My truck is marking its territory

[Dan W]

Hello, my 80 series is leaking from its rear diff. It's where the rear prop enters the diff. Could anyone point me in the right direction of repairing it. Does the whole thing need taking apart (please don't say this one) or can it be fixed from the prop side of things (please say this one)?

 

[BRE Fabrications LTD]

Funny that. Mines been doing since lincomb.

The seal can be replaced on the vehicle. You will need to drop out the props haft. Looks to be a straight forward job according to the FSM.

I'm minutes away from replacing the seal. I'll let you know how it goes.

 

[Dan W]

Excellent. Good luck with it then, where'd you get the seals from?

 

[Graham]

From what Ben always suggests, then don't get seals from Milners.
Always go to Mr Toyota.

Gra.

 

[Jon Wildsmith]

You can just change the seal, it's an easy job, but check the pinion for play while you have the prop off.

 

[BRE Fabrications LTD]

Well, All in all changing the seal was pretty straight forward. Though if your going to do it I'd suggest you do the bearing while your in there...

I struggled with a few things and would suggest that you make sure you have a torque wrench that goes up to 245 N.M. Mine, as I found out , only goes up to 210 N.M...

When I eventually managed to get the nut up to 210 N.M I could only get about another 1/8th of a turn on the nut. I then checked the preload as per the FSM which should be between 0.7 - 1.0 N.m with a used bearing. Mine is sitting around 20N.m... If your preload is too high the spacer should really be changed out. To get to the spacer you need to remove the bearing. May as well replace it.

Lastly I have noticed diff oil seeping out from the diff lock actuator...WTF? The new seal seems to be working but why would it be coming out of the actuator?! Could I have overfilled it???

Other than that it was pretty straight forward really...

One last tip tip, make sure you chock your wheels. Park doesn't really work when you remove your rear propshaft and that's no good when your drive is at a slight angle...

If you need a copy of the FSM drop me a PM with your email and i can forward the relevant section to you.

I'm starting to think I should change my signature to: "Learing things the hard way, so you don't have to..."

 

[BRE Fabrications LTD]

Oh ya, I bought the seal from Simon.

 

[Jon Wildsmith]

when you do the nut back up just put it back where it came from, don't go by torque or you risk crushing the spacer, buggering up your preload and the diff will need to come out to fix it... You'd need just the right puller to change the bearing with the diff still in the axle so it might technically be possible but that's probably more work than just dropping the diff out and doing it properly.

 

[BRE Fabrications LTD]

What would the implications of an over torqued bearing be Jon? I have taken the 80 for a drive and am not getting any whining or strange noises.

 

[frank rabbets]

A lot of heat Ryan. If the dif is quiet and cool after driving it's probably OK. Jon?

Frank

 

[BRE Fabrications LTD]

I drove a route of about 20mi. afterwards the rear diff was warm to touch and warmer than the front which I would say was Luke warm.

I'm guessing I need to do this again with a new bearing and spacer this time...

Any good tips of how to get the pinion bearing out once I drop the 3rd member out? Once the bearing has been replaced am I going to have to start mucking about with backlash on the ring and all that...?

 

[Jon Wildsmith]

As Frank said, quiet and cool is what you want. The rear should always be cooler than the front in my experience and at current ambient temperatures should probably feel pretty cool unless you really hammered it?

Once you have the diff out you'll need to remove the carrier bearing caps and remove the carrier, don't mix up the shim from each side as they'll need to go back in the same side. With the carrier out of the way you take the flange off the pinion, remove the oil seal and press the pinion out then the bearing is loose and can be removed. The spacer will be on the pinion, just slide it off and put the new one one then put it all back together. Don't forget to change the bearing race as well. You'll need to press the pinion back into the casing with the new bearing in place. When you do the pinion nut up go in small steps once the play is nearly all gone because the spacer gets easier and easier to crush as it collapses and it's very very easy to overdo it. When you put the carrier back in so long as you didn't mix up the shims it will be set up the same as before you started. Ideally you'd re-shim the carrier to improve the preload that will have been lost over time as the bearings wear while it's all 'on the bench'.

They are heavy things so all of the above is easier said than done without a frame to bolt the diff to.

 

[BRE Fabrications LTD]

What size press would I need?


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[Jon Wildsmith]

small one, 10 ton is plenty for this.

 

[BRE Fabrications LTD]

Is there anything else in there I should replace while I am at it?


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[Jon Wildsmith]

Depends how fussy you want to be? You could just change the crush spacer and be back to how it was. If you want to service it while it's out then you'll need some carrier shims (expensive for a full set, can be hard to get) to restore the carrier bearing preload and a dial indicator to measure the gear backlash. You could check the gear pattern is still ok but if not then adjusting pinion depth needs a special tool to press the inner bearing off the pinion without damaging the bearing and another set of shims to do the adjusting with. It's all much easier if you make yourself a frame to hold the diff, have a look at www.gearinstalls.com . Very enthusiastic 'off road' driving can cause the crush sleeve to crush slightly, losing pinion preload and affecting the gear engagement, even on the rear (more of a problem on the front usually), so another option to consider is a putting a solid spacer in, but you better have some patience for this stuff if you go with that option

 

[BRE Fabrications LTD]

Wow, fair bit of info in that link and some interesting reading. One thing is clear, I'm definitely no where near tooled up enough to carry out a full service. I think that's going to need to wait till it's time to regear.

So if I just replace the crush washer and leave the bearings will I still need to press the bearing off of the pinion?

 

[David Killough]

Just a quick thought. I replaced my rear pinion seal a few months back and torqued it up as best I could. It never gave me any problems and I've just run the truck through the gauntlet in Angola. One thing I will mention is be careful when greasing your rear slip yoke. I put a little too much grease into that fitting and it caused the drive shaft to act like a hydraulic ram and blow my newly replaced pinion seal. Ordered another one from our friendly Toyota supplier Simon and did the job again. Lesson learned, BE CAREFUL when greasing those drive shafts. A little grease will go along way.

 

[Jon Wildsmith]

So if I just replace the crush washer and leave the bearings will I still need to press the bearing off of the pinion?

Unless you have a puller that can grip the outer bearing and pull it out, you will have to press it off and back on again so carrier out, press pinion out, change sleeve, press pinion back in, tighten pinion nut very carefully, put carrier back in. Getting the new crush sleeve started can take a fair bit of force so you'll need a way to hold the diff securely and also something to stop the pinion turning.

 

[Dan W]

Hi guys. This looks like a fun job! Ryan, have you had to start agin because the preload was too tight? I've found a FSM section that deals with this. First though it says to replace the nut you'll be tightening up at the end, I only ordered a new seal so do I need to order the nut as well? It also says you need a SST for removing and another SST for installing the oil seal. And finally do I follow the FSM guide to torquing up the nut or is it likely to strand me in a world of pain, and if not how do you do it up properly?