Thwaites dumper stalls

[Amateur]

The magic number is in a different location to your pic, also the position of the transmission filter is is at the side of the box rather than in front like in your pic.
Gear box number 446/22802P and the letters JC 2 are adjacent to it, see gearbox pic.
Torque Converter number is 445-15707P and the letters JCT are adjacent to it, see torque converter pic.

 

[Pheasant Surprise]

Yep those are individual part numbers for the components in question, not of the unit.

For example 446/xxxxx is the JCB part number for the actual transmission casing and 445-xxxxx is the part number for the torque converter bell housing.

 

[Amateur]

here is a front view of the gear box in situ. I dont see any number on it.

 

[Pheasant Surprise]

also the position of the transmission filter is is at the side of the box rather than in front like in your pic.

That pic I posted was from an SS400. The SS500 has the same fore/aft positioning of the oil filter.

From the SS600 onwards the oil filter is position 'out the side' of the box.

So I reckon your synchro shuttle box could be an SS600, SS700 or possibly and SS750. I have a later model Thwaites 6T swivel dumper with a Power Shift PS750 box in it. Therefore I'm thinking your synchro shuttle may be either an SS700 or SS750.

 

[Pheasant Surprise]

here is a front view of the gear box in situ. I dont see any number on it.

Got it from your last photo. Its an SS700 (not SS700 Type 2). See that yours has a removable layshaft cover....

SS700 unit ID plate:

SS700 Type 2 unit ID plate:

 

[Amateur]

well done.
I notice chalk marks on top of the gearbox so it could well be a replacement, it never have chalk marks when new.
what year is SS700 ?

 

[Pheasant Surprise]

well done.
I notice chalk marks on top of the gearbox so it could well be a replacement, it never have chalk marks when new.
what year is SS700 ?

....actually I'm doubting myself now!

Have a look at the spool layout for an SS600 below. This looks more like yours. The oil filter is also 'out the side' on an SS600 and it also has the removable layshaft cover like the SS700.

Is there and ID plate shown as per the green arrow?

 

[Amateur]

u are dead right, I never noticed this before, see attached....

 

[Pheasant Surprise]

See other highlighted differences in pics, which suggest yours is an SS600 box.

- Absence of ID plate next to the suction strainer cover on an SS600 box. See green circle.

- Absence of rear mount hydraulic pump flange on SS600. See red circle.

- Absence of external oil union/fitting on SS600. See lilac/purple circle.

 

[Amateur]

a pic directly over the filter attached.
what is that electrical switch over the filter.

 

[Pheasant Surprise]

notice chalk marks on top of the gearbox so it could well be a replacement

How long have you owned it? It’s possible a previous owner put a ‘box on from a breaker. It looks like it’s been hit with a can of yellow spray paint at some point too.

I’d agree about the chalk, not something that would be seen out the factory (especially after more than 27 years of graft), more an auction or breakers yard I’d suspect..

 

[Pheasant Surprise]

u are dead right, I never noticed this before, see attached....

The ID plate is definitely there.

 

[Amateur]

I bought it in 2010 from a person I did not know -- not a garage/dealer, not registered, identification plate on foot guard missing, unknown origin! It had been sprayed long before then.
Yes, it could well be a breakers box, the entire innards are probably not original, look at the engine pipe.

 

[Pheasant Surprise]

I bought it in 2010 from a person I did not know -- not a garage/dealer, not registered, identification plate on foot guard missing, unknown origin! It had been sprayed long before then.
Yes, it could well be a breakers box, the entire innards are probably not original, look at the engine pipe.
View attachment 838122

Quality eh! To be fair, that's probably par for the course this age of machine.

 

[Amateur]

it worked very well until now ( a couple of minor issues I was able to fix) and is by far better than a tractor+trailer.

 

[Pheasant Surprise]

it worked very well until now ( a couple of minor issues I was able to fix) and is by far better than a tractor+trailer.

Undoubtedly. These dumpers are simple, but pretty hardy things.

For reference, here are the disassembly and assembly instructions for an SS600 box from the JCB transmissions service manual.

See if you can get a look at the ID plate beneath the F/R spool, that should conclusively tell you what box you've got.

 

[Amateur]

thank you. I will will check that ID pate in a few days.

 

[Pheasant Surprise]

thank you. I will will check that ID pate in a few days.

No worries. Here is the rest of the SS600 service manual (everything except the disassembly/inspection/assembly instructions in the previous PDF above) taken from a JCB rough terrain forklift service manual.

 

[Amateur]

Would imagine there for some kind oh heat exchanger sounds like you have water mixed with oil and had caused plates to stick in gearbox

Take rad cap off and see if it's all milky. I would loop the pipes if it's for the cooler change oil in the gearbox and try it see if it will work with proper oil in it

@lexion780tt great suggestion.
I cleaned the mesh filter at the bottom of the torque converter, drained the oiI, put in new oil and looped the pipes and it worked immediately.
I had it on axle stands for safety and ran it in forward & reverse for about 5 minutes.
Then I removed the axle stands and it drove perfect.

 

[Pheasant Surprise]

That’s a good result. Happy days!