Rear diff lock actuator

[vrecha]

Trying to add to the community knowledge ...

I too successfully repaired the rear actuator. The repair stretched to two months from first try to the working assembly. Long story cut short: ingress of water (wading - not tight breather ???) -> two magnets were off, glued with an average quick qulue -> worked untill next wading -> 3 magnets off -> decided to reglue all the magnets with special steel-to-steel glue -> not alive again :confusion-scratchheadyellow: -> opening again and again, checking -> eventually ripped off both commutator brushes -> bit of soldering and again we try -> no, no life yet -> leave it for two weeks and then -> magnets are not orientated as they should be -> undo the super glue and after a LOT of trial and error with the alignment - it works.
Now I'm avoiding the rivers until i sort out the breather (will extend it inside the cabin, as I did with the ones from the diffs).

Lessons learned:
- Tried to drive around with the blanking plate in the place of the actuator - no go, as the locking fork tends to lock the diff. Driving with installed actuator but without the bolt that connects the actuator and the fork (picture few posts up) is ok, did this for 4000 km without the problem.
- Think that the breather is a week spot (besides usual corroding because of the Al-Fe contact), especially when wading.
- The right alignment of the magnets is something I had to figure for myself, didn't find any help on the net. Below is the picture of the orientation (base picture borrowed from IH8mud). Note that small protrusions near bolt holes - these enable the unique orientation of the stator magnets.
- Don't worry about small misalignments of the magnets when gluing them - mine are a few degrees out and the motor works OK. The motor also works with just two magnets glued in the right place and the other two nonglued (free to move where they would like).
- Worth repairing if possible, not replacing.
- Post with nice pictures on Ih8mud: here.

Note: If anyone did replace the unit with a new one and don't know what to do with the bits of the old unit, I'm probably happy to buy them as I will very likely rebuild some more actuators in the future. Ask via pm or mail.

 

[frank rabbets]

I forgot that all my magnets were loose. Glued them back with araldite. Perfect for the job.

Frank

 

[warrenpfo]

Just to ask as I plan on taking a look at my rear locker on the 100. I would have thought that the fork that locks the diffs would have been lubricated by the diff oil or is this not the case as I could not understand how wd40 would solve the problem if its not been used and a little sticky.

Or have I got it wrong and it’s not lubed by the rear diff oil??

 

[Justin_Elliott]

Unless i'm missing something - The forks would be lub'd by the diff oil - but looking at the rebuild pictures on IH8MUD I'd suggest the wd40 would potentially free up the internal gears...

Rebuilds do look do'able - although I'm not sure how these compare to a 100's rear locker...

 

[Jon Wildsmith]

Just to ask as I plan on taking a look at my rear locker on the 100. I would have thought that the fork that locks the diffs would have been lubricated by the diff oil or is this not the case as I could not understand how wd40 would solve the problem if its not been used and a little sticky.

Or have I got it wrong and it’s not lubed by the rear diff oil??

The fork is inside the diff so in a bath of diff oil but the actuator motor and gearbox is external. I haven't read back to see where wd40 was mentioned but that'd be for the actuator motor and gearbox.

 

[Gav Peter]

Yes, thinking about it, I think it was Rob that suggested squirting WD40 down the breather tube on the actuator to try & make that part move more freely.

 

[hillbillysimon]

Hi, looking for a rear actuator, for my 80 (95 24valve manual), mine is unrepairable. Any rebuilt or secand hand units available???
Simon

 

[Ecoman]

Hi, looking for a rear actuator, for my 80 (95 24valve manual), mine is unrepairable. Any rebuilt or secand hand units available???
Simon

Hens teeth mate

Milners do them but they are not cheap.

 

[Rob]

Does anyone know if the Milners ones genuine? Seems unlikely for it to be an aftermarket part

 

[Chris]

Odd thing about Milner is that sometimes they have genuine parts and sometimes pattern.

I had a master cylinder from them and Carl said, hang on a minute, went into the racking, rummaged for a minute and came out with a boxed T part. Hello! £50 for a genuine factory M Cyl. I have had 90 series rear light clusters - genuine part. Other bits and bobs, genuine. It's really luck of the draw. I live 10 mins away so I always go in to buy stuff. I can have a bit of a chat about what I am getting.

When I started asking about lockers, it was clear that they had been able to source some genuine Mr T parts. I looked at one (80 rear) and it was defintely OEM. But the rear ones for a 95 at the time were not. They were copies.

I guess you need to speak to the parts desk and ask them. They wont know on the phones upstairs, ask if Carl is in. He really does know tonnes of stuff and is very helpful but can't make changes, so it seems. If you get hold of him, say that you have been talking to Chris in Wingerworth. They guy with the white cruiser that burned out. He knows me. You might grab a bargain. Or possibly not.


Chris

 

[Ecoman]

I had a mate who lived in Wingerworth on Setts Way. You couldn't miss his house as it always had a scrap looking capri on his drive and often there would be sounds of prog rock drifting from his bedroom studio.

He now lives in the middle of the Lincolnshire Wolds.....I wonder why

 

[Chris]

Get away. Only half a mile from me. We'd have been good mates with my scrap 80 on the drive!

C

 

[Ecoman]

 

[eatapeach]

You could try spraying WD40 down the breather pipe, this usually gets sticky actuators going again.

OK - the axle breather? - I'm confused...where is it located?

 

[Chris]

Holy old threads Batman.

There is a breather in the axle, but there is also a breather in the locker motor. Thin black pipe wound round with spiral plastic wrap. Looks like a wire.

Chris

 

[Gav Peter]

There's a small breather connection on the actuator - this is what Rob is alluding to...

And Chris too

 

[eatapeach]

Holy old threads Batman.


Chris

It's what the search function is for

cheers both

 

[Chris]

Absolutely! Be nice if people used it more often. The answers are out there. Most of the time.


Chris

 

[Old Fox]

Thread resurrection here.....

Long story short Cruiser put into garage for new discs,pads,shoes front and rear and calipers on the front due to me not having time to do it (work work work) anyway go to pick it up today and told that both rear diff locks are engaged and will not dis-engage and one of the front ones is engaged and will not disengage. I don't understand why they needed to mess about trying the diff locks to test the brakes on a test drive but, hey ho i know them so did not shout too much .

to the crux will squirting some WD40 down the breathers possibly free them off to disengage them or is there something else i could do or get them to do ?

 

[Chris]

Both rear diff locks??? That's a new one Old Fox. Do you mean front, centre and rear? There are only three. One in each axle and one in the centre transfer box.

THB squirting WD40 down the breather really isn't the cure here. Unusual for them to lock and then fail so they won't unlock. But, not completely unheard of. Especially for all three to lock up. I suspect that they have somehow wound up the drive shafts sufficiently to have locked the mechanisms. You don't get much wind up in an 80 because they are so well designed, but if they've been fiddling. Best thing really is to jack the truck off its wheels. All four would be best but at least one front and one rear. Then wiggle the wheels and it should unlock. Now someone will say drive back and forth and turn the wheel and ordinarily I'd agree but we don't know just how wound up they have got this so I'd suggest in the interest of not breaking something, lift the wheels. Also put the high / low transfer lever into neutral

That would be my first attempt. Make sure the rotary dial etc is turned off - obviously