Rebuilding/tightening inner tie-rods on steering rack

Well, so far we have Ford and DeTomaso (Pantera) using bronze in the cam gear rack, and one person saying not too. I cant argue it well, I dont have any data to back up one over the other, but it seems unlikely your going to wear out the shaft real fast sliding it back and forth through a bronze bushing. Neither of mine even had a bushing, they were disitegrated, gone, nada. The rack was banging around back and forth past the bare rack housing. There wasnt a wear mark on either shaft. I dont know what the shaft is made out of, but I would guess its some good hard solid steel. Probably neither one have been out of the car since they left Italy 32 years ago, so they lasted well enough.

As to the lube getting past the bushing, the Cam Gear rack has passage ways around the bushing, I guess the TRW rack dont. So if you have a Cam Gear rack its a non issue, lube will pass through from either side of the bushing.

So anyway, I think this is being way over analysed. The rack is nothing different than what came in a old MGB, and most of the (Cam Gear) parts are readily available through Superformance. If it wears out, fix it or buy a new one. If the bushing is shot, stuff something in there and drive the car. Plastic, bronze or steel, I dont think its going to matter a whole heck of a lot. I just dont want mine loose and knocking. Any slop at the outer bushing magnifies as you steer further to the right, and the end of the rack could be wandering around quite a bit with very little bushing to shaft clearance.

 

My 1977 Ferrari 308 owners manual shows the lubricant for the steering gear as the same lubricant for the gearbox, Agip F1 Rotra MP 85W90, something that probably doesnt even exist anymore. I put some generic Castrol EP 85W90 gear lube in mine. I dont think its real critical what brand it is as long as its 85W90.

 

I have always used an oilite bronze to fabricate the bushing and have had no issues at all over the years on both the street and race cars. For there to be any wear on a ground shaft supported by an oilite bushing it would require debris to embed itself in either part and that is what the boot is there for, to keep the debris out.

Lubricants have changed in 30 years and now have tenacity tendencies that will allow it to cling to parts unlike what was available in the 70's when the rack was designed. These lubricants more than satisfy the requirements for the slight friction in this application. The arguement can be made that these will then require service again in say...10-15 years... I doubt many will find that to be an issue as the mount busings will be gone long before that point and I think the decreased wear on the pinion and the far side housing from holding the rack rigid more than makes up for that arguement.

There is merit to the arguement that the plastic bushing does absorb some vibration which will be transfered to the steering wheel when bronze is used. In this application Ferrari saw fit to use very fine splines at the connection points and needle bearing u-joints in the shaft...no weak links there that will become an issue over time. Personally I cant feel any difference in the transfered vibration at the wheel when using bronze over the plastic bushing.

Yes it does require some special tooling to correctly final fit a oil impregnated bushing to the shaft and in the housing, not an easy chore to do it right but I figured we would be doing more than 1 rack every 5 years so the effort to fabricate the tooling was justified. I cant imagine trying to do this with a brake hone...lots of hone stone debris will surely be left behing somewhere with that method.

Stepping back and looking at it, I have to believe the decission to use the plastic bushing had to do more with future job security (look at the English cars from the early 60's, torn boots, no grease / oil...they are still tight) than anything else. Another possible point for the plastic was to prevent the rack from bending under a hard impact. Far better than 1/2 of the racks we do that used the plastic already have the rack gear bent and require them to be straightened and checked between center's to get them in good enough condition to use the bronze bushing. This is an area where spending some extra time and effort will assure a trouble free system for far longer than most will ever own the car and in all likelyhood will last into multiple future owners.

 

Bump from the dead......seems the most pertinent thread.

Anyone know if there's supposed to be a bush at the pinion end, or is there just the saddle to hold the rack in position? Something is wonky with the steering here, although the passenger side bush looks good (TRW).

Car has been involved in a side hit at some stage and someone has obviously pulled the steering, possibility of a bent rack has occurred to me as the root issue, as there's a distinct notchy feel.....at low speeds at least.

Tie rods appear to be staked, as a small difference. A mate suggests they look very Fiat 128 too.
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No evidence of a bush at the pinion end, on this thing.

Every other rack - that I've pulled apart at least - had one both ends. There's 3mm clearance between the rack and the housing, I'll turn one up in nylon and see what happens.
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I don't have experience with the TRW rack, but my CamGears rack didn't have any bushing on the pinion side. It was supported by the pinion and a seat (not sure what it is called) that kept tension on the pinion. My passenger side bushing definitely needed replacing.

What is the top picture in your second post (it looks out of round)? Before you took it apart, was there any play on either side? Maybe if the pinion bearings were excessively worn they could cause some play (just guessing here)?

-David

 

See the small piston at the top-right of my pic - that is the part in your description that applies pressure to the rack, to keep it in contact with the pinion and also to support it.
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Someone back over the page mentions the passenger side bushes are like that, it's too symmetric to be the result of wear.

Minimal play in the bush with the rack in place. I've rolled the rack on a surface plate, if there's a bend in it, my eyes can't pick it up. Lower bearing seems good, when I get a chance, will pull the upper. Do notice, there's no O ring as shown in Peter's picture of the CamGears rack. Still can't get the head around the idea that the saddle is the only thing aligning it at the pinion end.

 

I don't know what O-Ring you're refering to, but there definitely is one, as shown in the pic, that sits in that relief of that piston (the smaller portion of it).

 

Seems you went the long way round to fix your tie rods I simply went to a local steering shop with my mondial t he removed the worn one checked it's specs and found that a ford lasers is the same only metric so he re threaded and I had a new tie rod for $ 60 in answer to your question how much play... Absolutely none the tie rods should be stiff to move with no play. I put photos of the parts etc in my thread called tie rod replacement. Did this about 3 months ago.

 

Not questioning that, it's largely similar to the TRW unit here except for that addition and a slight difference in the profile of the saddle.

Believe I might have found the issue originates in the steering column now, as you can feel a tightness in certain positions. With the rack installed previously, all that was evident was a very minor amount of play in the unis.....anyhow, more disassembly to come, unfortunately!

 

Is John Haller still selling the rebuild kits?

Thanks

Rob

 

Don't have much to add - just wanted my 10,000 post to be in the Tech section in a thread where I knew some people. Although I don't get out much anymore, Tech is still my favorite section, back to the days of Rick Rainbolt.
I'm going back to doing Geritol shots now.
rt

 

Same question?

Have to rebuild my TRW rack this spring.


-Joni
from Finland