Leaking Dana 80 rear axle

eHoefler wrote:

Geocritter wrote:

rgatijnet1 wrote:
Since you do have a lot of rust under your coach, it might be a good idea to do a visual check of your steel brake lines. They can rust out and rupture at the worst possible time. Of course it is a good time to look at the rubber brake hoses also.

I checked over the entire brake system last year when I replaced the systems 20 year old DOT 3 brake fluid with DOT 5.1 brake fluid. The brakes were in surprisingly good shape. However, I do plan to overhaul the entire system next winter when I'm in Arizona. That's when I hope to replace the rear axle seals as well.

Steve

Oil soaked brakes will become sticky. This will lead to the brakes locking up, overheating, and possibly a fire. Oil soaked brakes are less effective and generate more heat than dry brakes.

I’ve had cars with bad rear axle seals that leaked gear lube into the brake drums and have experienced subsequent brake sticking. On one car I’d have to shift into reverse and give it a backwards nudge to release the rear brakes. On my RV I have disc brakes in the rear. Since I drove it over 4,000 miles with no problems I figure it’ll last for basically a flatland trip this summer from Texas to northern Wisconsin and then a return trip to Sierra Vista Arizona via mostly flatland interstates. BTW I have tire minders that will alert me if the tires become overheated via the brakes (like they did in Oregon last year). I’ve already priced out rebuilding the brakes (new hoses and complete caliper assemblies). It’s about $700 for parts and I plan to rebuild the system next winter. I’ll tackle the leaking seal at that time. I’ve been making the rig very road worthy and though I’d love to service every last little thing on my rig in a more expeditious manner it has enough issues that I have to pick and choose my battles.
Steve

Geocritter wrote:

rgatijnet1 wrote:
Since you do have a lot of rust under your coach, it might be a good idea to do a visual check of your steel brake lines. They can rust out and rupture at the worst possible time. Of course it is a good time to look at the rubber brake hoses also.

I checked over the entire brake system last year when I replaced the systems 20 year old DOT 3 brake fluid with DOT 5.1 brake fluid. The brakes were in surprisingly good shape. However, I do plan to overhaul the entire system next winter when I'm in Arizona. That's when I hope to replace the rear axle seals as well.

Steve

Oil soaked brakes will become sticky. This will lead to the brakes locking up, overheating, and possibly a fire. Oil soaked brakes are less effective and generate more heat than dry brakes.

rgatijnet1 wrote:
Since you do have a lot of rust under your coach, it might be a good idea to do a visual check of your steel brake lines. They can rust out and rupture at the worst possible time. Of course it is a good time to look at the rubber brake hoses also.

I checked over the entire brake system last year when I replaced the systems 20 year old DOT 3 brake fluid with DOT 5.1 brake fluid. The brakes were in surprisingly good shape. However, I do plan to overhaul the entire system next winter when I'm in Arizona. That's when I hope to replace the rear axle seals as well.

Steve

Since you do have a lot of rust under your coach, it might be a good idea to do a visual check of your steel brake lines. They can rust out and rupture at the worst possible time. Of course it is a good time to look at the rubber brake hoses also.

If you are leaking axle lube from the axle seal in the hub, you need to replace the seal immediately! If you are seeing it on the backing plate and the drum, you have oil soaked brakes and they also need to be replaced immediately!

Geocritter wrote:
Good to hear reply's! Back about 5,200 miles ago I replaced the pinion seal myself. It was pretty straight forwards, I even found a Youtube video. The only issue with it was, like everything else on the underside of my RV, RUST! The worst part was removing the fill plug from the rear inspection plate when I attempted to top off the rear end lubrication. Someone had rounded the square hole out. I ended up removing the entire rear inspection plate and it wasn't until I heated the plug red hot with an oxyacetylene torch that I finally got the damn thing unscrewed. I replaced it with a cast iron plumbing pipe plug with a huge square external head. I put Permatex gasket cement on the threads when I reinstalled the new plug so that it'd never stick again (a saltwater boating trick I'd learned).

I'll check the axle vent to make certain that it's open. With all the rust and such on the underside it could easily be clogged.

Fire up, if in the future the leak gets worse and I decide to replace the seal I'll give you a shout. I have a Chilton's manual and they make servicing the Dana 80 look a bit tricky with shims and specific torque specs and such. The Dana 60 axle looks much easier to service BTW. Do you have a Dana 80?

Steve

Steve,
The Axle mfg. in our coach is made by MBA and, from what I know, it's considerably larger than an 80. The lug nuts alone are at 450 ft. lbs. of torque. I'm posting pics of portions of it so if and when you dig into yours, you MAY get an idea of what you're looking at.
Scott

I place the vent tube as high as possible. Then place an old school fuel filter with the arrow pointed toward atmosphere. This allows air to pass both ways but not contaminants.

Good to hear reply's! Back about 5,200 miles ago I replaced the pinion seal myself. It was pretty straight forwards, I even found a Youtube video. The only issue with it was, like everything else on the underside of my RV, RUST! The worst part was removing the fill plug from the rear inspection plate when I attempted to top off the rear end lubrication. Someone had rounded the square hole out. I ended up removing the entire rear inspection plate and it wasn't until I heated the plug red hot with an oxyacetylene torch that I finally got the damn thing unscrewed. I replaced it with a cast iron plumbing pipe plug with a huge square external head. I put Permatex gasket cement on the threads when I reinstalled the new plug so that it'd never stick again (a saltwater boating trick I'd learned).

I'll check the axle vent to make certain that it's open. With all the rust and such on the underside it could easily be clogged.

Fire up, if in the future the leak gets worse and I decide to replace the seal I'll give you a shout. I have a Chilton's manual and they make servicing the Dana 80 look a bit tricky with shims and specific torque specs and such. The Dana 60 axle looks much easier to service BTW. Do you have a Dana 80?

Steve

Yes I had the very same problem with my Dana 80. Replaced the pinion seal at 75,000 miles. There is a very thin ad on sleeve available for the yoke adapter incase the seal wore a grove in it. My RR hub seal failed at about 95,000 because the caliper froze and over heated the hub. LR hub seal is still ok at 136,000 miles.

Richard
95 Bounder F53

Hey Geocritter,
NO, it's not "usual" for a little leak in ANY seal, on todays automotive equipment. Todays (as in the last several years) seals, are much better chemically constructed to withstand thousands and thousands of trouble free miles. If your seal is leaking, IT'S LEAKING period. If you've put too much oil in the rear diff, it would have leaked pretty close to right after you did so.

You don't say whether YOU replaced your pinion seal or, had it replaced. But, in any case, replacing an inner seal on any Dana diff, especially a full or, semi-floating one, is CAKE. If you've done any automotive type work at all, you're ok with doing this job.


The seal can run anywhere from $10 to $50 depending on what axle you have and all that. I did mine, on the drivers side of our '04 Itasca Horizon 36GD with the C-7 330HP CAT and, it took me about 3/4 of day which, included a bunch of cleaning of parts. Yours should about the same, if not easier.

If you're not sure of the process of how it's done, surely PM me and I'd be happy to walk you through it. Good luck.
Scott