I have a 91 cab/chassis DRW with a stretched wheel base. It has a Dana 61 in it now, nothing wrong with it. I have a Dana 70 DRW lying around for a spare. My future plans are to install a 12' bump box. My question is which axle is stronger 61 or 70? Both axles are drum brakes.

 

The 70 is stronger.

 

but it uses the same ring and pinion tho correct?

 

No a D61 does not use the same R&P as a 70.
Thanks Dave, looks like I will be installing the 70 then.

 

i have never herd of the 61 but i know the 60 and 70u and 70 hd R&P interchange why is the 61 different

 

I think the 61 was a special deal to get the 3.07 gears to fit if i am not mistaken.

 

I don't think that is true. The D60 has a 9.75 ring gear, all of the Dana 70's have 10.5" ring gears.
The D61 was used in 89-91 Dodge cummins trucks with a 727 automatic.

 

In the front. The 61 is different than the 60 because there are more teeth on the pinion, which means the case had to be different to offset the ring gear enough. This means that you cant put shorter gears than 3.07s in a 61. Well, you can, but its expensive.

Rears all had 70s.

The stock rear in your truck should be a 70. Unless you have a gasser chassis.

 

[b]In the front.[b/] The 61 is different than the 60 because there are more teeth on the pinion, which means the case had to be different to offset the ring gear enough. This means that you cant put shorter gears than 3.07s in a 61. Well, you can, but its expensive.

Rears all had 70s.

The stock rear in your truck should be a 70. Unless you have a gasser chassis.

 

big stinky as far as I know and I may be wrong, the 89-91 DRW Diesel automatics (3 speed) came with the D61 rear. My truck is a D350, cab and chassis, TF727 trans, it does have the rear 61. It was never a gas engine chassis. Now having said that, maybe the D61 was only used in the cab & chassis. The more I try to remember this I believe the D61 had a higher GAWR than the D70 because of the very thick axle tubes the 61 has. The pinion offset you mention also applies to the rear 61.

 

Well mine definitely has the 70 and its a '90. Although it is a stick.
Im pretty sure all rams with the cummins had the dana 70 rear.
All of the fronts on 89-91 auto trucks are dana 61s because of the 3.07 ratio.
From what i googled, 61 rears only came in fords and sterlings?

And back to the original question, 70s are stronger.

 

I did do a little google-ing but mostly it is threads in Pirate4x4. I have been a member there for a while now and I will say that BillaVista has good info. BUT and thats a big but, in the general forum there is some of the worst info and misinformation on axles (almost any axle) that I have seen. So take what you find in there with a large grin of salt.
Yes Ford and GM have used the 61 too as well as Dodge. Sterling is an axle itself not made by Dana. It is made by Visteon in Sterling Heights, MI where it gets its nick name of Sterling from. Visteon has been an axle supplier to Ford since the mid 80's. It is the most common axle used in 3/4 and 1 ton Fords since then.

 

All 727 trucks I know of came with Dana 70's. I know of Cab and Chassis trucks that have 70's in them as well.

 

You seem to know more about those axles than I do, so ill take your word for it... As far as your truck goes, does your abs light light up? Does that 61 have a rwal ring on it?

 

The truck does have rwal. I remember disconnecting it while trying to track down a poor braking issue, never did get that figured out.