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Deepwater Jeepin · 03-12-2010, 09:01 AM

Ok, Sunday is the big day that im going to tackle my regear and finish my axle swap. I have been doing alot of reading up on how to do the regear and i still have a couple questions.

Backlash: From what i understand, backlash is the clearance, or freeplay between the pinion teeth and the ring gear teeth. I know i need some kind of a dial indicator to measure the proper backlash. What i do not understand is from what two points i measure from to get an accurate reading. And then to adjust backlash do i change the shims on the carrier to move the unit left or right?

Deepwater Jeepin · 03-12-2010, 09:07 AM

Another thing im still a little unclear about.

How hard should i initially press my new bearing onto the pinion and carrier. I understand how to measure the preload on the pinion. Should i just put them on there snug and then when the pinion nut gets tightened down they will be where they should? And how about the carrier?

Thanks in advance for any help.

88fadedglory · 03-12-2010, 09:35 AM

Pinion preload is vitally important as it sets the bearings so the pinion shaft doesn't wobble and wipe out the pinion seal and increase wear and friction on the gears, but it must not be too tight to keep from wiping out the pinion bearings. (my XJ had the seal gone because it had not been torqued properly ... heck, the darn thing wobbled a quarter of an inch!!!)

Pick up both the Chiltons and Haynes manuals for your rig as one or the other has the specs for all your adjustments.

Backlash is measured on one tooth of the ring gear along the plane of rotation (parallel to the ring gear) and it's simply the amount the gear can rotate before turning the pinion.

BTW, an inexpensive place to pick up a dial indicator is Harbor Freight tools or see if you can rent on locally.

Deepwater Jeepin · 03-12-2010, 09:44 AM

I was going to rent one from autozone or someplace in town... hopefully.

So, if i have to much or to little backlash... do i move the carrier left or right through adding and subtracting shims to adjust that?

98xj_John · 03-12-2010, 10:45 AM

Yup I know my 8.25 is adjustable left to right with shims that screw in an out persay. the backlah for is between 7n10 an I'm at 10 an it nice! I put dial indicator at the top inside of on tooth then zero it out with it touching an turn back an forth an adjust from there. took like 40 min to get mine minty.

88fadedglory · 03-12-2010, 11:11 AM

Quote:

Originally Posted by Deepwater Jeepin

I was going to rent one from autozone or someplace in town... hopefully.

So, if i have to much or to little backlash... do i move the carrier left or right through adding and subtracting shims to adjust that?

If you have a DANA axle, yes. And it's often a "try, try, try again" procedure.

That's alwawys been my complaint with DANAs, those darn shims.

I also don't hold with the claim that "shims are stronger".

20,000 pound capacity Yale Forklift I used to work on had adjusters like a 8.25" or even a 9" Ford and it's ring gear was 15" in diameter. It was apart once in some 120,000 hours of operation ... for a $5 (1976 prices) set of bearings.

It took me longer to pull the axle (remove mast / hydraulics, disconnect brake lines, jack up and support 7"{to get the axle tubes,12"O.D., to clear the brackets}, pull axle shafts {full-float hubs}, un-bolt from trans then clamps, drop, roll out, pull pumpkin {Like a 9" or Mopar 8.75}, than to R&R the bad bearings {30minutes).

Then I had to reverse the process and bleed the brakes!

Down time: 5.5 hours working solo

4.3L XJ · 03-12-2010, 12:42 PM

Quote:

Originally Posted by Deepwater Jeepin

Ok, Sunday is the big day that im going to tackle my regear and finish my axle swap. I have been doing alot of reading up on how to do the regear and i still have a couple questions.

Backlash: From what i understand, backlash is the clearance, or freeplay between the pinion teeth and the ring gear teeth. I know i need some kind of a dial indicator to measure the proper backlash. What i do not understand is from what two points i measure from to get an accurate reading. And then to adjust backlash do i change the shims on the carrier to move the unit left or right?

You will need a dial indicator with a magnetic base. You set up the base anyplace on the housing where it will not wobble and set up the plunger parallel with the rotation of the ring gear. Depress the plunger slightly and put it up against a tooth on the ring gear. Then move the ring gear. There is no point of reference. You subtract the two values on the dial. For instance 27 minus 18 is .009 backlash. A little loose. You would move the carrier and ring gear over a couple of thousandths by taking a .002 shim from one side and moving to the other and measure again.

Deepwater Jeepin · 03-12-2010, 01:23 PM

Great, good info... thanks alot.

I wonder if i can rent one of those tools that holds on to the yoke for when im tightening and loosening the pinion nut. I have heard of people bolting it to a board?

Deepwater Jeepin · 03-12-2010, 02:03 PM

Ok, i just got off the phone with a buddy who says that taking the pinion out is a *$&%.

Is there a trick to it? I have heard you can use a punch, or thread the nut onto the pinion a little ways a use a hammer. Any insight?

88fadedglory · 03-12-2010, 05:02 PM

Quote:

Originally Posted by Deepwater Jeepin

Ok, i just got off the phone with a buddy who says that taking the pinion out is a *$&%.

Is there a trick to it? I have heard you can use a punch, or thread the nut onto the pinion a little ways a use a hammer. Any insight?

You'll need someway to hold the yoke (check the tool rental store or use a big, 18" or larger, pipe wrench, just don't get the jaws on any machined surfaces), a breaker bar with socket to fit the pinion nut and your buddy to do the wrenching so he can see it isn't that bad.

Before pulling the pinion, pop the ring gear out because the pinion comes out the back.

Once the ring gear is out of the way and the pinion nut is off, it slides right out.

The trick? Convincing your buddy to do the wrenching.

Deepwater Jeepin · 03-12-2010, 05:14 PM

The trouble he had with taking the pinion out was after the pinion nut was already out. I have heard others say that it should slide out fairly easily, but he said he had a hell of a time, ending up ruining the pinion becuase he used a hammer for persuasion.

I plan on useing the old ring and pinion to put in my Mustang, so i would like not to have to use a hammer.

JRW7072009 · 03-12-2010, 05:59 PM

Quote:

Originally Posted by Deepwater Jeepin

The trouble he had with taking the pinion out was after the pinion nut was already out. I have heard others say that it should slide out fairly easily, but he said he had a hell of a time, ending up ruining the pinion becuase he used a hammer for persuasion.

I plan on useing the old ring and pinion to put in my Mustang, so i would like not to have to use a hammer.

Dont hammer on the nut it will mess up the threads.

I pinion should not slide out easy it needs to fit tight, to get it out take a punch, small ballpeen hammer or a air hammer with a pointed bit or something to stick in the little indent and the end of the pinion. Have someone hold it with a rag or glove and have someone tap it out.

Dont use the nut and a hammer on the new pinion to get it out you will smash the threads. I say this cause you might need to take the pinion out a couple of times to shim it correctly.

88fadedglory · 03-13-2010, 12:42 AM

Quote:

Originally Posted by Deepwater Jeepin

The trouble he had with taking the pinion out was after the pinion nut was already out. I have heard others say that it should slide out fairly easily, but he said he had a hell of a time, ending up ruining the pinion becuase he used a hammer for persuasion.

I plan on useing the old ring and pinion to put in my Mustang, so i would like not to have to use a hammer.

First: Unless your 'Stang has the same brand and size of axle as your Jeep, the parts will not fit.

AFAIK, the only Danas that Ford used were the 60 series and some heavy truck 70 series.

Put the retainers for the U-joint back on the yoke, insert a large screwdriver, long socket extension or tire iron from each side and put the ends on the pinion shaft, bring the shanks up against the retainers and then pull hard on both at the same time. Might help to brace your feet against the axle housing.

Every yoke I've ever pulled that needed persuading popped right off like this.

Deepwater Jeepin · 03-13-2010, 09:16 AM

Quote:

Originally Posted by 88fadedglory

First: Unless your 'Stang has the same brand and size of axle as your Jeep, the parts will not fit.

AFAIK, the only Danas that Ford used were the 60 series and some heavy truck 70 series.

Put the retainers for the U-joint back on the yoke, insert a large screwdriver, long socket extension or tire iron from each side and put the ends on the pinion shaft, bring the shanks up against the retainers and then pull hard on both at the same time. Might help to brace your feet against the axle housing.

Every yoke I've ever pulled that needed persuading popped right off like this.

Im swapping in an 8.8, which is what im re-gearing for the jeep. My mustang also has an 8.8 rearend in it. Although it probably is the 8.8 with a lower spline count. I dident think it would make a difference though because the ring gear is still going to be 8.8'' and I would think the pinion would be the same size also.

4.3L XJ · 03-13-2010, 09:43 AM

Quote:

Originally Posted by Deepwater Jeepin

Im swapping in an 8.8, which is what im re-gearing for the jeep. My mustang also has an 8.8 rearend in it. Although it probably is the 8.8 with a lower spline count. I dident think it would make a difference though because the ring gear is still going to be 8.8'' and I would think the pinion would be the same size also.

Setting up used diff gears is more of a pain than new ones. They have to end up exactly like they were in the old diff or they will make noise and eventually fail. One thing that helps there is to measure the backlash on them before they come out so you can match it.