Thread: R380 bearbox, how is it different?

The R380 gearbox is an improvement on th LT77 gearbox as fitted to 200 Tdi defenders and Discoverys. It is a reasonably strong unit, better than any previous Rover 5 speed box, though not as strong as the old 4 speed RR gearbox. As long as you don't tow really heavy things in 5th gear and you use the correct oil it shouldn't give much trouble.

Yours is probablly different to mine as yours must contain bears!!
Look out if you have ever gt to open it. Those bears will be agro.

As said the 380 is better than the LT77.

Originally Posted by BigJon

The R380 gearbox is an improvement on th LT77 gearbox as fitted to 200 Tdi defenders and Discoverys. It is a reasonably strong unit, better than any previous Rover 5 speed box, though not as strong as the old 4 speed RR gearbox. As long as you don't tow really heavy things in 5th gear and you use the correct oil it shouldn't give much trouble.

Correct me if I'm wrong here, but reading around the impression I got of strength in gearboxes was that Series 1 was pretty dodgy, Series 2 ok, 2a tough, 3 quite a bit weaker, LT95 (Range Rover and V8 or Isuzu diesel 1980-1985) seriously tough (and stronger again in LT95a with the Army), LT85 5-speed (1985 - 1990? - "the Spanish box") a bit behind that, LT77 little better than a Series 3 and R380 pretty close to the LT95. The big problem with the LT95 is that it's only a 4 speed, so of the 5 speed boxes, R380 wins hands down.

The history of these boxes is interesting - the R380 is a re-engineered derivative of the LT77, which was originally a Jaguar gearbox never designed for off-road stresses. What the Series 3 box's excuse is I don't know. The numbers after LT refer to the distance between the input and output shafts, in mm. R380 stands for "Rated to 380Nm of torque."

Any comments from people who've broken any or all of those?

My understanding is the R380 is the best 5 speed, as you have stated, but it is nowhere near the strength of the old RR 4 speed. The gears inside those boxes are massive!

Originally Posted by scrambler

Correct me if I'm wrong here, but reading around the impression I got of strength in gearboxes was that Series 1 was pretty dodgy, Series 2 ok, 2a tough, 3 quite a bit weaker, LT95 (Range Rover and V8 or Isuzu diesel 1980-1985) seriously tough (and stronger again in LT95a with the Army), LT85 5-speed (1985 - 1990? - "the Spanish box") a bit behind that, LT77 little better than a Series 3 and R380 pretty close to the LT95. The big problem with the LT95 is that it's only a 4 speed, so of the 5 speed boxes, R380 wins hands down.

The history of these boxes is interesting - the R380 is a re-engineered derivative of the LT77, which was originally a Jaguar gearbox never designed for off-road stresses. What the Series 3 box's excuse is I don't know. The numbers after LT refer to the distance between the input and output shafts, in mm. R380 stands for "Rated to 380Nm of torque."

Any comments from people who've broken any or all of those?

The selector broke on my 96 defender, left me stranded not a gear could be found! ! some were alloy evidentley, had it replaced with new steel one, no probs since.

Sumo

mine was fine towing trailer around Aus spent most of the 35,000 k's in 5th gear and did not miss a beat. Lot better than the LT77

I broke the teeth off the shaft for reverse in an r380, mind you I had to be a complete idiot to make this happen.. It was in a 3.9 v8 disco

Instead of being smart and reversing the 500m required, turning around then reversing back to snatch out an overloaded well and truely stuck 4x4 I did it in reverse....

Murphy was not smiling on me... The snatch strap stretched just enough for me to hit some good ground, Full noise on the V8, tyres down to 15psi-ish full traction when the strap ran out of give, no vehicle movement and I was getting axle hop in reverse something had to give, reverse gear was it.

R380 technical info from Dave Ashcroft's web site:

Shift Improvements

In order to reduce the problems with 1 - 2 shift, a number of syncro improvements have been made, one of them being we fit stronger syncro springs, this makes the baulk ring bite the gear better to stop it "grinding" into gear.

R 380 Development

The R 380 was introduced in 1994 with the suffix J which was a significant improvement on the LT 77 it supercedes, differences included a steel oil pump (as opposed to the LT 77 fibre one), an additional 2 support bearings were used on the layshaft and the mainshaft, wider gears, bigger diameter syncro rings, syncromesh on reverse and a longer mainshaft spline.

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.

In 1999 the suffix K was used very briefly for a few months then came the suffix L that is used currently. The J and 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.

Cooling

It is not abnormal for the R 380 to run quite hot and this often results on either baulking or sticky shifts which can often be improved by either an oil additive or different oil. On the short stick boxes or it can cause the actual gearstick pivot ball to get tight in it"s socket which you can improve by stripped, cleaning oiling and replacing.

If you feel your unit is running too hot then bear in mind Landrover make for 2 main markets, Europe and Rest of World (ROW), the ROW spec TD5 Defender and Disco gearboxes are oil cooled but Europe spec are not, there is some debate as to whether they should be, especially if you live in south Spain or Italy Etc.

The temperature the box runs at will have an effect on it"s lifespan, please have a look in the misc section for details of oil cooling kits.