Bearing vs. Bushing in steering box c.1948

[SFjames]

I am re-building a 1940's Gemmer worm and roller steering box.

The sector shaft, which is about 5 inches long and 1.25" in diameter, is mounted on two roller bearing about one inch long. The needle bearings are on the outer edges of the shaft and have a distance tube between them.

The worm gear interfaces with the sector gear on one end of the shaft. The pitman arm is on the other end.

The shaft tends to wear on the bearing near the worm gear end. No doubt do to the loads of the worm gear.

By the late 1960's Gemmer (now Ross/TRW) changed the design to add a ball bearing to the outside of the shaft on the "other" side of the worm gear. I assume this was to distribute the loads onto both sides of where the gears mesh.

My question is: In the older design...instead of using two needle bearings and a distance tube, would I be better off using a single long bushing to help the load? On some of the Gemmer boxes they uses used two bushings with a gap between them and not the bearings.

If using bushings, are two bushings vs. one long bushing an issue ?


I looked over this thread and it adds somewhat to my thinking about this issue, but this is not an area of expertise for me. Thanks, James

http://www.eng-tips.com/viewthread.cfm?qid=229350&page=10

 

[MikeHalloran]

I rebuilt a 66 Ford's power steering box. The Ford dealer stocked the two bushings pressed into the housing (with a gap) for the sector shaft. Total parts cost was about two bucks, and it worked fine for a long time. The bushings looked just like cam bearings, except for the size.

Later I tried to rebuild a 72 Ford's box. No bushings present; steel on bare iron. The approved 'repair' was a hardened washer inserted in the seal cavity. Tore the hell out of the sector shaft in a matter of months.

Damn beancounters.



Mike Halloran
Pembroke Pines, FL, USA