The Ashcroft Underdrive

The ultimate transfer-case add-on

Ashcroft in the UK makes these underdrive units. They look fantastic and, as the folks who use them affirm, they work even better. With this you have 20 forward and 4 reverse gears. The finish and the quality is absolutely professional- as is the price. Count around 1500-2000£ for one of these babies + transport. For more infos contact Ashcroft directly. These units can also be had as OVERDRIVES.

 

The Maxi-Drive Low Range Gear set

Maxi-Drive engineering from Australia have manufactures a pair of gears for the LT230 Transfer box which reduce the low range by 31%. High range remains unchanged. Here's the text they wrote on it:

Original intermediate/low 19/40 = 2.10 reduction

Maxi-Drive intermediate/low 20/55 = 2.75 reduction

The low range driven gear situated on the centre differential is larger and has 55 teeth. The low range gear is fitted onto a sacrificed new low range shaft. The intermediate gear also requires sacrificing of a new intermediate gear. The low range portion of the gear is machined away and the remaining gear is bored and ground internally. To support the new pinion a new high capacity 3-part needle roller is fitted directly under the low range pinion. The genuine tapered bearing is rated at 12000 N while the new needle bearing supports 40000N. The new gears are machined from the highest grade EN39b case hardened steel that achieves, after heat treatment, approximately 1250 MPA with a hardness of 60 rockwell. (That's what a VERY good knife is)

The only change to the casing necessary is to grind .050" flat on the gear change selector shaft to clear the larger bull gear and grind a couple of casting pips off. There is no reduction in casing strength. Also the magnet from the drain plug must be relocated.

Kit consists of

MDE Low Range Bull Gear T55 fitted to new hub

New genuine Intermediate Gear modified assembly T20

Needle roller assembly (in gear)

Taper roller fitted and pre-adjusted for pre load with sensitive spacer (not a collapsible tube)

There's a lot of different transfer case gears out there. If we don't have the right one on stock, we'll make it using a new part suited to your case. But you must provide all the Infos on your car.