Project X - Just another Excursion Project

C

canyonryder

Member
So we chuck the pinion in the lathe . . .

IMG_20180805_111201-XL.jpg


Get it spinning and use some emory cloth to sand down the bearing surface. I started with 60grit and finished up with 320grit for a polished finish.
IMG_20180805_111359_1-XL.jpg


Result - bearing slips on as it should!
IMG_20180805_114932-XL.jpg


Then we install the pinion , along with the LSD and 4.30 ring gear. Check the backlash and tooth pattern.
IMG_20180805_152814-XL.jpg


Making progress!!

CR
 
Last edited:
Chorky

Chorky

Observer
Nice! Did you double check the new thickness to make sure you didn't take off a tad too much?? For some reason my memory seems to think those were a press on fit - but it's been a while...
 
C

canyonryder

Member
Chorky said:
Nice! Did you double check the new thickness to make sure you didn't take off a tad too much?? For some reason my memory seems to think those were a press on fit - but it's been a while...
Click to expand...

Thanks!

Its definitely slip-fit. Like an outer wheel bearing on a spindle. The inner race is captured with the pinion nut between the crush sleeve and the pinion flange - as you can see in this pic. That is what keeps the inner race from spinning.

IMG_20180805_200652-XL.jpg


The larger inboard bearing is pressed on. The other reason the outboard bearing has to be slip-fit is for when you need to change a leaking pinion seal. You're supposed to replace the crush sleeve anytime you remove the pinion nut (not everyone does) - so the bearing has to come off.

CR
 
C

canyonryder

Member
No worries, Corky! (y)

So late last night, I was still setting up the ring and pinion. I assembled it with the same shims that were installed at the factory - usually a good place to start. The carrier bearing preload was very good, but there was too much backlash (.009"; it should be under .004") and the tooth pattern was not quite right - but not awful. I decided to raise the pinion by adding a .010 shim (this usually changes the BL by about 70% of the shim thickness).

So disassemble, add pinion shim, reassemble, measure . . . now the BL is .002 (very good), but the tooth pattern is terrible because the pinion is too high.

So disassemble, remove pinion shim. This is where I called it a night.

Next we'll shim the ring gear over .010" to reduce BL and hopefully get a nice tooth pattern. Because we are happy with the carrier preload, we don't want to add/remove shims from the carrier and ring gear - we want to MOVE shims from one side to the other, keeping the total shim thickness the same - this will maintain our bearing preload.

I'll take a better pic later, but the carrier shims go between the axle tubes and the carrier bearings.
IMG_20180714_172242-XL.jpg


Outboard of the bearing caps.
IMG_20180805_152804-XL.jpg


Stay tuned!
CR
 
bknudtsen

bknudtsen

Expedition Leader
Awesome! I wish I had the experience to properly setup gears. Just so happens, I really need to do that right now on my truck.

Keep it up! I love the tech stuff,

Brad
 
19psi

19psi

The Devil Made Me
Just went through all that, got my 5.13s in the rear. Still have to do the front in the next couple weeks. I was hoping I'd feel a little more torque down low from them but it's not as noticeable as I hoped.
 
C

canyonryder

Member
Holy crap! Did CR fall off the end of the earth?! Nah - just life getting in the way of fun. Sorry I've been away, but I'm back at it again!!

Sooooo - where did we leave off? Oh yeah, I had just finished adjusting the pinion height, backlash and tooth pattern. Let's backup a bit. I always like to measure and document stuff as I disassemble. Here are the existing numbers on the rearend as it sat with 200k miles on it.

IMG_20181211_105630-XL.jpg


The pinion had 2inlbs of preload and the ring gear had 0.011" of backlash. Not bad at all for 200k miles. The existing Pinion shim was 0.027" - we used that as a starting point with the new pinion.

Here are the iterations of my setup - in my chicken scratch. Haha. Notice at the top in red are the specs we are shooting for. BackLash: 0.006 - 0.010" and Pinion Preload: 20-35inlbs

IMG_20181211_105653-X2.jpg


I have 4 columns of data:
PIN = Pinion Shim Thickness
RG = Ring gear side carrier bearing shim thickness
NOSE = Nose side carrier bearing shim thickness
BL = Measured backlash

Basically, I keep playing with the shims until I get the best pattern I can while at the same time getting as close as possible to 0.006" BL. I like to setup new gear sets close to 0.006 because the BL will increase as the bearings and gears wear in.

Once we are happy with the setup, we press the new bearing onto the pinion shaft with the correct shim. Install the pinion seal and using a new nut and crush sleeve, tighten until we have 20-35inlbs of preload.

It can take upwards of 600ftlbs to crush the sleeve.
IMG_20181221_164007-XL.jpg


We turn the nut a bit and check the preload, then do it again. You have to sneak up on it. If you go too far, you have to start over with a new crush sleeve and nut.

Measure the rotational drag (as it is moving) - 35inlbs.
IMG_20181221_164234-XL.jpg


The RG and LSD cleaned up and installed for the final time. Tip - I struggled with the standard shims that came in the gear set "MasterKit". I ended up buying a set of Yukon Interlocking Super Shims. Genius design! Holds all the shims together and prevents damage to the fragile thin shims. WAY easier!

IMG_20181221_172851-XL.jpg


OK - I promise another update in less than 4 months. Hahah!

CR
 
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