Thread: R380 rebuild after 5th gear failure

Hey Paul,

Thats a bugger.

I agree with TeamFA and would absoloutely replace the layshaft. It will have had a very hard time with no support from the broken rear bearing.

I would be certain its lifespan wouldnt be very long if you reused it. The tail is pretty small and it woudlnt have been enjoying itself in the last few hundred K's

cheers
Pete

is the oil pump something that gets replaced as a matter of course when doing these R380 rebuilds?

I would suggest it's a wise idea. They aren't very expensive

Originally Posted by Psimpson7

Hey Paul,

Thats a bugger.

I agree with TeamFA and would absoloutely replace the layshaft. It will have had a very hard time with no support from the broken rear bearing.

I would be certain its lifespan wouldnt be very long if you reused it. The tail is pretty small and it woudlnt have been enjoying itself in the last few hundred K's

Dave Ashcroft seems to think it will be OK. I might give him a call and discuss it further with him. Replacing the layshaft is my preference.

When you talk to Dave ask him if he's any further along increasing a couple of bearing sizes.

He'd found at least one bearing that was slightly larger and it looked like it was possible to bore out the housing to take it.

Can't recall now whether it was a layshaft or mainshaft one.

Was there a bit of a noise in 5th and reverse that you either ignored or hoped would go away?

The reason I ask is that as soon as mine developed a noise, I pulled it down and found that bearing looked like this.


I had no other damage. I think your bearing looked much worse than mine. I'm assuming it takes a lot of play in the bearing to cause broken teeth.

I guess what I'm looking for is some sort of reassurance that if I keep my ear tuned for the bearing noise, I can avoid the more disastrous failure that you have experienced.

I too recently replaced the 5th gear bearings on a R380 mine looked like VNX205s with no damaged gears.
I wonder if there is a point at which we should replace the layshaft due to fatigue?
I didn't but am now wondering if I should have

Originally Posted by vnx205

Was there a bit of a noise in 5th and reverse that you either ignored or hoped would go away?

The reason I ask is that as soon as mine developed a noise, I pulled it down and found that bearing looked like this.

I had no other damage. I think your bearing looked much worse than mine. I'm assuming it takes a lot of play in the bearing to cause broken teeth.

I guess what I'm looking for is some sort of reassurance that if I keep my ear tuned for the bearing noise, I can avoid the more disastrous failure that you have experienced.

Mine made no noise at all in 5th prior to the failure. The only noise that I had noticed from the gearbox was in neutral - the gearbox had a rattle which I assumed was a bit of bearing/gear slap caused by engine vibrations/harmonics. I have a Rakeway solid flywheel so I expected a bit of vibration and I really only noticed the noise after changing the flywheel.

To be honest, I think your bearing looks much worse than mine. The hardening on mine has started to break up but not to the extent that yours had.

I'm really not sure that the bearing had failed prior to the 5th gear damage. I think that the gear may have failed first and the bearing fell apart as I disassembled the gearbox.

Listening for unusual noises is definitely going to catch problems before they become more significant. Unfortunately for me this was the only noise I had heard in 5th ...