Thread: Various R380 gearboxes

Originally Posted by Psimpson7

Ben, I think Justin has just swapped out his r380 for an isuzu truck box. It did last pretty well, from memory I think he said the input bearings got noisy.

Flagg, I broke a suffix L r380 comprehensively on a td5, but even after that I still think they are a good gearbox

Yep got 8 years out of mine and it was still ok. Just noisy in 5th with a slight vibration. Yes we are running a 1.2 trans on 4:11 diffs on 35's.

Just remember ITS NOT A RACE CAR and treat it the same way. We ran 75 x 90 smooth shift Nulon in ours as well.

Yes Pete is correct we are now running a MSA 5G Isuzu box.

Yes late 03 04 V8 Disco box is the one you want.

Justin

110landy86

I have run R380s suffix L and K behind my 4BD1T for nearly four years and the best part of 190,000ks of very demanding driving. Ii have no concerns about the strength of the gearbox and regularly travel to some of the remotest parts of the country solo.

Ashcrofts told me that the suffix L and K R380s are the strongest LR 5 speed gearboxes and are capable of handling 440NMs of torque.

The gear ratios work brilliantly with the 4BD1T (1.2:1 TC)

FWIW

CHT

I've had a couple of 'J' suffix R380's (none behind an Isuzu) and they push the oil temps to high for my liking - I had to change the oil (fully synthetic) quite often because it was degrading from the heat.

I know others on this forum are happy using them behind Isuzus, but personaly I wouldn't go out and buy one to use with an Isuzu, because INHO they are not up to the duty, especially working hard (towing or lots of sand).

I know others on this forum are happy using them behind Isuzus, but personaly I wouldn't go out and buy one to use with an Isuzu, because INHO they are not up to the duty, especially working hard (towing or lots of sand).[/QUOTE]

Bush65

I have done in the thousands of ks, with the 4BD1T/R380, in sand - both with and without a trailer - without any issues at all. I have also towed trailers for many thousands of ks on the highway - again without issuses. I have given serious thought at times to fitting an LT95 but have now decided to stick with the late suffix R380.

FWIW

C H T

Originally Posted by C H T

Bush65

I have done in the thousands of ks, with the 4BD1T/R380, in sand - both with and without a trailer - without any issues at all. I have also towed trailers for many thousands of ks on the highway - again without issuses. I have given serious thought at times to fitting an LT95 but have now decided to stick with the late suffix R380.

FWIW

C H T

Also FWIW - PSimpson7 destroyed a late model R380 fitted to a TD5 90.

I agree with John - it would taks similar time, effort and $$$ to convert to an R380 as to convert to an Isuzu box. The Isuzu box is much stronger and runs cooler. However, TheGrubb's conversion/adaptor kit was not available when you did yours.

There have been LT77s fitted behind 4BD1Ts which have survived OK. Does not mean I would fit one though

Originally Posted by isuzurover

Also FWIW - PSimpson7 destroyed a late model R380 fitted to a TD5 90.

I agree with John - it would taks similar time, effort and $$$ to convert to an R380 as to convert to an Isuzu box. The Isuzu box is much stronger and runs cooler. However, TheGrubb's conversion/adaptor kit was not available when you did yours.

There have been LT77s fitted behind 4BD1Ts which have survived OK. Does not mean I would fit one though

I'd be dumb enough to use an R380 behind a 4BD1T but it's interesting what Dave Ashcroft's answer was to one of my questions on here when we were discussing mainshaft breakages and bearing failures on R380's.

They were mostly behind tuned TD5's or HS2.8's.

Seeing as a 4BD1T has gobs more torque at lower revs than either of those two engines the poor little Landy 'box could only be considered marginal, but if I did use one I'd make sure it had an oil cooler and use a really good fluid like Motul Gear 300 that could cope somewhat better with the firing impulses than an ATF or MTF94.

Originally Posted by C H T

I know others on this forum are happy using them behind Isuzus, but personaly I wouldn't go out and buy one to use with an Isuzu, because INHO they are not up to the duty, especially working hard (towing or lots of sand).

Bush65

I have done in the thousands of ks, with the 4BD1T/R380, in sand - both with and without a trailer - without any issues at all. I have also towed trailers for many thousands of ks on the highway - again without issuses. I have given serious thought at times to fitting an LT95 but have now decided to stick with the late suffix R380.

FWIW

C H T[/QUOTE]
If you have a good R380, a suitable bellhousing, and can have the modifications done, then I was not advising against that route.

What I was getting at is; if you do not have most of the above, then instead of going out and buying them, I would spend that money on something I feel can more comfortably handle the duty. BTW I didn't mention or have in mind the LT95, LT85 or dare I say LT77.

This is what i did to mine at about 115k km: (probably due to abuse of reverse in large rocks)



98% of the work that had done was running std power figures. The last 2% was probably 170bhp/400NM.

I really dont think the torque of the isuzu is sufficient to break a decent late suffix r380. I also think the chiped TD5s have a more agressive power/torque delivery, and also higher peak figures than almost all of the isuzus. (and I am not refering to twin turbod state side things..) just LR applications.

Not many people actually seem to offer proof of the 4bd1t outputs...

TD5 outputs are easy enough to find. (from the je engineering website)

stage 2 - 400nm at just over 1850rpm and 420 peak roughly


The only 4bd1t one I have seen was 332nm at 1750rpm with a VNT, although he did say it had been improved and he thought peak torque may be as low as 1400 now.


Anyone got one to offer up?

Rgds
Pete