The Stovebolt Site Forums The Shop Area Engine Shop 3/4 ton front bearings

Is there an upgrade available for AD 3/4 ton to use TR bearings, or am I stuck with ball bearings??

I spoke to a gent at Bill's Truck Shop in Toronto ( www.billstruckshop.com ) about upgrading to disc brakes on my 3/4 he said no problem, they can send the kit which included the bearings. Might want to give them a call and see if they will just sell you the bearings without the kit, or ask where you might be able to order them from.

I read a thread someplace from a fellow who worked for a bearing company. He said the ball bearings in good shape were fine and dissipated the heat better than roller bearings.

I have a hunch that they switched to roller bearings because they were cheaper to make, not necessarily better. It must be easier to make a steel rod and chop it up than to make steel balls one by one.

But if my ball bearings smithereened, I'd try to put in rollers.

From what (little) I understand, the point of tapered roller bearings is to counter the higher side loads generated by radial tires. If you are driving radials, and are working on the bearings anyway, go for the TR. I have seen kits for 1/2 tons around $165US for both wheels, but 3/4 ton sets run around 200 each side. If Bill gets them cheaper, let us know.

The rumors about the bearings that I heard was the switch was done to reduce damage during shipping. Ball bearings, having the near point contact to the races that they do, tend to sustain damage when hit with a sharp jar when they are not moving. Shipping vehicles by rail aggrivated that so when roller bearings became cheap to manufacture they were switched. Roller bearings also seem to stand up better to poor lubrication.

Ball bearings work just fine and seem to last about the same number of miles as rollers as long as you don't hit curbs and jump railroad tracks all the time. Many modern cars still use rollers, including BMW. They do offer less rolling resistance. The rear bearings on my BMW 325i are double row sealed balls, and they support disk brakes and the rear axle half shafts. I have only had to replace one of them in 165k miles because of a curb impact that also bent a rim.

You can buy several sets of ball bearings for the same price as one of the conversion kits.

I'm no expert on the subject, that's for sure. Being a mechanical engineer, it just makes sense to me that the job of carrying axial loads would be better served by TR bearings. All that being said, the bottom line is I can't find any such TR bearings to replace the balls, so........ I'll just clean,pack,adjust for minimal side play and run. The old bearings will probably be just fine unless I do something stupid like use big fat tires and run the slalom course. Thanks for the input though!!!!

johnnyboy:

I had a heck of a time with my 3/4 ton balls. lol.... I finally just packed the crap out of them and did the unthinkable, I mixed my greases. This gave me a slightly thiner grease which works really well. It worked for me.

If you don't want to mix your greases as did I (which is quite understandable) just pack tons of grease in there. So much so that it is almost overpacked. This is the key to heathy balls.

I had a guy at the local auto parts look up some roller taper bearings for me that would fit my 62, 3/4 ton. He found some that had good specs. I didn't try them though because method is working fine.

Does anybody have a link for the conversion kits?

The main problem to converting is coming up with grease seals for the inner bearing. The ball bearings have a lip machined into them that accepts the rawhide seal. Most modern design bearings are either factory sealed units or rely on other methods for grease seals.

No, you just pack the TR bearings and install them. A lot of cars use TR bearings that are not factory sealed. But rather than having the convenient grease fittings, you have to periodically remove them from the axle to repack them.

My ball bearings are about shot. Strong vibrations at anything above 60 mph. They need changing, but I too would rather have the tapered roller bearings.

If anyone knows of a place that makes a conversion kit, please let us know!!!

I tell ya, I haven't had any problems since I thinned down my grease with a white lithium grease and packed the crap out of them. Grease started to spit out past the seals but I didn't really care as long as those costly bearings held together.

It is my firm belief that standard wheel bearing grease is to thick for ball bearings. Cold weather will exacerbate the situation.

I did that. I packed them until old grease pushed out everywhere. It helped things but I believe I actually have bearing damage. There's definitely a bad vibration, and at this point, I am concerned with race damage as well.

When I bought the truck in Wyoming the bearings were almost dry. I used a tube and a half of grease refilling all the dry grease locations. But I'm too late. Bearing damage has already occurred and I have to do something about them.

If I can't find a retrofit tapered bearing kit, I'll replace the ball bearings and inspect the race.
Although I plan on replacing the suspension with a more modern 1968 GMC 4x4, I'll be running this set up for some years to come still. So I'd better address the bearing issue this summer!