Real time axle help, please! (1 Viewer)

[cps432]

Hello good friends,

This weekend I swapped my diffs out with some drop ins from cruiser outfitters. Went from 3:73 to 4:10

Everything’s been going pretty smooth until I started to put the rear axles into the new diff. They go all the way to the end of the side gears and get hung up on something. They engage the gears and turn. When I went to pull them back out they were stuck. Had to put my entire body weight against them to pull them back out.

This is an early 87 fj60. Not sure what year the diffs came from.

We’re there differences in axle splines from the 40 and 60?
What am I missing here?

I also swapped out rear bearings and seals with koyos.

Any help would be appreciated. I needed I get to work today but not sure it’s gonna happen.

 

[Randy88FJ62]

Show us some pictures of your axles.

 

[Cruiserdrew]

Should be exactly the same. Any burrs on the splines of the axle shafts?

I'd also make sure the new bearings are fitting over the bearing surface of the axle. Any chance those are backwards? (though not sure if that would prevent the axles sliding in.)

 

[cps432]

It seems that the side gears in the rebuilt diff are coarse spline and my axles are fine.

 

[cps432]

This is a shot of the side gears from the outside of the axle.

This is about as far as I can get the axle into the housing. I can push a bit more but it gets jammed.

This is the spline pattern on my axle shaft.

I see no burrs that could be hanging up. Everything is clean. It should just drop right in.

I’ve been on the phone with cruiser outfitters this morning and Bryce is speaking with their installer. He says I can pull the side gears from my old diff and install them into the new one using the same thrust washers. But I don’t see how I can do that without taking the diff out of the truck. I don’t have a shop space and setting gears is above my pay grade at this point.... but I’ll do it if I have to. I really don’t want to tear into this diff. That’s why I ordered drop in units that would be hassle free..... ha... hassle free and landcruisers... water and oil...

 

[Travis 76]

You need to pull the pinion shaft out of the diff. Then you should be able to see how the axle sits with the gear. You need to pull the block out to get the c clips on your axle.

 

[DirtRoads]

I’ve been on the phone with cruiser outfitters this morning and Bryce is speaking with their installer. He says I can pull the side gears from my old diff and install them into the new one using the same thrust washers. But I don’t see how I can do that without taking the diff out of the truck. I don’t have a shop space and setting gears is above my pay grade at this point.... but I’ll do it if I have to. I really don’t want to tear into this diff. That’s why I ordered drop in units that would be hassle free..... ha... hassle free and landcruisers... water and oil...

Diff will have to come out. Just count the turns on the adjusters, mark everything left and right. Open it up, swap side gears, reassembly is the reverse of disassembly.

 

[cps432]

Alright, so once you’ve removed the spiders, the side gears slide out without having to remove any bolts or preload. It can be done in the truck.

It turns out that the side gears are in fact correct for this axle shaft. I believe the issue, now, to be related to the carrier bearings or the adjusting nut.

There is a spot on the axle shafts that were machines from the factory and it seems that either the carrier bearing or adjusting nut is catching the axle shaft at that point.

Something is catching on this groove here, and it happens on both sides. It’s sloped so if I force the axle in it gets wedged.

I tried to insert the axle with no side gear in place and it’s still getting hung up.... soooooooo......

 

[Cruiserdrew]

Is your axle housing bent?

Looking at your pics, you do have fine spline side gears so that's all correct.

You do need to sort of tilt the axle shaft up to enter the side gear and then it helps to have an assistant slowly turn the pinion side to side as it meshes. It won't just slide in because the end of the shaft will hit the adjuster nut. Once it hits the nut, tilt the end up just a bit and it should go in.

It also looks like your spacer block is still in place. That will have to come out, axles installed, C clips installed and then spacer and pinion shaft reinstalled with the lock bolt. (Sounds like you got all that out.)

One other thing and I don't know the answer, but the sheet metal guide inside the axle housing seems to be missing in yours. That helps align the end of the axle shaft too. But your vintage of FJ40 may not have that.

You will get this, it all looks correct. You are going to have to lever the axle shaft so the far end goes higher and is will engage the side gear if everything is correct.

edit: A couple of tips

When people post, it can be hard to be precise. For instance, pinion, pinion shaft and pinion gears are all different.

When I say turn the pinion from side to side, I mean the pinion flange. It turns the pinion which in turn turns the ring gear.

When another person said the pinion shaft has to come out, he means the central shaft in the differential that engages the small pinion gears. It also holds the spacer block in place when it goes back toghether.

Do not mess with your side bearing adjusters. They set backlash and that is a very precise and important measurement. Zuk describes how to reset and increase side bearing preload for improved differential strength, but don't do that if you've never done it before.

 

[Spike Strip]

Chris, in the pic where your finger is pointing doesn't make contact with the side gears... And there shouldn't be anything around it at that point, to bump into...

With the rear cover off, you can't see what's causing the obstruction?

 

[cps432]

Is your axle housing bent? No

Looking at your pics, you do have fine spline side gears so that's all correct. Yes, I sorted that much out.

You do need to sort of tilt the axle shaft up to enter the side gear and then it helps to have an assistant slowly turn the pinion side to side as it meshes. It won't just slide in because the end of the shaft will hit the adjuster nut. Once it hits the nut, tilt the end up just a bit and it should go in.
Yes, this was my experience. I have a friend who was helping get the pinion in the proper orientation too. The axle goes into the side gears and engages but stops flush with the inside disallowing me to install the c clips.

It also looks like your spacer block is still in place. That will have to come out, axles installed, C clips installed and then spacer and pinion shaft reinstalled with the lock bolt. (Sounds like you got all that out.)
Yep, got that. I just snapped that picture with the spacer still in place.

One other thing and I don't know the answer, but the sheet metal guide inside the axle housing seems to be missing in yours. That helps align the end of the axle shaft too. But your vintage of FJ40 may not have that.
I’m working on a feb 1987 FJ60. I know the front end has that alignment guide you speak of but I’ve never seen it in the rear. Not my first time having the axles out.

You will get this, it all looks correct. You are going to have to lever the axle shaft so the far end goes higher and is will engage the side gear if everything is correct.
Thanks for your help!

 

[cruiserpilot]

Shoot a pic of the 3rd inside the housing from the rear

One with the axles out and one with the axles in as far as you can get them. Are both sides hanging up? Or just one side?

BTW, do you have a spare pair of axle seals? By the time you go back and forth in and out a few times, they might
be nicked up. Once you do get it installed clean, then I'd consider installing new seals last time in.

 

[Dynosoar]

You said you put new bearings and seals in I would start there. Pull the third out, its easy, the axles are out already, and see if the splines slip in easily. My feeling is, it is the bearings you put in.

Dyno

 

[cps432]

Chris, in the pic where your finger is pointing doesn't make contact with the side gears... And there shouldn't be anything around it at that point, to bump into...

With the rear cover off, you can't see what's causing the obstruction?

So I pulled the side gears from the old diff and swapped em into the new one. No dice. The splines fit nicely onto the axle shafts. This prompted me to install the axle without side gears. Still catching in the same place on both sides. Upon further inspection I noticed a bevel on the face of the original Nachi bearing.
Seen here.

Here is a shot of the new carrier bearing. Notice there’s no bevel.

I felt the new bearings against the side gears with my fingers. Being a woodworker who works in 1/16 and 1/32 in veneers I have a good sense of thickness with my hands. I feel like the new bearing is slightly beefier than the original Nachi. Or perhaps it was installed backwards? I’m not sure if that’s a possibility or if they’re even directional.

I’ve sent these pictures to Kurt at cruiseroutfitters to see what his take is. On the phone he didn’t seem so sure the axle would hang up on the bearing, but without side gears I can’t see anything else to hang up on.

I’m 100% sure the new wheel bearings and seals are installed and seated correctly. They’re Koyo and OEM.

 

[cps432]

You said you put new bearings and seals in I would start there. Pull the third out, its easy, the axles are out already, and see if the splines slip in easily. My feeling is, it is the bearings you put in.

Dyno

Bearings and seals are Koyo. They’re in spec. I think it’s the carrier bearings. See my reply above to spikestrip.

 

[cps432]

Shoot a pic of the 3rd inside the housing from the rear

One with the axles out and one with the axles in as far as you can get them. Are both sides hanging up? Or just one side?

BTW, do you have a spare pair of axle seals? By the time you go back and forth in and out a few times, they might
be nicked up. Once you do get it installed clean, then I'd consider installing new seals last time in.

After spending two full days on this entire project while breathing heavy smoke filled air from several massive forest fires I had to call it. I put everything back together as best I could and stowed my tools. Time for a burger and a beer. My dog is getting bored too hahaha.
I’ll snap a photo later if I feel like getting greasy again or if I hear anything back from Kurt I’ll post here.

 

[Cruiserdrew]

You could pull the diff out, and do a test fit of the axle shaft. If it fit's together and goes in far enough to put on the c-clip, then the answer has to be in the install of the new wheel bearing. There are different bearings and they have a specific orientation. THe older style bearing was smaller in inside diameter. The later ones ride on the axle shaft itself where it's been hardened.

This has to be a really simple problem. Time to definitively eliminate possibilities. You could remove the 3rd in 5 minutes, poke the axle shaft nin the side gear, then you'll know if the carrier bearing is not compatible (I doubt this but who knows). If it isn't the carrier bearing or the side gear (which you know it isn't) it has to be the wheel bearings/seal because that's all that's left.

I'm going to go pull out a couple of spare diffs and look for you.

Smokey here too.

 

[Cruiserdrew]

Some pictures to confuse you more.

First pic: Stock FJ62 rear. From the factory. Bevel clearly visible. Unmolested original, came out for Harrop install.

Second pic: Depth it allows stock rear axle to penetrate to accept c-clip. Same diff as first pic.

Third Pic: Rear FJ60 differential with 4.56 gearing. Swapped bearings with the gears-replacement bearing has no bevel. Pretty sure these were Koyo bearings speced for this truck. Worked fine for years. Removed when I did 80 axle install.

edit: It's possible these are Timkin Bearings. My old installer guy likes Timkins and doesn't use Koyos unless you give him the Koyos with the diff. That was like 15 years ago and I just don't recall what we did.


Discussion: I can see where the bevel would make it easier to install. But it's only a few mm extra clearance and I doubt the lack of a bevel would prevent axle install entirely as things are out too far in your pictures.

Looking forward to learning something once you figure this out. Please post a follow up.

 

[cruiserpilot]

^^^ that's what is should look like. Yup

 

[cps432]

You could pull the diff out, and do a test fit of the axle shaft. If it fit's together and goes in far enough to put on the c-clip, then the answer has to be in the install of the new wheel bearing. There are different bearings and they have a specific orientation. THe older style bearing was smaller in inside diameter. The later ones ride on the axle shaft itself where it's been hardened.

This has to be a really simple problem. Time to definitively eliminate possibilities. You could remove the 3rd in 5 minutes, poke the axle shaft nin the side gear, then you'll know if the carrier bearing is not compatible (I doubt this but who knows). If it isn't the carrier bearing or the side gear (which you know it isn't) it has to be the wheel bearings/seal because that's all that's left.

I'm going to go pull out a couple of spare diffs and look for you.

Smokey here too.

I’m starting to think you may be right... the old bearings were destroyed when I pulled them out so I can’t measure them. Maybe you’re onto something.