Ashcroft Transmissions have developed this MT82 6 speed gearbox Upgrade Kit to try to solve the problem of the spline on the rear output shaft wearing. This can cause a complete loss of drive as the spline frets due to it being dry. This is similar to the earlier LT77 & R380 mainshaft splines wearing in the transfer case.
The Puma Defender MT82 mainshaft exits the gearbox with a female to female coupling shaft (LR030054) fitted with a large bolt. The male to male coupling shaft (TUD500020) fits into this with the other end entering the transfer case input gear.
The spline that wears is the one at the rear of LR030054 and the front of TUD500020.
Ashcroft Transmisions have devised a method to make this splined interface wet with oil which in turn ceases the shaft from wearing.
A brand new coupling (similar to LR030054) has been produced with spark eroded slits in the face of the shaft where it fits to the bearing. On top of this loose two teeth from the front spline at 180 degrees to eachother (to let the oil through), then spark erode another two small slits on the rear face under the clamping bolt, this now allows oil to 'leak' out of the mainbox to this spline. We then machine a thread on the outside diameter and also make two O ring grooves.
The new shaft (like TUD500020) has a ground diameter that the transfer case input seals runs on, we machine this diameter further up towards the gearbox for the O rings below) to seal on.
A new alloy part has been manufactured which slides over the shaft, this has 2 O rings fitted to its inner diameter and this seals on to the new ground diameter of the shaft. It then has both a diameter to seal on the outer coupling O rings and a thread to fit it to the coupling.
A tube spanner is supplied to fit this part.
