Quote:
Originally Posted by rac390
I realize this is resurrecting an old thread, but I was trying to rebuild my 1969 911 steering rack. I removed the oil seal and pinion with the top bearing without a problem. When I tried to slide the rack out of the housing, it only goes so far before feeling like it’s hitting a hard stop. Has anyone else run into this?
Thanks,
Rick
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Hi Rick,
I am doing my rack now and find that if you don't remove the bottom plate and puck the rack cannot be removed because the flat surface Machined on the bottom of the rack only goes about as far ass the teeth on the top. Look at the exploded view of the rack in post one. When the rack is moved to the end of the flat surface, the puck prevents any further movement.
If the tie rods are removed the rack can be moved left or right until the pinion runs out of teeth on the rack, (not good for the gears, "teeth"), or the puck hits the end of the machined surface, as in your case, since the pinion is out.
We don't want either event to happen. This is prevented by the gaiter mounting flange between the rack end and the tie rod, or on the turbo tie rods, by the inappropriately named "Spacer" - it really is a stop to prevent rack travel being limited by the puck, or the pinion running out of teeth on the rack.
An observation... the rack is basically a round rod running in round bushings at the rack housing ends. The two things that keep the rod from turning are the puck pressing against the flat Milled on the bottom AND the pinion meshing with the rack teeth. If the rack is rotated axially, as in trying to twist off the tie rod, it seems very likely that either the puck face or the pinion could have incredible force damage either - this could be avoided by preventing the rack from turning while unscrewing the tie rod or tightening the new one. When I figure out the wrench size and holding method, I'll report. Suggestions welcome. I believe the tie rod wrench size to be 32 mm. 1-1/4 is a snug fit. Grind the side off a harbor fright wench. Looking for a better rack holding device than a sloppy 1 inch wrench. I do not see how this can be done in the car without stressing the puck/pinion.
For sure, the pinion bearings are low speed and low load, but they are important. For an extra buck or two, I think it makes sense, (Pelican speak for "Wise"), to use a fully sealed bearing, rather than an unsealed, or single side sealed bearing, - the difference was less than a beer.
For the top roller bearing, I found that an ACE, #85 "O" ring was a nice fit.
I am also installing a Quaiffe "quick" rack and pinion. Really glad to be getting back into the build on my dad's car.
Advice welcome,
Thanks, chris