Thread: R380 rebuild after 5th gear failure

Thanks for the detailed reply Dave.

Thanks mate, great news!

Resurrecting an old thread. My r380 has 350,000 on it. It had done towing over time including quite often a 2tonn boat. I tow lower weight now but it has had a 4.6 in for a while and heaps of torque. I have always towed in 5th. I find now in normal driving a vibration in 5th if I use 5th at 60 or 60kph. Still there at 100 but not as noticeable - in each case a down change to 4th on the straight through drive and vibration is completely gone. The 4.0 pulled 5tb easily at 70kph and the 4.6 does is easily at 60. So... I suspect I have stressed the box. Would it be flex in the lay shaft bearings causing the vibration ? Or teeth chewed on 5th? Combination?

I am thinking I'm up for a reco.box soon.

Cheers

Originally Posted by ozscott

Resurrecting an old thread. My r380 has 350,000 on it. It had done towing over time including quite often a 2tonn boat. I tow lower weight now but it has had a 4.6 in for a while and heaps of torque. I have always towed in 5th. I find now in normal driving a vibration in 5th if I use 5th at 60 or 60kph. Still there at 100 but not as noticeable - in each case a down change to 4th on the straight through drive and vibration is completely gone. The 4.0 pulled 5tb easily at 70kph and the 4.6 does is easily at 60. So... I suspect I have stressed the box. Would it be flex in the lay shaft bearings causing the vibration ? Or teeth chewed on 5th? Combination?

I am thinking I'm up for a reco.box soon.

Cheers

You could just pull the transfer box then the alloy 5th gear housing and replace the bearings and oil pump and go again.
I have done this and it keeps going fine

Thanks mate. Did you have the same symptoms or just noise? Cheers

Originally Posted by ozscott

Thanks mate. Did you have the same symptoms or just noise? Cheers

No I was just conscious that it could happen so did it as preventative maintenance
I did buy a 90 000 k old Defender gearbox with stuffed 5th gear bearings I redid the bearings with the intent of keeping it as a spare
Just haven't used it yet

Granny Ozscott stress 5th?!?

Yep I know Pete....hard to imagine hey?

Cheers