Stamey

The rear pinion bearing my the Dana 70 in my truck went south and took the pinion with it (two teeth). I have seen videos on setting up the new gears and people seem to use a specially modified front bearing that is a slip fit, not a press fit, while they are getting the shims right for the pinion.
Am I going to have to buy two rear pinion bearings to modify one for setup purposes? It seems like the only way to get the press fit bearing off is to destroy it.

I am open to ideas as I have never done this before.

Thanks,
Chris

bentwings

In the auto shop days we had a few rear bearings that we made slip fit, Dana 70 was one.

We did run slip fit ones on the racer but it isn't the best idea.

I'd just bite the bullet and make a slip fit, do it right.

Sometimes you get lucky and the numbers on the new pinion match the old, then you should be able to do it once. I would not chance it today, as the gear sets are generally not as good as they were 40 years ago.

BigIron70

We call them Dummy bearings they are not real bearings. They are used just for setting up purpose. Or you can do what this guy did to some old bearings. We use a special puller that can remove the bearings without destroying them. You will also need a shim kit. These are not the easiest diff's to rebuild especially if you do not have the proper tools to set them up correctly. Pinion turning torque, pinion depth, side bearing preload and gear backlash. These adjustments need to be set properly if you want a quiet diff that will go many miles without problems. Make sure you have a good digital micrometer you will need it. Good Luck

Stamey

I suppose I will have to buy two and hone one out, then.

Thanks,
Chris

BigIron70

If you are interested in detailed procedure for overhaul PM me.

Philip

On the pinion, shims go under the inside bearing race in the housing not under the bearing. The outer bearing on the pinion is a slip fit already. You will need a pair of setup bearings to do the carrier.

Make sure you have a pinion install kit. You will need a good dial indicator and a set of dial calipers.

Here is a link with rebuild instructions. It covers front and rear axles. Just use the gearing section for what your doing.

http://www2.dana.com/pdf/5312-9.pdf

On Dana axles I normally do not recommend doing them if you have no experience. These are not a good beginner axle.

Stamey

Well, I have just gotten the pinion and carrier out. Have not removed the pinion bearing, and per previous post, guess I don't have to, as if I get an install kit it should have the necessary shims or oil slinger to go under the pinion bearing.
I see what you are talking about with the pinion shims, and that's a load off my mind. Does the rear pinion race slide in, or is it a press fit? I ask because I am wondering if I will be banging it and out to adjust the pinion depth.
When I was looking at the pinion, it looks to me like there is something between the bearing and the pinion gear, perhaps and oil slinger.

It looks like the carrier shims are behind the bearings on the carrier, so I guess that means I have to either salvage my old carrier bearings to modify for setup bearings or buy two extra carrier bearings to modify for this purpose.

Pics of the damage for your amusement:





Thanks for everyone's advice on this. I'm gonna get this done slowly, as I do have another truck, and can spend time doing this right.
Oh, and I have the necessary measuring tools. I do machine work
in my garage so am familiar with all of them.

Thanks,
Chris

Philip

Rear pinion race is a light press in. A hammer and punch will remove it. Just remove and reinstall as needed. Now read the instructions over very well on the pinion install. They will be talking about the old shims under the inner race. There will be a chart with the install kit that gives you information on figuring out how many shims you need to add or subtract to set pinion depth. That link also has it on page 4-7.

Use new bearings as setup bearings on the carrier. You old bearing are worn. They will give you wrong readings most likely. They are 387A bearings.

Reuse the oil slinger. It will not be in the install kit. On the link I posted on page 1-5. The oil slinger is item 8. It is shown in its correct location.

Look over page 4-11 real good. When pinion depth is set you must hit the pinion turning torque setting of 10 lbs in. This is bearing preload setting. Or what ever setting your install instruction sheet says.

Look the axle housing over real good for the outer races on the carrier bearing turning. Look the carrier over for the bearing inner races turning. When your doing setup on the carrier bearings. Try to not use real thin shims. The thicker you can use is better. Thin shims like to split and work out causing the carrier to move around.

totalloser

This might be helpful for setup. http://www2.dana.com/pdf/5717.PDF

Stamey

Got it all apart now, races and bearings. Found .070" in two shims on pinion shaft and what I'm guessing is a crush sleeve under them, although I do not see that part in the Dana parts explosion on page 1-5. It was found behind number 5 on the explosion. It has 3 nubs around the ID to hold is away from the pinion shaft.
Rear pinion race had no shims under it.
Carrier gear side had .063" and diff side had .056" in shims.

I have not pulled the rear I'm getting the gears from apart yet.

Chris

Philip

That's not a crush sleeve. It is just a thick spacer. Every 70 I have had apart had one.

Stamey

Got my rebuild kit. The only issue I see at this point is the pinion depth. I don't have the special tools to measure it. All I can figure is to use the shim thickness that came out of the housing and look at the pattern to see if it is in the middle of the ring gear.

Thanks,
Chris

Philip

There should be an instruction sheet with the install kit. Look at the settings on the end of the old pinion. Then look at the settings on the new pinion. Then the chart will tell you how much shims to add or remove to set pinion depth.

Remember I told you a DANA 70 is not a good beginner axle.

Philip

How are you getting along????

Philip

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How about a update.