How the heck does this work?

[koda2000]

Ever seen one of these? How does it work?
Ratech 10006 Pinion Depth Gauge 8.8 Ford (81-up) | eBay

 

[974X4BLACKSPORT]

It looks like the mount for a dial indicator when used to measure pinion depth. Just a guess, never uused that type before.

 

[imp]

Ever seen one of these? How does it work?
Ratech 10006 Pinion Depth Gauge 8.8 Ford (81-up) | eBay

@koda2000
Damned if I know! However, pinion depth is measured to it's face from the gasket surface of the housing, I believe. A depth micrometer is what I would use, how a dial indicator would be of any use, I dunno.

Lots of stuff, I dunno, though. Are you setting up gears? NEED to know, let me know, I'll copy set-up instructions from Ford Shop Manual. Year and model? imp

 

[koda2000]

@koda2000
Damned if I know! However, pinion depth is measured to it's face from the gasket surface of the housing, I believe. A depth micrometer is what I would use, how a dial indicator would be of any use, I dunno.

Lots of stuff, I dunno, though. Are you setting up gears? NEED to know, let me know, I'll copy set-up instructions from Ford Shop Manual. Year and model? imp

No, I'm not setting up a diff I just ran across this thing while looking at diff covers. I've never seen anything like it.and wondered how it's used.

From what I know the pinion depth is measured by using a dial gauge and measuring the play between the pinion and ring gears. Then as necessary shims are then added/removed to the pinion shaft to get the play to be around .005. I've never done a diff, but from what I've seen it's not something I want to do.

 

[CDW6212R]

I have that tool in my Summit wish list, also not knowing how it could be used.

I need to begin learning how to set up the front D35 carriers now. I have an old one to learn with for my Mercury, since I swapped its old one into my 98 Limited. Then once I can do it, I have two new diffs to install into my 99 truck, and the 98 also.

 

[imp]

No, I'm not setting up a diff I just ran across this thing while looking at diff covers. I've never seen anything like it.and wondered how it's used.

From what I know the pinion depth is measured by using a dial gauge and measuring the play between the pinion and ring gears. Then as necessary shims are then added/removed to the pinion shaft to get the play to be around .005. I've never done a diff, but from what I've seen it's not something I want to do.

@koda2000 @CDW6212R
Good time to pick my brain, before it gets any older! I cut my teeth setting up 9-inchers long ago.
Pinion Depth is a dimension number imprinted on the Pinion Gear used in determining initially how much shimming the Pinion needs to locate it in the housing fairly close if not exactly, to where it must be to accomplish proper gear tooth mating pattern. Thrown in with this is the fact that the Pinion has shims to also preload it's 2 bearings. Pinion Depth has nothing to do with gear tooth clearance, known as "backlash", or "lash", though the depth affects lash.

Backlash is clearance between the teeth of the pinion and the ring gear, usually slightly more than 0.010" measured at the outer periphery of the ring gear, at a right angle (tangent) to it's rotation. Lash is accomplished either through the use of shims behind the differential carrier bearings, the cone & roller assy, or use of threaded "nuts", which are round and cup-shaped and have perforated holes in them to allow turning them.

The threaded adjusting nuts:

• 

Measuring backlash:

• 

'Course, you guys will be stuck with the shimming method; few axle designs used nuts. This means that without the sophisticated measuring tools shown in the Ford Shop Manuals, you cannot predict exactly how much shim "stack" you will need, for either pinion bearing preload, depth, or lash. Depth and lash both affect tooth contact pattern, and while lash may be right-on, the pattern may be so far off, the gears will sing like hell!

A comparison of tooth contact pattern. Done by lightly "painting" teeth with Prussian Blue grease, and rotating the ring gear by hand while holding a rag tightly around the pinion yoke, to "load" the teeth:

• 

The real reason for all this shim monkey-business lies in the tolerances present due to manufacturing practices. Every part in use has some tolerance associated with it, thus when a ring and pinion must mesh accurately within a few thousandths of an inch, set-up must work around tolerances. Want more pics, just ask! imp

 

[koda2000]

@koda2000 @CDW6212R
Good time to pick my brain, before it gets any older! I cut my teeth setting up 9-inchers long ago.
Pinion Depth is a dimension number imprinted on the Pinion Gear used in determining initially how much shimming the Pinion needs to locate it in the housing fairly close if not exactly, to where it must be to accomplish proper gear tooth mating pattern. Thrown in with this is the fact that the Pinion has shims to also preload it's 2 bearings. Pinion Depth has nothing to do with gear tooth clearance, known as "backlash", or "lash", though the depth affects lash.

Backlash is clearance between the teeth of the pinion and the ring gear, usually slightly more than 0.010" measured at the outer periphery of the ring gear, at a right angle (tangent) to it's rotation. Lash is accomplished either through the use of shims behind the differential carrier bearings, the cone & roller assy, or use of threaded "nuts", which are round and cup-shaped and have perforated holes in them to allow turning them.

The threaded adjusting nuts:

• 

Measuring backlash:

• 

'Course, you guys will be stuck with the shimming method; few axle designs used nuts. This means that without the sophisticated measuring tools shown in the Ford Shop Manuals, you cannot predict exactly how much shim "stack" you will need, for either pinion bearing preload, depth, or lash. Depth and lash both affect tooth contact pattern, and while lash may be right-on, the pattern may be so far off, the gears will sing like hell!

A comparison of tooth contact pattern. Done by lightly "painting" teeth with Prussian Blue grease, and rotating the ring gear by hand while holding a rag tightly around the pinion yoke, to "load" the teeth:

• 

The real reason for all this shim monkey-business lies in the tolerances present due to manufacturing practices. Every part in use has some tolerance associated with it, thus when a ring and pinion must mesh accurately within a few thousandths of an inch, set-up must work around tolerances. Want more pics, just ask! imp

I recall those threaded nuts with the holes in them as a Mopar thing, but maybe it's just an older method used to set the carrier bearings on the Dana diffs.

Doesn't the crush sleeve also help to achieve a certain amount of resistance on the pinion?

 

[donalds]

When I rebuilt the 8.8 on my truck I had to learn all this stuff
The easiest way to set it up for me is to have a set of barring s to use to set everything up in the pinion gear depth then install everything with a new crush sleeve set the preload

I used yellow chalk to check the gear pattern
Luckily I was able to use the factory spacer on the pinion but not the ring

 

[imp]

I recall those threaded nuts with the holes in them as a Mopar thing, but maybe it's just an older method used to set the carrier bearings on the Dana diffs.

Doesn't the crush sleeve also help to achieve a certain amount of resistance on the pinion?

@koda2000
Yes. Crush sleeves provide a way of causing "tightness" of the nut while preloading the bearings. It takes a lot of torque on the nut to crush it, and the amount of crush is great enough to allow for placing "squeeze" on the bearings facing each other (crush washer is between them) while checking the amount of preload, the torque necessary to rotate only the pinion supported by it's bearings. This highlights two very important things: re-using a crush washer after, say, replacing the seal, is not highly recommended, has been done by many, sometimes results in insufficient preload, then early bearing failure/gear noise. The front bearing (towards the yoke) is easily pulled out after the yoke, seal, and (sometimes) oil slinger are removed, the crush washer then pulled out and replaced.

The resistance you refer to, bearing preload, is usually in the range of more than 10 inch-pounds, but less than 30 inch pounds, WITHOUT the seal. Dilemma is, ya gotta remove the nut, to put in the seal, thus relieving force on a "used" crush washer. Most Ford specs call out preload with a seal installed; the seal, well-lubricated, only adds a couple of in-lbs to the twist needed to turn the bearings. New bearings call for high-end preload, used a bit less.

Ford high-performance vehicles, police cars, taxi cabs, fleet vehicles often have a factory-installed non-crushable spacer; they are made in quite a number of thicknesses in increments of about 0.002", eliminating the "sponginess" of a crush washer altogether. The nut then can get tightened REALLY tight w/o over tightening the bearings. Much harder to set-up, however, and too thin a solid spacer tightened in there can mean a cracked bearing race. imp

 

[CDW6212R]

I've read a lot of that before, and it takes some thought to get the hang of it. I've only set backlash on three 8.8's. That isn't very hard with the best shim kits. But doing the pinion bearings is a bit different, I haven't had to mess with them yet.

 

[donalds]

And do not under any circumstances use a impact wrench it destroy your new barring

I used a beam style torque wrench to tighten the nut it took 190 fp to turn it
I went in VERY small increments 1/16 turn at a time

 

[CDW6212R]

The Ford techs use a special long tool to tighten the pinion nut. I've watched that part done, the bar about three feet long took very little effort, with the car on a lift, pulling down from below. That's a slick tool compared to doing it on jack stands.

 

[donalds]

I took a big punch and stuck it through one of the unused holes on the flange and tighten it down

It was hard to do under the truck

 

[shucker1]

Done by lightly "painting" teeth with Prussian Blue grease,

Now that stuff is fun....

Put some under the drawer pulls of your buddies tool box!!!!

Better than NeverSeize.

 

[david4451]

I thought it was a tool for getting stones out of horses hoofs.
We live and learn!