280z RACK RE-BUILD

[Captain Obvious]

Nice work. I recently went through a bunch of discussion with @Mike W about this exact topic of rack rebuilding, and one of the topics was the spacer to be used to take up the gaps created by the thinner bearings.

One suggestion was to use a hardened spacer. The pinion is hard, the bearing races are hard, and I think the spacer(s) used between them should be hardened as well. Especially if you are using the way you did by spacing the inner race. And that brings me to a second suggestion...

If it were me, I would do the spacing on the outer race instead of the inner race. My thinking is that there is a much greater load area and you can spread the forces across the whole spacer instead of just the end profile of the pinion teeth. Might not matter, but I would use the outer race.

My thinking would be... Drop in a spacer of appropriate OD FIRST before you pressed the lower bearing back into place, and then place a second spacer similar on top of the upper bearing right before you screwed the retaining cap back onto the housing. Or, as an alternative, you could put both spacers on one end or the other, but if you wanted to keep the pinion gear in the same location on the rack, you need to put spacers on each side.

I don't think I would go back in to change anything, but just some academic stuff to think about? 

[plucker]

I agree partially, I would have picked one on the back side of the bearing, however when I found the shims that fit the ID perfectly and they were machined. I realized that spacing out on the ID would work just as well.   

I do not think the shims need to be hardened. the compression load is not that much ( almost none if you shim it correctly )so almost anything will withstand the compression loading.   ( heck I have used notebook paper to shim the side bearings on a R180, worked great for 5 years of road racing ! , looked brand new after I took it apart ! )

Also the axial location of the pinion does not matter. as long as you don't run into the rack with the bearing, it wont care at all where it is , unless your pinion is worn out and you need to match the wear marks.   axial play and preload are important,  location is not.

 

while I agree in theory with your points, but practically I think you have to remember this is a rack and pinion, not a high speed, high load  application.   I will report if it works out ok !

Thanks