Manitou transmission noise

We've got a old manitou mlt630 120lsu 4 speed manual, the first time I drove it down the road when under load it sounded ok, but as soon as you let off the throttle going down a hill it growls like mad, honestly sounds like the transmission is going to explode.

I took the 90deg box and transmisson out of it yesterday expecting to find the transmission in a hell of a mess inside, but its not, its mint. The oil is like brand new, no bits of metal in it anywhere, all the bearings are like new all the gears are mint. I think its either had a new one in or its recently been rebuilt.

Just took the 90deg box to bits the main shaft looks in good condition, abit of wear on the hydraulic pump splines but for the age of it I can live with that, the big nut was a little loose, maybe 1/8th of a turn but I don't think its done any damage to anything. Bearings seem in good condition. And very little backlash on the gears when it was assembled.

The only thing I can find that are knackered is the shaft from the engine to the 90deg box (i've got a new one for it), and the 2 gears in the 90deg box have some damage to the teeth.

Would the damage to these gears cause such a loud growling noise when going downhill ? Not sure if I'm barking up the wrong tree with it, or the 2 gears are the only problem with the whole thing.

I've got a good 2nd hand 90deg box and transmission for it out of a burnt one as I thought one or both were going to be completely destroyed inside, but thats not really the case.
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Sharpy

Member
Livestock Farmer
We've got a old manitou mlt630 120lsu 4 speed manual, the first time I drove it down the road when under load it sounded ok, but as soon as you let off the throttle going down a hill it growls like mad, honestly sounds like the transmission is going to explode.

I took the 90deg box and transmisson out of it yesterday expecting to find the transmission in a hell of a mess inside, but its not, its mint. The oil is like brand new, no bits of metal in it anywhere, all the bearings are like new all the gears are mint. I think its either had a new one in or its recently been rebuilt.

Just took the 90deg box to bits the main shaft looks in good condition, abit of wear on the hydraulic pump splines but for the age of it I can live with that, the big nut was a little loose, maybe 1/8th of a turn but I don't think its done any damage to anything. Bearings seem in good condition. And very little backlash on the gears when it was assembled.

The only thing I can find that are knackered is the shaft from the engine to the 90deg box (i've got a new one for it), and the 2 gears in the 90deg box have some damage to the teeth.

Would the damage to these gears cause such a loud growling noise when going downhill ? Not sure if I'm barking up the wrong tree with it, or the 2 gears are the only problem with the whole thing.

I've got a good 2nd hand 90deg box and transmission for it out of a burnt one as I thought one or both were going to be completely destroyed inside, but thats not really the case.
View attachment 1038448

View attachment 1038449
That is fubared. End of story.
 

ACEngineering

Member
Location
Oxon
I think i'll replace them and give it a go, i just don't want to put it all back together and to have missed something simple.

Them gears are scrap on its or buts about it😂

If your mainland uk then let me know if you want parts, could have just saved you a load of hassle and sold you a new 90 deg box but can do the parts aswell.

If you have shims to preload bearings you want to ditch them for calibrated spacers and theres an upgrade to input bolt and washer.
Loctite the hell out of the big nut but I would replace the main shaft and the flanges myself.

Do it right and wont be going back in there again, skimp and I guarantee you will be back in there again, there so common to fail.
 
Thanks for the advice

I think we are just going to replace the bevel gears, bearings and seals. Rebuild it and get it back together. And see what its like. It only gets used for off loading bales in the yard so does probably less than 100 hours a year.

Its not been the most reliable machine since it turned up, so I don't fancy chucking 2 grand at it for something else to go wrong with it next week. It already needs the hydraulics sorting out after its put back together, i think they just need calibrating and some new ball joints on the throttle sensor. If not it will be looking for a new owner, hopefully somewhere hot and far far away.
 
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HSENI names new farm safety champions

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Written by William Kellett from Agriland

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The Health and Safety Executive for Northern Ireland (HSENI) alongside the Farm Safety Partnership (FSP), has named new farm safety champions and commended the outstanding work on farm safety that has been carried out in the farming community in the last 20 years.

Two of these champions are Malcom Downey, retired principal inspector for the Agri/Food team in HSENI and Harry Sinclair, current chair of the Farm Safety Partnership and former president of the Ulster Farmers’ Union (UFU).

Improving farm safety is the key aim of HSENI’s and the FSP’s work and...
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