2nd Gen Non-Engine/Transmission Dana 70 Rear failed!

[AClayton]

About the only thing I haven't touched on my truck has failed now. 170miles and my rear has a loose pinion. How many miles do you guys get out of these rears?



Alan

 

[JLandry]

Alan,



When I had the gear ratio changed on my truck around 80,000 miles, I had the shop replace ALL of the bearings in the axle just to be safe. Obviously they don't last forever and since they had it apart I thought it was a good opportunity.



Even though I haven't had any problems yet, I'm thinking about preemptively replacing all of the original u-joints this summer.



Good luck,



John L.

 

[HBarlow]

Alan,

You won't like my answer because you'll know what I am thinking. I got 325k miles out of my '01 with a Dana 80. The truck now belongs to my mechanic buddy who has worked on it since new and it has around 355k on it. The original Dana 80 works fine. The fluid was changed at 50k intervals when I owned it.

 

[GAmes]

810k on my Dana 80. I have replaced the pinion seal twice and the axle seals about 30k ago. 50k oil changes.

 

[Bob4x4]

The Dana 70 is marginal in the Ctd
It has never been used in a manual trans
Configuration. with your power mods it has
Been on borrowed time.
I would be shopping a Dana 80

 

[Midnite]

I'll disagree--the D70 is okay for normal use. Don't try to tow 20,000 lbs with it and it'll be perfectly happy. Yes, sometimes things take a dump, D80s included. Especially when you throw Mach 4s into the mix and romp hard on the throttle.

There are a lot of 1st gen owners who would disagree with your statement that the D70 has never been used in a manual transmission configuration. Believe it or not, Dodge did actually make trucks with the Cummins prior to 1994.

Alan, I agree that with the Mach 4s and other mods you should be looking for a D80.

 

[Bob4x4]

Lol yes a 70 is fine with 160 hp
The op is alil above that level

 

[Bob4x4]

Forgot to mention
I saw way to many issues with first gens
Under the 12-12 warranty to ever buy one

 

[AClayton]

Alan,



You won't like my answer because you'll know what I am thinking. I got 325k miles out of my '01 with a Dana 80. The truck now belongs to my mechanic buddy who has worked on it since new and it has around 355k on it. The original Dana 80 works fine. The fluid was changed at 50k intervals when I owned it.

Yep... ... ... I know exactly what you are thinking and totally understand your opinion. But, I took the truck to my mechanic and he said the yoke was loose on the pinion spline. The pinion still has a little play in it but a very small amount. He added a new yoke and re-tightened and I am good until it fails again. He said the ring and pinion 'look' good and will probably buy me some time until I can upgrade to the 80.



Your son-in-law doesn't own the 01' any longer???



Alan

 

[HHhuntitall]

..... as for me, my 70s have all been in 1st gens, and not many of them were 160hp. I've dropped the Getdragged out of 'em so many times I need to put studs in the bell housing!! But my 70s have all held up well. My '89 was the highest mileage, but also the weakest pumped truck I've had a 70 in, at @550k. It needed some serious help when I sold it, but I've gotten several 100k out of others that weren't stock. My '93 is close to 140k on this rear, which has almost 200k on it, and it's still real tight. The Getdragged is laying next to it in the floor at this moment, unable to be turned by hand... ... the new NV4500 is already in place, waiting on the T-case and daylight to be finished..... I've never run a 70 behind the p-pumped Cummins, or the 24 valve, but Gale Banks runs a D60 under his SideWinder pickup, and has only had a problem with it once..... or twice...

 

[Cummins12V98]

My 98 12V auto 4X4 Dana 70 had 300k when the pinion gear broke. The bearings and gears looked great. The original no grease u joints have 350k and are just fine.

 

[HBarlow]

Yep... ... ... I know exactly what you are thinking and totally understand your opinion. But, I took the truck to my mechanic and he said the yoke was loose on the pinion spline. The pinion still has a little play in it but a very small amount. He added a new yoke and re-tightened and I am good until it fails again. He said the ring and pinion 'look' good and will probably buy me some time until I can upgrade to the 80.

Your son-in-law doesn't own the 01' any longer???

Alan

No, it had been sitting around unused most of the time for the last year or two and my sil has about eight late model Chevy pickups that his job superintendants drive that he can call on for a quick job. My sil and daughter know and like Freddy, my young mechanic friend, and know that he wanted it so my daughter asked her husband to price it low for Freddy and carry a note to let him buy it. My sil sold it to him for $4000 about four months ago and lets him make payments. It is a great old truck in excellent condition except for the odometer which shows 355k. It will still produce 20. 5 lbs of boost. Even has good Michelins on it. My friend loves it.

I'm glad yours was cheap and easy to repair.

 

[DSpringstead]

I got 161,000 on mine before the pinion started to scream at me. Had mine totally rebuilt by Randy's ring & pinion. New pinion, ring gear seals & bearings. One thing to watch for is most of the time the inside of the housing has to be machined to be flat for the shim stack. D70's have a habit of moving around in there coming from the factory. Of course the previous owner was a "farmer" out of East Bellingham. No telling what happen there.

 

[Shadrach]

My buddy tore the teeth off the pinion in his Dana 70 equipped 1st gen twice ( It has a tweaked 96 engine in it ) We are currently in the process of installing a Dana 80. If he blows this one up it's time to retire. Shadrach

 

[Bob4x4]

I got 161,000 on mine before the pinion started to scream at me. Had mine totally rebuilt by Randy's ring & pinion. New pinion, ring gear seals & bearings. One thing to watch for is most of the time the inside of the housing has to be machined to be flat for the shim stack. D70's have a habit of moving around in there coming from the factory. Of course the previous owner was a "farmer" out of East Bellingham. No telling what happen there.

Yup... ..... very common to see them eat the housing. my local diff shop-Uni trax has been remachining them since about '95 IRRC.

The Chrysler fix is to replace the housing,a bit more pricey.

 

[aviatorman]

Rear Diff Failure

Dana 80 Rear diff with 4:10 gears failed at 77K. Reason for failure was 3 out of the 4 bearings were made in china. The only thing that saved my ring and pinion gear was the Amsoil lube. The rear pinion bearing and both carriers were chinese products that were contaminated with corrosion pitts when assembled into the rear end at the factory. The front pinion bearing was Ok as it was American made Bendix.

 

[CharlieFoxtrot]

190K on mine, never been touched. Auto trans and probably a lot less power than you, but a good bit more than 160... .