Outer Limits 4x4 Board

Any thoughts if we can manage to do that? would be ideal to keep the 3.54s in the diffs which are by far the strongers, and we can get a nice crawl ratio of 3.32 x 3.32 x 3.32 x 3.54 = 129

Well, I assume you are aware of the M-D gear set. Gives 4.34:1.

http://members.shaw.ca/red90/gears.html#tcase

Ashcroft was making a 2.69:1 underdrive, but have discontinued production.

I have looked it this a little bit and I dont think it would be to hard to to make an underdrive using the 3.32:1 planetry reduction out of a viscous transfer case out of a '89 to 94' range rover especially if you are running a ZF auto.

Basically the transfer case would stay where it is and you modify the spud shaft so that instead of driving into the transfer case is pokes all the way through and out the back of the transfer which is where you mount the planetry reduction. In the roughest form the spud shaft could just be cut and extended by welding. Then you just got to weld a locking dog onto the planetry reduction outer part to drive back into the transfer case on the back of the gear. This is standard way all the underdrives and overdrives work. You would then end up with an extra selectable 3.32:1 rteduction because the plantry is selectable to 1:1 or 3.32:1.

The only problem is that I feel an extra 3.32:1 reduction wouldnt be worthwile you would basically end up with a 10:1 transfer gear ratio which IMO would be a lot too low.

Sam

Red90, I know that the MD exists, but was wondering whether or not the doubler would be possible since it would be MUCh cheaper and a lot better.

Sam,

Thanks for your input...was hoping you'd join in this topic.

The final crawl ration of 11:1 in L/L is indeed a lot, however, that would allow us to stick to the 3.54 diffs, which are far stronger than anything out there. I was hoping that we can use the same driveshaft front and rear, which would be ideal in the spares department.
If we do the math, for 1st gear, High/Low, as that would reflect somewhat all other gears, this is what we get per set-up:
1. 1.20 x 3.32 x 4.11s = 16.37
3.32 x 3.32 x 4.11s = 45.3
2. 1.20 x 3.32 x 4.7 = 18.7 (what I currently have and need more)
3.32 x 3.32 x 4.7 = 51.8
3. 1.20 x 1.20 x 3.32 x 3.54 = 16.9 (H/H)
1.20 x 3.32 x 3.32 x 3.54 = 46.8 (H/L)
3.32 x 3.32 x 3.32 x 3.54 = 129.5 (L/L)

Choice #3 is nice since you'll get highway economy with the 16.9, mud and "ooomph" capabilities with teh 46.8, and rock crawling attributes with the 129.5! I like this!

Having the Choice is a good idea, and the fact that you are using LR components means that parts are pleanty and cheap (as far as the Lebanese market in concerned).

One thought though...slapping 2 LT230s together means that we'd have DUAL LOCKING CENTER DIFFS...how the HELL will that work? One constantly locked and the other open for normal use, and then lock the other one??? Confusing, head hurting...Sam...

IMHO doubling with 2 LT230's is not on. No practical way to get the output from the 1st LT230 to be input to 2nd LT230.

This was available.
Ashcroft Transmisions England, but they have recently stopped manufactuer. Cost was 1500 pounds.

Michael.

HSV Rangie

Take the spaces out of the file names for attached pics.

I know about the Ashcroft and the MD 4.3:1 and so forth, but the idea of using stock LR parts is just too tempting, and knowing that most of us have access to LR wreckers and so forth, its really a good idea in my opinion...making it or not, is what you guys are here to do...

MAKE THIS HAPPEN!

what about dual hilux cases...what sort of ratios do they come in and how strong do you reckon they are compared to LT230....just a thought

Dunno about Toy stuff, but frankly, their axles are better, and we're using them, their cases are better, and now we're considering them...just makes me feel "ikky" inside to have a good drivetrain and not a s****y one...

So...Dual cases in a LR...any thoughts?

Sorry dual LT230's just aint going to happen. The arrangement of gears and shafts is not suitable.

You could put the LT230 behind some other transfer case with an inline rear output. I wouldn't use more than 2:1 doubler reduction, even then the strength of the centre diff would be suspect.

Bush65 wrote:Sorry dual LT230's just aint going to happen. The arrangement of gears and shafts is not suitable.

You could put the LT230 behind some other transfer case with an inline rear output. I wouldn't use more than 2:1 doubler reduction, even then the strength of the centre diff would be suspect.

Agreed - although what I suggested before would work but thats really an underdrive as opposed to a doubler.

Sam

what about putting dana gears into an overdrive box and bolting that in?
i know of at least 2 of these in melbourne. they are in fairy casings and behind a series box and a lt95.
both very series rovers. (offroad rovers' 2 trucks)
i'm not sure of the availability of overdrives to fit later rover transfers though??
my 2c

modman