Pinion Depth
 

I have read and the more I read the more confused I get. I got a pinion depth setting tool and understand how to use it (for a dana 80). The problem I have is, it says if I have a + to remove shims or a - add shims to the pinion to get the correct depth. I do not see a number anywhere on the pinion other then 5.812 this is on a USA Standard gear set. It's going in a puller and I have been thru 4 sets in 10 passes. I feel the pinion is not setup correctly but backlash is 0-.002. So can anyone tell me how to read the 5.812 number since there is no +/- number on the pinion?

I run ours deep and tight. May not be right but its always lived that way

Your backlash is too tight for the record.

On the head of the pinion should be hand engraved (usually) the (+/-) number. If it's not there buy from a gear manufacturer that doesn't suck.

Take a picture of your gear pattern and toss it up when you think you've got it dialed in. Also, take a picture of some of the failed gearsets. Those will tell you exactly what's failing.

His backlash is to tight for a street truck not a pulling truck. I've always run 0 backlash and even to the point it's hard to turn.

Thanks for the reply guys. I will get a pic of the old gear sets. Jermey, when you setup your pinion preload, how hard is it to turn? I set on up where it took both hands and bar and the other one to 40 in lbs. Did not seem to matter. When this set goes in it will have 0 backlash for sure to see if I can make it work.

Gear sets came from Randys R&P. One has a 19 on it and the other a 70 on it. No +/- next to them.

I don't believe in zero backlash. Pullers that guys have brought here that run 0 the gear sets are burnt/hot spots with terrible wear. We run .003 lash, pinion preload just over factory specs(too tight is robbing horsepower) set shims up behind the race not the pinion bearing, and change every 10-12 passes. I ran my current one for 16 passes before it broke.

What's a good starting point for pinion shims? .060, .070 or what?

I've never head of running zero backlash and I don't understand the reasoning behind it. You're essentially preloading the gears at that point ensuring deflection once they're warm removing the ability for any sort of oiling which ruins the hardened surface of the gears. I understand pullers replace their gears frequently, but it's hard to see how that wouldn't force the gears to fail prematurely.

cumins01: Google how to use a pinion depth finder. You don't need the markings on the head of the pinion with a depth finder.

If there are no numbers on the pinion use the depth finder as stated, that should get you close on the first shot, then adjust accordingly.

I ordered a pinion depth setting tool just waiting for it to arrive.

Oooooh, I apologize then.

I don't use a pinion depth finder when I regear simply because tool budget money is always spent elsewhere since I only do a few axles a year now. When I start from scratch I either try to find the shims that were under the previous pinion and start there (always making bold adjustments to get into the ball park) or I start with 0.07" and make bold adjustments from there. If you don't have the pinion that came out of the axle, a pinion depth finder knocks off around a hour of constantly installing and removing everything.

I'm assuming you have a set of setup bearings?

deep and tight here too. Never had a gear set look burnt or discolored from getting hot. Pinion is tough to turn with one hand once setup.

Thanks for the input Jesse. With R&P installed or just pinion?

Yes have a set of setup bearings thank god. The old pinion is long gone along with the shims that came out of it. I had a dana gear set last almost 3 years pulling but this year I can't keep one in. Have no idea what I am doing different. Hope the pinion tool gets me close then I can see how far off the one really was.

I only run Dana Spicer or Nitro gears, but I'm not a puller.

There's a common belief among a lot of mechanical engineers in the rock crawling world that once a gear set has violently disassembled itself into modern art that the housing is then junk/questionable. I'm on the fence about that as cast iron has a lot of "movement" to it. Do you have a different housing to try?

no I do not

well scrap that idea then...

Have all the gear sets you've blown up been the same manufacturer?

Yes all were USA standard except the first set which was a dana gear.

If your pattern looked good and it wasn't a pinion depth issue I'd go to a different gear manufacturer and/or find a donor housing.