Steering Rack Disassembly and Refurb

[Captain Obvious]

I've been doing a bunch of suspension work to my 77 this off-season and part of that work has been on my steering rack. I suspect this is old hat for lots of people, but it's my first time this deep into the rack and I've been trying to take pics of the interesting spots along the way.

This whole project started with the rack mounting bushings. My previous owner installed polyurethane bushings on the rack mounts and they didn't look like right. The project snowballed from there, but let's start with the bushings.

On the pass side, the bushing looked too narrow for the mounting slot on the rack and after some digging on the forums, it appears that the width of the P/S rack mounting slot got wider on the later cars. It appears that he used an early kit on a later car. Here's a pic of the bushing he put in. You can see the gap where the mounting slot is wider than the bushing:

The solution appears to simply use the correct year bushing kit. Here's my replacement bushing installed. It was a tight fit. I even had to put a little silicone grease on the bushing and tap it into place with a plastic mallet. Much better fit:

I've seen pics of this before from others, but for posterity, here's the older narrow style compared to the newer wider style:

And on the driver's side there was a large gap where the bushing didn't wrap around the rack properly and was pinched by the mounting strap. Here's a pic of the driver's side bushing. You can see the gap and notice the deformation on the left side from not fitting into the mounting strap correctly:

Problem was... When I first installed my replacement bushing, it was no better than the one that came off the car. I had the same problem and couldn't get the bushing to wrap around the rack far enough and I ended up with a huge gap where the ends were supposed to meet.

After looking things over, I came to the conclusion that the replacement poly bushing wasn't designed properly. The rack has a smooth radius fillet on the inside corners at the bottom of the slots, while the bushings have squarer corners molded into them. As a result, the bushings don't fit comfortably into the slots.

Here's a shot of the shot in the rack. Note the smooth rounded fillets in the corners:

And here's a shot of the bushing that's supposed to fit in that slot. Note the inside corner that is much sharper than the receiving slot in the rack:

Thankfully the poly was hard enough that I was able to cut it with a new very sharp fine tooth file. Using a file I was able to round the inside corners of the bushing to better fit the rack. Here's a shot after I rounded the corners:

Finished filing both sides of the bushing and tapped into place with a plastic mallet. Note how much smaller the gap is once the bushing fits snug in the slot and slides all the way to the bottom of the groove without hanging up on the corners:

That's what started the project. I'll post more pics as the work progresses.

[rcb280z]

That's good info Capt. I wonder how mine looks. If mine is the same it could explain the slight vibration I'm getting through the steering wheel. I have tried everything else but the rack bushings. So maybe I will take mine out soon. Who supplied the bushings?

[EuroDat]

Thats a big difference in size. I didn't know they changed the size over the years. After seeing that I went out to the garage and checked mine. It looks tight, no gaps, I must of been lucky and got the right one, I guess.

Chas

[siteunseen]

Here's my pictures from when I did mine. Glad to see you went with the color of grease, I did and then read the black was less likely to squeak. Something about graphite?

[Captain Obvious]

siteunseen, I remember talking about those two little plastic plugs that are circled in your pics. I took some close-up pics of mine. Here's one side:

And here's the other:

Still not sure what they are, but I can tell you that they are NOT plugs for grease fitting holes. Not only are they too small, but if you look inside the rack tube, there are no holes through. Here's a pic inside the tube No holes:

So after looking and picking at them, my only theory is that they have something to do with the fitting and alignment of the two major components of the rack tube. I'm thinking that maybe since alignment of the long tube into the cast portion that houses the pinion gear is important, that maybe they loosely fit the two parts together, locked them in an alignment jig, and then used a hard setting thermoplastic to lock the two together. Similar to what they did with the throttle linkage? Just a theory.

[Captain Obvious]

I have tried everything else but the rack bushings. So maybe I will take mine out soon. Who supplied the bushings?

rcb, Haha! Well I gotta admit something here...

I've been doing all this suspension work you see... And I knew that I had an old set (NOS) of strut inserts packed away in a box in the storage area of the garage. Now mind you, I bought those struts maybe fifteen years ago for the 260 I was working on at the time. Well when I started all the suspension work on my current 280, I went looking for those struts.

I found the struts, but they are rears for the 240/260 and won't fit anywhere on the 280. BUT I also found a box of other parts that I bought at the same time with the intention of putting them on the 260. Been so long, I completely forgot I ever even bought them. And one of the things that was in that NOS box was the steering rack bushings. How unbelievably convenient!!

So, long story short, I bought them so long ago that I have no idea where. Probably MSA or Black Dragon.

And for siteunseen, I didn't consciously choose the black. That's what I found in my NOS mystery box!

Here's a pic of the paperwork that came with them. Has Mfgr name and P/N's on it. No idea if this place is still in business, but that's all I got! You can see on the paperwork that they differentiate between "early" and "late", and the P/N I bought was for "late":

[Captain Obvious]

After I got the bushings sorted out, I disassembled the rest of the rack. This means you have to pull the inner tie rods off. You really only need to remove one end, but since I wanted to clean out all the old grease, I removed both ends.

Remove the dust bellows and you're looking at this:

Remove the plug from the inner tie rod grease port:

Loosen the lock a little bit nut:

And unscrew the inner tie rod from the end of the rack gear:

After you get the tie rod off, inside you'll find the ball seat and it's associated spring. In this pic, the seat is out laying on the paper towel, and you can see the tip of the spring poking out of the hole in the end of the rack:

Ball seat and spring cleaned up:

Pull the lock nut and "spacer" off the end of the rack gear and you're left with this:

If you pull the other inner tie rod end as well, just be sure you don't mix up the parts from the ends and make sure you put everything back on the same end it came from originally.

[Captain Obvious]

So Chas, You mentioned in another thread that you cut the welds on your inner tie rods so you could tighten them up a little?

Do you have any pics of that process? I'm still thinking that I don't need to go to that extreme (yet?), but out of curiosity, how deep do you think you had to cut?

[Captain Obvious]

Got some more pics uploaded. To get the rack gear out of the main tube, you have to take off the tension adjust shoe and the pinion gear. Most of this stuff has been handled before so I'm not going to include as many pics, but thought I would include some.

To get the tension adjustment shoe out, first remove the lock ring:

Then unscrew the big slotted adjustment cap exposing the parts inside. Remove the washer and spring. Note that I could not fish the tension shoe out of the hole from here. It's not in there real tight, but there's just no place to easily grab it down in the blind hole. I was able to push it out easily from the other side once the rack gear was removed from the housing. You can see the shoe still installed in the housing:

To get the pinion gear out, remove the two bolts holding the retainer in place and pull the retainer off. Note that I put some masking tape over the shaft splines to protect the grease seal while it is being slid over the splines:

Pull the pinion shaft, upper bearing, and gear up and out of the rack. Mine came out without a fight:

Don't lose or bend any of the spacer shims that adjust the pinion shaft end play:

After removing the pinion gear, here's what it looks like inside the housing. The rack and lower pinion bearing are still in place:

Once you have the tension shoe loose and pinion gear removed, you can silde the rack gear out the end of the housing. Obviously, if you only removed one inner tie rod end, then that's the direction you'll have to go, but if you took them both off like I did, then it will slide out either end. And then once the rack gear is out, push the tension shoe out of the housing:

[Captain Obvious]

So one of the interesting things about the rack is that they used bronze bushings at the ends of the housing on which the rack gear slides. There is no discussion that I could find in the FSM's that talk about those bushings. I'm sure they're off the shelf items and are certainly replaceable with the right tools and replacement parts, but I'm guessing they were never intended to be a fixable item. If they're wallowed out, you're probably supposed to replace the whole steering rack assy? Note the lube groove cut in the bushing:

Also note the dent where the inner tie rod end grease plug was hitting the bushing at end of travel. This brings up a question for me... What is supposed to limit end of travel of the rack? On my rack, it was clearly the heads of those little bolts bumping up against the bushings and that just seems wrong. Makes me wonder if my rack was put together correctly. I'm going to file the deformation off the bushing, but unless I do something else, it's going to recur.

So back to the question about end of travel limit... I had these two black washers installed just inboard of the tie rod end lock nuts that floated stupidly in space between the grease plugs and the tie rod lock nut. The washer in question is just to the right of the grease hole in this pic:

Here's another pic showing the washer after the tie rod end has been removed. The washer in question is top center in this pic. They are thick metal washers with a hard black vulcanized rubber coating applied to the outside:

To me... That washer just screams "End of travel bump stop!!". But with the grease plug bolts installed as they were on my rack, it never gets that far. So I'm wondering if those grease plug bolts are correct. I'm thinking that if I used headless set screws instead to plug the grease holes, then not only would I stop denting my bushings, but I would also decrease my turning radius a little.

So a question for the suspension experts... What is is that is supposed to limit end of steering travel? Is it supposed to be those black rubber coated washers, or something else?

[240260280z]

Some photos in links below. No obvious hex heads protruding:

http://www.classiczcars.com/forums/help-me/37639-inner-tie-rod-help.html

http://www.classiczcars.com/forums/help-me/12727-tie-rod-help-needed-quick-before-school-starts.html

S130 Slammage! - Page 24 - Project Datto - Ratsun Forums - Page 24

[240260280z]

One More: http://i418.photobucket.com/albums/pp264/Aussie260z/190120095551640x480.jpg