Had to rebuild the Dana 70 in my '01 2500 last week. I noticed the pinion seal leaking after my last trip to the track towing my 24' enclosed trailer. Turned out to be worn pinion bearings and the carrier bearings needed replacing also. R&P looked great.

The bearings I took out of it were KOYO bearings. Were these used from the factory? I'm wondering if this rear had been gone through prior to me owning the truck. It has 197k miles on it now, had 164k when I bought it.

Koyo bearings were in my 93 dana 70 too, but it had been rebuilt. My 92 totally stock dana 60 had timkens.

I knew the 93 had been rebuilt b/c the date code on the limited slip carrier was 1997.

From what I have seen if there is Koyo bearings its been worked on.

I guess I'm surprised this rear needed the bearings replaced before 164k miles. I know the 1/2 ton trucks in the '90s and early 2000s had rearend issues, just figured this big ole dana would have lasted longer. Of course, for all I know, this truck may have had a big trailer behind it for all of the 164k miles that were put on it before I got it.

Is it a manual trans truck?

FWIW, the CTD was known to eat up the shims behind the carrier bearings with the 1st gen D70s and a 5 speed.

No, it's an auto.

I am going through the rear in my 1996 2500 now. I read that the Dana 60 and 70 should get new bearing every 100K miles! The rear in the 96 I bought new was shot at 85K miles when I traded it in. Seems the 96 2500 I have now has a Dana 60 being a 5.9 gas engine. I just got a rear out of a 94 V10 automatic truck and it seems to be the same. The 92 rear I took apart was a Dana 70 as it was a Cummins truck. Took apart a perfectly good rear before I realized it wasn't going to work.

I cannot speak for Dana but Chrysler certainly has used KOYO in factory equipment. Given the choice I would use KOYO over Timken anyday. They set up better, turning torque is always smoother and more consistent.

One of the Dana 60s that I built recently had to have the inside of the case machined where the carrier bearing cup fit in the housing because it had spun under stress. That seems to be a common issue in high mileage and heavy duty use. My answer to that is to be very careful in the pre-load setup and to use synthetic gear oil with a large capacity cover for more gear oil. I wish I was building a S60 with the adjustable carrier bearings, but I build what I have.

Rhino...Needing bearings every 100k miles seems excessive to me. I guess if you do nothing but tow heavy loads that would be reasonable.

No races spun in mine, just generally worn out bearings...pitted rollers and grooved races. Everything went back together nice and tight.

Thanks for the info yall.

If your axle was built at Dana in Columbia, MO, it would have been built with NTN (Japan) bearings. Probably would have been the same bearings if built at Dana BV in VA, but not 100% certain on that.

There were other bearing manufacturers used among the variety of axles we built at the Columbia plant. Back at that time, the Timken bearings were hands-down the best by far, bar none. Japanese bearings were good. The worst were the SKF brand which were manufactured in Mexico. Their quality control was so far off the charts, it was unbelievable. I most often worked at the front of the assembly line where we started building each axle with just the ring & pinion and the bare carrier. The production lines slowed considerably when using the SKF bearings.

Interesting! I lived in Columbia, MO in 1969 and my sister still lives there. Where is the plant located?

Hi Rhino,

To get to the plant, you take what used to be known as the "AC" exit. Traveling from north to south, this is the 3rd exit south of I-70, on hwy 63. Upon taking the exit, you turn left (east) and then take the first left to go back north. This is LeMone Industrial Blvd. The Dana plant is on the right (east), about 3/4 mile down this road. I believe there's only about 40 people still working there at this time. Business has been really slow for this plant over the last several years. Dana filing bankruptcy a few years back didn't help matters either.

TJ