Thread: rack and Pinion movement

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Originally Posted by rspears

In Navy's original post he says that

He also says in the post with the picture,

This says to me (could be wrong) that the system is totally plumbed, engine running, pressure to the rack unit when it twists, which adds to the dilemma. With that I'll await the next installment from Navy.

WOW! I missed that too! Gotta start reading better, lol....

Originally Posted by Navy7797

I installed a brand new T-Bird Rack and Pinion and bushings in my 40 ford truck. Its powered by a GM pwr steering pump with reduction valve installed.

Here's a thought, is the rack set up for a GM pump without using the pressure reduction valve? Mine is set to run with the GM pressure.

I have new rack and pinion bushings and I'm wondering about the amount of slop with the bolts and inter steel bushing . There's 45 thousands difference and that seem loose to me but I never had one apart before. Does it even matter after all when things get tightened down ? Thanks for the input.


Rember this post?????

Originally Posted by jerry clayton

I have new rack and pinion bushings and I'm wondering about the amount of slop with the bolts and inter steel bushing . There's 45 thousands difference and that seem loose to me but I never had one apart before. Does it even matter after all when things get tightened down ? Thanks for the input.


Rember this post?????

Yes that rings a bell, but the bolts are not moving, the housing is moving on the rubber bushings. I'm going to take a video and post it. It maybe the the rubber bushing are just to dam soft ??

Originally Posted by 36 sedan

Here's a thought, is the rack set up for a GM pump without using the pressure reduction valve? Mine is set to run with the GM pressure.

I already had the valve installed from my old rack so I just left it in the pump. I don't think less pressure would cause this problem. it turns smoothly, its just movement at the spline output shaft that has me concerned.

How about a couple of fender washers on the bolts to better contain the bushings from bulging out? Just a hair brained thought....

Are the tie rods level from the rack to the control arm, or do the slant up or down when the car is at ride height?

Originally Posted by Henry Rifle

Are the tie rods level from the rack to the control arm, or do the slant up or down when the car is at ride height?

I agree, I'm still where I was on the forces you're seeing -

Originally Posted by rspears

Navy, I'm having a hard time understanding how a force can be generated to cause the whole rack to rotate against the bushings. Unless I'm wrong the rack & pinion are both simple straight or spiral cut spur gears which don't cause any torque load. The gear lash adjustment on the rack & pinion is only to deal with excess play in the wheel, as I read about it (at the very end of the link 36 sedan posted above).
The only thing that makes any sense to me is that maybe your steering arms are describing a vertical arc as they turn, imparting a "twist" on the rack? I'd try loosening the lock nuts on the threaded steering rods to allow them to rotate a bit as you turn and see if the housing movement disappears. If so you may need to tweak your steering arms for better alignment?

Does it rotate one direction ( up/down) when you turn the shaft one direction and the other way when you turn it the other way? this would indicate mounting issues to the crossmember-

I see that the rack your using only has 2 mounting points----------there were some that used 3 and early ones even a u-bolt around the right side

Navy, I have used several Mustang II racks which might be & do look similar to your setup, on a set of bushings I recieved from Heidts the rubber on the bushing was much longer than the metal insert that the bolt goes through and is tightened with a nut to the crossmember mount, I had to trim off a small amount of that rubber as it folded over and was pinched when the rack was mounted, making the rack & pinion wobble and not mount firmly in mockup. I did this build in 2006 and never found any info on those bushings as I remember looking but after the trimming its been on the road since then with no problems. I hope this helps. Matt

Here's results from my pwr steering work.
I took apart the bushings and found that the metal sleeves in the rubber bushings were longer than the rubber so there was no compression of the rubber leaving things to move around to much. I cut down the sleeves about 1/16 th and tried them again and while I still have some movement its very little, problem fixed I hope.