Steering Rack Adjustment

[PeterTR7V8]

I noticed a bit of play in the steering rack so I got another rack from the local parts hoarder, got that rebuilt & then swapped it. Once it was discovered thatthe RH ball joint was packed out with a washer behind the nylon bush (!) it seemed to be nice & snug but on the test drive there was a second movement of the steering after I turned into a corner. It is like you give it the correct amount of turn for the corner which the car responds to but after a second or two the front is suddenly turning too far & needs to be hauled back. On the straight it runs nice & true with no wandering but I can wiggle the wheel a bit without any change in direction - maybe 1/2" or 1.5cm. Is this telling me that the pinion/rack gear is worn?

I looked at my old rack & thought about swapping parts into the new one but how do I extract the pinion gear. I've bashed it mercilessly with no result. I did find that the big nut that holds the grease nipple has a spring under it & the nut is shimmed. Do you think I can improve the new rack by playing with the shims or does that just regulate the effort required to move the rack left & right?



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[Marsu]

I had a similar problem to what you described that was rectified by replacement of the steering knuckle and lower shaft. The second movement in the steering only occured when it was under load. There was not a lot of movement detectable from the uni, but obviously it was sufficient. Not sure if this is your problem, but worth checking.

The shims under the big nut that holds the grease nipple control the rack shaft side movement, 90deg to shaft axis. (See ROM Operation 57.35.09).

I don't think excessive clearance here would cause the problem you describe, but rather, more vibration/shimmy.

[Marko]

amount of shims regulates by how much you preload the spring that pushes the rack to the pinion.

Less shims = more force.

There is exact procedure is described in the manual.

Freeplay in the rack should be noticable when the car is stationaray. By turning the steering wheel you should feel the freeplay between the rack and the pinion. If any, remove shims untill freeplay is gone.

edit:

ive read your post more thoroughly. If everything is tight on the front. Sounds like rear axle bushing stiffnes. Giving you a rear wheel steer, on sweeping bends.

[Hasbeen]

Peter, perhaps you should loose the hammer!

You probably don't need the pinion out anyway. I have not found a 7 rack yet that was worn enough to need a full overhaul. This included one where the grease was so old & hard it must have been original.

The racks are of course always more worn in the centers than at the ends.

Remove some shimming from under the big nut, but no more than 10 thou to start with. [I have found 5 thou is usually enough]. Pack in some grease, reassemble, & test from lock to lock, to see if it's too tight on full lock.

It can be a bit of a compromise between binding on the unworn rack at full lock, & a little slack on straight ahead. However the only one I have found like that was one that was loose in the boot of my spares car, when I got it, so probably thrown out.

Hasbeen

[Jolyon39]

Hi Peter,

If you decide to replace the to universals on the steering column..... yes I have both, brand new. Same as the last deal, just replace them for me

Jolyon

[PeterTR7V8]

Fixed it. I took the UJs off & found only miniscule play in the top joint, not enough to warrent replacing it. Then, with the car on the hoist I watched the pinion as I moved the wheels left & right. There was absolutely no play there but I did notice that the pinion went up & down as the rack changed direction. Not sure what that meant except that it must be the way the pinion gears are angled. Next I removed the tensioner cap & I saw it was a different design from the old rack. Instead of a 1 peice cap with shims it was a barrel & lock nut. Hmm. Because the old cap had a grease nipple I swapped it over & played with the shims until it was 1 wafer thin shim away from locking the rack. This didn't make the rack any harder to turn mind you but it did reduce the up/down movement of the pinion by about 50%. I put it all back together & holding a metre long length of wood up against the wheel I could see that the tiniest movement at the wheel was being reflected in the front wheels with zero play. Finally I had to do a 20-point turn to get the car out of the workshop & the steering was so light I didn't even break into a sweat. Went for a test drive over a curvy hill road (pretty much any road in NZ) & it was perfect. If anything I found the lightness a bit disconcerting.

I still want to know how to get the pinion out. I might revisit that old rack with a bigger hammer.



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[Marko]

if i remember corectly and i do, there is a fork shaped key that you need to remove the pinion gear.

you can take a piece of pipe, and cut it with a angle grinder to that shape, and use it to remove the nut thats holding the pinion bearing. And then you just pull it out.

you have seal, then that nut inside.