Front differential gasket (1 Viewer)

[jvincig01]

I am going to rebuild my knuckles here in the next few days. While I was at it, I thought about removing my front differential and resealing it with a new gasket and seals.

Question. Is this something I can remove on my own from underneath the truck? I will be doing this on my garage floor while on jack stands (good times).

 

[cwwfj60]

I am going to rebuild my knuckles here in the next few days. While I was at it, I thought about removing my front differential and resealing it with a new gasket and seals.

Question. Is this something I can remove on my own from underneath the truck? I will be doing this on my garage floor while on jack stands (good times).

Yes it can be done, heavy awkward sob

 

[pb4ugo]

Are you removing the whole frtend or just the 3rd member? Either way you can do it. The whole frtend is heavy and cumbersome. I think removing the 3rd is easier breaking loose while the housing is installed.

 

[mattressking]

Yes. Make sure to clean the surface with a wire wheel and install gasket dry.

If the diff is stuck or the PO failed to use a gasket, just rtv, be ready to use a jack to persuade on the pinion. It can be a bear to break the seal sometimes.

 

[pb4ugo]

I thought the gasket between the housing and 3rd was more like a paper or a thin fiber type gasket material?

 

[Steamer]

I thought the gasket between the housing and 3rd was more like a paper or a thin fiber type gasket material?

I thought that also and the rear as well. Cork for the rear cover.
And a couple of long bolts with the heads cut off will help guide it back in and hold it in place while you get some bolts started.

 

[B y r o n]

Unless your third member is leaking I would just leave it be.

 

[POPO AGIE]

They are heavy and would not do it under the truck unless you have a jack to support it. If it is not leaking don't touch it.

 

[jvincig01]

Are you removing the whole frtend or just the 3rd member? Either way you can do it. The whole frtend is heavy and cumbersome. I think removing the 3rd is easier breaking loose while the housing is installed.

I'm redoing the whole enchilada.,,, Knuckles, brakes, etc. Just figured since I had the birfields out, now would be the time to do it.

 

[jvincig01]

I thought the gasket between the housing and 3rd was more like a paper or a thin fiber type gasket material?

I am not sure yet. I ordered OEM so I will see when it gets here. I think its fiber-like paper. I was going to use that gasket with orange toyota fipg

 

[jvincig01]

Unless your third member is leaking I would just leave it be.

Good call. 99% sure it's leaking, though. I can degrease it first, run it a bit, and then see how it does.

 

[mattressking]

I thought the gasket between the housing and 3rd was more like a paper or a thin fiber type gasket material?

Ha you’re right! Completely forgot it’s a thin one up front. Rear diff cover is cork. Disregard my stupidity. Edited original post.

 

[POPO AGIE]

The rear cover gets a cork gasket but both differentials get the paper gasket.

 

[Living in the Past]

I'm redoing the whole enchilada.,,, Knuckles, brakes, etc. Just figured since I had the birfields out, now would be the time to do it.

Have you replaced the front axle in your FJ40? My original FJ40 is newer than yours and is still a ball and claw setup not Birfields.

 

[jvincig01]

Have you replaced the front axle in your FJ40? My original FJ40 is newer than yours and is still a ball and claw setup not Birfields.

The previous owner did. It has a later FJ40 axle (not sure of year, but has birfields) and 80's mini-truck knuckles and brakes.

I sealed the knuckles when I first bought it 13 years ago and did a terrible job.

The brakes have always been less than ideal, so my hope is the new late 80's calipers with vented rotors will improve the brake fade.

 

[kerryjcox]

I am going to rebuild my knuckles here in the next few days. While I was at it, I thought about removing my front differential and resealing it with a new gasket and seals.

Question. Is this something I can remove on my own from underneath the truck? I will be doing this on my garage floor while on jack stands (good times).

Let me know how this goes. Really curious to see what others are doing.

I just pulled the calipers off my '77 FJ40 and will be starting on my knuckles this weekend. I've been wondering about my front diff as well. Not finding much online about anyone redoing their diff locker or replacing the crown wheel or pinion or anything else. Even though my FJ40 is 45 years old, I don't think the one and only original owner did anything to the front or rear diff.

Good luck!

 

[POPO AGIE]

I have a 78 FJ40 and it has over 100k miles on it.

I rebuilt the transmission and transfer case before I sold them to a Mud Member. I removed the rear differential to install in a FJ60 rear axle that I converted to a full floater. The rear differential did not need any work done other then installing a locker. The back lash was fine so we left it alone.
I disassembled the front axle and the front differential only needed to have the back lash adjusted and I also installed a locker in that one.

For the amount of miles on the drive train did not have that much wear. The output shaft and input gear in the transfer case were worn and replaced. I installed new bearings in the gear boxes that came with the kit.

The knuckle bearings also looked good but were replaced with 25mm bearings for the high steer kit.

I bought the FJ40 when I was 20 and was hard on it when it was my daily driver which came to an end when I had an accident that left it totaled. The other thing found in the front differential was surface rust from above the oil level.

You wont really know until you open it up and see the condition. The differentials are heavy so removed them with help and a jack that has a cradle for differentials.
I removed the axles and set them up in an axle dolly for removing and installing the differentials and that was still a pain to do. I has a support for the pinion but they still want to roll the axle and point to the floor.

 

[jvincig01]

Let me know how this goes. Really curious to see what others are doing.

I just pulled the calipers off my '77 FJ40 and will be starting on my knuckles this weekend. I've been wondering about my front diff as well. Not finding much online about anyone redoing their diff locker or replacing the crown wheel or pinion or anything else. Even though my FJ40 is 45 years old, I don't think the one and only original owner did anything to the front or rear diff.

Good luck!

I ended up leaving the differential alone because It wasn't leaking.