How hard should it be to install the outer pinion bearing?

[Nothing Special]

I'm trying to set up the gears in my high pinion Dana 44. This is the second time I've done gears, but the first time I was just installing a locker so I never moved the pinion. This time I'm doing the whole thing.

I bought a ring and pinion from Yukon. I also got the install kit from them. I think there's way too much interference between the pinion shaft and outer pinion bearing. It's about .0008" interference, and the bearing won't go on without some really solid blows from a hammer. I can install it that way, but I'll never be able to get the pinion back out without damaging the bearing.

I called Yukon tech support and they said that .0008" interference is well within specs. That industry standard is to have this "light press fit" to ensure everything stays centered. The pinion shaft that came out had a .0002" clearance with the bearing so the bearing just slid on and off freely (but wasn't sloppy). Yukon tech support said that was the sign of a poor quality or worn out pinion shaft.

Does anyone with more experience than me have any advice here?

 

[Apogee]

I've only built my HPD44, but a light press fit is pretty typical for that bearing, and .0008" would definitely be consider a light press fit. I used a hydraulic press to assemble mine, and it didn't take much to push them on in terms of force. That said, for gear setup and getting the pattern where I wanted it, I reused my old bearings and make a set of setup bearings by flap sanding out the ID so they'd slip on and off with minimal force and wear and tear on the pinion shafts.

 

[Nothing Special]

I've only built my HPD44, but a light press fit is pretty typical for that bearing, and .0008" would definitely be consider a light press fit. I used a hydraulic press to assemble mine, and it didn't take much to push them on in terms of force. That said, for gear setup and getting the pattern where I wanted it, I reused my old bearings and make a set of setup bearings by flap sanding out the ID so they'd slip on and off with minimal force and wear and tear on the pinion shafts.

How do you use a hydraulic press to install the outer pinion bearing? It doesn't go on until the pinion shaft is in the housing, right before the yoke and nut. And if you do press it on, how do you get it off to take the pinion shaft out?

As far as using setup bearings, I tried that the first time I did gears. I was just adding a locker that time so I never touched the pinion shaft. I used setup bearings for the carrier, but after figuring out what shims gave me good backlash, pattern and preload I used the same shims with my "real" bearings and wasn't even close. So i made a puller to get the bearings off the diff and went through the whole exercise again. With the puller it was easy enough to install and remove the bearings that I figured I'd do the same thing here. It's easy to install and remove the inner pinion race (where the shims go to set pinion depth), so it's just the outer pinion bearing I'm fighting now.

As far as .0008" being a light press, like I said, it takes some pretty serious whacks with a pretty big hammer to get it to go on. I can do that, but I'm afraid I'll damage the bearing and race if I have to beat on it that hard to disassemble it.

 

[bax]

Its not that hard of a press. Perhaps a hammer is not the best tool to take the bearing back off. But once you get pinion set you really have limited options to get it back out. That's why it not that tight of a press. Driving it back out is pretty much your only option. Brass hammer and an old nut in the pinion is a must have. Go easy.

 

[Nothing Special]

Closing this out, it was that hard of a press. So I chucked the pinion shaft up in a lathe and used some emory paper to polish it down to where I could get in on and off with hammer taps rather than full swings with a 32 ounce hammer.

But now the entire gear setup process is done. Most of it is documented in this thread.

 

[jamesroney]

...
As far as using setup bearings (snip) . It's easy to install and remove the inner pinion race (where the shims go to set pinion depth)

I watcched your other thread but didn't comment since you seemed to be making good progress.

But I am a little bit worried about your inner pinion race comment. I am wondering how you managed to install and remove the inner pinion race (numerous times???) without damaging the edge of the baffle. I have never been able to do that without destroying the inner lip of the baffle.

Most people don't have a problem with the baffle, because they are doing low pinion installations that don't use the baffle. But the High Pinion requires both the pinion slinger, and the baffle in order to retain oil in the bearing cavity. I've seen a lot of guys leave them out, but that's bad. the Factory Service manual shows the Ford part number ID #4670, Inner Front Baffle, and #4670 Inner Rear slinger. The Dana Spicer install kit comes with a new one. But you only get one chance.

Curious how you did it.

 

[Nothing Special]

I didn't use the baffle until the last time I put the race in. Then I measured the baffle thickness and took out the same amount of shim. If I'd had to take it out again, yes, I'd have destroyed the baffle. But my install kit did come with 2 so I had a spare.