Steering wheel bearings revisited

[javadog]

The other day another steering wheel bushing thread popped up and after the usual recomendations to buy a Mitch Leland bushing were offered, I made a suggestion that maybe the OP should look a little deeper. It went downhill from there, so I thought I'd start a new thread to talk about the steering column in a little more detail, for those of you that have never had one out of a car before. Have a look at this picture:




The picture shows a steering column and it's major components. There is an outer housing, a shaft, two bearings and a few odds and ends (washers, circlips, etc - which are not shown). The splined portion of the upper end, where the steering wheel attaches, is on the right side. The splined portion on the left side is where the first joint attaches, underneath the black cover that runs down to the smugglers box. There are actually a couple of joints, two more short shafts, another bearing, etc. but these other parts are all exposed, once you remove the black cover. The two pieces welded to the shaft are present to allow the steering lock to lock the shaft when the car is parked. A plunger extends from the steering wheel lock and fits into one of two slots and locks the shaft. You have to turn the wheel to one of two positions (where the plunger is aligned with one of the two slots) to lock it.

This particular column is from a 1977 model car. It's basically what they used from 1974 onwards. The columns up though 1973 are a little different. This particular car was showing ~90k miles on it when the column was removed.

The bearing at the bottom is a fairly standard radial ball bearing commonly used as a wheel bearing, nominally a 6003- number, which is available with and without shields or seals. This particular one was made by FAG and is a 6003ZR, which is a bearing with one open side and one side with a shield. The open side faced up into the inside of the column.

The other bearing is an odd one. It's an angular contact bearing in an obsolete size. It measures 24mm ID, 40mm OD and 8mm thick. The ID is actually stepped; the upper half is 25mm. This one is an HJK/INA F-58080. When new, there was a plastic sleeve installed in the ID of the bearing to reduce the inner diameter down to the 22mm of the shaft. The bearing was originally installed with its open side facing down into the interior of the column.

It's the disintegration of this plastic sleeve that causes the symptom of failure, that being some up and down play of the steering wheel. In the past, Porsche's recommendation was to install a metal sleeve, a part they robbed from the 928 parts bin, to fill in the gap. The repair consisted of removing the steering wheel and a couple other bits, pressing the sleeve into the gap and putting everything back. Over time, some concern was raised that plastic would be a better solution, as some of the repaired cars were showing wear on the column from this metal sleeve. Thus, Mitch's bushing was born. It does essentially the same thing as the metal sleeve, it fills the gap.

When making this repair, you remove whatever plastic pieces you can, then push the remainder into the column when the new sleeve is installed. I never liked that, as sooner or later I figured what was left of it would migrate down towards the open side of the lower bearing. Extraneous crap introduced into a bearing doesn't do it any good.

A less obvious issue, and one that is seldom discussed, is the condition of the original bearings. Because the removal of the bearings is normally done with the column out of the car, and getting one of those out of the car closely resembles real work, as opposed to the 10 minutes of garage tinkering involved in a sleeve replacement, it is seldom done. I'm here to say that it ought to be given a little more consideration.

Our first clue was the problems noted in some of the cars fitted with the metal sleeve. Worn columns come from relative motion between the column and the metal sleeve, when the sleeve doesn't rotate. This is because the bearing no longer wants to rotate and the point of the least friction is where the relative motion takes place. The bearing has failed and regardless of which sleeve you install to "fix" the unwanted play, more wear is going to be coming down the pike. Shortly...

Does the plastic always fail before the bearing goes tits up? Does the bearing failure always precede the failure of the plastic sleeve? Some of each? No idea. It's pretty difficult to judge the condition of either bearing, when they are installed in the car.

In this case, the lower bearing was functional, but there was some crap in it (big surprise). The grease wasn't really grease anymore. It would have gone a while longer, mainly because there isn't really much load on it. The upper bearing was trashed. It was very reluctant to spin at all and was very rough in operation. You can see some wear on the shaft where the bearing is installed. It's the shiny portion of the shaft just above the bearing in the picture. The wear on the shaft was about .003" and you could see damage to the lower portion of the inner bearing race, where the shaft was laying on it. In this case, replacement of both bearings is warranted. A simple bushing/sleeve replacement would have only bought some time.

It's worth a little thought, the next time you run into this problem.

JR

PS: A word about bearings. The lower bearing is widely available. The upper bearing is harder to find. I'd suggest you want the one supplied by Porsche, which can be bought through Pelican. If you talk to a bearing supply house, you will learn that there are good bearings on the market and ****ty ones. The ****ty ones are made in countries better known for making fried rice, or a good curry. You want the ones from Germany, Japan and countries that make nice cars, or cameras. Complicated stuff, in other words. You've been warned...

[wayner]

Excellent write up, I've added it to my project list. thanks!

(Some of theses otherwise useful threads that degrade remind me of a honkey tonk. The type where the band plays behind a cage and people throw beer bottles at bad bands but also some excellent talent)

Thanks again for making this clear and easy

[TheSt|G]

Nice breakdown, added to my list. I love a comprehensive approach instead of a band-aid. Thanks for this.

[jrgogol]

I liked your article too, very detailed. I purchased the simple plastic bushing too, of all things, hammered it in, with a mallet and 27mm socket, to a stop, between the upper bearing and the steering shaft on my 220k '83 SC. Before so, I looked inside after vacuuming some yellow old grease or plastic, kind of the same after this time, I took my tiny screwdriver and rotated the inner race. Worked fine. Yes, eventually that bearing will need to be replaced, but for now, to rest easy all the folks with hammer in hand, the 10 minute plastic bushing works fine.

john gogol
Materials Engineer

[island911]

Indeed an excellent write up. I especially appreciated having the measurements posted. This made it easy to quickly make my own spacer. Thank you!

I will add that I don't think people need to worry about the disintegrating original plastic causing problems for the lower bearing. First off, I found that, behind the bearing, the old plastic was in one-piece and ring on the shaft. (it's not going anywhere too far). Furthermore, if the plastic did find its way into the lower bearing, there is no way the debris would damage the lower bearing. --The ball bearing is very hard steel, the disintegrating plastic is mush.

With the dimensions, I easily 3D-printed my spacer out of ABS, but can also see that anyone can make one out of something as simple as an old credit card (heat gun required). This is just a 1mm thick plastic spacer - not rocket surgery.

[KTL]

I've "rebuilt" a handful of these steering columns and the worst part is getting it out of the car. I agree the bearings generally are in good shape. Typically the lower bearing can be flushed with solvent and regreased. Regreasing isn't as straightforward in the upper bearing. But it can be done.

Here's some info I shared years ago. Not trying to one-up JR's info on the steering bearings. Just adding to the discussion.

Note that my first statement about using the 928 sleeve should be ignored since we've since found that its not a good solution! Steering column bushing ordered...any tips?

[MConn]

Thanks for the post javadog.

I just bought a column from a California Pelican to rebuild and swap out with my worn out column. Any details on the rebuild procedure will be helpful - Locktite on the u-joint bolts? - what grease to repack the bearing with? - steering lock issues?
Thanks again for the nice picture, and all of the other informative posts you've made.

Mike

[javadog]

Loctite never hurts on critical bolts but a fresh nyloc nut, properly torqued, is probably just fine. I don't repack the bearings. The upper bearing isn't designed to be repacked and the lower bearing is cheap enough that it doesn't make sense to not replace it. My preference would be to replace the lower bearing with one that has shields or seals on both sides, anyway.

I'd suggest cleaning the locking mechanism of the ignition switch while you have everything apart.

JR

[island911]

Originally Posted by KTL

... Steering column bushing ordered...any tips?

Wow - Great pictures in that post.

Originally Posted by KTL

...
Here's what the upper bearing should look like:



Here's the backside you can't see when installed:



The silly plastic insert just pops right out with little effort, and this is why using the 928 sleeve is such a piece of cake.



The small pieces of the plastic insert shown here are why the bearing goes "bad" and the steering wheel gets sloppy:

I had no idea there was such a large flange of plastic, on the back-side.

The large flange appears to be a dust-cover for the bearing.

[javadog]

Yeah, I don't think many people realize just how much plastic there is that can fall into the bearing at the bottom, when it disintegrates. One problem I have with the design of the column is the open bottom of the upper bearing will leak any oil that separates out of the grease, which is inevitable. Sooner or later, that grease isn't doing any good. The bearing I pulled out of the column above was junk after 90k miles and 35 years.

JR

[island911]

Yeah, but that upper bearing isn't seeing high loading. Both the load and the velocity are relatively tiny. And, most wheel bearing grease will stay stable for decades upon decades. The biggest threat to that bearing is rust.

Again, on the lower, that big ring of degraded plastic is just that. Hardened steel bearings will squish that stuff back to a petroleum product - hey, new grease! (kidding)

[Ferrino]

Thanks for a great write-up. What is the approx. cost of replacing the 2 bearings? Wondering if they should be replaced while I have (relatively) easy access...

[javadog]

I'd have to look the prices up. The upper bearing is only available through Porsche and I think it is 40-something dollars. The lower bearing is widely available and quite a bit less money. Have a look in the Pelican catalog.

JR

[Ferrino]

Thanks. So if the upper bearing was to be replaced entirely, you would just remove the plastic it comes with and replace it with the Leland part from the get-go?

[javadog]

I'd probably just run the Porsche bearing as-is and figure I'd get at least 25 years out of it. That's long enough.

The alternative might be to use a more common bearing, and buy one with seals, then install a separate bushing in it. Mitch's bushing, one I made, whatever was the right size.

JR

[tdw28210]

Javadog,

Looks like I need to go in and replace the bearings on my '87. Any tips on removing the entire steering shaft to get to both bearings? I have searched a couple threads and it seems like it might be a real PIA.

[javadog]

I don't know what tips I can really give you. It's not a quick job, it's every bit as difficult as it looks, as there's a lot of stuff that has to come out and some of it involves dealing with tamper-resistant bolts, which are a pain in the ass.

JR

[tdw28210]

Originally Posted by javadog

I don't know what tips I can really give you. It's not a quick job, it's every bit as difficult as it looks, as there's a lot of stuff that has to come out and some of it involves dealing with tamper-resistant bolts, which are a pain in the ass.

JR

Thanks for the expectation setting. I was sort of afraid you were going say something like this. : (. Wish me luck.

[javadog]

Good luck...

[KTL]

Take a look at this thread, where my pictures of the above bearing came from

Steering column bushing ordered...any tips?

Bottom line, not a fun job to take the column support tube out.