Old Magnet,

I'm planning out this "correct" measurement on the sprocket/hub. First off, a couple real "dumb" questions.

1. The splines inside the sprocket itself- That center part does not remove does it? It's splines/sprocket/sprocket teeth all in one right?

2. When referring to the hub, we are talking about the shaft that is still on the dozer with the other splines correct?

Now I understand what I need to measure- put sprocket back on dozer, tighten large round castled nut, remove nut, measure from face of sprocket to end of spline on dozer shaft or hub correct? I know you listed the specs. as .060 to .190, so don't I want the number to be closer to the smaller spec. .060? That would leave me more room to press it on further. Am I thinking of all this correctly? Should I just hold the feeler gauge against the sprocket until it's even with the end of the splines, or is there a more accurate way? Thanks for answering my "dumb" questions.

Yes on the first two questions.
Yes on putting the sprocket back on and seating it with the retaining nut.
No on the spec interpretation.
The minimum protrusion spec is 0.060
The maximum protrusion spec is 0.190

Ideally you'd like to be in the middle leaving plenty of room to accommodate the 30 ton press fit. Problem is, who knows how much travel the press fit will produce. Maybe edb could comment on this.

In any event the closer you get to the 0.060 the less there is to work with.

The easiest tool for this measurement would be the depth probe of a dial caliper if you have one, reading from the face of the sprocket to the beginning of the splines.

On the back lash check, with the sprocket off (don't want the weight) you need to re-establish the axis as though the unit were assembled and the inner bearing (tractor side of bull gear) seated. Use the outer bearing cage holder (with the keyway) to support the hub and somehow provide pressure towards the tractor to seat the bearing. Then take your back lash measurements.

I don't think I'll ever hit those measurements anyway, based on my "incorrect" measurement. If I had a gap (.020) in this case between the nut and sprocket when tightened, what good was the nut anyway? I'm guessing it's (sprocket and hub) pretty well worn and the nut was unable to do it's job (holding sprocket tight) due to the too-far-worn splines. We'll measure her up tonight and see.

Would agree, if the nut won't even reach the sprocket and with lock in place even, and assuming it is not a thread problem than it's over and measuring is a waste of time. It's new hub and sprocket time. Still should do the backlash check.

Here is another part number for the adjuster screw (takes in more models)
7H4876

Hi OM & Joel,
sorry I could not tell you how far the 30 tons will push the sprocket on from the seated position with worn components, but 0.060" sounds a good round figure, and 0.020" or so for good components.
I have closed my eyes at the clients request before today and have pressed on sprockets to see the measurement at 0.020"-0.040" of hub spline protruding from the sprocket. To my mind the over travel of the sprocket on the hub would work for the more flexible bellows seals only as the less working dimension change tolerant floating ring (duo-cone) seals get too overloaded on the case side and underloaded on the outer side.
The main problem with worn splines is the wear step (unworn splines) at end of the hub and sprocket do all the work if you do not relieve them--grind back.
Joel, you ask if the sprocket bore splines are all one piece, they are, if you can see a change in the wear--contact pattern-- on the splines chances are the hub is cracked in from the radius in the area where the bellows seal plates sit. On heavily worked D4's & 955's it was usual to see cracks--breaks-- here to the point of the hub bit each side of the sprocket proper being tight and the sprocket bit being stripped of splines to the hub--no drive.
I think the first thing to do is see if there is dirt wear to the teeth and bearings in the F/D before we get too deep into what if's and maybe's. With the junk in the F/D that Joel pictured I suspect there is trouble ahead for the pinion and its bearings also.
Good luck with it Joel.
Cheers,
Eddie B.

Tonight's findings-

Last night when I was measuring wrong I could feel play between the hub and sprocket. Tonight when I slid the sprocket onto the hub I gave it a good shove in, and it certainly seated further/better on the spline. No more of that play that I saw and felt last night. So I took the measurement as indicated by Old Magnet. Distance between the sprocket face and end of splines is 0.125 (according to my depth caliper). I can see, on the sprocket hub, where some of the splines have been flattened down a bit- perhaps from a press fit? There is no play in the splines when shoved on hard by hand. By the way, I went to take pictures and the camera needs charged

On the back lash- I pulled the final drive cover. That went surprisingly smooth, and that thing isn't near as heavy as it looks! Once inside the cover, I did the normal visual inspection. All the teeth have good square edges, and the only nics in the teeth were a few minor ones on the face (looking directly at) the pinion gear. There was a small amount of filings in the bottom (about enough to cover the drain plug hole). The backlash on top of the bull gear itself is somewhere in the neighborhood of 0.073 to 0.083 everytime I check it. Everything appears to have been getting lube. After all I added gear lube to this thing constantly before using it. I got the buckets in the garage to prove it!

Nothing (obviously) is put back together yet so pictures will follow.

Well, we're defiantly getting data:D
but signals seemed to be crossed:confused:
What happened to the situation you described where the sprocket retainer nut wouldn't reach the sprocket???
Also did you read the material on how to get more accurate backlash readings??

We now have a new issue of repeatability.
The new sprocket readings look good....to good...although that is without the press fit which will be included in the spec range.
I suspect the readings look good because the indexing of the sprocket to hub has rotated (unless you center punched or marked the original location before disassembly)
To verify this good news I'd ask that you repeat the process at least a couple more times with new indexing each time to see what you get. If it averages out pretty close it seems there is enough travel available to accomplish the press fit and still be in spec.

Anxious to see the pictures.

Hey OM and edb,
Do the hub (male) splines ever stick out past the face of the sprocket, or are they still recessed (minimum 0.06"?)even when the press has done it's job?

The spec. is 0.060 in. min. with a 30, 35, 40 ton press, depending on which one you want to believe:D
Even though it's the same parts the press requirement increases as though there was a problem:rolleyes:

That's with the hub splines recessed in the sprocket.

Hi ccj,
as OM says idealy the splines on the hub shoulder are below the sprocket face by the spec. amount. However I have had to fit up hubs and sprockets with worn splines and finished up with the opposite undesirable hub shoulder protruding the sprocket face situation--all at the clients request and risk in writing.
Hope this clears it up a bit for you as it is confusing unless you have done the proceedure.
Hope this scan helps.
Cheers,
Eddie B.