Manitou burning rubber

[Swedeboy]

Our mlt 735 120 lsu burned the rubber thingy on the main drive shaft. New unit had less rubber and lasted two months, next one lasted even less and now it broke again.. Manitou replace it at their cost but now we can't trust the machine not to stop.
Anyone has the same problem and found a solution?
Thanks.

 

[BK741]

How old is it and which engine is fitted? There are kits available to convert older Perkins engines to use the latest flywheel damper plate fitted to the latest Deutz engine MLT.

 

[fergie35]

@ACEngineering

 

[ACEngineering]

Our mlt 735 120 lsu burned the rubber thingy on the main drive shaft. New unit had less rubber and lasted two months, next one lasted even less and now it broke again.. Manitou replace it at their cost but now we can't trust the machine not to stop.
Anyone has the same problem and found a solution?
Thanks.

Their is an upgrade to the original GKN shaft to suit most machines, and there is also a very good after market replacement shaft. the original GKN shaft is still available from Manitou but under a new part number just for machines that cant use the modification kits.

You will see a picture of the medication kit on my website as well as the aftermarket replacement shaft.

Both are very good and last well. The key to making them last is the engine must be dead in line with the transmission.
for which there is a special tool to bolt in place of the shaft so you can move the engine up down left right etc to suit. there are shims available from Manitou to put under the engine mounts to do this.

The tell tail sign the shaft is not dead in line is to run the machine for 15 to 20 minutes at idle speed then stop machine and feel the shaft, it should be cold, if its starting to warm up then its not lined up right.

See picture of the genuine Manitou tool, this is one I borrowed and I have since made my own.
Also see pictures of the modification kit and the aftermarket shaft. Which do you have?

I think there is also another poor aftermarket shaft on the market but not sure on that? do you have a picture of yours?

 

[Swedeboy]

And here is mine, any good this one?
I belive you are correct with things beeing out of line since this one took the bolts clean off.

 

[ACEngineering]

View attachment 403240And here is mine, any good this one?
I belive you are correct with things beeing out of line since this one took the bolts clean off.

They do this when the flanges are damaged, normally they get damaged when the flange is not fitted square and bolts tightened evenly or not tightened enough.

The bolts are supposed to be locitited/glued as well but I don't bother as they never give any trouble or come loose if they are fitted properly.

You need a new shaft or yoke and a new flange on the gearbox with new bolts. and make sure engine is aligned correctly.

 

[Swedeboy]

Thank you for your kind effort towards my education on this matter, I hope this will make us trust this otherwise very good machine!

 

[Morph]

I know nothing about this machine but, was always told ujs had to be at right angles at each end of the shaft. Something to do about shaft speed change during use.
If manitou do as the picture the alignment would have to be spot on to prevent failure.
Not trying to be clever just after some enlightenment in this installation.

 

[ACEngineering]

I know nothing about this machine but, was always told ujs had to be at right angles at each end of the shaft. Something to do about shaft speed change during use.
If manitou do as the picture the alignment would have to be spot on to prevent failure.
Not trying to be clever just after some enlightenment in this installation.

yokes should be inline not at right angles, this is the general rule of all propshafts/PTO shafts. is this what you are getting at?

and yes the more spot on aligned it is the longer they last. as it does not stress the rubber couplings and you also have less movement on the ujs so they wear less in theory, but UJs wearing out is not the ops issue its the rubber coupling and the fact its throwing the shaft off the flange and breaking bolts which is down to some one at some stage not fitting the shaft right in the first place so it fails and then its a never ending reoccurring problem of breaking bolts etc

 

[CarpenterPaul]

After 5 years of owning a used 1337 SLT I am still trying to sort out this terrible vibration at idle speed, especially under load (turning the steering wheel while standing, for example). The prop shaft gets into this resonating vibration that's so bad that the bolts on the engine side of propshaft come out even if they are loctited. After a while two bolt holes on the flywheel lost their threads, so I had the old holes welded and new bolt holes made. They barely squeezed the new ones in between the main flywheel mount holes. I think the new holes sent the flywheel slightly out of balance. Which didn't help the vibration at idle at all.

We did align the two propshaft mounts a couple of years ago. It's a little bit out of alignment again, but nothing criminal. I am attaching a pic of one mount. We had to raise it by about 10mm with homemade aluminum shims.

So, I am now wondering if:

1. I need a new flywheel?
2. I need new engine rubber mounts? What's the sign of them wearing out?
3. Could it be something out of balance inside the engine?
4. Something is wrong inside the angle box? Hydromotor connection to the angle box?

Also, related to this: is 1337 Manitou (with Perkins 1004-40T AK engine) supposed to rev up the RPMs automatically at idle under load? Because mine does not and I have to rev up the engine with my own foot.

Thank you for your answers in advance.

 

[barleybasher]

The charismatic Manitou Death Rattle! You can hear them coming!

 

[ACEngineering]

After 5 years of owning a used 1337 SLT I am still trying to sort out this terrible vibration at idle speed, especially under load (turning the steering wheel while standing, for example). The prop shaft gets into this resonating vibration that's so bad that the bolts on the engine side of propshaft come out even if they are loctited. After a while two bolt holes on the flywheel lost their threads, so I had the old holes welded and new bolt holes made. They barely squeezed the new ones in between the main flywheel mount holes. I think the new holes sent the flywheel slightly out of balance. Which didn't help the vibration at idle at all.

We did align the two propshaft mounts a couple of years ago. It's a little bit out of alignment again, but nothing criminal. I am attaching a pic of one mount. We had to raise it by about 10mm with homemade aluminum shims.

So, I am now wondering if:

1. I need a new flywheel?
2. I need new engine rubber mounts? What's the sign of them wearing out?
3. Could it be something out of balance inside the engine?
4. Something is wrong inside the angle box? Hydromotor connection to the angle box?

Also, related to this: is 1337 Manitou (with Perkins 1004-40T AK engine) supposed to rev up the RPMs automatically at idle under load? Because mine does not and I have to rev up the engine with my own foot.

Thank you for your answers in advance.

Yes you need a new flywheel, and most likely a new shaft too. Everything has to be perfect with that shaft or you will get regular problems.
You shouldn't need to shim the engine mounts by that much! the brackets will have come loose and sagged on the bolt holes to the engine.

You almost certainly do have wear in the 90 deg gearbox and on the splines driving the hydraulic pump which will be were a lot of the vibration you speak of will be coming from.

Engine needs to idle at 850 to 900 rpm often they are set too low
and no the engine is not supposed to rev up automatically under load.

There is a up rated shaft kit but by the sounds of it your machine might be too old for that to fit?
The up rated kit does not use the 4 bolts in the flywheel like the old shaft.

 

[ACEngineering]

The charismatic Manitou Death Rattle! You can hear them coming!

its fixable but not cheap!

 

[CarpenterPaul]

You shouldn't need to shim the engine mounts by that much! the brackets will have come loose and sagged on the bolt holes to the engine.

Is this the sign of worn-out mounts then?

 

[ACEngineering]

Is this the sign of worn-out mounts then?

No. If mounts are worn out the rubber will have perished and that cup on mount will be sat on the frame work.

In over 16 years I probably only replaced a hand full of them type mounts.
But often have to reposition the brackets on engine.

 

[barleybasher]

It's been a barsteward on 3 successive Manitou's that we owned before giving up on them. Probably fine if you don't shuttle back and forth a lot or do any hours, but then it is a loader!