2nd Gen Non-Engine/Transmission Dana 70 problems

[AClayton]

Guys,



I had all the bearings in my rear done 2 summers ago in June. I've been noticing a slight whine when de-accelerating and pulled truck into my shop. Took driveshaft out and to my surprise... . yoke is loose - again! The yoke was not replaced back then and wondering if that would be a good place to start. Mechanic said ring and pinion were good but replaced all the carrier bearings and axle bearings and seals but did not replace yoke..... it tightened up so he said it was good. Should I just go ahead and order a new one and try that?? I tried to tighten with a 1/2 Snap-On impact but it did no good. What do you guys think?

 

[NIsaacs]

Is the yoke loose on the pinion shaft or is the pinion shaft loose? If the pinion bearings are loose you can't tighten the yoke and help them, they are spaced with shims. If they are just loose and not bad you can pull some shims. If they are bad you need to repalce them. The bad part is you can only inspect the outer bearing. To inspect the inner bearing you will need to remove the pinion.



Nick

 

[HBarlow]

The '01 and '02 HO six speed trucks had a modified Dana 80 that was much tougher and more durable. If I was going to keep a modified truck pulling a heavy trailer I would find a disc brake Dana 80 and replace the Dana 70.

 

[AClayton]

I am no expert at all... ... but I did try to tighten it. I read the yoke would require a puller to remove, yet mine popped right off after removing the nut. I did a search on here and from what I gathered, this nut requires 400ft. lbs. Maybe I just don't have enough torque on the nut. Maybe I need to take it to a mechanic that has the proper tools to hold the yoke while tightening.

 

[AClayton]

The '01 and '02 HO six speed trucks had a modified Dana 80 that was much tougher and more durable. If I was going to keep a modified truck pulling a heavy trailer I would find a disc brake Dana 80 and replace the Dana 70.

I understand what you mean, however, I am within axle ratings towing my rig. Granted, the very high end of those ratings. I always thought a 70 was a durable axle but I guess they all have their limits!

 

[NIsaacs]

Is the yoke loose on the pinion shaft or is the pinion shaft loose?



Nick

If you used a Snap-On impact the nut is tight enough. If you still have yoke movement, the bearings are loose. I am not sure why after only two years they are loose. It might be they are cheap ones, not set up right or the housing was not clean and the contaminated oil destroyed them again. The D-70 is a good axle as a rule but can have issues with the left hand carrier bearing comming loose on the carrier.



Nick

 

[AClayton]

Thx Nick..... took it to the mechanic that did the work and he wants to pull it apart and have a look. I feel pretty confident that I'm not over-working my rear because I know my axle-weights are within truck guidelines. I also have a diff temp gauge that rarely sees over 220* unless going up a hill - a steep hill that lasts for miles! Unloaded... . the temp hovers around 160*

 

[Joe Mc]

I had taken a D70 out and replaced with another unit. I took the old yoke off the pinion shaft to place on the newer D70 and the point I'm getting at is once the nut came off the yoke required a few taps with a mallet and poped right off. So I'm not certain why it would require a puller to remove? It'll be interesting to see what the Mechanic finds when he inspects. I'm guessing there's something going on w/pinion bearing. If the rear is down that far you may want to consider a new gear set... My $0. 02

 

[AClayton]

I have located an 07' AAM axle. Can that axle be converted to SRW and installed in my truck? I know my driveshaft will need shortening but what else should I expect as far as problems installing this axle?

 

[Joe Mc]

I'm not sure, but recommend getting the folowing info from seller:

length hub to hub (flat where wheel mounts), length from center of axel to spring pack mount, width of spring pack and diameter or axle shaft housing. If these measurements match yours you might be OK, however, I'd ask the seller to send you the u-bolts, mounting pads and any spacers that are from the factory. The other considerations could be: sway bar mount to rear and shock mount, then there's the brake set up and ebrake systems.



Can't you find one for an 01. 5 - 02? I know they're scarce and expensive if you find one. What was the outcome of the Mechanic's inspection with your loose yoke?

 

[NIsaacs]

The ratio will be wrong for sure. Is yours not repairable? If I were to change it out, I would look for a D-80, they were in all 2500, 2nd gen manual trucks. The later model ones had bigger brakes and outboard drums, with the '01. 5-02 having disc's.



Nick

 

[AClayton]

I'm not sure, but recommend getting the folowing info from seller:

length hub to hub (flat where wheel mounts), length from center of axel to spring pack mount, width of spring pack and diameter or axle shaft housing. If these measurements match yours you might be OK, however, I'd ask the seller to send you the u-bolts, mounting pads and any spacers that are from the factory. The other considerations could be: sway bar mount to rear and shock mount, then there's the brake set up and ebrake systems.



Can't you find one for an 01. 5 - 02? I know they're scarce and expensive if you find one. What was the outcome of the Mechanic's inspection with your loose yoke?

My mechanic hasn't even had time to look at it yet. I am just basically scouring the net trying to find an axle and I happened upon the 07' AAM. With the weight I pull, I'm looking for a 4. 10 so I know a front gear change will be necessary regardless. The seller says it will bolt up but my driveshaft will need to be shortened and e-brake and drum to disc conversion and a host of other stuff. Everybody thinks I need a bigger rear but a 70 should do what I expect of it. Maybe I have a bad housing. It's all just speculation until I actually hear from the mechanic though.



@Nick - Evidently, the 80's are hard to come by around here. I will actually be in AZ. early in march, which explains my urgency to get this repaired.

 

[HBarlow]

I have not read a report of swapping an AAM from a Gen III into a Gen II with Dana rear axle but my guess is nothing will fit without modification. I predict an expensive effort to adapt it.

 

[AClayton]

I have not read a report of swapping an AAM from a Gen III into a Gen II with Dana rear axle but my guess is nothing will fit without modification. I predict an expensive effort to adapt it.

Yeah, that's what I'm gathering also. The 80 is going to be a challenge as well, unless I can secure the whole donor truck. According to the AAM website, their axle has a higher load and torque input rating than the 80, but only marginal.

If I wasn't so rushed to get this repaired it would be a little easier to make a decision. I have another truck to use to tow my brothers rig out west but it's a gasser and only gets 10mpg unloaded..... pulling a 23' Toyhauler may only render about 4mpg!

Hopefully I will hear from the mechanic today.

 

[JR]

Are you set against rebuilding your axle or worst case replacing with another 70? Granted the 80's are stronger but Ive not heard of any real issues with the 70 they are a pretty stout axle overall and should be easier to come by. If your like me and bought a 2500 because you dont need a 3500 they should be more than sufficient. The big exceptions would be higher horsepower situations, sled pulling or drag racing.

 

[HBarlow]

If you're desperate I just noticed a post by another member wanting to sell a Dana 70. I don't think another Dana 70 will last you very long with the power and weight combo of your truck meeting in the driveline but it would get you down the road for another couple of years.

 

[AClayton]

Yeah..... Thx HB! I saw that last night and talked to him..... Unfortunately, it is a 1st gen 70! We are still researching to see if it will work in my truck.

@D4life- I feel exactly the same way..... a D70 'should' be more than enough for me, but I need to determine whether it is my mechanic that possibly didn't do it right or maybe a faulty bearing. Just don't know at this point until he looks at it. Btw... ... my sig shows about 500hp to the wheels with my power upgrades but I daily drive and tow with only 350hp... ... which has been more than enough! One would speculate that a 70 would be substantial but I guess our trucks just develop so much torque that it brutalizes our drivetrains. I don't dragrace or sled pull or anything..... I do however drive a little briskly at times just because it so much fun. But nothing, IMHO that would otherwise be deadly to the suggested time expectancy of a dana 70!

 

[AClayton]

Yeah..... Thx HB! I saw that last night and talked to him..... Unfortunately, it is a 1st gen 70! We are still researching to see if it will work in my truck.



@D4life- I feel exactly the same way..... a D70 'should' be more than enough for me, but I need to determine whether it is my mechanic that possibly didn't do it right or maybe a faulty bearing. Just don't know at this point until he looks at it. Btw... ... my sig shows about 500hp to the wheels with my power upgrades but I daily drive and tow with only 350hp... ... which has been more than enough! One would speculate that a 70 would be substantial but I guess our trucks just develop so much torque that it brutalizes our drivetrains. I don't dragrace or sled pull or anything..... I do however drive a little briskly at times just because it so much fun. But nothing, IMHO that would otherwise be deadly to the suggested time expectancy of a dana 70!

 

[AClayton]

Yeah..... Thx HB! I saw that last night and talked to him..... Unfortunately, it is a 1st gen 70! We are still researching to see if it will work in my truck.



@D4life- I feel exactly the same way..... a D70 'should' be more than enough for me, but I need to determine whether it is my mechanic that possibly didn't do it right or maybe a faulty bearing. Just don't know at this point until he looks at it. Btw... ... my sig shows about 500hp to the wheels with my power upgrades but I daily drive and tow with only 350hp... ... which has been more than enough! One would speculate that a 70 would be substantial but I guess our trucks just develop so much torque that it brutalizes our drivetrains. I don't dragrace or sled pull or anything..... I do however drive a little briskly at times just because it so much fun. But nothing, IMHO that would otherwise be deadly to the suggested time expectancy of a dana 70!

 

[AClayton]

Yeah..... Thx HB! I saw that last night and talked to him..... Unfortunately, it is a 1st gen 70! We are still researching to see if it will work in my truck.



@D4life- I feel exactly the same way..... a D70 'should' be more than enough for me, but I need to determine whether it is my mechanic that possibly didn't do it right or maybe a faulty bearing. Just don't know at this point until he looks at it. Btw... ... my sig shows about 500hp to the wheels with my power upgrades but I daily drive and tow with only 350hp... ... which has been more than enough! One would speculate that a 70 would be substantial but I guess our trucks just develop so much torque that it brutalizes our drivetrains. I don't dragrace or sled pull or anything..... I do however drive a little briskly at times just because it so much fun. But nothing, IMHO that would otherwise be deadly to the suggested time expectancy of a dana 70!