Thwaites 4x4 artic steer drum clutch removal/ajustment

[gettothechoppaa]

Hello everyone, this is my first post, i have recently bought a lovelly little dumper, it is powered by a petter ph2 18bhp, its artic steer and hydraulic tip, its chain driven to a drum clutch which im told needed adjusting due to slipping when loaded so i went to turn the square adjuster i read about but it was siezed and sheared off, now before i go taking the whole unit off i wanted to make sure how to do it, does the whole setup come off complete with undoing a big nut in the middle? Also im interested to find out which model i have and carrying weight id guess a ton and a half judging by the skip size, the only other dumper which is the same i could find is on you tube comes under "dumpy the dumper" any way id like to say this is a very interesting site and hope i can help out with other peoples problems sometime

[essexpete]

I would guess it was the two ton machine before the 4000 aldrive arrived. 1970s machine?

[bangertrack]

Hello - I have one of these - I believe it is the first Thwaites Alldrive - mine is number 48585 - manufactrured in 1976.

The clutch is removed by compressing the release bearing and then undoing the custom nut (may be lock wired from memory) from the actuation rod. You will have to figure out how to release all the spring pressure (maybe a jack? - I have always managed it without much difficulty). The backplate should then slide off the gearbox output shaft (often with difficulty). I will have a look at the clutch again tomorrow and report any other details - I have written this from memory!

[gettothechoppaa]

Thanks alot, i will probably have a go at removing it tommorrow and see if there is any meat left on the brake shoes,if there ok ill just clean them up and refit, oh then ill have to try get hold of a new adjuster as i sheared the square head off, i may just try and free it off then weld a nut or cut a groove to get me out of trouble for now, so would you say its a 2 ton dumper?

[gettothechoppaa]

Great, i managed to follow your instructions and got it off, wernt half as bad as expected, all i done was wedge the clutch down with some wood then undid that custom nut you mentioned with some grips and slowly let the pedal up, then i had to disconnect the clutch arm linkage pin to allow me to slip the clutch assembly off, the shoes will go again but will replace the adjuster as wad siezed solid and i broke the square head off anyway, i ordered a triumph herald brake adjuster, it looks very much the same but if it isnt i shall make it fit... Took a few pictures incase anyone is interested whats in the clutch unit

[bangertrack]

The clutch all looks pretty good - and no contamination. When you come to adjust it - as I remember, you can increase the load on the shoes by turning the adjuster with the clutch pedal wedged down. If you still have trouble with clutch slip - I have cleaned up the drum on a lathe which seems to do the trick as a last resort.

No idea of the weight capacity of the machine but I have never had any bother loading it right up - mine is an excellent machine - I have replaced all the chain sprockets, steering and bucket pins etc etc. Can be a problem to start in winter - getting your hand from the starting handle to the decompression lever - when the weather gets a bit cooler, I warm up the inlet manifold with a blowlamp and it starts no matter the temperature.

Good luck

[gettothechoppaa]

Got the new adjuster today, fitted it and refitted the clutch then adjusted up, all seems good but not had it loaded yet, i used cable ties to compress the spring for refitting which helped make it easier, took a photo while i had my phone next to me

[meleager]

Hello everyone, my first post too!

I've just bought of these - and it has slipping clutch.

But how the heck does it come off?

The cast collar assembly behind the spring slides on the gearbox input shaft and is retained by two "guides" mounted in the backplate that stop its rearwards movement. One is a substantial bolt, the other is a rod that presumably actuates the shoes inside and has a cylindrical top on it that shows no sign of being able to undo.

I can see no sign of a "custom nut" but then I don't know what to look for. Is that the cylindrical thing on the end of the actuator rod?
So if that comes off then it's partner the bolt must come off too, but this bears no resemblance to the description given above.

Are there any publications covering this? What model is it exactly? The data plate is pretty battered and can't be read.

Totally flummoxed.