Thread: R380 Layshaft failure

Hey Pete, I think you should get Sam to drive all the hard tracks in future - she is much gentler on the drivetrain

Let me know if you need a hand pulling the box out.

Ok I got this out and on the bench by Wednesday evening.

Grimace has just given me a hand to strip it down and it doesn't look good.





Casing damage

were there any signs leading up to the failure.....I can only assume it will happen to mine sooner than later....98 110 with 2.8tgv and tow 1.8t 5 days a week......

This suffix J did unfortunately have a couple of design flaws which gave the R 380 some bad press, they were prone to the mainshaft shearing across the oil feed holes, the layshaft also sheared at a stress concentration behind the sandwich plate causing loss of 5th and reverse also early ones still suffered from mainshaft wear until the cross drilled transfer case gears became fitted as standard on the suffix G transfer cases.
In 1999 the suffix K was used very briefly for a few months then came the suffix L. The K and L are virtually identical, the only difference I have found is the L outer main casing has an additional strengthening rib, internals are the same. The J and K/L are very different, 2 of the bearings were substantially uprated and pinion and layshaft teeth were widened again, this results in a much stronger unit.

From Ashcrofts.



It's sheared as the earlier 'J' boxes did.


Looking at it I'm guessing an insufficient radius or a step or some other form of stress raiser where the shaft sections from the bearing to the gear ?

[edit] Should someone PM Dave and ask his opinion ?

Would be interesting to see what his opinion is.

I am assuming the rear housing is scrap because of the damage around where the oil pump goes.

Serg, there was no warning what-so ever. My girlfriend was driving, doing a steady 100k on a light throttle opening in 5th when it let go.

Its a shame that there don't seem to be any upgrade options for them.

I may start looking into an Auto conversion.

Hi,

it need'nt cost that much to fix, an auto conversion will be much more :

layshaft £ 85
2 x support bearings £ 32
pump £ 34 (includes ali housing)
5th main if required £ 38
5th lay if required £ 38
layshaft nut £ 3
rear seal £ 3

Dave

Thanks Dave,

Thats good news. Will give you guys a shout during the week to order some bits!

Rgds
Pete

Quick update on this one.

I ordered a load of bits on Thursday night at about 9pm from Dave, and they arrived at 10am this morning!

Very impressive. Have since discovered I needed a few more bits, so emailed Dave and they will be shipped today.

This is what I ordered in the first order:

layshaft , genuine
2 x support bearings - rear of extension housing, lay and main shaft.
Oil pump and o'ring.
layshaft nut
rear main shaft oil seal
Oil seal collar
ring oil feed
Oil filter
2 x Oil bypass Orings
main shaft circlip (Fitted to main shaft within extension housing)
front cover oil seal

The extra bits are the front and centre layshaft support bearings (TZZ100200 and FTC2385), the reverse idler bearing, and the steel ring that sits in the front of the oil feed ring.

I've already fitted the oil pump, seal and bearings in the extension housing.