ARB RD153 install in an FJ62 front diff (1 Viewer)

[maxbob002]

Since my arb install has held together ok for a few hundred miles, @wngrog asked me to swap one into a third member for his pig. It’s an fj62 front diff that will be his rear locker.

Following the Zuk method I checked the backlash, pinion preload, and gear pattern before disassembly. Backlash was 0.17 and varied somewhat similar to my diff install. Pattern is below. Preload was on the low end and 5 to 7.5 in lbs.

Next came disassembly. I marked the bearing caps using some harbor freight punches.

Everything went well and then I realized the rookie mistake. I know and have read it multiple times and have even seen a pic on Zuk’s site. I didn’t remove the cross pin before I tried to remove the ring gear. There isn’t clearance to remove it once the gear is pulled up from the diff. The gear won’t slide over it either. I had to use the press to move the ring gear back down into place before removing the pin.

Looks super neat and ready to come apart until you realize it.

For the main pinion bearing, first I cut the cage off with a dremel and then used a large bearing splitter with the press to take it off. The pinion shim measured 1.25mm.

 

[maxbob002]

Finally tapped out the two races and everything is apart.

Next time to clean everything and paint the housing. Below is the nitro kit that will be used. Comes with race shims and pinion shady shims. Also comes with the gasket and two different pinion seals.

 

[maxbob002]

First everyone goes in the pool for a good scrub.

Then laying out for a sun tan to air dry.

The primer and paint for the casing. I’ll drill and tap it and scrape the gasket off before a final inside cleaning before reassembly begins.

This may be a slow build like my other stuff. Life is busy and all but I do love turning some bolts.

 

[Prairie Swamp]

You don't have info on the donor do you? They made changes in November '89 and guess what - mine in November 89. This drove me nuts during my front ARB install.

Likely won't be a problem for you. I had to machine my solid pinion bearing spacer way down for example. Just something to watch out for.

 

[maxbob002]

Not sure I can get that info. I think it was pulled long ago. I’ll have to bust out the carpets and measure the bearings then. Thanks for the heads up.

 

[maxbob002]

So checked the bearing from my 84 diff and this diff and they are the same luckily.

84 diff

Fj62 diff

This is a close up for the 62 pinion shim. Neat that it was imprinted from the bearing riding on it.

New bearings. The two carrier bearings are at the top. I had read somewhere that races should be kept with the bearings themselves so they get labeled as I remove them from the package. Also because of how I press(hammer) them on the diff one must go on the long side first.

 

[wngrog]

Cool!

 

[maxbob002]

Had some time to do more work today. Started by drilling and tapping the case.

Interestingly the 62 case is slightly different from my case. The horizontal fin is higher in the 62. Below is my case. The fitting is 1/4 npt and it is important not to tap it too deeply as it is a tapered thread.

Then came the ring gear. About 30min in a 200 deg F in the oven and it slipped onto the greased diff with ease by hand

The four bolts were just snug to allow everything to cool before final torque.

 

[maxbob002]

The stock shim under the pinion was 1.29mm plus or minus a hundredth. Since I do not have that special tool to pull the pinion bearing intact I chose to split the shims between under the bearing and under the race. This will give the ability to press out the race and adjust the shims of the stock size doesn’t pattern well. I spent a fair amount of time finding the closest group to the stock shim. Ended up about 0.64 in each spot.

Then pressed the bearing onto the shaft.

Of note the shoulder for the bearing was long enough that the inner race I was using pressed onto the shaft as well. Used the bearing splitter to pull it off.

Then time to press the outer races into the case. Again a liberal amount of grease was applied and old races used to press.

Shims and the race after.

 

[maxbob002]

Race pressed in and you can see the grease being forced out. It’s important to fully seat the races and it will affect the pattern and preload if they shift.

Back to the ring gear. Bolts were pulled and red loc tite applied. I torqued them in two stages alternating sides. First to 60 ft lbs then to final 81 ft lbs. A white paint marker was used to track progress. Finally each was again checked to be 81ft lbs. The gear is on.

 

[maxbob002]

I used a hammer last time to press the bearings on the diff. It was time consuming and wore out the arms. I was determined to use the press this time. I hit up Lowe’s and found that a straight conduit pipe fit just inside the bearing race but over the diff extension. It’s important that the long arm of the diff not be damaged. The air supply rides on two orings on that surface. Scratched would cause increased wear, an air leak and likely premature failure of the orings. Also the longer side went first so I could press against the longer side for the last bearing.

And this is how it was left. Ready to start final assembly and patterning.

 

[Tennessee80]

Fresh...

 

[wngrog]

Excellent tutorial

 

[maxbob002]

Had some more time to work today. Installed the pinion without the spacer or slinger or seal and use the old Nutt. Tightened until preload was 10 to 15 inch pounds.

Gear oil on everything and then began assembling.

Be sure the caps and their labels match.

 

[maxbob002]

Follow the fsm to set carrier bearing preload and backlash. Managed to get 0.17 similar to the original backlash.

Torque the main caps and then paint a gear pattern.

Way too deep. So it all comes apart.

 

[Dustin Messina]

Man this is looking good @maxbob002 !!

 

[maxbob002]

After alternating each tap side to side the race came out. I had used a 0.63-0.64mm shim. Found a combination that came out 0.53-0.54 and pressed it in.

Same deal with preloads and set the backlash to 0.16

And now way too shallow. Apart it comes for the second time.

 

[maxbob002]

Third time is the charm. Went with a 0.60 combination and pressed it all together. Set the backlash to 0.17-0.18

I was happy with this pattern so time to put it all together.

 

[maxbob002]

The smaller pinion bearing was a press fit onto the pinion shaft. It required a deadblow hammer to get the shaft out and so I pressed it back on. This also gave me the chance to crush the sleeve some. Of course I didn’t take a pic sorry.

The seal gets installed also. Lots of gear oil on the flange also.

The nut was flanged so didn’t use the washer with it. Finally set backlash and carrier preload again and torque to 88 ft lbs per fsm.

 

[maxbob002]

Torqued the pinion nut to 150ft lbs. It felt very low so added quarter turn to the nut. Then checked the preload.

Still low so added a little over 1/8 turn. This brought it to a hair over the 17.5 in lbs tick mark. Well within spec.

Staked the nut and we are in the home stretch. Air system is next but had to leave it here for now.

Here is my bar with an old driveshaft bolt to hold the flange. This with the torque wrench and a 3 foot pipe give me the leverage I need to crush in small increments.