14 Bolt Issues... Need HELP!

[duncanstives]

Over the past couple of days I have been setting up 4.10 gears for my 14 bolt. I am following Pirate's guide to setting up the gears, I have all the required equipment (most borrowed from the cal lab at work) but I CAN NOT get the &%*# pinion depth right... The contact pattern will not go to the center... It is centered between the root and tip just fine but will not center between the toe and heel... I tried to guess at setting up the shims (since there were none in there to begin with thus no starting point). The pattern indicated I needed to remove some... Which I did. This improved it slightly but not much so I took more out... Again, slight improvement I THOUGHT but wasn't sure so I add a whole bunch (just to make sure it went the other way)... Hard to tell if it made it worse or not. I screwed around with it for awhile until I finally had ONLY the very smallest shim in there... This is definitely the best its been but it still looks like it is way to low a pinion depth. I am fauirly sure that if I took this one tiny shim out it would not make enough of a difference so I put a little gear oil in and ran it around the block to see if it made lots of noise ot did anything wierd. The engine was running badly (another problem I gotta work on) and is noisy anyway so it was hard to tell... Seems to have way more creaks and grinds and funny handling stuff than I remember but none seemed to be distinctly coming from the back and this could be a result of lots of lift, no sway bars, no shocks and a really badly running engine (could be partly my pessimistic side getting the better of me after two days also). So tomorrow I remove the cover and see if anything looks out of place (metal bits in the oil or wear marks on the teeth). In the mean time can someone tell me:
How critical this heel to toe spacing is? Can I cause major failure if its wrong?
How I might fix it?
What happens if I just run it? (after two days I am pretty sick of looking at it).

Key facts that might be helpful:
I AM applying the brakes to get a clear pattern
I am using prussian blue marking compond
THe pattern is BIGGER in terms of total size then shown on pirates
I tried adjusting backlash (both ways) but it just made my root to tip alignment go out of wack
I am checking pattern on both the front and the "coast" side of the gears. Same either way.
Its driving me nuts!

The last fact is probably not one that "may be helpful" but if anyone could give me some advice I'd sure appriciate it!

Thanks and sorry for the long post.

[Blake]

get some actual gear marking compound. prussian blue works, but it sucks.

also pay attention to what side of the bearing you are removing/adding shimms to/from

[duncanstives]

What do you mean "what side of the bearing"?

[Blake]

I haven't setup a 14bolt in a very long time, but I've setup gears on many, many, many 4x4's. Some axles give you the ability to use shims on either side of one of the pinion bearings. I don't remember if a 14b is like that or not.

If you are hearing noises from your diff, then something is up.

You don't wanna mess up your gears by having them installed incorrectly. Are they new or used gears? I've read that used gears are harder to get a good pattern, although personally, I have not had a problem.

So are you sure you are setting the backlash correctly? A 14b has those nice adjusters, so that's pretty easy to do. Is your gear ratio and carrier the same "break"? In other words, you can't put a 5.38 gearset in a carrier that is for 3.54. The depth will be off.

[duncanstives]

I haven't setup a 14bolt in a very long time, but I've setup gears on many, many, many 4x4's. Some axles give you the ability to use shims on either side of one of the pinion bearings. I don't remember if a 14b is like that or not.

If you are hearing noises from your diff, then something is up.

You don't wanna mess up your gears by having them installed incorrectly. Are they new or used gears? I've read that used gears are harder to get a good pattern, although personally, I have not had a problem.

So are you sure you are setting the backlash correctly? A 14b has those nice adjusters, so that's pretty easy to do. Is your gear ratio and carrier the same "break"? In other words, you can't put a 5.38 gearset in a carrier that is for 3.54. The depth will be off.

I think the carrier is correct? Its 4.10 gears in a 3.73 case (I think anything ABOVE 4.10 requires a new carrier). They ARE used gears so maybe that has something to do with it? Unfortunately I did not take a picture of the exact pattern. I am pretty sure the backlash is set correctly because the dail indicator reads in spec (.008-009 depending on where I measure) and the root to tip pattern looks good but other than that I have no way of being sure.

BTW: I am not sure there are any noises coming from the diff... Hard to tell.

[Heimeken]

If the gears are too worn they will not setup in the "text book" way. Main thing is to center the gear contact top to bottom and backlash will be a bit larger than specs on used gears. So it sounds to me like you are OK.

[duncanstives]

Thanks... I am going to drive it again today to see if anything sounds amiss.

If not I guess I will call it good and see what happens... If I ruin it I guess I am out $100 that I paid for the gears and I have to set it up again which admittedly is more unpleasent a proposition to me than paying for another set of gears... It was a PITA given the working in the dark (since i have been working late) and how cold its been.

[duncanstives]

Took the oil I had put in last night OUT and it looked OK... A small quanity of tiny metal particles but the diff had some metal particles when I took it apart and cleaning them all out was impracticle since its hard to reach in there and I was about out of brake cleaner. It was also a very strangle color which I am attibuting to the the gear marking compond. Got engine running much better (vacuum leak fixed!) and took it for another drive... Got noticable griding only this time it was distanctly only when stopping. While driving it seemed great.... Got back, checked all over. Found I have installed a brake pad upside down so the metal part is against the rotor. Great Googley MoogleyGreat Googley MoogleyGreat Googley Moogley?!! How I did something that dumb I can not imagine!

Apparently I am an idiot.... So ANYWAY....

Diff was mildly warm... Cool enough that it MIGHT have been just the difference between warm gear oil (from the store) and the surroundings but I kind of think it actually got a bit warm... Is this normal? Front was cool but the note about gear break-in that came with some parts from Randy's Ring and Pinion mentioned letting the diff cool down during break-in and not letting it get to hot so maybe this is normal?

BTW no unusual markings on the gears at all when I took the oil out.

Anything else I should do/check? Really hoping to move on to other stuff tomorrow if I can.

[j20brett]

It will get warm to the touch, but should never be able to sizzle water on it.

[duncanstives]

It will get warm to the touch, but should never be able to sizzle water on it.

Definitely no where near warm enough to sizzle water on. Warm enough to be pleasent to the touch given that it is cold out but if I had my choice of ideal hand warmers I still would have wanted it about 15 degrees warmer.