Thread: R380 rebuild after 5th gear failure

Even with Syntrans, 20,000km is the absolute maximum life of the oil IME, it has started to shear by that stage and you can really notice the improvement in shifting and lower noise when you do an oil change.

The lube just cops a pasting in these 'boxes, I'm guessing a combination of (too small) a small volume of oil and the iron case retaining heat just clobbers the oil.
A decent oil cooler should definitely help.

For the last few years (over 80,000km) I've been using a 75W-90, first Torco RTF (not really suitable for an R380) and then Motul Gear 300 which so far has been very, very good.

I've jumped that way as the Tdi doesn't have an oil cooler and with Redline MTL and Syntrans I was getting a lot of gear rattle, with the shift quality deteriorating at high ambients/loads. (anything from 35*C up.)

The last week here peaked at 41* officially, and I measured 43* 1m above the ground in the shade between two digi thermometers that I've checked calibration. The gearbox noise and function was absolutely normal.

As a question does the R380 5th gear take a bigger pounding with the Discovery transfer case vs the Defender transfer case?

Just got this in an email from the supplier in the UK when ordering bearings

I’ve just had a chat with a few of our suppliers, it seems like they are offering NSK instead of RHP for the OEM bearings now because NSK are the parent company,


Dave Ashcroft do you have any comment on this?

Originally Posted by uninformed

awabbit6, If you havent already bought from them, check their pricing with Gibbs Truck Parts....when I did, Gibbs was about $100/20lt cheaper than QDS

Already purchased 3 x 1L bottles.
I decided that I'd never use 20L. That and the fact the the budget didn't really stretch far enough for 20L.

Originally Posted by robbotd5

... What are your thoughts on towing in 5th? Also, did you have to use any special tools to strip the box?

I'll still tow in 5th but I will be more careful about how much I allow it to load up before I change back to 4th. The problem with the remapped ECU is that the Disco easily pulls the camper up significant hills in 5th. Rather than letting it work in 5th and admiring the torque, I'll drop back to 4th.

No special (LR) tools are really necessary. I did buy a press to do the job but that is because I have other gearboxes (non LR) to rebuild in the future. A good bearing puller is also handy. The R380 is quite an easy gearbox to dismantle.

Time for an update.

Parts have arrived and I have started putting the gearbox back together. I hadn't removed any of the tapered bearings from the layshaft or the input shaft until the rebuild kit arrived as I was certain that they were going to be damaged during removal. I wanted to make sure that I had new bearings infront of me before I destroyed the old ones.
The kit contained everything that you would normally replace in an overhaul - very comprehensive.

The remaining bearings came off pretty easy. The only one that slowed me down was the bearing race for the pilot bearing in the end of the input shaft.



There is little to pull on internally and I don't own a pilot bearing puller which is the only tool that I could see moving it ... Then, I was reminded of a trick for removing internal races. Weld around the inside of the race! As the weld cools, the race contracts and drops out. Out with the TIG!



I did a few short welds and by the time I was half way around it started sliding out of the input shaft! Works really well ... if you have a welder ...

Putting the new syncro rings next to the old, the wear is even more evident.



So at this stage, I have reassembled the mainshaft (input and output) with new bearings and syncro baulk rings and fitted new bearings on to the layshaft. The oil pump is back in with a new o-ring and gasket and the shifter is reassembled with new bushes. Taking my time at this stage to avoid mistakes.



Tomorrow I'll dummy fit them into the housings to check for excessive end float then onto final assembly.

The lube just cops a pasting in these 'boxes, I'm guessing a combination of (too small) a small volume of oil and the iron case retaining heat just clobbers the oil.
A decent oil cooler should definitely help.

That's the reason I fitted the Roverdrive increased volume transfer sump with cooling fins. Filled with Syntrax. No probs thus far.
Regards
Robbo

Originally Posted by djam1

Just got this in an email from the supplier in the UK when ordering bearings

I’ve just had a chat with a few of our suppliers, it seems like they are offering NSK instead of RHP for the OEM bearings now because NSK are the parent company,


Dave Ashcroft do you have any comment on this?

Hi,

Yes I do ! NSK and RHP can be treated as the same company,

This week we have found out that the 2 R380 rear support bearings, LR numbers FTC2385 and FTC3371 or bearing numbers RJ2023 and RJ2022 have been made obsolete !!!!!!!!!!!!!!!!

Ie RHP are no longer making them !!!!!!!!!!!!!!!!!!!!!

They are a special design for LR and will not make anymore for anyone else.

There are 3 other brands worldwide,

Newsun/ Chinese, don't last 3 months
Britpart/ Indian ?, maybe 3-4 months
A & S Fersa, Spanish, last 6 months

Even the RHP isn't great and they are often the first thing to fail in the 380, I think that's what has cause this 5th gear to fail, the bearing fails and the gear teeth come out of mesh and strip,

I have bought up all RHP I can find and am looking for an alternative without machining the casing but I may have to do this due to the weird sizes,

Dave