Setting Pinion Depth

[HectorM52]

Okay, I am switching from 3.42 gears to 4.10 gears. I yanked apart the old stuff. Measured pinion depth at 4.668" using a straight edge and caliper.

Took the old pinion out and had the bearing yanked off. I had him put the old shims on new pinion. So the depth of the new one should be pretty close to the old one, right?

Okay, so I punched the old races out of the housing and then set the new ones in place using the old ones as a guide.

So I did a TON of reading up on the install. Basically I know to not yank the old pinion up too much...could go past the 4.668" and ruin the crush sleeve.

Well, my problem is that I can't seem to tighten the nut enough to snug everything up. I'm at 4.300" or so...and I need to snug up the nut to get it closer to 4.668". I can literally jiggle the pinion inside the races. I guess that's the .368" that remain.

Why can't I tighten the pinion nut any more? It's like its stuck.

I re-used the washer that was under the old pinion nut. I'm wondering if I've bottomed out the nut or something.

Anyone see anything I'm doing wrong???

I'm still dirty, but thinking I'm quitting for the night. This is frustrating.

[David Pozzi]

The proper pinion depth for the NEW pinion will be etched on it. It will not be exactly the same as the old one. Most new gear sets measure pinion depth from the rear surface of the pinion to carrier bore centerline. Measuring across the cap parting line is not exactly the center. To find center, put the cap on, tighten the bolts and measure bore diameter, then remove the cap, put a straight edge across the housing where the cap seats if that's where you are measuring depth from, and measure bore to straight edge. What you need to do is figure out how much off the cap surface is to center and allow for that in your pinion depth measurements.

The crush sleeve must be deformed when you tighten the pinion nut, this takes a lot of force. Usually it takes a 3/4" impact gun.

It doesn't sound like you have the experience to to this job correctly. I highly recommend you find someone to guide you through the process or you could easily make a mistake and ruin the new gears and bearings.
New gears usually come with instructions on how to install them that would cover this stuff. Where did you get yours?
David

[HectorM52]

Thanks, David. You're correct in saying I don't have much experience doing this. Though I typically try to read and learn as much as possible before starting a task like this then ask for advice during each step of the process. I've found it's a good way to learn how to do this stuff and most of the time I can stay on track.

I'm REAL close to yanking the rear end out of the truck and taking it somewhere...as I don't have access to a 3/4" impact nor some of the precise dial calipers needed.

Thanks for the info you've given so far...may have to hit you up again if I try anything further. But probably not.

[MrQuick]

I agree with David here, without the proper tools you are just throwing money out the window.

I have a 3/4 breaker bar and 4 foot torque wrench just for this purpose.

Vince

[Ron S]

What rear are we working on? 10 bolt, 12 bolt, 9". I do have the depth tools, but truthfully the only time I break them out is if I was given a bare housing with no refrence points. Dana's always have a + or - number on the head of the pinion,which is the pinion depth reference. So basically Dana uses a standard shim thichness, and if the pinion says +3, you add .003 of shim to the standard.So if you take out a -2 and put in a +3 you will be adding .005 of shims.

A good 1/2" Snap On, Matco etc. will usually crush the crush sleeve, it will wear your ass out though.

[HectorM52]

Ron, the rear is an 8.5" GM rear end.

There IS a number stamped on the head of the pinion. I will make sure to use that number when doing my checks.

I'm trying to use a 1/2" Ingersoll Rand impact.

I do have a large breaker bar and a pipe for an extension. Any suggestions on how to hold the pinion in place while trying to wrench on this thing?

[Ron S]

The 8.5 seems to be the easiest crush sleeve to crush, but it will still be a PITA. Sometimes it feels like your going to break the pinion off before the crush sleeve starts to crush, but it will, once it starts crushing its much easier after that. On the 8.5 if you use super shims for the backlash adjustments its alot easier then the factory non-adjustable ones.Its gambling but on an 8.5 I will use the original factory pinion depth shims, and adjust if needed after checking the pattern.

[HectorM52]

Aight, well I'll give it one more shot before I give up and take it somewhere. It sounds like I need to invest in a tool or two...

[MrQuick]

Ron, the rear is an 8.5" GM rear end.

There IS a number stamped on the head of the pinion. I will make sure to use that number when doing my checks.

I'm trying to use a 1/2" Ingersoll Rand impact.

I do have a large breaker bar and a pipe for an extension. Any suggestions on how to hold the pinion in place while trying to wrench on this thing?
You can make a holder for the pinion, basicaly a 1/4" flat bar, 3 foot long that has a slot cut into it to fit the pinion yolk. Put that on have a helper support it against the leaf spring and adjust your torque till you have 20-25 inch pounds of rotating resistance. I go 28 on new bearings and no lube.

I've seen some requiring 400-500 foot pounds to get the sleeve going, once it goes than its easy after that and you must go slowly.

[John Wright]

once you have started crushing the sleeve, go slowly as Vince said....if you crush it too far, you'll need another crush sleeve, so go slow.

[Ron S]

Ron, the rear is an 8.5" GM rear end.

There IS a number stamped on the head of the pinion. I will make sure to use that number when doing my checks.

I'm trying to use a 1/2" Ingersoll Rand impact.

I do have a large breaker bar and a pipe for an extension. Any suggestions on how to hold the pinion in place while trying to wrench on this thing?


Missed the second part of the question, I usually just wrap a rag around the yoke if I'm using a good impact, and hold it with my hand. If you are using the breaker bar and a peice of pipe, I use my humungus pipe wrench to hold the yoke.

[David Pozzi]

Leave the crush sleeve out, use the old pinion nut and tighten it down until you feel some drag on the bearings. Then you are ready to check pinion depth and perhaps do a pattern check.

Don't waste time crushing the sleeve until you are sure you have a good gear setting. I use a 3/4" impact and hold the yoke with by hand using a thick welding glove. The sleeve just holds the bearings from spinning on the pinion shaft. When all the measuring is done, you can then use the new nut and crush the sleeve.

Did those gears come with step by step instructions?
David

[HectorM52]

Thanks again guys.

I was trying to hold the yoke by hand - it was vibrating a little bit. I'm sure that putting something solid like suggested would do better.

Sorry, David, I saw your question earlier and forgot to answer; I picked up the gears used and they did not come with instructions.

I bought the Truetrac online (new) and the instructions suck. So I did some searching and found a thread on here that linked to a couple decently detailed instructions online. ***EDIT*** It was Vince who posted the links that I found, didn't even put that together till just now***EDIT*** I've got them printed out and sitting on the back of the truck.


So you're saying that I can put all parts together EXCEPT the crush sleeve and essentially perform all the gear checks I need to do? I thought I had read that, but wasn't sure if it was as easy as just leaving out the crush sleeve or not. Confirm that if you don't mind...

Thanks again, guys. I knew I posted on the right forum with the smartest guys around! :)

[John Wright]

Check out this pdf.....it might help.

http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf

[John Wright]

and some more links....

http://www.ringpinion.com/HowTo.aspx

[Ron S]

David is right about using the old crush sleeve and nut, check the pattern, if its OK, then put in the new ones. That way you don't waist the the sleeve and nut if you have to change the pinion depth.

I do remember the first crush sleeve I used, I thought it would never crush. Sometimes I will still use the breaker bar to get it all started, then switch back to the impact.

[David Pozzi]

You can leave the crush sleeve out, do the gear setup then install and crush it later during the final install. The sleeve only holds pressure on the cone roller bearings to help them resist turning on the pinion shaft at high speeds. It won't affect a thing to leave it out for setup.

Download some good instructions from Richmond Gear or Motive Gear. You also need a shim assortment for backlash adjustment.

If that 8.5" is the same as second gen Camaro it has left hand threads on the ring gear bolts. The aftermarket bolts I used had smaller heads which reduced head contact to the washers and allowed the bolts to come loose. Be sure to use factory ring gear bolts with the proper heads.
David

[HectorM52]

Thanks again, guys.

We used the directions from Yukon to verify a few things. Who is "we," you ask? Well I took it to my favorite machine shop and had him help me finish up the build.

We measured the pinion depth and it was right-on with the shim from the original pinion. We left the crush sleeve out for all of this.

The carrier shims from the 3.42 did NOT work and required some switching around. Though eventually we got it right. Backlash was set properly (WITH a dial).

He had a SERIOUS impact that didn't stutter crushing the sleeve once he turned up the juice. So no problems there.

Snuck out of there for a buck-fifty and I'll consider it a good tutoring session for pretty cheap.

Now I know the tools I need for the next one.

I appreciate the tips, having read all of this gave me some good knowledge when we were doing everything.



The rear is back in its rightful home! I'm letting the Permatex dry for a night then I'll fill it up with fluid tomorrow.

At least now I know the procedure and like I said the tools needed. And hopefully I'll be good for years to come!!!

https://static1.pt-content.com/images/pt/2010/08/IMG_0701sized-1.jpg