2 tooth steering sector rebuild

G

Gold Digger

Well-known member
When if ever I can lay my hands on some new parts I need to rebuild one of my 5 model A steering sectors. I have always used bushings like the originals in the sector housing but I am considering going with the needle bearing type. I have heard good and bad about the bearing type. If they fit tight enough and last well enough I may go this way. I like the Lipe seal they have and have heard they steer easier which would be a plus. I wonder about the trust washer that goes between the sector and the needle bearing in the sector housing if it has a good ware surface. I would like to here from the crowd the good and the bad points on this matter and what is the life expectancy.
 
You are better off with the original bushings. The rotation motion is very limited on that shaft. You want the tight fit because any looseness at all results in steering wheel slop. You can still machine the sector housing to accept a lip seal.

Easier steering depends more on the thrust bearings on the kingpins being fit properly, such that they fully support the weight of the car without being so tight that they bind.
 
Reliability of needle bearings largely depends on the manufacturer of the rollers and what the sleeve material is that makes up the inner and outer bearing journals. Some are made well such as those for modern U-joints but those that have a thin shell for the outer journal can deteriorate more rapidly. Quality manufacturers make good ones but we all know there are off shore companies that cut corners. Few bearings are still manufactured in the US but I hope that changes in the future. We can't run our war machines on crap bearings.

I think that the average owner of a model A could get by quite a while on the needle bearing but Jim has a point. The key to get a good bushing installation depends on a very good reamer to finish the bushing properly. Don't use an adjustable reamer. Get a good one to cut that bushing. I get reamers from McMaster-Carr and I usually get the carbide ones but they are expensive.
 
We've talked about machining needle bearing installations so tight that the shaft has to be "wound" into the needle. You need to maintain that kind of tightness to equal the functional tightness of bronze bushings/new shaft.

In addition with needle bearings there is the problem of "imprint." You go over a bump and give the front axle/spindles a thump and the force is transmitted to the drag link/pitman arm/sector shaft. The needles have a tendency to break or "imprint" themselves into the sector shaft. Leading to crunchy steering or "lumpy steering."

There are ways around this with "hardened sleeves" but that is a technical construction probably better left to those of ability. Or go with Randy Gross' steering box - which will yield better steering in technical advancement.


Joe K
 
I did two boxes with needle bearings,in the late 70's or early 80's.The needles wore grooves into the sector shafts.One got so bad I could feel it.I've been told,well you must have used repro sector shafts,and they're soft.No,I didn't use repro shafts.I got them from boxes that had been parked in a backyard since the war.I do have a couple of new conversions that were bought exchange from one of the vendors in the early 90's,but a new sector is loose in them too.
 
I recently took apart my steering gear restored in the late 60s with needle bearings and o ring seal held in with washer ( not leaking there)
no wear or needle marks
I suspect it depends on the hardness or lack of it.
In 1936 Ford used needle bearings and I have several aftermarket sectors that came with bushings.
Are the parts places still selling AA/BB kingpin bushings as sector bushings?
they don’t have enough material to hone /ream for full contact and some sectors would fit without any machining with a very low surface contact area—- basically pre worn out
I rebuilt a lot of Mercedes steering gears and they had needle bearings and none of them ever had issues with them
 
I worked on the little Hughes Schweizer 269 series helicopters for many years and there are needle bearings in the main rotor flapping hinges. They have large special bolts that secure the blade grip to the two needle bearings in the hub. The rotor blades flap up and down but the travel is likely less than just a few degrees due to the 16-tons of centrifugal force applied to those bearings. The main rotor drive is torn down for inspection a minimum of every 24-months so all the bearings are inspected regularly. The needles mark there spot on the races but they don't wear through the hard surface very fast as long as the 25 hour grease service is performed as required. They use a rather light grease (Shell 14) but they can last from 1500 to 2000 hours or more depending on conditions. Once they wear through the initial hard surface of the inner journal, they start brinelling and stop moving as they should. They will eventually crack the hardened steel race that is nearly 1/8" thick. The inspection is every 400-hours or two years on these so I always checked them closely for signs of brinell on the races. They were a $1,500 bearing tha last time I changed one so folks would sometimes call them good when they shouldn't have. That's why they eventually cracked the race.

I always thought it was amazing that those bearings could take the beating they did. Another example was when Harley Davidson changed from loose rollers to a big needle bearing on the transmission output shaft. The old loose rollers last forever it seems but the new needle bearing is lucky to last 50,000 miles before it starts knocking the oil seal out. Not all needle bearings were designed for the purpose the manufacturer intended.
 
You must log in or register to reply here.
Back
Top