Manitou 523 turbo drive problem

[tweedale terrier]

Good evening all. My neighbor has an intermittent fault on his manitou. It is a 1995 with mechanical shuttle. Sometimes when engaging drive it seems to be under strain (like the handbrake is on). If it is then stopped and started again it drives ok. Oil and filter have been changed. Open to suggestions!

 

[ACEngineering]

Good evening all. My neighbor has an intermittent fault on his manitou. It is a 1995 with mechanical shuttle. Sometimes when engaging drive it seems to be under strain (like the handbrake is on). If it is then stopped and started again it drives ok. Oil and filter have been changed. Open to suggestions!

MLT 626 or 725 at a guess?

Could well be the handbrake?
The cable does seize up now and again but more common are the levers on the front axle the cable attaches to.
the levers seize up on the shaft were they enter the axle.

Unless of cause its a series 2 with carraro axles which have a dry disc handbrake on the top of front axle drop box, which even if seized on will not stop it driving as they are just rubbish and will burn out in no time.

The other issue you could have is a problem with the section valve, there are orings on the main shaft I think which I assume if failed could leak oil to the wrong clutch pack? or you could have a internal issue with clutch packs etc

Once handbrake is ruled out you really need to pressure test the forward and reverse packs to see whats going on.

 

[ACEngineering]

From memory main transmission pressure in neutral at about 2000rpm is 80psi.

this pressure then rises to 180 psi in the clutch packs when they are engaged, the idea being an early form of soft shift so they were not bang in and out of drive but more gradual. It worked well.

 

[ACEngineering]

Edit didn't notice the MLT 523 model in the heading! it makes no odds its the same gearbox as the 626 and 725 series 1, 2 and 3.

How ever the axles are different so forget what I said above.

it could be 1 of 2 types I think? its more likely to have the carraro axle with the nasty Knott brake actuators on the top of it? you could have one or both of these actuators seized up, or I have had issues with the brake discs them selves warped but they bind on all the time. also the discs sit on some dowels/pegs these wear groves in them and do not allow the discs to float/move on them giving bad braking and sticky brakes.

 

[Sparkplug]

So the old MLT523 - bomb proof - pity the brakes weren't better- springs in the top of the transmission spool valve - easy too check but a little short on room - dump pedal is cable controlled on this model -worth checking for correct operation - can not be brakes as stated above - pressure test as said above always a good place to start -

 

[Sparkplug]

Could be brakes - as @ace says

 

[ACEngineering]

Could be brakes - as @ace says

always a nightmare trying to interpret a customers idea of the problem

 

[Sparkplug]

always a nightmare trying to interpret a customers idea of the problem

Had a customer several years ago who had everyone looking at his M426CP Manitou Transmission, and one day he arrived with it on a trailer - we stripped it but found no fault - sent it back and he still said it wouldn't drive - so I took a ride over only to see it parked on the concrete yard on full lock, bald tyres with only about 20 psi in them - I jumped on the seat and noticed it was in 4 wd - straightened the steering, rocked back and too to get it out of 4 wd (manual lever) blew tyres up to correct pressure and it drove perfectly - there never had been a problem - just that wound up on concrete with flat bald tyres plus the weight of around 5 tons, the transmission just had not got the power drive with everything wound up on slicks!! - when he saw me driving it round the yard normally he nearly fell over with disbelief - 2 trays of eggs was the payment from memory.

 

[tweedale terrier]

Thanks for all your help men. I'll pass the information on and see how we go.