Thwaites dumper stalls

Amateur · Oct 2, 2019

I found this video on directional valves

.
Without some assistance transmissions/gearboxes are beyond my competence unless its something really basic.
There is no serial number stamped into the chassis, it looks like there was a badge pot riveted to the driver guard but its gone. I was told the five stud 6 ton were manufactured between 1989 & 1999. It has a perkins phaser engine
AA 50324*U569038V* , non turbo. It has been trouble free until now.
Previously I contacted Thwaites parts department but without a serial number they are reluctant to help.
If the torque convertor & gearbox did not change much in those years then a manual from any relevant year would suffice. Any suggestions ?

essexpete · Oct 2, 2019

Amateur said:
I found this video on directional valves

.
Without some assistance transmissions/gearboxes are beyond my competence unless its something really basic.
There is no serial number stamped into the chassis, it looks like there was a badge pot riveted to the driver guard but its gone. I was told the five stud 6 ton were manufactured between 1989 & 1999. It has a perkins phaser engine
AA 50324*U569038V* , non turbo. It has been trouble free until now.
Previously I contacted Thwaites parts department but without a serial number they are reluctant to help.
If the torque convertor & gearbox did not change much in those years then a manual from any relevant year would suffice. Any suggestions ?

I am surprised. I found a Thwaites technical or (parts ICR) guy really helpful a few years back with a much older machine.

Pheasant Surprise · Oct 2, 2019

Amateur said:
I found this video on directional valves

.
Without some assistance transmissions/gearboxes are beyond my competence unless its something really basic.
There is no serial number stamped into the chassis, it looks like there was a badge pot riveted to the driver guard but its gone. I was told the five stud 6 ton were manufactured between 1989 & 1999. It has a perkins phaser engine
AA 50324*U569038V* , non turbo. It has been trouble free until now.
Previously I contacted Thwaites parts department but without a serial number they are reluctant to help.
If the torque convertor & gearbox did not change much in those years then a manual from any relevant year would suffice. Any suggestions ?

Just looked up the date code of the Perkins engine and it comes up as 1991 vintage. So it likely puts your dumper at 1991 or 1992 model year I'd say.

How To Identify Your Perkins Engine | Tractors | Massey Ferguson

Below is the information on how to identify your Perkins Engine to help you use our website. All Perkins engines should contain one of the two following formats for engine identification and numbering.

www.anglo-agriparts.com

Pheasant Surprise · Oct 2, 2019

Link here to the workshop manual for the Perkins engine.

Amateur · Oct 2, 2019

Thanks, you may be right on the age of the engine.
it could be a replacement engine.
One of the engine mount bolts was missing when i got it, it could have fallen out but unlikely.

Pheasant Surprise · Oct 3, 2019

With any luck your problem is external to the box and hopefully somewhere in the relatively simple control circuit of the forward/reverse/dump pedal/shuttle switch circuit.

As an amateur @Amateur (sorry I had to get that one in) I don’t think opening up a power shuttle gearbox without a shop manual / guidance or previous experience would be a smart idea.

At that point you’d probably want to get professional help to pressure test the box and if necessary open it up and overhaul it, but let’s hope it doesn’t come to that and the problem is relatively simple, straightforward and accessible to resolve.

Zetor · Oct 4, 2019

Is it starting off the key ok?

Amateur · Oct 4, 2019

yes, it is starting off the key fine.

Pheasant Surprise · Oct 5, 2019

Amateur said:
yes, it is starting off the key fine.

So can you give more details of what actually happens.

You can start the machine and it runs fine. You engage forward and it moves (for a little) or doesn’t move at all or moves then stalls the engine? Which is it. What about reverse?

Have you checked and traced the wiring for the seat switch / operator present circuit and the dump pedal switch as @Zetor says?

Without a wiring diagram it makes tracing faults a bit challenging.

Pheasant Surprise · Oct 5, 2019

Amateur said:
no, I recently removed the mechanism because it needs replacing.

Another thing, as above you said you removed the handbrake mechanism, did this problem tie in with that at all? Is the new handbrake functioning correctly or have you removed it completely?

Was there a safety switch or circuit with the handbrake that you encountered?

Amateur · Oct 5, 2019

The handbrake mechanism was removed 3 months ago and not replaced. Everything continued to function fine after that. I did not see any safety switch or a wire to any part of the hand bake. So I presume there is no connection.
I hope to have a diagnosis up date later today or tomorrow.
I will first test the voltage at the solenoids when f/w engaged. No voltage = wiring problem. If there is a voltage I will check the resistance of coils, if coil resistance similar to each other then it must be either the directional valve or in the gearbox.

Amateur · Oct 6, 2019

update part1:
13 volts at the solenoid on right hand side when reverse position selected, see pic for location.
I removed the solenoid and measured the resistance, it was 5 ohms. Then I connected it to a
battery charger and it drew current. So, I no longer suspect the electrics.
The spool valve could still be faulty but I cannot easily check that.
Then I noticed the gear level was in neutral and when I tried to put it in second gear while reverse was engaged
i got a screeching noise, so I moved the shuttle out of reverse to neutral and was able to engage a gear.
It did not move when I put it in reverse.
I then tried moving the gear stick while reverse shuttle selected and it moved freely into every gear without noise.
For all of the above I had clutch pedal short circuited at the connector (equivalent to pedal up).

Amateur · Oct 6, 2019

update part 2:
What I did not mention before is that a leak appeared at the bottom of the radiator at the same time the dumper stalled. I did not think it could be related but now I am wondering about the 2 pipes, one connected to the torque unit & the other connected to the gear box. These 2 pipes connect to a pipe between the water pump and the bottom of the radiator. Is there a pipe within a pipe in the pipe attached to the bottom of the radiator ?
Before I started the dumper yesterday I topped up the transmission oil with an ATF oil. Today I checked it again and it looked very a thin watery oil.
Can someone explain what these 2 pipes are for, see pics. One pipe is connected under the directional control valve as in pic 172859.jpg, pointed to by a red pencil.
The second pipe enters on the left hand side into what I believe is the torque unit (correct me if this has a different name), see pic 121758.jpg, screw driver points to pipe.

Smith31 · Oct 6, 2019

Amateur said:
update part 2:
What I did not mention before is that a leak appeared at the bottom of the radiator at the same time the dumper stalled. I did not think it could be related but now I am wondering about the 2 pipes, one connected to the torque unit & the other connected to the gear box. These 2 pipes connect to a pipe between the water pump and the bottom of the radiator. Is there a pipe within a pipe in the pipe attached to the bottom of the radiator ?
Before I started the dumper yesterday I topped up the transmission oil with an ATF oil. Today I checked it again and it looked very a thin watery oil.
Can someone explain what these 2 pipes are for, see pics. One pipe is connected under the directional control valve as in pic 172859.jpg, pointed to by a red pencil.
The second pipe enters on the left hand side into what I believe is the torque unit (correct me if this has a different name), see pic 121758.jpg, screw driver points to pipe.

There is an online ground working forum called planttalk some very knowledgeable folk on there, maybe worth a try on there.

lexion780tt · Oct 6, 2019

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

Pheasant Surprise · Oct 6, 2019

Amateur said:
update part 2:
What I did not mention before is that a leak appeared at the bottom of the radiator at the same time the dumper stalled. I did not think it could be related but now I am wondering about the 2 pipes, one connected to the torque unit & the other connected to the gear box. These 2 pipes connect to a pipe between the water pump and the bottom of the radiator. Is there a pipe within a pipe in the pipe attached to the bottom of the radiator ?
Before I started the dumper yesterday I topped up the transmission oil with an ATF oil. Today I checked it again and it looked very a thin watery oil.
Can someone explain what these 2 pipes are for, see pics. One pipe is connected under the directional control valve as in pic 172859.jpg, pointed to by a red pencil.
The second pipe enters on the left hand side into what I believe is the torque unit (correct me if this has a different name), see pic 121758.jpg, screw driver points to pipe.

Oops. That was quite an important little thing you didn’t mention before

As said, I would drop the oil from the gearbox completely and check it’s volume and condition. It’s a likely you have either a low oil condition (best case) or worse an oil / water contamination in the ‘box due to the heat exchanger leak.

As @lexion780tt says this will cause the friction material in the clutch packs to absorb the water in the oil and fudge the clutch packs, potentially causing them to permanently lock up. If that’s the issue then the only resolution is a full strip down to remove and replace the packs in the F/R clutches.

ACEngineering · Oct 6, 2019

Amateur said:
update part 2:
What I did not mention before is that a leak appeared at the bottom of the radiator at the same time the dumper stalled. I did not think it could be related but now I am wondering about the 2 pipes, one connected to the torque unit & the other connected to the gear box. These 2 pipes connect to a pipe between the water pump and the bottom of the radiator. Is there a pipe within a pipe in the pipe attached to the bottom of the radiator ?
Before I started the dumper yesterday I topped up the transmission oil with an ATF oil. Today I checked it again and it looked very a thin watery oil.
Can someone explain what these 2 pipes are for, see pics. One pipe is connected under the directional control valve as in pic 172859.jpg, pointed to by a red pencil.
The second pipe enters on the left hand side into what I believe is the torque unit (correct me if this has a different name), see pic 121758.jpg, screw driver points to pipe.

Sounds to me like the transmission is knackered and due an overhaul plus a new transmission oil cooler. All common JCB stuff.
Probably just as cheap to move it on and find another that works IMO!

Amateur · Oct 6, 2019

ACEngineering said:
Sounds to me like the transmission is knackered and due an overhaul plus a new transmission oil cooler. All common JCB stuff.
Probably just as cheap to move it on and find another that works IMO!

does one of the old jcb versions (or other machine) share the same torque & gearbox as the Thwaites dumper?
Clearly a separate oil cooler

Pheasant Surprise said:
Oops. That was quite an important little thing you didn’t mention before

As I said earlier, I am an amateur. Even my old ford 655D digger has a separate oil cooler.
Assuming it is a heat exchanger mechanism the inner pipe must be damaged and the pressure caused the radiator to leak ?
I was so surprised to see this set up I had to check the pipe connective twice!!
A pic of the leaking radiator attached.

ACEngineering · Oct 6, 2019

Amateur said:
does one of the old jcb versions (or other machine) share the same torque & gearbox as the Thwaites dumper?
Clearly a separate oil cooler

As I said earlier, I am an amateur. Even my old ford 655D digger has a separate oil cooler.
Assuming it is a heat exchanger mechanism the inner pipe must be damaged and the pressure caused the radiator to leak ?
I was so surprised to see this set up I had to check the pipe connective twice!!
A pic of the leaking radiator attached.

your external rad water leak has nothing to do with it, there is a separate oil cooler for the transmission almost certainly the common JCB round tube type that often leak water in to the transmission.

ACEngineering · Oct 6, 2019

Amateur said:
does one of the old jcb versions (or other machine) share the same torque & gearbox as the Thwaites dumper?
Clearly a separate oil cooler

As I said earlier, I am an amateur. Even my old ford 655D digger has a separate oil cooler.
Assuming it is a heat exchanger mechanism the inner pipe must be damaged and the pressure caused the radiator to leak ?
I was so surprised to see this set up I had to check the pipe connective twice!!
A pic of the leaking radiator attached.

theres very little oil pressure in the cooler, will be more water pressure than there is oil.

Thwaites dumper stalls

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