I need to replace a pinion bearing that is whining. As long as I'm in there, I may as well do all the rest of the bearings and seals at the same time. 228k miles is plenty, even considering it's been babied. This is one of only a few jobs I've not yet attempted, though I think I understand the concepts. FWIW, here is the best online description I've found:
http://www.richmondgear.com/01instructions.html
The depth gauge is frighteningly expensive, and is a tool for which I simply cannot see any other use. Randy's Ring and Pinion sells a "professional" ($400) and an "econo" ($200) version... and according to one of their salesman, he wishes they didn't even list the econo version in their catalog because it's a serious pain in the neck to use. His description of it sounds very similar to the tool shown in Jegs catalog for $100, which looks like a simple dial indicator with a flat mounting plate and a bunch of precision-length attachments.
http://www.jegs.com/cgi-bin/ncommerce3/ ... rmenbr=361
In searching for an instruction manual for it (or a similar type unit), here is the best I've found. Basically, it involves measuring from the flat surface of the bearing caps, and calculating an offset because the split of the caps is not likely to be directly on the centerline of the carrier bearing:
http://www.tavia.com/05001_instructions.html
In contrast, the "professional" version is strapped directly inside the carrier bearing caps, with a couple of hockey puck shaped attachments, so it knows where the centerline is automatically. And therefore it introduces a proportionately smaller margin of error, I'm sure. But I figure if I'm even within a couple thousandths, I should be able to get a reasonable contact pattern on the gear teeth... or is that foolish? Given all the horror stories I've heard about gears that start whining, even if you take it to a shop and have them do the job for you... ayi. Whining gears is not an option, in my book.
Given all the "wear pattern charts" I've seen, it seems like I ought to be able to set up a rear end perfectly by simply reading the contact pattern, but of course with a whole lot of trial and error... although I do LOVE the trick I read about, of buying an extra set of pinion bearing cups and sanding down the inside surface until it slides on and off the pinion without needing a press. Then when you've got the shims right, you take off the "checking" cups and press the real bearings on. A pretty good wear pattern chart is at the bottom of this page:
http://www.drivetrain.com/ringpinioninstal.html
Charlie, who knows a great deal more than I do about this, has cautioned me that it ain't that easy, and that I really need the depth gauge. However, since then, I read somewhere that OEM gears may not have a depth spec etched onto the pinion head, anyway... in which case the tool will be relatively (if not completely?) useless... has anyone else stumbled into this same problem? I really have no need to replace the gears, since I'm happy with the ratio, and the wear pattern is perfect.
And yea, this particular job is for a (ahem) Ford product, but the next time I do it will be for a Chrysler... and the basic technique and considerations haven't changed in 100 years, anyway. So I'm looking for any help I can get.
Thanks!
- Erik