1975 Sanderson 726 speed shift gearbox fault

[Lesliecaddy]

Can anyone help my Sanderson 726 will engage forward and reverse and drive but will not move up the gears

 

[essexpete]

@ACEngineering

 

[ACEngineering]

Can anyone help my Sanderson 726 will engage forward and reverse and drive but will not move up the gears

Got any error codes?

 

[Lesliecaddy]

Got any error codes?

Thanks very much for your attachments I really appreciate it, it didn’t seem to have any error codes but I am going to get back on the machine later on today and will let you know

 

[Lesliecaddy]

Got any error codes?

Just got back on machine and it has come up with error code ES

 

[ACEngineering]

Just got back on machine and it has come up with error code ES

Okay. That speed sensor so take a look at its wiring. I cant be certain but I would almost bet money on it that sensor is obsolete.

 

[Lesliecaddy]

Hi thanks for your help , the speed sensor was loose I removed it looks like it has been rubbing I tested between the two connections it Reads .339 ohms so looks like it could be good . I am going to refit by gently screwing it in until it comes I contact with cog then back off 2 mill I assume it is similar to an abs sensor on braking system , does the wiring go back to the ecu do you know ? also finally do you nave any wiring diagrams ?Again many thanks Les

 

[Lesliecaddy]

Just thought will the display automatically reset when the fault is cured ?

 

[ACEngineering]

Just thought will the display automatically reset when the fault is cured ?

yes once the fault is fixed that error will disappear. it wont be stored anywhere.

i have no idea what reading one should get on it or what gap there should be on it.

take note of any markings on it, i know of another speed sensor on a manitou that has to be in line with the direction of gear travel. not sure if thats same with others or not?

I do have a copy of wiring diagram for one but its very very poor you cant really make anything out on it!

The best advice i can give you is NEVER jump start it on 24volts! it will instantly fry the transmission ECU which is obsolete and render the machine scrap.

EDIT actually the best advice would have been not to buy a speed shift model in the first place but stick with the standard gearbox

 

[Lesliecaddy]

yes once the fault is fixed that error will disappear. it wont be stored anywhere.

i have no idea what reading one should get on it or what gap there should be on it.

take note of any markings on it, i know of another speed sensor on a manitou that has to be in line with the direction of gear travel. not sure if thats same with others or not?

I do have a copy of wiring diagram for one but its very very poor you cant really make anything out on it!

The best advice i can give you is NEVER jump start it on 24volts! it will instantly fry the transmission ECU which is obsolete and render the machine scrap.

EDIT actually the best advice would have been not to buy a speed shift model in the first place but stick with the standard gearbox

Thanks again for your help

 

[Lesliecaddy]

Hi would you or do you know any body who may have a schematic drawing of the speed shift gear box please , manny thanks Les

 

[ACEngineering]

Hi would you or do you know any body who may have a schematic drawing of the speed shift gear box please , manny thanks Les

What do you mean. Mechanical side of gearbox or electrics?

If electrics all you need to know is what I already posted. The solenoid sequence is absolute key to pin pointing faults.

The gearbox itself is very weak. The shafts shear off the clutch drums. Gearbox was only made for Sanderson no one else and only used in the later 726 type/style machines after that it was discontinued and never entered production again.

 

[Lesliecaddy]

What do you mean. Mechanical side of gearbox or electrics?

If electrics all you need to know is what I already posted. The solenoid sequence is absolute key to pin pointing faults.

The gearbox itself is very weak. The shafts shear off the clutch drums. Gearbox was only made for Sanderson no one else and only used in the later 726 type/style machines after that it was discontinued and never entered production again.

The mechanical side

 

[ACEngineering]

The mechanical side

Dont think I do. Still not got any drive? Spin the oil filter off see if you got oil pumping or and pressure. Pump might have failed or converter lugs ripped off or both.

 

[ACEngineering]

Dont think I do. Still not got any drive? Spin the oil filter off see if you got oil pumping or and pressure. Pump might have failed or converter lugs ripped off or both.

For get that you got pressure cause it drive in at least 1 gear both directions. So assuming you got no electric issues and solenoids are powering up in the right sequences required for each gear, I say you have the common failure of a sheared clutch pack drum off the shaft.

The only way you can fix that is by a very skilled man to reweld the drum to shaft and rebuild the box.

Problem is the weld often distorts the shaft/clutch pack and the weld has to be oil tight or it leaks oil pressure out the pack and in too the pack on the other side which in time will burn the plates out.

To be brutally honest I doubt the machine is worth fixing! I would check over all the axles and other common wearing points first before committing to a transmission repair.

 

[Lesliecaddy]

For get that you got pressure cause it drive in at least 1 gear both directions. So assuming you got no electric issues and solenoids are powering up in the right sequences required for each gear, I say you have the common failure of a sheared clutch pack drum off the shaft.

The only way you can fix that is by a very skilled man to reweld the drum to shaft and rebuild the box.

Problem is the weld often distorts the shaft/clutch pack and the weld has to be oil tight or it leaks oil pressure out the pack and in too the pack on the other side which in time will burn the plates out.

To be brutally honest I doubt the machine is worth fixing! I would check over all the axles and other common wearing points first before committing to a transmission repair.

Cheers for your help if you do happen to come across a diagram I would greatly appreciate it.
Thanks les