robguitargod1

iTrader: (4)

Since I'm a differential noob, but have learned quite a bit I thought I'd share my setup with everyone.

What I have:

Strange S-seried 3.25" Nodular Iron center section
OEM pinion support
Motive 4.57 gears
Detroit locker
Chromoly 1350 yoke

What you'll need:

Dial indicator
Inch pound torque wrench
250lb-ft torque wrench
aprox 1.6" inner diameter pipe
mini sledge hammer
Install kit (bearings/shims/bolts)
Gear marking compound

Start by setting up your pinion support. Here's everything you should have. NOTE: WHEN USING A CHROMOLY YOKE AND OEM PINION SUPPORT YOU MUST USE A SPACER BEHIND THE YOKE. It's Strange part number N1918:



First press on your rear bearing onto the pinion. You can use a press, or a mini sledge and the 1.6" pipe.


Then lube with some oil and set the pinion into the bearing. I didn't cover installing bearing races because I didn't have to. If you have to you'll need a race install tool. Something like this.


Then install your preload crush sleeve or spacer on top of your rear bearing. (you can see it in the pic above) I used a spacer. Using digital calipers, measure every shim included in your install kit. Mark the diameter on the shim using a marker. You can then pick a shim and install it. Then install your front bearing and press on with the same pipe and sledge or press.

Then install your splash washer, spacer, and yoke and torque to 200lb-ft


NOTE: IF YOU'RE USING A CRUSH SLEEVE AND NOT A SPACER YOU WILL INSTALL AND OIL THE SEAL BEFORE INSTALLING THE YOKE. THEN INCREMENTALLY TORQUE THE PINION NUT (IT IS VERY DIFFICULT) UNTIL YOU REACH THE DESIRED ROTATIONAL PRELOAD OF APROX 20IN-LBS.
In my case however, I'm using a preload spacer which is somewhat different. You'll torque down the pinion nut too 200lb-ft then check the peload using your smaller in-lb torque wrench.

Torquing the nut with the yoke in a vice:

robguitargod1

iTrader: (4)

Measuring preload:


You're aiming for 20in-lbs of preload. If it's too high ADD shims to reduce preload. Too low SUBTRACT shims to increase preload. To do so you'll have to support the pinion support and press off the top bearing after removing the pinion nut and yoke. then replace the shim with a smaller or larger shim, and reassemble just as before until your preload is correct.

When you're on the money, remove the yoke again to install the seal (remember to oil it). Then torque again, recheck preload, and you're done with the pinion.



Now onto the center section. First install the rear (3rd) pinion support bearing into the center. Use some oil of course. Use the previous pipe to get it started, then the correct size socket to fully seat the bearing.







Then install the retainer using the same procedure


from the rear:

robguitargod1

iTrader: (4)

Now install your pinion just to make sure everything fits without interference.




I don't have the rest of the pics uploaded yet, so I'll finish later tonight!

robguitargod1

iTrader: (4)

Then install your ring gear and torque the bolts using loctite. Here's how I did it:




Now install your carrier in the housing making sure to position it away from the pinion so that you'll be able to install it later. now tighten down the adjusters using a spanner wrench or screwdrivers like I did:



You want to feel some preload on the carrier when tightening the adjusters. I've been told it's difficult to over tighten them, but I made a little preload measuring tool anyway. It's a scrap axle with a 9/16th's nut welded to it so I can check preload on the carrier. I was only able to get 10-12in-lbs of preload on the carrier, but it should be plenty.





Now install your pinion WITHOUT the seal so that adding shims will be easier. You will add shims that came in your install kit to get the correct pinion depth. My Strange instructions recommended .020" of shims to start, so that's what I used. Be sure to measure each shim just the way you did with the pinion preload spacer shims.

Then use a couple of bolts in the pinion support to hold it in place. Now you'll be checking ring gear backlash. This is the distance between the ring and pinion gears, and is measured with a dial indicator. You should notice a small space that allows the rings gear to rock back and forth, this is what you're measuring:

robguitargod1

iTrader: (4)

When you rock the ring gear back and forth you should see the dial indicator move between this:



and this:



That's .010" of backlash, right where I want to be. To increase backlash, move the ring gear AWAY from the pinion. To reduce backlash, move the ring gear CLOSER to the pinion gear. ALWAYS LOOSEN THE FIRST ADJUSTER, THEN TIGHTEN THE SECOND. AS LONG AS YOU MOVE THEM AN EQUAL AMOUNT, YOUR PRELOAD SHOULD STAY THE SAME. Now tighten your main cap bolts to 70-80lb-ft and reinstall your adjuster stops. I used loctite on mine, but not the main caps.

Now you need to adjust pinion depth. Like I said I started out with the recommended .020" of shims, and this is how you determine if it's OK, you need more, ore less shims.
Using your gear marking compound, paint 3 or 4 teeth with it, then holding the carrier to simulate a weight load, spin the pinion past the paint in both directions.



You're looking for a centered contact pattern in the paint. Something like this:



Adjust accordingly of your contact pattern isn't centered. Check both drive and coast sides too. Add/remove shims, adjust backlash and recheck your pattern until you're centered. Make sure everything torqued to spec, and install in your housing:

Tony V

iTrader: (5)

Perfect. I'll be R&R'ing my center section this weekend. Going from a spool to a trac-loc.

This thread will come in very handy...

robguitargod1

iTrader: (4)

Thanks. I'll tweak as necessary and maybe add pics here and there too.

Robbie_S

Just finished installing a Currie into my Iroc. Much larger than before... How has the rear been for you?

robguitargod1

iTrader: (4)

Big changes, same gears and lockers though.

S&W torque arm, welded sway bar mounts, powder coated housing.

Check it out in my build thread starting post #414

https://www.thirdgen.org/forums/memb...ml#post6161796

Robbie_S

Thanks, will do.

articwhiteZ

iTrader: (56)

notice how the carrier just rides the housing...I had to remove some aluminum from my housings...when test fitting the parts..
same H carrier. 3.250 bearing units..