Swapping front diff and replacing bearings (1 Viewer)

[JAFO2014]

Replacing the seals, all steering bearings and wheel bearings. Doing the rotors as well.

Back side with new felt.

New steering bearings in place. All ready for new grease and to slip the axle in once I swap the diff.

Will install new rotors.

Removing old rotor.

Passenger side cleaned and ready to start putting stuff back.

Cleaned all the old grease out.

Installed new seal.

Installed new race in top and bottom on both sides.

New seals and gaskets

 

[DTSkyCop]

I have to do this to mine soon, nice pics of your progress. Title says "swapping front diff". What are you swapping it for? Just curious... Nice progress so far!

 

[JAFO2014]

Hey. About 1 1/2 years ago I put a FJ60 diff in the rear for slightly better highway driving. Actually, I did not really notice much change in how it drove after installing the FJ60 diff. At that time I did new rear axle bearings, seals, etc, but never got to the front. Plan was some day put the FJ60 into the front. Anyway, finally got to doing the front. I had already installed the new pinion flange back in 2014 on the Fj60 diff, so it is ready. I haven't been able to use 4x4 since the gear ratio was different. I would like to be able to use it if needed, though I do not take this off road. I had purchased all the seals and bearings for the front, since I was going to be most the way in to do the diff I figured I'd just do it all (new bearings, seals, etc).
Worked about 7 hours today. Should finish it all up tomorrow. Nuts are off the diff and it is ready to come out. Axles out both sides. Everything is cleaned and ready to go back. Drivers side is basically done. Is a lot of work.

 

[JAFO2014]

I have the manual and it states if replacing the knuckle to measure for what shims will be required. Since of am replacing the bearings (not the knuckle) I wasn't sure I need to bother, but I thought I would do the measurement. I don't have the special tool, but came up with a way to take the measurements. My dial caliper is not large enough to measure the outside diameter of the knuckle housing, but it is long enough to measure from top steering bearing to bottom bearing. So I used a long bolt to put the pre-load on the bearings. Then measured that distance bearing to bearing. Then I installed the upper and lower pieces that insert in the bearings back into the housing. Then measured the inside diameter between the top and bottom piece. Subtracted that number from the other which gave me .000092 inches (92 thousandths) worth of shims to obtain pre-load. After all this, ends up the original shims were the exact measure. I guess I will also measure the passenger side, but I might be wasting my time. I guess bearings are fairly consistent in size so the pre-load measure will be the same.

 

[78fj40mg]

Nice work so far!

Love the JAFO!...Just Another F..ing Observer.

 

[JAFO2014]

Yeah...Blue Thunder.
So, I won't finish today. Being too finicky, but want it all put back right. Did a lot of parts cleaning today and sand blasted/painted the backing plates. Got all the hub bearing race installed. Old diff removed. If I were doing off road this would have been the beast. Both front and rear look to be some type of locker diff I think. Anyway, All that is left will be bolt on the new rotors, grease wheel bearings, install hub seal, install the FJ60 diff, slip in the axles and pack in lots of grease, install hubs, etc. I guess one more long evening or maybe just wait until next Saturday.

Removed the old race from the hubs.

Close up of hub with old race removed.

Nice new wheel bearing race installed on both sides after cleaning up the hubs.

New wheel bearing race installed.

Sand blasted and painted the backing plates with some caliper paint.

Breaking the diff loose with a bottle jack. Works good to break the seal.

Old Diff is out.

Old 4.11 diff. Looks like it might be some type of locker.

 

[JAFO2014]

Finished everything up last night. This job is definitely a lot of work, even if you don't clean and paint stuff.
All the bearings and seals up front are now replaced. Drove the 40 to work today. All seems good.

Getting backing plate, spindle and dust seal on is interesting. I saw were someone posted to use a stud to help guide stuff on. I didn't have one, but did use some high-tack gasket compound to stick the gaskets to the backing plate, knuckle and dust seal. Then it was less stuff to try and keep lined up as you started the first couple bolts.

 

[roma042987]

nice work! that looks line an old gov lock locker you have in the diff. Havent read many good things about those

 

[Mace]

yeppers gov lock..

 

[Cruiserdrew]

I've never seen or even heard of gov-bomb in an FJ40. What's the story?

 

[Mace]

12 bolt gov locks (and most 12 bolt stuff) just takes a little machining to fit a Cruiser. It was a common mod before other, better lockers became available.

they were fine if you didn't have a tendency to use wheel speed much. If you did, the parts would have a habit of scattering all over the inside of your diff.. It's a ridiculously complex limited slip.

 

[Cruiserdrew]

Wasn't the theory, though, that you needed a bit of wheel spin to produce enough angular momentum to move and thus lock the weighted part of the locker? The problem I remember is that a sudden lock up with quickly spinning tires, would break everything inside instantly. Hence, the well known "gov-bomb" reputation.

Cool to actually see that in an FJ40.

 

[Mace]

Yep, wheel speed was necessary to make the weights work. And what also made the weights go BuhBye..

12 bolt full spools work too

 

[JAFO2014]

Never heard of that gov lock. Thanks for the info. Those are out of my FJ40 now! Just have some plain Jane standard diffs from an FJ60. Not as good as having some limited slip, but will do for now and don't have tons of money in them.

 

[JAFO2014]

I guess you could go in and gut the gov lock to render it harmless maybe.
The diff I removed from the rear didn't have all that stuff as shown in the pic in this thread, but it does have some really large springs and such that made me think it is also some type of limited slip, but not the same type as this gov lock. I'll post some pics of the one that came out the rear.

EDIT-
This is the 4.11 diff that came out of the rear...

 

[Mace]

IT's a limited slip, but I'm not positive what type that is..

Auburn is slightly different.