Dumper gearbox Head scratcher

[steve bailey]

Hi,
I have a 1979 Thwaites alldrive 6000 dumper, which i have just spent weeks rebuilding the Petter PH2 engine. I now have a problem with the gearbox ? i think, the gearbox that is suppose to be in my machine is a 40m42 but some one has fitted a 40m101, im not sure of the difference but my problem is the dumper only does about 5 mph flat out in top gear, my question is, am i going down the right roads thinking gearbox ?

 

[doobin]

Is there a reduction box on it too?

@JD450A will be along with better suggestions soon I’m sure.

 

[JD450A]

Plant engineering services.... All day. I have a feeling the 101 has a reduction set on the output shaft but I could be wrong.

I may have a complete box but it'll want a rebuild.

 

[Mick-the-fitter]

Photos of the drive train, Mach number from the serial plate!

 

[steve bailey]

Thanks for the reply’s, the Thwaites serial number is 58641, it’s a 1979.
The number stamped on the original top of the gearbox is 40m42/ 74669 . No idea of a Mach number. The top plate on the gearbox is original, but as you can see by the colour, it’s a different gearbox .

 

[Mick-the-fitter]

Ok I’ll have a look at serial number

 

[Mick-the-fitter]

Is that all of the serial number?

 

[V8Druid]

Is that all of the serial number?

guessing that's the casting number Mick .. he shows a pic of it

 

[steve bailey]

The dumper serial number I got of thwaites, the gearbox number is stated, it is off the top plate, this is how thwaites traced the machine. There is a pic of the number of the fitted gearbox

 

[steve bailey]

Ok I’ll have a look at serial number

Hi Mick, did you manage to find out any info for me ?

 

[Mick-the-fitter]

Sorry been out on site will look today

 

[Mick-the-fitter]

Serial need a letter and 4 numbers

 

[steve bailey]

Hi Mick, there is no letter on the plate on top of the gearbox, just 40m42 74669, i have found a number on another part of the gearbox, which i think is a reducing unit, which is 40m655, please correct me if im wrong, if im right , could i not source a difference reducing gear ? or am i just clutching at straws.

 

[Mick-the-fitter]

Hi Mick, there is no letter on the plate on top of the gearbox, just 40m42 74669, i have found a number on another part of the gearbox, which i think is a reducing unit, which is 40m655, please correct me if im wrong, if im right , could i not source a difference reducing gear ? or am i just clutching at straws.

Serial plate on the dumper! Or chassis number if you can find it?

 

[steve bailey]

The serial number Thwaites sent me is , 58641 , it’s a 1979 all drive 6000, they found this through the gearbox plate number

 

[Gecko]

it’s a 1979 all drive 6000, they found this through the gearbox plate number

Strictly, all you can say is: "that gearbox left Thwaits in a 6000 4x4 in 1979", not necessarily yours.
Below is a Mk2 with a transfer/drop box mounted on the front diff. If yours has that, it won't need a second reduction box.

 

[steve bailey]

I presume it’s in the first pic, can you tell me what the second pic is ? Sorry I don’t have a clue when it comes to drive trains

 

[Mick-the-fitter]

Strictly, all you can say is: "that gearbox left Thwaits in a 6000 4x4 in 1979", not necessarily yours.
Below is a Mk2 with a transfer/drop box mounted on the front diff. If yours has that, it won't need a second reduction box.

View attachment 63909

Correct seems you have both, one you don’t need unless you need to hill climb

 

[Gecko]

Yep, the first pic is the transfer/drop/reduction (pick one) box.
The second looks like a planitary reduction box (epicyclic gearbox if you want to be precise).
At this point, I'm running thin on suggestions as I've never seen one of these in flesh - dumpers do exist in Oz, but not in serious numbers.

Just to add some fun to the party, if you replace the gearbox with the original type, the first (top) prop-shaft will probably be too short and will also need replacing.

 

[steve bailey]

Plant engineering services.... All day. I have a feeling the 101 has a reduction set on the output shaft but I could be wrong.

I may have a complete box but it'll want a rebuild.

Hi, yes it has a reduction set on it, have you got a complete box with propshaft connector ? if so what sort of condition is it in ?