Pinion depth setting, 9.25

Bruce,

The 9.25 adjusts a lot like an 8.75 Mopar.

If you're using the same gears but all new bearings you will need to at least check the pinion depth as the new bearings can be off a few thousandths then adjust if needed. Then set your lash and depth according to specs.

Budd

The manufacturing tolerances of the pinion bearings are way tighter than the choices you have for pinion depth shims, IOWs, the bearings are made closer to size than you can account for with a .001" pinion shim. Replace the bearings and use the shim that's in there now.

You could hone out a new rear bearing to use to check pinion depth, but I wouldn't install it permanently, you'd risk it spinning on the pinion gear and causing unwanted damage.

Thanks people!

I checked the pinion depth and mesh pattern before removal so I have a good reference. I suppose I could just go for it and use a new shim of same thickness, then install and recheck the depth. If it comes up short, I could add shims behind the bearing race in the housing. If it comes up long I have a problem (50-50 chance)!

I'm glad I read about the problems people are having with pinion bearings here. I started to get the "whine" that at first sounded like tires. I figured that at 70k my gears should still be fine but after reading about early failures I blocked up the rear and ran it unloaded and in gear...(ugh)!

Just as a data point, the truck is a 98 w/70k miles (2wd, 5.8L, 1500) and has towed the occasional heavy load but in general has been treated well. The only other problem has been an annoying coolant leak at the thermostat housing.

-Bruce

As a further data point, has the fluid been changed at regular intervals?

Roy

Maybe not as often as it should have, every 25K or so (two changes since new).

-Bruce

Thanks much for the info.

Roy

What's really odd, in my opinion, is the old 79 D-150 my son now drives has the 9.25 axle in it with over 400,000 miles on it, AFAIK. I put one set of outer bearings in it at just under 300,000, otherwise, untouched.

So, what's gone wrong with that axle design since 79????

There is nothing wrong with the design Budd, what is wrong is the cost cutting in the parts (such as in the bearings) used to make them now.

Chinese bearings instead of US made Timkens?

This is what I was expecting based on what I read. The bearing at the yoke end of the pinion shaft is/was a Timken. I haven't pulled the carrier bearings of the case yet but I'd wager they are Timken as well.

-Bruce

I also rebuilt my rear axle recently for this problem and was very surprised to pull out failed TIMKEN bearings.

I bought the complete bearing set from local hi-lo/ oreilly auto parts place for around $100. It's the National / Bower BCA brand and everything went together fine with great input and assistance from this group and especially Tom Lawrence.

I just wished I could have found a reasonable priced locker unit to put in the housing instead of the stock single track unit. I just didn't have the $450 that most places wanted.

My truck is a '98 1500 quad cab with 81K miles on it. Sounds just like yours, pulled a few trailers, but nothing near abuse.

As far as changing fluids, they've all been serviced regularly, but I've never seen bearing failure like this in anything I've owned.

We also have a 2000 Durango with 52K on the clock. I guess it'll be next.

Curtis

If you're referring to my old 79 and it's 9.25" diff, it was originally a BLM truck for the State of Colorado, went thru two more owners then I got it at just under 250,000 miles.

The engine was overhauled ( actually, just a nickel rebuild, rings, bearings and a valve job) and then with 2000 miles on the new parts, towed/hauled an estimated 12000 lbs over Vail Pass near Denver Colorado in late 1999.

Nope, it was never abused . . . .

Sadly, it appears that even though Timken bearings are still being used (as seen by others posts here), cost cutting to keep the contract has degraded their quality as well. QC is expensive and cutting it down a notch can save significant $$$$ but their is a cost to doing it as seen with the increased failure rate or these rears. I can only hope that the replacement ones they sell to the open market are still of the same quality that they built their reputation on in the past but I have my doubts.

I'll still buy Timken and other US brands as often as I can to keep our money here and not in foreign pockets.

I just bought Timken bearings from Car Parts for the rear axle of my Lebaron. The quality looks excellent to me.

On this point we completely agree.

I need to buy some replacement bearings in a month or two as well so thanks for the heads up. It looks like I will buy Timken as well.

Pulled my Dexter axle apart today. Outer wheel bearings are made in Russia, inners are Chinese. Wonder if the grease came from Iran?

Al

Dey's just dino squeezins.

The ones that existed before the world was created according to your book?

beekeep

Ah, look who's injecting religious content. . . . .