CTD NUT

The 70U uses the exact same carrier and pinion bearings has a D70....all internal components are the exact same size as a standard 70. The difference is with the housings. The 70U has a housing with and offset pinion bore that allows for pinion gears with a higher tooth count than what a standard 70 can allow for....thereby, allowing ratios less than 3.54. The only D70 that uses a different bearing from any of the others is the 70 HD which uses larger carrier bearings as the result of using the D80 sized carrier.

CTD NUT

Will it work as advertised? Yes....but it will also lock up when you don't want it to and will compromise tire life and will definitely be a poor choice for towing heavy. I'm not a fan of the lunch box lockers in general but they do offer a decent bang for the buck.....but in cases such as these, you will get what you pay for. IMO, I would never install an auto locker in a truck that is primarily for street use.....the Plok is superior in pretty much every aspect for street use and light offroad use. If your truck was going to spend a lot of time offroad, then I would certainly suggest an auto locker....other than that, they only bring more down sides than up sides for street use.

I think at this point you are splitting hairs on the cost difference....I don't see the point in spending a couple of hundred bucks less to live with a component that is a terrible compromise for street use compared to having one that fits the bill perfectly.

Again, I'm not certain but I believe the carriers are the same between a D70 and a D70U....the only difference that I can think of might be the raceway (shoulder) machined into the carrier that locates the ring gear on the carrier might be a slightly smaller diameter on the 70U to allow for ring gears of a slightly smaller diameter but again, they might even be identical - I'm just not certain. Randy's or Reider should be able to readily answer that question. The only obvious difference will be the side gear spline count which could be 32 or 35 but that characteristic is not specific to having a 70 or a 70U.

What did this 70U come out of?

CTD NUT

I'm a little confused as to why a 70U would be in an OEM 2nd gen application at all?? But I suppose here in lies the problem on why D70 applications are so confusing in general. Since there isn't an actual requirement to use a D70U in a 2nd gen because they were never offered with ratios of less than 3.54, they would have to use a thicker ring gear from the factory. I would still like to see it clarified that the 70U carrier has a smaller raceway for the ring gear....

JKM

It's not the cost difference that is killing me , it is availability... sort of. I would like to find a good used power lok. any junk yards around here wouldn't sell just the carrier , even if they had one , they will only sell a complete axle , for over 1000$.

I read some information somewhere ( i have no idea where now) that lead me to believe I had a dana 70U under my truck, due to the 32 spline axles, I wish I knew where that information was now.

How can I positively identify the axle that is under my truck?

I have seen a few R&P kits that state they are for both the 70 and 70U axles , so I assume the ring gear raceway is the same diameter?

CTD NUT

After doing some more digging on 70U's, It appears I will have to retract some statements I made about them as not all of what I previously stated appears to be correct!

So, here is the low down on the U : It does indeed use a smaller pinion bearing than every other incarnation of a 70 but may have an additional suffix added onto the model designation if it is an offset pinion bore housing....ie D70-U-XX or something like that. If no letters follow the "U", it will not have an offset pinion bore in the housing and WILL accept standard D70 ring and pinion sets. There are NO 2nd gens with a D70U that have anything less than 3.54's so there will be no D70-U-XX style housing issues to deal with. Also, to clarify, the U model is the only D70 equipped with 32 spline shafts.....depending on the application a standard D70 could either have 30 or 35 splines but only the U has 32.

So, this is really quite simple now! If you have a 32 spline 70, it is a U, no ifs ands or buts. It absolutely does share the same ring and pinions as a standard 70 and the carriers are physically the same with the only exception being the side gears will have to be 32 spline if the carrier is to be fitted into a U with stock shafts.

Dana 70-U OEM Powr-Lok can be bought new from Randys. They aren't so cheap anymore but you will get a brand new unit for less than buying an entire junkyard axle.

Tate

I thought all the 70's were equipped with 32 spline axles in the 2nd gens? I also thought only the 80's came with 35 spline in the 2nd gens.

Do the 2nd gen D70U's have the smooth underside, like the older ford's? I know those seemed to be the hot ticket back when I hung around the fullsize ford forums.

JKM

Thanks for the info CTD NUT, I am going to include the standard dana 70 carriers in my search too, there has to be something around here that I can buy for less than an entire axle.

If I can find a regular 70 carrier I will buy it and the axle shafts.

mobetta

OK- to revive an old thread - I have a d-70 HD in my truck. I need to replace the carrier and gears.

Do I need a carrier from another HD?

will ring-pinion gears fit from a d-70?

I thought that the only difference was the bearings, I did not realize the carrier was different.
seems the pinion bearings are different, too. does that mean the pinion is different?

There goes my $150 fix....