Dumper rear axle problem help please

[Tommyf]

Evening chaps,

I have an oldish thwaites 7000 3 ton 4wd dumper and yesterday after an unusual groaning noise one of the rear wheels locked up. I have removed the half shaft on the offending side and the hub started to spin freely again so I am now thinking that it may be a diff problem and not an outer bearing that I hoped it was. Anyone come across this before or know a breakers that would have a complete axle?

Many thanks, Tom

 

[normspanners]

When you say rear wheel is it one of the steer wheels coz most dumpers are rear wheel steer? It is just with you saying you removed the half shaft coz it would surely be a drive shaft with a UJ in it ?

 

[piman]

Hello Tom,

take the axle cover off and have a look inside, possibly a collapsed bearing on that output side?

Alec

 

[normspanners]

Diff side brg would seize the diff not the wheel / hub

 

[piman]

Hello Norm,

no, it's exactly the same if you lose grip on one wheel the other stays static and the rest of the differential rotates.

It's very rare though, I can't say I've heard of it happening before?

Alec

 

[octo0072000]

When you say rear wheel is it one of the steer wheels coz most dumpers are rear wheel steer? It is just with you saying you removed the half shaft coz it would surely be a drive shaft with a UJ in it ?

they pivot in the middle Norm no UJ's on axles
like this one
http://www.ebay.co.uk/itm/3-ton-Thwaites-7000-dumper-with-Lister-3-cylinder-engine-/151159592431

 

[normspanners]

Yeh had a look on ebay pivot steer (my bad) looks to me, if rear axle is prop driven and the same as front, it has small diff then epicyclic reduction units to allow the reduced diff size could be one side epicyclic has seized, just thought! could be it has, inboard, brakes same as a tractor and one side has locked, but also if hydrostatic drive and seperate motors, that one side hydraulic motor could have seized

 

[normspanners]

Hello Norm,

no, it's exactly the same if you lose grip on one wheel the other stays static and the rest of the differential rotates.

It's very rare though, I can't say I've heard of it happening before?

Alec

sorry but you are wrong if a side bearing seizes, the diff assembly stops turning, still allowing both side gears and therefore 1/2 shafts to turn within the diff housing and would not stop one side only. Also the drive into the diff ie the prop shaft would not turn, effectively locking the WHOLE drive if it had equal traction,
If aside gear had seized into the diff assemble housing it would effectively lock the diff but it would still drive both shafts /wheels in a straight line.

 

[octo0072000]

planet gears in the diff could have broke up

 

[normspanners]

planet gears in the diff could have broke up

would still drive the axle like a locked diff

 

[normspanners]

I still think it may have inboard brakes/ reduction unit that has locked

 

[octo0072000]

I still think it may have inboard brakes/ reduction unit that has locked

not 100% sure but seem to remember that have transmission brake on the gearbox/props like a landy

 

[Tommyf]

Thanks for all the replies
I forgot to say that I also disconnected the short prop shaft from the transfer box to the rear axle and the. Only brakes including the hand brake are on the front axle .
Cheers

 

[piman]

Hello Norm,

yes of course, you are right. The carrier is in that bearing with the half shaft passing through it. But what else could seize the half shaft? Back to the hub area and or the brake?

Alec

 

[normspanners]

Right having the prop off makes a huge difference, when you turn the side that is not seized,ie the one with the wheel on does the prop flange turn?

 

[Tommyf]

Yes it does.

 

[ford34/2]

Locked up

so if you can lock the good wheel up-- stop it turning, now turn the prop shaft flange by hand,-- what happens??

Stan

 

[normspanners]

Then the fault cannot be in the diff i would have said slip the half shaft back in with a couple of loose bolts and see where the lock up occurs ie does the hub turn and take up the slack in the bolts . because if the prop flange is turning the diff housing must be turning and if that turns so should the half shaft. has it got hub reduction ? the half shaft might have a gear or splines on the outer end.
Ps before fittingthe half shaft look at the inner splines and check the witness marks and see if there is only one set of witness marks where the drive gear has run if there are two sets of marks there may be some form of locker in the diff but I doubt it.

 

[normspanners]

Outcome?

 

[Tommyf]

Thanks for all the replies chaps,
I managed to sort it in the end. The sun shaft planetary gears and outer ring were all mashed up. I got some second had parts and it's now as good as new. Only problem now is, because I steam cleaned it before doing the work the clutch is now stuck ( I think rusted on to the flywheel). Anyone got any good tips how to free it up?

Cheers Tom