Pinion leak and play - Dana 70 Dually - '97 Crestline Ambulance.

[Bikersmurf]

Just got back from a shorter trip, and before ja few days before that we drove 1700 miles (round trip) through the Rockies. I was checking over the truck for a 1300 mile trip through the Rockies again, and I found that the pinion seal (rear axle) is weeping a bit. On its own I wouldn't be too concerned, but there is noticeable play side to side and up down. It also feels like it is ramping up a bit.

It has about 260k miles on it.

Should I pull the third member before the trip?

I think, at a minimum, I should unbolt the driveshaft and make sure the pinion nut hasn't loosened off and investigate further. I haven't pulled a Dana 70 apart before and don't know if it uses a crush sleeve or shims or just what.

Any thoughts or suggestions about what I'll find? How urgent is a rebuild?

Thanks in advance.

@ujoint @Abitibi @iggi

 

[Bikersmurf]

I unbolted the driveshaft, removed pinion nut, and pulled the flange. The flange is worn where the seal rides, but it looks like it’ll probably seal with a new seal. For the time being I threw it back together and cleaned the housing. After a short drive I found it’s leaking fairly quickly so at a minimum I’ll be replacing the seal.

I was able to tighten the pinion nut and reduce play marginally. However, after I pull the old seal out I’m going to pull out the pinion bearing and make sure it’s not too worn. I’m hoping that replacing the bearing will take some of the play out of the pinion.

If I could pull the complete 3rd I’d tear it down and replace all the bearings… but I’d rather not strip it down and rebuild it this week if I can avoid it. However, if it’s necessary, I’ll just do it.

It’s tempting to look for a Disc rear axle and ditch the complete axle. Unfortunately it’s not in my budget to swap the complete rear axle at this time.