steering shaft universal joint question
 

I replaced a unversal joint (the one closest to the fire-wall) on my car's ('78 SC) steering shaft this past Saturday. I've tried adjusting the position of these joints (very limited movement) on the shaft but I still get resistance on the steering wheel like a joint is binding. I get resistance about once every half rotation of the wheel. I feel very little resistance when the front end is jacked up but when I drop it down and drive it I feel a very pronounced resistance every half turn of the wheel. Has anyone had this problem? Any tips or tricks to replacing this joint? I couldn't find any marking or info that would suggest the joint had to be oriented any particular direction and the replacment (thanks Pelican) looks just like the original.

Any insight appreciated.

Jerry M
'78 SC

Did the old one do the same thing?

Jerry,
The parts drawings show the U-joints are attached to the intermediate shaft with a definite relation to each other.
The yokes attached to the shaft are oriented in a mirror image. That is they are not turned 90 degrees in relation to each other but are on the same plane.
I believe if you look carefully at the shaft, you will find a radius cut into the side of the splines which orients the clamping bolt for the yoke.
My guess is your U-joint is turned on the intermediate shaft in relation to the other end.
Drive shafts are done the same way to keep things smooth.

Thanks Doug. I'll take another look to be sure, but I don't think I could have assembled the shaft with the joint yokes in differing planes because (as you say) the relief cut for the bolt forces only one possible location of the joint.

Jerry M
'78 SC

The U-joints can also bind if you tighten them down without the car on the ground. you can loosen the lower joint so that the lower shaft can slide up and down in it, then drive around the block, then tighten it up. This should allow the suspension to settle and relieve any suspension induced binding.

Doug

If you installed a new joint (rather than a used one) then you have to replace the other one to match. The new parts are different.

It feels as if the steering is locking up when the steering wheel is rotated, so goes loose, tight etc....

Doug - The car was down when I tightened the joint bolts and I, subsequently, loosened and re-tightened the bolts. It got better but not good enough.

Britwrench - I was afraid of that (it occured to me just this morning). I did replace just one joint with a new joint. Sounds like I'll need another new joint so they match.

Thank you gentlemen.

Jerry M
'78 SC

On two cars, I have relieved the binding by extending the flat on the splined shaft. The splines go deeper than the flat and it's easy to do on a bench grinder. I had no problems after that. You have a bump steer kit installed, I'll wager. This does crowd the assembly beyond its apparent design.

...or if the car is lowered and a rack spacer kit is installed, the steering shafts will become closer. To avoid unecessary stress, it's recommended to loosen and reset the shafts in the steering u-joint. However, sometimes one shaft will extend too far into the u-joint and interfere with its angular movement as the steering wheel rotates. If so, grind off the excess material for clearance.

Sherwood

Right on, Sherwood, I forgot that I had to grind off the corresponding amount at the end. :D But, just bottoming out both ends was not enough on either car. I guess it should be noted that I ran those cars pretty low. So, I managed almost a half inch of spacer on the rack. A "real" bump steer kit is better and I'll be leaving my next steering rack in the stock position deferring to a BSK.

Milt & Sherwood,

No spacers installed but I think you've hit on the problem. I'll extend the flats on the shaft tonight. I should have thought of that, guess I'm getting older.

Jerry M
'78 SC

@Zeke which shaft did you grind the flat on please?

Mr. Sherwood! Good to see your name again. I am soon replacing my steering U Joints and Hope I get the Phasing right. With my Electric Power Steering, I have to use a special U joint on the end closest to the Steering Wheel. I can still remember the notchy feel when I had them in Wrong.

FYI:

http://forums.pelicanparts.com/porsche-911-technical-forum/1105622-notice-passing-another-great-enthusiast-sherwood-lee.html