Hi,

due to ongoing demand in the US and Europe we decided last December to make another batch of Underdrives. We are now in the final stages and time to make it public knowledge.

They have been designed to allow us to improve manufacture and make a larger batch size than before allowing us to reduce the costs to hold the final price down.

We are making 50 initially and aim to have them available from early July 05, we have had a lot of initial interest and I think these 50 will sell quite quick, if they do, we will make more but this will take a few months.

I have watched the ongoing thread with much interest and if nothing else it has shown these items are by no means easy to make, I don't say that to show how clever we are, I say that to help some customers understand why the unit is quite expensive.

we have also developed a Crawler low ratio gear set for the LT230, this gives a 1.222 ratio high and a 5.95 low ratio.

More details on these two here :

http://www.ashcroft-transmissions.co.uk/category_12.html

we will be adding more info and new photos shortly,

Dave,

Congrats on this - it is an achievement. The demand of such a product has sprouted many a great effort from around the world and all people that went into this have indeed provided to the effort.

Nadim

Dave, was their ever talk of a fix for the jingle the Gen 1's make.

afraid not, I think was due to the earlier type of selector fork,

Wow that underdrive is very cool.
OK, now I understand why folks want to put the SM465 infront of an LT 230.
6.53*3.321*2.69*4.7=275:1 final
With 3.54 gears its still 200:1
Oh my, oh my, oh my
Where my exchange rate calculator?
:D

i suspect that the low range gears will sell quite well- i applaud your effort on that one and i look forward to purchasing a set from you eventually!

Wow that underdrive is very cool.
OK, now I understand why folks want to put the SM465 infront of an LT 230.


Oh, you mean like this?

http://tawayama.com/gear/crewcab/divorcedtcase.jpg

:flipoff2:

Nice job Ashcroft. I know that just getting one is tough (I watched a one-off custom job built locally in the US). Getting many is a job to congradulate.

:D

Nice job Dave.

Tell me are the 1:1 gearsets available yet?

Nice job Dave.

Tell me are the 1:1 gearsets available yet?

I am told W/C 20/6/5

we have also developed a Crawler low ratio gear set for the LT230, this gives a 1.222 ratio high and a 5.95 low ratio.

Now that sounds great for us guys using the PTO output for other things!

Dave,

:bounce2: :bounce: :bounce2: Thanks for taking your time and effort to bring us rover guys some new toys :smokin:

Is there any possibility of you offering a crawler gear for the 1.4 ratio transfer case?

I see a lot of benefits in a 1.4 crawler gear set and think it would be a very popular update for the following reasons.

1. It would allow you to retain the stock ring and pinion which many consider to be stronger than the aftermarket 4.10 and above that are available for the rovers.

2. The stock R&P are readily available in case of failure and here in the US we have seen several times in the last 2 years where the aftermarket R&P were on a huge backorder. Not sure of the reason but it seems that the well runs dry here in the US from time to time.

3. I think it would be an attractive upgrade for anyone considering upgrading the R&P because they could get the 1.4 and a crawler at the same time. This would save them from having to service both diffs and the tcase.

Oh, you mean like this?

http://tawayama.com/gear/crewcab/divorcedtcase.jpg


Yeah but with a 20 foot wheelbase you have room to do chit like that :flipoff2:

Exactly. I didn't see the need to do that if you can just go and use a Dana-18 w/an OD, or evan an atlas with a double jointed drive shaft.

But this new product from Ashcroft is just awsome. :smokin:

Been running all sorts of numbers. Cant figure out if the low range gear set, or the underdrive will be the best way to go.
With the underdrive and then use the Ranger overdrive between the engine and tranny, 8 reverse gears and 32 forward :eek:
Keep the stronger 3.54 gears, run 36" tires, and still have a kick ass crawl ratio.
Now to figure out if the combo would actually fit into a 100" WB.

Exactly how far apart are your tranny and tcase Michael? Any reason a shorter shaft couldn't be used?

The Ranger is only 7.5" so if the divorced distance is only 4.5" then the rear drive shaft doesn't change at all over its current length. But currently its a DC jointed, 26" flange to flange so I have some room to shrink it up.

Current exchange rate is killing me, but the low gear set for the LT-230 would be cheeper then an atlas.

Sweeet. Ashcroft rules.

JP

OK how about this combo
Ranger under drive 1.17
SM 465 6.53
Klune V 4.0
LT 230 3.321
Ashcroft UD 2.69
Axles 4.77

1300:1 crawl ratio. So running at 2600 RPMs tires will turn twice a minute. So traveling around 300 inches a minute, 5 inches per second. Put the vehicle in gear, point it where you want to go, set the hand throttle. Get out and eat lunch while watching your vehicle woohooo :flipoff2:

A chart I did to ensure that i can turn them 42s...:) (can you see what it says?)

http://www.discoweb.org/forums/attachment.php?attachmentid=4217&stc=1

1300:1 crawl ratio.

..just like a Unimog.
Well, maybe a little higher geared :p

Can someone break all this math down into idiots terms? I am having a hard time with understanding what the different ratios in the t-box low + the 1.2 or 1.4 high + diff gears actually equates to.

Pete, you seem to have a good understanding, care to share?

Thanks,

$2732 !? how much for shipping-handling!

Please email me for freight quotes,

The math I was using is basically
1st gear ratio * t-case ratio * axle ratio to get final gearing.

If you have a say the 2.69 underdrive then you multiply that by the above
If you have an overdrive installed, say a 30%, then you multiple the above by .7
This is your final gear ratio

If you take a given engine RPM and divide by the final ratio you will get the number of times the wheels turn per minute.

Multiply that by 60 and number of revs of the wheels per hour.

Pi * Wheel height gives you wheel circumference
Divide that by 12 and divide again by 5280 and you have how many miles your wheel covers in one revolution.

Multiply by number revs wheel makes in an hour and you get the vehicle speed for a given RPM

If you have Excell or another spread sheet, in the first row put

Tranny Ratio, T-case Ration, Axle Ratio, Under Drive, Overdrive, Tire Size, RPM

If you don’t have an OD or UD put 1 in the cell.
So that will be cells A1 through G1

In cell A2 cut and paste this in
=(((G1/(A1*B1*C1*D1*E1))*60)*(PI()*F1/12/5280))
In cell A3 cut and paste this in
=A1*B1*C1*D1*E1

A2 is your MPH and cell A3 is your final ratio.
You can now play with the numbers in the first row, and the values in A2 and A3 will change.

So can my vehicle really pull 36” tires?
Power for my engine is best at 18-2000rpms
SM465, D-18, Coiler Gears, No UD, Saturn OD
My 1st row would be
(1) (1) (3.54) (1) (.7) (36) (2000)
and I get 86mph. Change the OD to 1 and I get 60mph. Geared a bit hi.
4.1 gears 75mph in OD. 53mph not in OD.
That’s almost exactly where I am at right now with 32” tires and 3.54 gears. So I know when I build my new axles I will be putting 4.1s in.

Hope this helps.
I have a spreadsheet all set up. I made a complete table that lets you compare two different tranny/t-case combos and displays a wide range of RPMs, mine is set 100-2500 by 100s.
If anyone wants it
right click and save as
www.aloharovers.com/AxleRatios.xls
Only change the values in the yellow highlighted cells.
The values at the top showing all the different tranny, tcases are there just for a reference.

Pete

Awesome explination Pete! This will give me something to play with on my laptop while Mrs. Rhino and I head to Mississippi for our Bed & Breakfast weekend! Surely it will piss her off that I am still doing Rover shit! :D

Exactly how far apart are your tranny and tcase Michael? Any reason a shorter shaft couldn't be used?

Exactly? Dunno. I'm guessing around 14-16 inches. A shorter shaft could definitely be used. We have off the shelf parts from Six-States to make up that driveshaft, which is one of the things that dictated it's length. It has about a 4-inch slip yoke, which may or may not be needed (I think it's a good idea personally, since both the trans and t-case do move around a bit).

If you could find a shorter shaft that you wanted to use, it would be totally doable.

Sorry for the hijack.

Again, nice job Ashcroft. :D

Now, how's about an overdrive/underdrive for my LT-95! :flipoff2:

Dave,

How much is a complete LT 230 with the crawler gear installed? This would be for a '95 Disco with a R380 transmission.

Thanks,

Norm

Micheal, care to sell a set of those parts for the drive shaft or share the parts list?

Dan