2nd Gen Non-Engine/Transmission Rebuild dana 80 or not? Opinions wanted.

[SMorneau]

I have a SRW Dana 80/70 axle with over 300k miles on it. There are no indications of anything wrong with it other than a leaky pinion seal and the clutches in the Limited slip unit are very tight (it squeals on almost every slow tight turn).



The rear end has had regular changes with amsoil and has only seen light towing use for maybe 20k miles.



At least one guy in the industry recommends having that rear end have a re-bearing job every 150k or so. What do people here say to that? Opinions please.



Thanks,

Scott

 

[drag racer]

Dana's are pretty stout. Given you don't tow too much, probably ok to service the leaky pinion and keep going. Kind of depends if you have a wild hair to get into it and spend some $ or not. If you do get into it, then yes, have it overhauled and put a Detroit locker or other diff in it.

 

[GAmes]

I say try putting in a little additive for the L/S and replace the seal. About 70% of my miles have been towing something from 3000 to 14,000 pounds. I've replaced the seal twice, that is all. I even have the original brake shoes, never had a drum removed.



That one guy who recommends new gears every 150k or so is blowing smoke. I wouldn't trust him as far as I could throw him.

 

[SRath]

The only part of the housing that wears at all is the spindle seal surfaces for the hubs. So why wouldn't you keep a perfectly good housing?

If you have done so very little towing and have used Amsoil, and have changed it far more than you needed to, what in the world are you worried about?

The LSD differential was worn out a few thousand miles into it's short life. So replace it. Then you will at least have a good excuse for throwing away perfectly good carrier bearings and, as mentioned, can install a locker.

Good grief! The rearends in our semis go for a million miles or more under the heaviest of use with far inferior oil. The strength-to-weight of your axle and pickup is overkill compared to them.

 

[SMorneau]

Thanks for the input. One question though, if the limited slip is worn out shouldn't it slip easier?

 

[GAmes]

Thanks for the input. One question though, if the limited slip is worn out shouldn't it slip easier?

I believe SRath was tongue in cheek. Put some additive in the oil, that should get rid of the squeal/chatter in tight turns.

 

[SRath]

SMorneau, If yours isn't slipping too easily, count yourself even luckier. It sounds to me like you already have a rearend that will last you many thousands more miles. Continue taking good care of it and it should outlast most of the rest of the truck.

If you are like me, a compulsive treasure hunter/parts hoarder, and you happen to someday run across a fantastic deal on a really good spare rearend, scarf it up. They have already stopped making the Dana 80 for Dodge trucks and there are thousands of Cummins trucks out there which will last over a million miles. There will always be a market for it if you never need it.

GAmes is right about the additive, btw. Amsoil claims you may not need it with their oil, but if you do experience chatter, they recommend their additive be used.

 

[SMorneau]

Thanks for the feedback. I will have the pinion seal replaced and take a look at the backlash, put some new lube in and call it good if all looks well.

I have a few spare parts around already. If I purchase anymore they will be part of a whole truck.