What DANA rear axle is in the single rear wheel W350?

[Motorhead]

The 1990, W350, 4x4 I just bought has a 4:10 rear ratio. It is a Dana axle. Id it a Dana 80 or a Dana 70? Also, did any of them come with Posi Traction or were all first gens an open rear axle?

 

[RWherley]

It's going to be a 70 the 80 didn't start until later in the 2nd gen run, 1st gens did come with limited slip rears as a option the tag on the bottom of the hood should tell you every thing.

 

[ENafziger]

Yup, Dana 70. If you send Dodge your VIN, they'll give you a complete build/options list for your truck. They did for my 1st gen a couple years ago. Free service...google around for the link. If you can't find it, I'll see if I can dig it up.

 

[cerberusiam]

Dana 71 rear axle, slightly different bearing specs than the run of the mill 70. A Dodge specific application for the diesel option. The LS was an option, the older clutch type. May not have one, or, may be wore out. Just have to pull the cover and check.

 

[Motorhead]

Thanks for the info. I had the rear axle completely up to check and adjust the brakes. I spun the one wheel forward with a quick jerk motion and the other wheel spun the same direction. Every OPEN diff I have seen, the opposing wheel would turn opposite.

 

[cerberusiam]

You have the typical clutch type LS in it.

 

[Motorhead]

You have the typical clutch type LS in it.

Thanks, Good to know.

 

[NIsaacs]

The 1990, W350, 4x4 I just bought has a 4:10 rear ratio. It is a Dana axle. Id it a Dana 80 or a Dana 70?

It should be a standard Dana 70 with 35 spline axles. The way I understand it, in late '91 Dodge went to the 70U with 32 splined axles, not sure why??

I also think the D71 was specific to the 3.07 ratio, to fit the large pinion they offset the housing more rather than the carrier.

Something else I read years ago, was that Ford had exclusive rights to the Dana/3.73 combo....maybe one reason why Dodge moved to AAM?

Nick

 

[RXT]

Dana 71 rear axle, slightly different bearing specs than the run of the mill 70. A Dodge specific application for the diesel option. The LS was an option, the older clutch type. May not have one, or, may be wore out. Just have to pull the cover and check.

Thought I'd chime in here with a slight correction. Not to be nit picky, but there really was never a Dana 71. It was likely that people concluded that there was a Dana 71 because there is a Dana 61. The Dana 61 is a modified version of the Dana 60, differing in pinion offset to allow tall 3.07 ratio gears. Obviously, there also has to be a 3.07 ratio in the rear thus the conclusion of a Dana 71. But Dana never offered a Dana 71. They used what is called a Dana 70U. This also contains an offset pinion to allow for the taller 3.07 gear ratio, but the 70U can accept other ratios, whereas the 61 doesn't. The 70U, had a Powerlok LS option too.

Ed

 

[Motorhead]

Thought I'd chime in here with a slight correction. Not to be nit picky, but there really was never a Dana 71. It was likely that people concluded that there was a Dana 71 because there is a Dana 61. The Dana 61 is a modified version of the Dana 60, differing in pinion offset to allow tall 3.07 ratio gears. Obviously, there also has to be a 3.07 ratio in the rear thus the conclusion of a Dana 71. But Dana never offered a Dana 71. They used what is called a Dana 70U. This also contains an offset pinion to allow for the taller 3.07 gear ratio, but the 70U can accept other ratios, whereas the 61 doesn't. The 70U, had a Powerlok LS option too.

Ed

Doesn't sound nit picky to me. What you tell me is the exact model and the type of LS in it. Thanks!

 

[cerberusiam]

The Dana 71 was in fact a model and a listing in many parts catalogs 20 years ago. In the first gens at least, it was the model designated to be used in all the Dodge diesel trucks.

To Dana the designation was 70 with several revisions, HD or U or B. The 71 designation was used to note the addition of DRW sized hubs, bearings, and brakes to a SRW used in the 250 and 350 series diesels. Dodge essentially used the DRW axle configuration in an SRW application to get the load ratings a standard Dana 70 would not support. The axle was likely a 70U or 70B with larger 70HD bearing sizes and brakes.

The gas version used the standard SRW parts and pieces, the diesels mated DRW pieces to the SRW application. Obviously you could not have 1 designation to cover 2 dissimilar configuration so someone, Dodge or parts suppliers, coined the D71 designation to ease the parts matching problem. Some parts books did break the D70 down into sub assemblies for the larger parts but it was still very hard exactly what parts were there. Enter the D71 designation with the DRW bearings and 2 choices of brake width. It helped somewhat but the drum situation never was easy. The drums actually trace back to a HD dually rear end that started in the 60's.

 

[Motorhead]

Quote: " Enter the D71 designation with the DRW bearings and 2 choices of brake width. It helped somewhat but the drum situation never was easy. The drums actually trace back to a HD dually rear end that started in the 60's."

FWIW, when I pulled a rear wheel, I noticed "BUDD" drums on the rear and they are real wide.

 

[cerberusiam]

Did you check the brake shoes to see if they were 3" or 2.5" width? I would guess on a 350 SRW they should be 3" but that never stopped the narrower ones form being installed.

 

[Motorhead]

Didn't pull a drum. I saw through the adjuster hole that the star wheel was new and not extended very much. I manually adjusted them up a bit and my brake pedal was up near the top. I have personally found that the auto adjusters worked so-so on large drum brakes.

 

[NIsaacs]

Doesn't sound nit picky to me.

I agree, that's how we learn.

Nick

 

[RXT]

The Dana 71 was in fact a model and a listing in many parts catalogs 20 years ago. In the first gens at least, it was the model designated to be used in all the Dodge diesel trucks.

Uh, I would have to disagree. Personally I have never seen anything listed in any parts catalog for a Dana 71, 20yrs ago. Perhaps I am wrong, but has anyone ran into any Dana axle with a "71" cast into it? About the only place where the Dana 71 designation exists is on truck related forums when discussing 3.07 equipped axles. It's really nothing personal, I'm simply pointing out that there wasn't a Dana 71

To Dana the designation was 70 with several revisions, HD or U or B. The 71 designation was used to note the addition of DRW sized hubs, bearings, and brakes to a SRW used in the 250 and 350 series diesels. Dodge essentially used the DRW axle configuration in an SRW application to get the load ratings a standard Dana 70 would not support. The axle was likely a 70U or 70B with larger 70HD bearing sizes and brakes.

Dana had been producing the Dana 70 since the 1950s and it had seen many modifications to the basic design over the decades. The modifier was usually the letter cast next to the "70". In the case of the DRW sized bearing on a SRW axle, the modified designation was known as the Dana 70-2U. However anytime the "71" designator was brought up was in reference to the 3.07 r&p ratio, and the belief that they, like the Dana 61, used an offset pinion. The Dana 70U has a pinion slightly offset to allow for a tall ratio like the 3.07, but it can accept other ratios. But you first have to know what you're working with to order a set of gears or any other parts for a Dana 70, since there are several variants of this axle.

Ed