Thread: Transfer Box Replacement

its a pretty straight up job, theres nothing special about it other than a bit of weight and you need to be carefull of the input seal on installation.

I did mine last weekend, as Dave said fairly staightforward, do yourself a favour and get a rave CD from the shop section on this site, and follow the instructions. Like Dave said be careful with the input seal when you are putting the t/c back in.

Cheers, Mick.

Make up some long bolts with heads removed to guide the t/case onto the gearbox, and leave the input gear out until after the t/case is bolted up.

Then you will have no worries with the input seal.

Originally Posted by Bush65

and leave the input gear out until after the t/case is bolted up.

Not possible on 1:1 cases AFAIK. But possible on 1.4:1 - which I assume the vehicle in question has.

Originally Posted by isuzurover

Not possible on 1:1 cases AFAIK. But possible on 1.4:1 - which I assume the vehicle in question has.

I have a project in progress where it will be possible. Have to get around to reassembling LT230 with 1.003:1 high range.
It is impossible to insert the 26 tooth standard input gear which drives the 41 tooth middle gear on the intermediate shaft cluster with the gearbox output shaft in place in the transfer box because you cannot get it past the larger 44 tooth high range rear gear on the cluster.
Having slightly faster high and lower low range in 300Tdi Defender 130 would be improvement for my purposes. It looked to me that dimensions in a 1.003 box would allow a 22 tooth input gear lined up to drive the rear 44 tooth high range gear (like series transfer boxes but back to front).

Anyway, I got a gear made. Not quite as expensive for similar result to installing Maxidrive 30% reduction gears in Discovery transfer box. Only one gear to cut, but helical and with internal spline. Didn't bother with PTO /overdrive dogs - expensive and very unlikely to be wanted. Overall result 1.27:1 high range - not quite as fast and 4.21:1 low- not quite as slow. With standard helical low gears, no whine as with straight cut Maxidrives. Note Maxidrive gears could be installed as well for extra slow low range.

This special input gear, which meshes with the rear (high range) gear on the cluster can be installed with the transfer box bolted to the gearbox.

Intend to post some photos in maybe a couple of months time when hopefully I will find time to assemble it. Haven't yet heard of anyone else trying this non standard input gear idea. Only worth considering for 1:1 boxes even if shaft centre distance with others allows a properly meshing gear to be cut. With 1.2:1 types, would make little difference to ratios and with 1.4 Defender type, both high and low would be faster than standard.

Note the bloke who cut this special gear for me has recorded the dimensions. So if anyone happens to want another one after mine has been tested, he does not need a box for measurements or to do more design work.

Thanks for all the info everyone, i can now make an educated desision and save a few $$

cheers Tristan

No one mentioned the need to seal the threads on the two bolts which protrude into the TC from the front. If you don't do this it will leak like the input seal is knackered.

BTW does anyone know the finer details to adjusting the quadrant box for a good feeling shifter????

Peter: SE QLD
White 96 Defender Bigcab 130 HCPU

If you are replacing the original t/case with a different one, be careful to check the dowel pins.

When a t/case is separated from a gearbox, it is pot luck as to whether the locating dowels stay with the t/case or the gearbox.

If the replacement t/case has a dowel pin in the same location as a dowel pin in the gearbox, you will have a problem getting the t/case to bolt up properly.

Conversely, if any dowel pin is missing from both the t/case and gearbox, proper alignment is not assured.

I recommend fitting the t/case up to the gearbox while the input gear is removed. Be aware that to get the input gear in there is only one position of the intermediate gears where a tooth space on the high range gear is in line with a tooth space on the gear that the input gear meshes with.

If you have a good look at this while the t/case is out of the vehicle it should become clear. It is best to be clear about this before you try to fit the input gear. Before you fit the input gear, rotate the drive shaft flanges to position the intermediate gears where the 2 tooth spaces line up and let the input gear slide into place.