a way to misalign slightly as the shaft turns (like what a U joint does). This becomes more the case if the old style bump steer spacers are installed.

[KTL]

Good point/reminder Scott. The fat rubber disc does allow for some very slight misalignment. But I think it really is very slight because my steering with the solid connection (the one I cursed at in the video) never had any binding.

There’s also a few places that I know of who provide solid couplers. Tangerine and Rebel

http://www.tangerineracing.com/otherproducts.htm

https://www.rsrproducts.com/product-page/rebel-s-racing-rsr-steering-coupler

I think the best rubber-less solution is the one Smart Racing Products came up with years ago. They called it Smooth Steering Upgrade and it’s actually a factory upper shaft that is cut and welded with w Sweet Manufacturing universal joint in place of the rubber disc.




But even that solution isn’t perfect. I got a used one from the classifieds here on the forum awhile back and it turned out to have a hitch/binding spot in it when I pivot the joint. So that was a bummer and I need to disassemble the joint to see if I can replace the needle bearings in it. Or just buy a new one and take the bearings from it. The joint is welded to the shaft. So I either try to get parts for it or get a used shaft and cut to length to be welded into a new joint. The u-joint is an “08” joint

https://sweetmfg.biz/product.php?productid=2603&cat=74&page=1

['78 SC]

First of all, thanks to all the contributors who made this thread and its links a treasure trove of steering rack information.

Second, some good news on the replacement parts front: the star clips that retain the steering rack bushings are available from McMaster-Carr as SKU 90635A415.



And a request...
Did anyone ever locate a source for the steering rack bushings located at the ends of the steering rack housing? One of mine is cracked, probably as a result of the rack wiggling a bit after the other bushing popped out when the retaining clip failed (likely due to not having the required spacing washers between the turbo tie rods and rack ends). This part:


Thanks in advance,
Steve

[burgermeister]

I've been wanting to turn a set on the lathe (mine are not cracked, but definitely have some play) but as usual other things have gotten in the way. Mostly I am unsure of the material to use! The bushing is really soft, and almost, but not quite, looks like a steel version of oillite bronze.
Maybe 1018 steel, or 660 bearing bronze, would be good - certainly don't want to abrade the rack.

What does the cracked surface look like?

['78 SC]

Here's the bushing. I'm beginning to think it is grooved, not cracked (wishful thinking?)



Burgermeister, I can't help with the material. Magnetic, so likely ferrous as you observed. Would there be a downside to oiliite? Delrin? Given that the bushing is supported by two rubber rings and does not contact the housing, there is probably not a large lateral load.

My new working theory is a burr on the rack scratched a groove in bushing. The burr was raised by the pinion gouging the flat area of the rack. There are also marks on the bearing that correspond to the "corners" where the round and flat portions of the rack meet. Remember the bushing at the other end of the rack had popped out after its clip failed so the rack was wiggling slightly. Here's the gouge left after I filed the burr down.



The moral of the story: if you have turbo tie rods, make sure the large washers to limit rack movement are in place to prevent over extension of the rack (like John Walker said several pages ago). Should be easy to feel them under the boot.

Steve

[burgermeister]

I took one of mine and checked it more closely, including breaking it. I would take a guess at a nodular cast iron. It can be deformed, but not much, before it just cracks open. Hardness is comparable to a few gray cast iron parts I've got lying around (mid-50's on the Rockwell 30T scale). The rack itself is around 70-80 in the area where the bushing sits, also HR30T. For reference, 30T is a superficial hardness scale, and correlates not quite linearly with Rockwell B.

I will probably order a chunk of nodular iron from McMaster and turn myself a couple of bushings. Let me know if I should make 2 sets.

[chrismorse]

This stop is particularly important when tightening the yoke onto the pinion, as it prevents the type of damage you see on the rack. Counterholding the yoke also helps when loosening or torqueing.
Additionally, without the washer, the inner end of the tie rod hits the outboard rack bushings.
looking at the bottom of the rack, you will notice a flat machined into the bottom of the rack. This is the flat that the puck supports - to maintain good rack and pinion contact.
You will also notice that this flat does not extend the full length of the rack.
What worries me is the possibility of the puck encountering the transition from flat to round, possible buggering the edge of the puck, then rapidly wearing the surface of the puck and rack.

I know the ball bearing is not t a high speed or highly loaded bearing, but in my ADD mind it can't hurt to spend another 5 bucks for a fully sealed, (not just shielded) bearing, particularly since it is at the bottom of the rack and any debris or water will sink to that low point.

deeply troubled,
chris

['78 SC]

Originally Posted by chrismorse

This stop is particularly important when tightening the yoke onto the pinion, as it prevents the type of damage you see on the rack. Counterholding the yoke also helps when loosening or torqueing.
Additionally, without the washer, the inner end of the tie rod hits the outboard rack bushings.
looking at the bottom of the rack, you will notice a flat machined into the bottom of the rack. This is the flat that the puck supports - to maintain good rack and pinion contact.
You will also notice that this flat does not extend the full length of the rack.
What worries me is the possibility of the puck encountering the transition from flat to round, possible buggering the edge of the puck, then rapidly wearing the surface of the puck and rack.

I know the ball bearing is not t a high speed or highly loaded bearing, but in my ADD mind it can't hurt to spend another 5 bucks for a fully sealed, (not just shielded) bearing, particularly since it is at the bottom of the rack and any debris or water will sink to that low point.

deeply troubled,
chris

Chris,

The flats (both sides) extend full length on my rack (steering housing casting date 6/85). Maybe some years were different?

I did see "bite marks" where the pinion teeth bit into the flat section of the rack beyond the rack teeth (see photo above) due to overextension. Maybe in time this would have broken the pinion?

I agree about the need for the washers - undoubtedly my broken retaining clip was the result of the turbo tie rod bashing it (as John Walker warned).

Burgermeister, I sent you a PM about bushings.


Steve

[Walt Fricke]

If you can weld, not too hard to replace the hockey puck with a U joint.





Not sure this made steering any better, though. I did it so I could raise the rack higher than the normal spacer bump steer stuff does so I could avoid bind in the external bearing in its rubber housing.

[Harpo]

Originally Posted by burgermeister

I took one of mine and checked it more closely, including breaking it. I would take a guess at a nodular cast iron. It can be deformed, but not much, before it just cracks open. Hardness is comparable to a few gray cast iron parts I've got lying around (mid-50's on the Rockwell 30T scale). The rack itself is around 70-80 in the area where the bushing sits, also HR30T. For reference, 30T is a superficial hardness scale, and correlates not quite linearly with Rockwell B.

I will probably order a chunk of nodular iron from McMaster and turn myself a couple of bushings. Let me know if I should make 2 sets.

Mine fell apart after powder coating the housing. I replaced them with bearing material from IGUS and turned it down on my lathe.

[David Inc.]

Could anyone point me to the part number or size for the circlip holding the lower 6202 bearing on the pinion? When I removed it the clip immediately vacated this universe.

[KTL]

You can use an external retaining ring, which will make it easier to install with the appropriate circlip pliers if you have them. Doesn’t need to be an actual C-clip

They’re 15mm inside diameter. I got a bag of 5 stainless from McMaster Carr

[David Inc.]

You're the man, thanks!

[KTL]

I have a few extras of those 15mm retaining rings. I can put one in an envelope and drop it in the mail for you, if you would like me send it out to you.

[G450X]

Thanks for the tips & photos, I will be tackling this soon.

[David Inc.]

Originally Posted by KTL

I have a few extras of those 15mm retaining rings. I can put one in an envelope and drop it in the mail for you, if you would like me send it out to you.

Oh heck, I already ordered them. Thanks for the offer though!

[David Inc.]

Hmmm.... So what happens if the rack doesn't go in the same way it was before? I took my marking tape off the end of it, then absent mindedly flipped it while greasing and now it's a 50/50 if it's in there the same way.