Newage 40M bearing issue.

[GlenM]

I have a 1984 Thwaites Alldrive 6000 which I am still using at work for my building company.

I have a recurring problem with the Newage 40M2S gearbox. It was fitted with new bearings by the previous owner but about 18 months ago my Father stripped it down because it was getting noisy. We fitted new bearings,and some other parts, but the main issue was that the needle roller bearing at the front of the layshaft had disintegrated. After the re-build it seemed much quieter and worked very well.

I have just had to take it out again, because it has become slightly noisy, but mostly because when I changed the gearbox oil there were pieces of needle roller bearing in the sump plug. Again the front layshaft bearing has broken up and we think that the shaft is moving forward and chewing up the bearing and the brass cup that it sits in.

According to the parts list there is a spacer at the rear of the layshaft but not at the front. Is this correct? There appears to be enough clearance at the front of the shaft to fit a similar spacer, which would give the bearing a better chance of survival. Is there any other reason for the bearing getting damaged? There does not appear to be any significant wear on the nose of the layshaft and it still measures exactly 1".

Thanks,

Glen.

[GlenM]

An update on this thread.

The gearbox went back in a few weeks ago with a couple of shims added at the front of the layshaft. It's probably not an ideal solution as the shims will inevitably restrict the amount of oil that gets to the needle roller bearing, however, without them it gets destroyed anyway. Since it was re-fitted the machine must have shifted a couple of hundred tonnes of soil, scalpings, rubble and concrete, pretty good for something that is now 31 years old.

I am going to try an pick up another gearbox to overhaul and keep as a spare.

[Jeremy Rowland]

Thanks for the update Glen and good luck with the modification; it will be interesting to see how it stands up long term?

Jeremy

[GlenM]

The gearbox is still hanging on at the moment, although I am sure it has started to whine a bit more recently.

I have seen a 40M833T123 gearbox for sale, would this be a straight swap for the 40M2S?