Thread: Suffix 'K' vs 'J' R380 ??

I've read Dave Ashcrofts description of the differences between the 'J' and 'L' 'boxes,

Ashcroft Transmissions
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 on the suffix G transfer cases.
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.

Just wondering what was different in the 'K' 'box, seeing as my very late '98 has one !

Originally Posted by PAT303

Dave what do you run in your R380's oil or ATF?I have been thinking about running a thread to see what people run and how long they last and problems they have to find out if there is a difference in it.From what I have gathered ATF seems to give longer life. Pat

from their FAQ

What oil should I use in my R380 gearbox? We recommend MTF94 in your R380 box.



Ashcroft Transmissions