Good Diff Reassy thread? (1 Viewer)

Vae Victus

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I'm putting back together an Fj60 3.70 diff I bought from Roma, disassembled . Problem is, FSM doesn't show exactly how to put the 4 small gears back in. Actually they (I've checked 3 different year FSMs) don't show the shaft or bolt that goes in there at all.

Anyone got a better reference or some photos or just a textual description to help?

Confused....
 

Vae Victus

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FSM doesn't show these parts. I assume these are part of the diff.

ImageUploadedByIH8MUD Forum1413059420.546786.jpg


ImageUploadedByIH8MUD Forum1413059445.769460.jpg
 
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The parts are the spider gear pinion shaft, the pinion block and the shaft retaining pin for your average rear cruiser differential from 1958 to 1992. The shaft holds the spider gears in place, the pinio block is used in rear C-clip axles to retain the clips and the pin holds the shaft into the carrier. I know the FJ40 FSM shows where these go.
 

Vae Victus

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Thanks @Pin_Head. So front and rear are different. This is the front that I'm setting up/swapping out. Can I make this work for the front?

And thanks B y r o n. Great reference. Learning a lot with all those pictures of rebuilds.
 
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The front and rear diffs are the same, with the exception that the rear needs to have the pinion block installed to retain the C-clips while the front does not need it and may not have it.
 

Vae Victus

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The front and rear diffs are the same, with the exception that the rear needs to have the pinion block installed to retain the C-clips while the front does not need it and may not have it.

If I have the block I can install it - correct?

Surprised there's not a "how to" on the pinion gear installation. That's tricky.
 

Vae Victus

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Installed the gears, block, shaft and pin. Inserted axle to rotate the gears and check things.

The block is stopped from rotating by the axle shaft coming into contact with it, correct? Otherwise if the axle is flush with the side gear, the block rotates, which I'm sure isn't good.

Below, Temporarily inserting axle to rotate and check gears.
ImageUploadedByIH8MUD Forum1413142242.926068.jpg



Below, Block rotating if axle isn't touching block. Clearly there is a wear pattern on the block from the axle end.
ImageUploadedByIH8MUD Forum1413142261.613369.jpg


Below, Block held in place by axle end touching block. I'm assuming that the axles will align precisely and lightly touch the block when it is all assembled.
ImageUploadedByIH8MUD Forum1413142277.440745.jpg


Am I good here?
 
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If it is a front, I would leave the block out.

For a rear, you need the block and it goes in last, after the C clips.
 
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So far so good. I did a conversion to fj60 gears into my fj40. As pinhead said the rears have c clips and the front does not
 

Vae Victus

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If it is a front, I would leave the block out.

For a rear, you need the block and it goes in last, after the C clips.

Makes sense. Thanks yet again Pin_Head. This is about question #50 you've helped me on. (and others who helped!)
 

RWBeringer4x4

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I've been messing around in my diffs all summer - I would say if there is any component of these trucks that are seriously lacking a good write-up here on MUD, it's the differentials. Sounds like it's time to make another @Vae Victus level step-by-step rebuild thread!

As Pinhead already pointed out - you're going to want to install that block and the cross-pin last. First push the axles into the space in the center, then install the C-clips. Pull the axles back out so the C-clips "lock" against the side gears, then install the block, push the cross pin through it, and button it up with that bolt/pin and lock washer at the bottom of the carrier.

Don't forget the domed washers that go outside the spider gears, between the back of the gear and the carrier - they like to slide out (or at least mine did). It was tough to keep them in place, and run the cross-pin through the washers, gears, and block at the same time. They will all be held in place by the cross pin once everything is in place.
 

Vae Victus

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I've been messing around in my diffs all summer - I would say if there is any component of these trucks that are seriously lacking a good write-up here on MUD, it's the differentials. Sounds like it's time to make another @Vae Victus level step-by-step rebuild thread!

As Pinhead already pointed out - you're going to want to install that block and the cross-pin last. First push the axles into the space in the center, then install the C-clips. Pull the axles back out so the C-clips "lock" against the side gears, then install the block, push the cross pin through it, and button it up with that bolt/pin and lock washer at the bottom of the carrier.

Don't forget the domed washers that go outside the spider gears, between the back of the gear and the carrier - they like to slide out (or at least mine did). It was tough to keep them in place, and run the cross-pin through the washers, gears, and block at the same time. They will all be held in place by the cross pin once everything is in place.


Dude, where were you a few hours ago? I had to figure this put all by myself! (Poor me). Saw your update on the Aussie Lockers just before looking here. I just did the front, so no block, no c-clips.
 

RWBeringer4x4

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Well, I only spend about 1/2 the day on Mud... :D You have my number, feel free to use it.

Although today I would have been a little slow to respond, engagement photo shoot with:princess:

Glad you got it figured out!
 

Vae Victus

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Now I just have to repeat this entire frickin process with the rear axle. Sigh. But we love this, right?
 

Vae Victus

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Is the rear assembly R and R in the FSM or should I use the hanes?

I am merely swapping 3.70 chunks for my stock 4.11s

Let's put it this way, I own a paper copy of the Haynes, and I don't know where it is. I downloaded 3 different year engine and chassis FSMs from TrollHoles thread where he put them.

Between FSM and Mud, I get it done.

I'm doing the same. It is plug and play except for the flange that attaches to the drive shaft. You need a universal one of those for each diff since the splines are different sizes between the 40 and 60 diffs.

See photo of the 40 flange,

image.jpg





And the Universal (why can't I add photos from the IPad app when I'm editing a post? Frustrating)

image.jpg
image.jpg
 
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