Rowdy94

iTrader: (13)

The install guide referenced in the sticky (I read it, and a lot more.) says that that person has always simply reused the pinion shim and been done with it. Is this a good way of thinking? I don't have the money for a pinion depth gauge.

Can I just go by the contact pattern if it shows that an adjustment needs to be made?

chicane

HELL NO. Whom-ever stated that is full of ****. Its like 1000:1 to get that. And even getting that is all moon and stars aligned correctly... kinda luck.

On a more constructive note... yes... you can go by a paint pattern alone, without fail. I have done well over 8500+ differentials with it... so it must not be so bad. I have probably only had to use a pinion depth checker... maybe... maybe... 250-300 times.

I say you'll be good with the paint.

monzaz

That is not entirely wrong on the shim. Using your original shim will very often work and is always a good place to start. Almost always you will have to either increase shim or decrease shim depending on which way you are going witht he ratio.

Yes the pattern is always the way to go on checking to see if the gear is in the correct depth and backlash. Some gears show better at a wider backlash like Richmond (.010) I never like my gears set at this backlash too loose for me. GM is (.005-.008 ) Yukon and Motive have been good gear for us. They seem to have a good lap and show the pattern well when you get it right.

Doing a rear diff is rarely a one tip set-up ...it will usually take a least 2-3 assembles and disassembles checking the pattern. TIP : When ever you change the pinion depth shim you need to reset the backlash again to this must be a constant or you will drive your self crazy on trying to find that pattern...lol. if you are using .007 to the backlash try to keep it pretty close to that so you know if your moving in the correct direction. Look for a good wipe of the gear face from peak of the tooth to the root and try to keep it centered on both sides (coast and drive) . Good luck with it. Jim J D Race

Rowdy94

iTrader: (13)

Awesome. Thanks a lot fellas.

chicane

Well... that is the no brainer part of it. Start with what you have... but unless you are installing the same ratio, from the same manufacturer... its a 1000:1 shot that it will be a direct transfer.

Its a good place to start, unless you have done enough ratio changes and have observed a pattern of depth requirements for specific sets from manufacturers.... and can stuff it the first time.

I can remember a few years back... when the ole 5.slow and 3.55's were all the rage. I did 7 in a single 8 hour day, with an hour and a half lunch, and stuffed them all on the first hit. They all got USGear 3.55's and they all took 0.021"...

Talk about lucky.

SScam68

iTrader: (20)

So, how close does the tool get you?

chicane

Depending on your skill with using precision measuring equipment... it can be as accurate as the micrometer you are using.

The only reason that I would even use one is, if I had a gear set that wouldnt even look close... to looking like a useable pattern... I would pull it out and set it to the recommended depth, and run it. However, the majority of the units set up with a PDC were DANA 60's, DANA 61's, DANA 70's and DANA 80's... with a few 15k GVW Rockland and EATON's thrown in there.

But I have never had to used one on a GM7.5/7.625/7.75", GM8.5", 12 bolt, Toyota 7.5, 8 and 8T... or Ford 8", 8.8 or 9"... or non-DANA corp /DodgeChrysler.

keliente

iTrader: (22)

Ouch. I guess I just got lucky! I had to play around with backlash but the depth was ok. The pattern looked good in the paint and it held up for a lengthy time of abuse...and finally what threw in the towel was the torsen (surprise!) the gears still looked good and had worn well.

ps chicane if you ever get bored (you know, when the baby has you up til 3am) and want to write up the ins/outs of using the depth checker, that would be great to add to the how-to. Pics too.

Rowdy94

iTrader: (13)

I have another question for you guys. I don't have access to a bearing puller/installer/press. I'll probably just have to get the carrier bearings swapped and the pinion bearing taken off at a machine shop. I don't want to get the new pinion bearing pressed on when I do that because I would rather bore the original out a little so that I can pull it off and put it on by hand. That way I can get the pinion depth set with the old bearing and no crush sleeve, before having the new bearing pressed on.

My question is, is there any other way of pressing the pinion bearing on besides going back to the machine shop? Can it be safely installed with a hammer and a chisel or 1/2" drive extension?

I don't want to ruin it, but I'd like to just take one trip to the machinist.

chicane

FINALLY... !! The Kelster steps in to take the . Do you have any idea how long I have been waiting for you to stick your head in this thread ?? The damn joke ran out... like... two days ago. Damn woman !

How come nobody laughs at my jokes ??

BJM

iTrader: (1)

Count me in as one for whom the stock pinion shim was wrong. The factory set up was off and the pinion shim was not correct for my new gear.

keliente

iTrader: (22)

You're such a crusty curmudgeon that no one knows when you're joking


(please don't beat me!!)

WS6WRX

iTrader: (1)

no way, do not try to hammer the bearings on, you will ruin them.