Front & Rear differential 5.29 re-gear for 80 series non e-locker

[Bear80]

Jon broke his front diff out at Hidden Falls. To be exact he broke teeth off the ring gear and teeth off the spider aka pinion gears. I guess I need to check out what all the fuss is over Hidden Falls as I have yet to go there. He decided to have the front and rear diffs re-loaded with 5.29 gears, bearings and solid pinion spacers.


Originally I planed to spend just one Sunday doing this work. However, due to delays in parts I spent a few hours during the evenings doing the work. I also chose to do the work without a press to 1. show how anyone with a few specific hand tools can do this and 2. not have to drag out a press that takes up a parking space in my garage.

 

[Bear80]

Spent a little time tonight measuring the oem setup.

1. BOTH the front and rear had no carrier bearing pre-load. The ring gear moved with the lightest of pressure while I was measuring the backlash.
2. I did not bother with a pattern check.


FRONT: Backlash check...and check out those missing teeth!!

OUCH! 0.011"!! FSM calls for 0.005" to 0.007"! I would say WAY out of spec and no wonder why it gave. I measured a few other teeth on the ring gear and got a consistent 0.011".

Jon also broke some of the spider aka pinion gears. They are the small gears that ride on the pinion shaft inside the carrier. The larger gears that the axles engage into are called side gears. Assembled it is hard to check the backlash of the side gear.

Per the FSM we are looking for 0.002" to 0.008" and...I got a 0.008" to 0.009" Toyota specs 3 different sized shims that go behind the side gears to set the backlash. We will see if new shims are needed after the new spiders arrive. I suspect it would be worth trying new shim combinations to get the backlash closer to 0.002".

REAR: Checking the backlash. I didn't bother to align the zero mark since we are only looking for the difference between the two points.

0.008". Not in spec of the 0.006" but not as bad as the front.


Next the tear down / clean up. Goodnight!

 

[Bear80]

I got 2hrs this evening after work to break down the diffs.

Rear is all ready for a cleaning and tomorrow's setup. Food containers make for great parts bins! I knew a restaurant would come in handy with 'cruiser work!

The front was almost ready...just have to get the outer pinion race out without destroying the oil retainer ring.

 

[devildogcruiser25]

Nice work sir. I am excited to get this thing back together! You have been a pleasure to work with thus far, and are a great resource to the club! I only wish I had the time to watch you do it so I could tackle my next rig by myself. As for hidden falls, I am trying to get up there the second weekend of April to test everything out before I head to Moab in May, you should tag along!

 

[Bear80]

Front carrier apart. New pinion gears on the left, old ones on the right. Side gears where inspected and are okay for re-use.

Closeup of the broken spiders.

Now to measure the shims located behind each side gear.

Both shims measured 0.067". Toyota lists three shims for the non-elocker side gears: 0.063", 0.067" and 0.071". We will be ordering the thicker 0.071" (p# 41363-40021) to tighten the backlash up. Unfortunately these shims may take a few days to arrive.

That's all for now. The rear is done but I'm going to wait to post it until later.

 

[devildogcruiser25]

Got your text last night, but I was too sleepy to respond lol. I hope those new shims get in soon!

 

[Bear80]

Ring gear goes on the carrier with firm hits from a rubber mallet (front shown)

The rear had a little trouble...

The proper method is to remove the spider gear pinion BUT as you can see it cannot be installed/removed when the thicker 5.29 ring gear is in place.

Time to bust out the angle grinder!

A vise makes holding the carrier to torque the ring gear bolts very easy. 80 lb/ft for the rear, 70 lb/ft for the front and red loctite (supplied in the Sierra Gear master kit)

Carrier bearings are cake when using the old inner race as a drift. Note the notch from the dremel cutting disk. I cut the cage off and then cut the inner race making sure not to cut through. Then with a chisel hit the race cracks and simply sides off the carrier.

Front pinion bearings cooking up. 300* in for about 1-2 hrs and presto! Slides right on the pinion! Of course this only works if the pinion shims are going behind the outer race. If you are using shims that go on the pinion behind the bearing you will need a press or fancy pinion bearing puller tool. (front bearing shown first, second pic is of the rear pinion)

In reference to post #3, the front oil retainer was reusable.

I think that is enough for tonight.

 

[Bear80]

My audience

AND why they can't hang out in the garage...the QC inspector was on duty.

 

[Bear80]

A big thanks to ZUK and his www.gearinstalls.com website. I referenced his cheat sheet to choose shim depths to start with. Otherwise the proper method is to start with the original shims from the old gears.

The Sierra Gear install kit comes with shims that go behind the bearing race in the case and not behind the bearing on the pinion. This is a good option if you do not have a press. To adjust the shims, you have to knock the race out each time. The kit is supplied with 0.010", 0.005" and 0.003" shims that you stack to gain the needed thickness.

Started with 0.055" and talk about right on the money!

I wanted to make sure we couldn't get it a little deeper. Tore it down and loaded 0.057" which was a touch deep.

I chose to go back to 0.055". Originally I wrote this post that I left it a touch deep at 0.057" but I decided against that.

It's about a 20min process to check the pattern, tear down, re-shim and assemble each time.

Also I should mention the patterns appear different mainly due to the backlash. I didn't get it exact in the 0.057" but you can still tell depth without it dead on.

 

[Bear80]

The Sierra install kit is NOT compatible with the components of itself! Using the supplied pinion shims that go in the case behind the race will NOT work with ANY pinion spacer, solid or crush! The crush spacer and all other spacers are machined to a length taking in to account pinion shims on the pinion behind the bearing!! Sierra needs to make mention of this or supply the correct pinion shims or a longer crush spacer. If a longer spacer is the solution then a longer solid spacer would also be needed. In this case I happen to have more TOYOTA shims I can stack on the solid spacer to hopefully get it long enough. (Strangely this was not an issues on the rear, also the Nitro solid rear spacer came with plenty of shims anyway).

Photo evidence that the bearings did pre-load properly even with an incorrect length spacer! When I would remove and retorque the nut with locktite the pre-load would jump to over 40 in/lbs. This double check afterwards is what I feel many shops would have overlooked...you have to always double check and then do a final check.

Good thing I still had the original pinion gear with bearing in place to set side by side! New pinion on the left, old on the right. The line shown with a black arrow is where the outer bearings stop on the pinion. Notice the area shown with a yellow arrow is greater on the new pinion. This is because it was designed with the assumption that the pinion spacers are going behind the bearing. Without a spacer behind the bearing, the distance in red increased.

That distance measured exactly 0.083"...nearly the same thickness as say a pinion shim ...which in this case a 0.079" was used. Serious lack of thought on Sierra Gear's install kit! I really don't think an average shop would have caught this...seriously. Sierra Gear has not!

Measuring old crush spacer, new crush spacer (as supplied by Sierra) and solid spacer (with all shims supplied in place).

With the increased distance of 0.083" and the original 1.860" it is safe to assume we need a spacer of 1.943" minimum thickness. Notice the supplied crush spacer is almost exactly 0.01" short. Never would have worked with the components supplied in the kit! Noting the solid spacer's length we need about 0.045" more shims.

 

[Bear80]

To torque the pinion nut to the proper 180+ lb/ft I have a t-bar that bolts to the flange and I stand on it as I torque the nut. Process is the same for the rear.

The FSM is written for a crush spacer in which you slowly tighten the nut after reaching 180 lb/ft, checking the pre-load after each small incremental turn. If the pre-load is too much you have to use a whole new crush spacer. Maximum torque on the pinion nut is something like 320 lb/ft.

When using a solid spacer like we are, you simply torque to the 180 lb/ft range and check pre-load and exchange shims until the proper pre-load is reached.

 

[Bear80]

0.084" too deep.

0.079" I got a good pattern, depth and centering.

From this point on only the pinon bearing pre-load needs to be set (as mentioned above) and then the carrier bearing pre-load. Since the backlash is set to check the pattern, simply mark the carrier adjuster nuts before tearing it down again. After the pinion bearing pre-load is setup reassemble the carrier aligning the marks for the adjuster nuts. Then evenly crank on both carrier adjuster nuts to set the carrier bearing pre-load. Last double check the backlash to make sure it didn't change. It would also be a good idea to do one last pattern check. Sounds easy until you get an incompatible install kit and cannot get the pinon bearing pre-load set.

 

[Bear80]

So a few notes about the diffs.

Pinion shim 0.079"
Backlash 0.004"-0.007" (gear marked 0.006") variance could be due to gear, carrier or case.
Pinion bearing pre-load 7.5 in/lb
Carrier bearing pre-load 12+ in/lb

Pinion shim 0.055"
Backlash 0.007" (gear marked 0.007") very little variance between teeth.
Pinion bearing pre-load 17 in/lb
Carrier bearing pre-load 10+ in/lb

 

[Bear80]

A few interesting points.

The rear pinion bearing supplied in the Sierra kit is different from the original. I'm not sure if this is a Toyota superseded part or just a compatible bearing Sierra sourced. Both are Koyo of course. However, I would prefer the original that has more of a taper to it.

The rear pinion spacer did not have the same issue as the front. The crush spacer supplied by Sierra would have been long enough to make up the added length resulting from a lack of pinion shim behind the bearing. In our case a Nitro solid spacer was used and came with adequate shims.

I have another picture of the clearance between the head of the pinion and carrier on the front diff. The thickest measuring shim I had was 0.032" but it appears there is probably 0.034" or so of clearance. It would be a good idea to grind off the top edges of the pinion if the clearance was less than 0.020".

 

[Bear80]

Hey John, after the first heat cycles and 500 miles of break in, I would recommend the lightweight shockproof from Red Line. The heavyweight can also be used but I'm not sure how well it does in cold climates if you move out of Texas. You may want to talk to Red Line for more info and if they recommend changing from heavy to light later. http://www.redlineoil.com/product.aspx?pid=43&pcid=8

 

[cool breeze]

Nice job!

 

[scottryana]

Very good work

 

[devildogcruiser25]

So Ive put 640 miles on the ODO since gears went in, I think thats just over 500 miles in corrected distance. Am I right?? Anyway, could not be happier with the new gears, its like driving a brand new truck. The drive to Moab will be interesting as ill be up around 2600 rpm the whole way. Time to change the diff fluid!