Front Diff. Yoke Pinion Bearings

[Blaine]

On 87 Comanche 4x4.  

 

On my front axle the yoke has some up and down play and small fluid leak, obviously the seal needs replacing but will replacing the race and bearing right behind the yoke get rid of the play or does it have to be both pinion bearings 

 

also i do know the procedure to do both, but any trick, hints, side-notes would be awesome

[Bornindesert]

The pinion bearings are preloaded such that when the yoke is rotated the torque is about 15 in-lbs with the carrier, axles and seals removed. So, it sounds like your axle has some wear on both bearings. What establishes pinion preload are shims behind the outer pinion bearing cone & rollers and a shoulder on the pinion. Since the outer cone & rollers have a mild press fit on the pinion, you normally have to drive the pinion shaft through the housing, again with the carrier out of the way just to add or remove shims. Removing pinion preload shims would basically be part of a rebuild or ring and pinion set up. Basically, you could remove several shims, regain pinion preload, replace the pinion seal and reassemble.

 

It's recommended that you replace the pinion nut any time you've disassembled the axle.

 

With the carrier installed and a new seal, probably adds 7 to 10 in-lbs above the target of 15.

 

Pinion nut torque is 160 - 200 ft lbs.

 

There are some decent write-ups out on the web forums. I don't know of any short cuts, sorry. I went all the way and rebuilt / regeared both axles and did the set ups according to the procedures I gleamed off the web.

 

Here is one off the tools I made to torque the pinion nut while the axle was out of the vehicle.

 

[64 Cheyenne]

Tough call...

So far I've regeared 4 of my axles from info i learned off of the web. (no formal gear set up training, self taught)

Would I suggest you try and break this down to replace the pinion bearings....no. That is unless you have a shop, tools and know how.

Breaking down the axle would require a gear "set up" not sayin you can't do it, just be prepared.

Myself, I would try a couple of things first. 1. Replace the seal, install new outer pinion bearing or if the current one is still intact possibly reuse, might just be pinion nut came loose. If that fixes the slop and leak, cool, don't fix it anymore. If that don't fix it, then your next options are to tear into it or my better suggestion... if you are lacking time, space, know how...replace the axle. Many 3.55 and 3.07 geared axles out there can be had for reasonable price.

How much do you want to learn, curse or spend, take your pick.

[Blaine]

The pinion bearings are preloaded such that when the yoke is rotated the torque is about 15 in-lbs with the carrier, axles and seals removed. So, it sounds like your axle has some wear on both bearings. What establishes pinion preload are shims behind the outer pinion bearing cone & rollers and a shoulder on the pinion. Since the outer cone & rollers have a mild press fit on the pinion, you normally have to drive the pinion shaft through the housing, again with the carrier out of the way just to add or remove shims. Removing pinion preload shims would basically be part of a rebuild or ring and pinion set up. Basically, you could remove several shims, regain pinion preload, replace the pinion seal and reassemble. It's recommended that you replace the pinion nut any time you've disassembled the axle. With the carrier installed and a new seal, probably adds 7 to 10 in-lbs above the target of 15. Pinion nut torque is 160 - 200 ft lbs. There are some decent write-ups out on the web forums. I don't know of any short cuts, sorry. I went all the way and rebuilt / regeared both axles and did the set ups according to the procedures I gleamed off the web. Here is one off the tools I made to torque the pinion nut while the axle was out of the vehicle.

 

ok, outer bearing is the one right behind the yoke, now can i replace outer bearing and race with the pinion shaft still in place? and is it crush collar or just spacers?  nice tool MacGyver style, i like. but ill be doing this under my truck, could use if carrier is out.  the only thing i don't have is a press to do the inner bearing and the thing to test preload, what is it? other than that i do. Is there any way to pull inner bearing off without press?

[Bornindesert]

There's no crush nut on the Dana 30 front axle, but if you have a Dana 35 rear axle it uses a crush ring.

 

With the Axle under the Jeep, and wheels down you shouldn't need a yoke tool to torque and un-torque the nut. Biggest problem I think you'll run into is getting the cone to come towards you after you pull to yoke out. If it slides off, great. You could then grab the shims and slide them off. The race, if they make a tool to pull it out off a Dana 30 I've not come across one. Not saying it's not out there, but without a bearing race puller there's no way to get that sucker out. If you pull the diff cover, axles and carrier, then you can punch it out with a drift pin or brass rod. That's more than I think you want to get into at this point so it really comes down to just a pinion seal, pull out a shim if you can get the cone bearing out and reassemble.

 

Before you pull the nut, put a socket and Rachet on there and get a feel for how much resistance you get when you twirl it, wheels off.

[64 Cheyenne]

I agree, well said Bornindesert

[Blaine]

so its possible to change outer bearing (the cone), but what if i left old race in if not damaged, would the diff. wear patterns be a problem? with the shims, put new ones in, reassemble it and torque to 160 and check preload and gradually increase till in spec. what is that tool called to do preload? and what would it be with carrier and axles but no tires on it, don't really want to pull my axles out just yet 

 

ive seen videos of people marking the nut, thread, and yoke,  and yoke to axle so when reassembled and all lines matched it was basically back to factory, if the nut wasn't loose to begin with. 

 

any good or not?

[Eagle]

so its possible to change outer bearing (the cone), but what if i left old race in if not damaged, would the diff. wear patterns be a problem? with the shims, put new ones in, reassemble it and torque to 160 and check preload and gradually increase till in spec. what is that tool called to do preload?

 

It's an inch-pound torque wrench. Rather than hold the yoke and tighten the nut on the shaft, you let the yoke rotate and measure how much torque is needed (in INCH-pounds, not foot pounds) to make the pinion shaft rotate.

[Blaine]

alright so just need an inch pound TW, any way you would know what the torque spec would be, with axles in carrier, with no tires on truck,

i know its 15 inch pound without carrier installed, add another 7-10 with it installed and new seal, but how about with the axles installed as well. or would that be unreasonable? 

[Bornindesert]

 

Here is a pic of the inch pound TW, the small one with the little black knob. The running torque that Eagle describes is sensitive to the pinion nut torque, so you would creep up on the 160 ft lbs and take a measurement at like 25 ft lb increments.

 

Without any preload, the situation you describe, the initial in-lb measurement you get with axles in and tires off would be added to the 15 in-lb target for preload without carrier. Make sense? The only variable would be old seal verses new seal, so add 3 in-lbs.

 

Most would advise against installing a new cone roller in an old race. Would it be an improvement to your current situation? Probably. I'd lean toward re-using the old roller bearing if it didn't look like a South Bend Indiana road in May...full of pot holes.

 

Remember, you may not be able to even get the roller out so the next step would be pulling axles and carrier and drive the pinion out.

[Blaine]

 do i have to do preload if i just replace the seal?

[Bornindesert]

No. Preload is set by number of pinion preload shims and pinion nut torque. You could use a 250 ft lb TW and get an idea of the pinion nut torque required to get it to break free, loosen. Pry the old seal out, drive new one in and reassemble to the same nut torque plus 25 in lbs. You'll likely have a similar condition, some play in the yoke. Might by you some time, dunno.

[Blaine]

appreciate the input everyone  :thumbsup: