Hi

I am in need of lower gearing. I am running 4.75 R&P with 36" on my discovery and it is a manual. My first low is a 52:1 and I am sure you guys know my truck turns off when I need these low low revolution
Has anyone installed the Aschcroft crawler gears or the Aschcroft underdrive?
Or anyone fitted custom dual transfers on rovers?

Any quick temporary air flow set or elctrical set up that I can to avoid the constant engine turn off in rockcrawling situations?

Thanks
Jay

yes I have the under drive and a couple of mates have the crawler gears.
the crawler gearset would suit the 1.2 transfer box you have, and be a cheaper option.
the underdrive is supeb IMHO a write up on the install etc available in the tech section of the forum below.(see sig)
underdrive is very easy to install on a Defender the Disco may need a bit of a floor mod(read reshaping)
see www.ashcroft-transmissions.co.uk for the spec/prices

Do you have a final low in mind??? The ashcroft underdrive would make you way too low in my honest opinion if you kept everything "as is" now and then added the crawler box.

Just so you know, they offer a 4.1 and a 4.3 for the LT230 low replacement.

Do you have a final low in mind??? The ashcroft underdrive would make you way too low in my honest opinion if you kept everything "as is" now and then added the crawler box.

Just so you know, they offer a 4.1 and a 4.3 for the LT230 low replacement.

Way
The fina low I am considering a is 90:1 on 1st low. i thought they offer one type of reduction gear set.

Tony
on your defender what is you 1st low with the underdrive engaged? Do you find it too low

Does Maxidrive offer more than 30% lower reduction gear set

Or anyone fitted custom dual transfers on rovers?



I think someone makes an adapter for one of the Toyota transmissions... so you could run dual Toyota Tcases... in theory..

Hmmmmm...

jay
1st low in crawler is perfect for winch assist driving on tickover
for steep desents I use 2nd as long as there is some grip it is superb for getting down safley.
the biggest bonus being I retain all the standard low range which is ideal when on 33's rather than 35's

Hi
My first low is a 52:1 and I am sure you guys know my truck turns off when I need these low low revolution

Any quick temporary air flow set or elctrical set up that I can to avoid the constant engine turn off in rockcrawling situations?


Shouldn't you be at about 56.7:1 (4.75*3.32*3.6).

Temporary measure - in the slow stuff in the rocks drive with one foot on the accelerator and one (lightly) on the brakes - not the best for the brakes but if you can do it right it stops the engine stalling.

If you can afford/justify the expense I would buy the crawler/underdrive - proven to be strong and gives you the widest range of ratios.

Shouldn't you be at about 56.7:1 (4.75*3.32*3.6).

Temporary measure - in the slow stuff in the rocks drive with one foot on the accelerator and one (lightly) on the brakes - not the best for the brakes but if you can do it right it stops the engine stalling.

If you can afford/justify the expense I would buy the crawler/underdrive - proven to be strong and gives you the widest range of ratios.

Nop it is 52.37:1 (3.32*4.75*3.32) LT 230

The underdrive will require more work to fit under disco scarificing the rear seats and is more expensive plus it will have some similar gears as the current low and high on the 4.75 (mainly 4 th and 5th) so you are paying for xtra gears you already have.

Tony
Have you fitted the underdrive on a D-90 or 110??
Are you running 33" when using the underdrive on first low
On xtreme rocks what are you using?
For steep climbs requiring some momentum does the 3rd low with underdrive do the job?
Again assuming you have an LT 230 and 4.75 R&P.

The underdrive will require more work to fit under disco scarificing the rear seats and is more expensive plus it will have some similar gears as the current low and high on the 4.75 (mainly 4 th and 5th) so you are paying for xtra gears you already have.
-------------------------------------------------------------------------
you won't loose the rear seats just a section of the floor that'll require a mod to accomodate the box.
-------------------------------------------------------------------------
Tony
Have you fitted the underdrive on a D-90 or 110??-D90
Are you running 33" when using the underdrive on first low 33's or 35's
On xtreme rocks what are you using? -on our version of rocks 35's
For steep climbs requiring some momentum does the 3rd low with underdrive do the job?-IMHO yes unless there is hardly any grip then even with both ARB's in generally muddy conditions it'll spin the wheels
Again assuming you have an LT 230 and 4.75 R&P.LT230 3.54 R/P

there is a write up of my install and others on the forum below/tech section

The underdrive will require more work to fit under disco scarificing the rear seats and is more expensive plus it will have some similar gears as the current low and high on the 4.75 (mainly 4 th and 5th) so you are paying for xtra gears you already have.
-------------------------------------------------------------------------
you won't loose the rear seats just a section of the floor that'll require a mod to accomodate the box.
-------------------------------------------------------------------------
Tony
Have you fitted the underdrive on a D-90 or 110??-D90
Are you running 33" when using the underdrive on first low 33's or 35's
On xtreme rocks what are you using? -on our version of rocks 35's
For steep climbs requiring some momentum does the 3rd low with underdrive do the job?-IMHO yes unless there is hardly any grip then even with both ARB's in generally muddy conditions it'll spin the wheels
Again assuming you have an LT 230 and 4.75 R&P.LT230 3.54 R/P

there is a write up of my install and others on the forum below/tech section

Tony

At first low your gearing is much different than mine as I am running 4.75 rather than 3.54 CR&P.
What is your opinion on having overlapping gears with the underdrive?
Do you know of anyone who has installed the underdrive on a disco?

i am still trying to find your write up.
Rgards
Jay

http://forums.lr4x4.com/index.php?showtopic=76

No the ones installed here are in Defenders that I know of.

there are overlapping gears having a choice of 24 but some just aren't used.
but it leaves all the standard gearing in place.
running 33 and 35's I did not want to use the Maxi drive gearset or the crawler gears from Ashcroft as I wanted to retain the 3.54 R/P
1st low in crawler is very very slow you can get out and walk ahead of the truck, ideal for winch assisted driving.
the unit is compact, I reckon a small box fabrication into the rear floor section is all that would be required to allow the unit to fit.

I've sold the discovery so can't measure for you easily.
I can measure the distances on mine if you need them

Way


Does Maxidrive offer more than 30% lower reduction gear set


yes, they also offer 49% reduction, same set up, ie. drop in gears to replace low range gear set in lt230

with this and 4.11's i'll be 75-1, but still have an overlap from 5th low-1st high

cheers, serg

Tony

Can you take some measurement or the underdrive?
With 35 and 3.54 you are at 69:1 (3.32*5.95*3.54)
I will be at 90:1

What are the must have ratio for rockcrawling and at the same time momentum climbs?
Thanks
Jay

90:1 sound very low indeed.
the crawler gearset(not the underdrive) that fits your transfer box maybe a better option
these are:

This kit was designed for those that wanted the wheels to turn at ‘winch speed’.

This crawler kit drops low ratio from 3.321 to 5.95, a drop of 80%. The high range ratio is fixed at 1.222. This means that there is no overlap between high and low range, i.e. high range is a continuation of low range.

The kit consists of 4 gears that can be fitted to any LT 230T, i.e. suffix ‘B’ onwards. The kit retains the PTO drive dogs but cannot be used with an overdrive or underdrive. The gears are manufactured from high-grade steel and are ground after hardening for quiet operation. Both high and low range are “helical” gears, retaining the “Q” form on high to give virtually silent operation. The speedo will remain unchanged when fitting these kits.

We understand this 1.222 high range ratio may not be ideal for those who have fitted larger tyres and to remedy this we are able to supply the 4.11 R & P gears at a greatly reduced price when ordered with the Crawler gear set. This combination gives approx the same high as the 1.410 but much lower low. If for example you have the most common Defender LT 230 high range ratio of 1.410 then fitting both the 4.11 R & P gears and the Crawler gear set will effectively keep high range about the same but you will be dropping the low range twice, 80% by the gear set and a further 15% by the R & P’s.

If you are not able to fit the kit yourself we can supply a rebuilt LT 230 with the kit installed. We are able to offer the same options for the 4.11 R & P’s.

The kit is priced at £650 and the 4.11 R & P gears will be reduced from £195 / axle set to £125 if purchased with the gear kit. To fit the crawler gear set to your transfer box there would be additional charge of £125.

We understand that some people are reluctant to change to 4.11 from the stock 3.54 in case of a failure when far from home as the 3.54 can be found fairly easily anywhere in the world. In light of this we are happy to supply a spare 3rd 4.11 R & P set at £125 also.

We tested six sets in customer’s vehicles, which have been successful, and to quote:-

“The manoeuvrability and ability to control what you are doing at this speed is fantastic. It feels as if the reduced snatching and wheel spinning may well reduce wear on drive components rather than increase it due to the greater torque.’”

“We think that on the road it works perfectly, it goes well and only give a little rumour when taking the foot of the throttle. Off road (only hard conditions due to the weather, everything was frozen), it worked well. We did some quite steep hill climbs and descents, where other well-prepared vehicles could not follow. Most of the time we were riding in 2nd & 3rd.”

Available from 22nd June 2005. Orders being taken now.

All prices are plus carriage and VAT where applicable
from here:http://www.ashcroft-transmissions.co.uk/part_46.html

what measurements would you like I'll go and do it.

With 35 and 3.54 you are at 69:1 (3.32*5.95*3.54)
I will be at 90:1


Jay, I forgot you had the V8 ratios in your R380.

Tony, don't have have a Tdi/R380? If so you would have the about 73:1 (3.692*5.95*3.54)???

This page has install pics of the old ashcroft underdrive (dimensions seem to be about the same as the new one)
http://www.pirate4x4.com/forum/showthread.php?t=244617&page=2

Jay, I forgot you had the V8 ratios in your R380.

Tony, don't have have a Tdi/R380? If so you would have the about 73:1 (3.692*5.95*3.54)???

This page has install pics of the old ashcroft underdrive (dimensions seem to be about the same as the new one)
http://www.pirate4x4.com/forum/showthread.php?t=244617&page=2
Ben
mine is
3.32(low range)*2.69(crawler reduction)*3.54(diff ratio)

Tony, you forgat first gear, which is what Ben was chatting about....

OK, here is a List.

1) V8/R380/Ashcroft Crawler Gears/3.54 R&P
3.321 * 5.95 * 3.54 = 70:1

2) TDI/R380/Ashcroft Crawler Gears/3.54 R&P
3.692 * 5.95 * 3.54 = 78:1

3) V8/R380/Ashcroft Crawler Gears/4.75 R&P
3.321 * 5.95 * 4.75 = 94:1

a) V8/R380/Crawler Box/3.54 R&P
3.321 * 3.32 * 2.69 * 3.54 = 105:1

b) TDI/R380/Crawler Box/3.54 R&P
3.692 * 3.32 * 2.69 * 3.54 = 117:1

c) V8/R380/Crawler Box/4.75 R&P
3.321 * 3.32 * 2.69 * 4.75 = 141:1

Thanks John
so 117:1 it is I thought it was Very low but no idea it was that low.
4.75 R/P you'd be better suited with the crawler gearset IMHO

TDI/R380/Crawler Box/3.54 R&P
3.692 * 3.32 * 2.69 * 3.54 = 117:1

also

TDI/R380/3.54 R&P as you keep this option with the crawler box
3.692*3.32*3.54 = 43:1

The nice thing with the crawler gears is there is no gear overlap. You get 10 separate gear ratios. With the stock box, 3rd low and 1st high are about the same, so there are really only 7 gear choices. It really is a smart design.

If/when I have the money I would go that route. Unfortunately for me it is a few expensive mods and many years away. Unless Dave needs a Canadian tester/promoter.. :laughing:

Another possible option (may) be coming from Roverdrives. They have apparently developed an overdrive/underdrive combination unit. I have no idea what the ratios are going to be, but I believe they have had one in there test rig for a while now. I suspect though that it won't be as much reduction as Jay is looking for.

Jay, I forgot you had the V8 ratios in your R380.

Tony, don't have have a Tdi/R380? If so you would have the about 73:1 (3.692*5.95*3.54)???

This page has install pics of the old ashcroft underdrive (dimensions seem to be about the same as the new one)
http://www.pirate4x4.com/forum/showthread.php?t=244617&page=2

Ben

i have 4.75 CR&P so it will be :
3.32*5.95*4.75= 90:1
I am worried about loosing my current 33:1 (2 nd low) it is my ideal gear for hill climb or medium crawl
with the 4.75 and Crawler Gear Set (Note I am not getting the Underdrive it is too $$$ for me)
my 2nd will be a 60:1 and3rd low will be 39:1 and 4th low will be 28:1

Do you think the combo 39:1 and 28:1 can make up the lost 33: 1 i currently enjoy.
My other option is to back down to 4.11

P.S.
Does someone know the high ang low for an LT 95 4 speed

Apprecaite your feedback

if you change from low to high on the move you need OVERLAP. by the time you do all the shit to make a smooth transfer change, and considering you are doing this in sand or the like you will loose momentum. needing 4wd in these sistuations, you need 1st high to be lower than 5th low. now this is for deep sand driving and the like. if you are just playing in low and only using high range on dirt tracks and sealed roads thats up to you. i change from low to high off and on road and i would not have gear ratio's without overlap.

cheers, serg

Basically 5 low and 1 high are the same ratio, so that solves the shifting problem, IMO.

You guys need to get Marlin to make a Toybox for your application..

http://www.marlincrawler.com/dual_toybox.html

Give him a call and see if he is interested.

The way the Rover transfer case is arranged, it is not possible.

There are more than enough options out there.

M-D Gears: 4.3:1
Ashcroft crawler gears: 5.95:1
Ashcroft underdrive: selectable 2.69:1, 3.32:1 and 8.93:1

The way the Rover transfer case is arranged, it is not possible.




Why???

I guess I should really have said the way a Rover is arranged. There is no room to move the t. case backwards.

The underdrive option makes more sense as it is basically a straight bolt on with no or little vehicle mods and inserts a 2.69:1 gearbox into the drivetrain.

You guys need to get Marlin to make a Toybox for your application..

http://www.marlincrawler.com/dual_toybox.html

Give him a call and see if he is interested.

Marlin Crawler has many cheaper options for lower gearing(an underdrive at$1,300 even a conversion from CV to Dana Knuckles but for TOY only it seems.
I wish I started with a TOY sometimes with all the economical options available.....

Marlin Crawler has many cheaper options for lower gearing(an underdrive at$1,300 even a conversion from CV to Dana Knuckles but for TOY only it seems.
I wish I started with a TOY sometimes with all the economical options available.....
See, now you are thinkin ;)

Rovers have a cool factor to them. Anyone that loves british crap as much as Rover owners do should get a medal. ;)

The cool thing about Marlin's toybox is that they use a conventional Toy reduction box with a simple adapter that works with almost any transmission that you can think of (with some mods).

The second Tcase is a boon. I have a SM420/dual minitruck tcases in my cruiser and am about to put a Toybox in my 60. It basically means I have a 80:1 and a 200:1 low range when I want to annoy people :)

Like I said, if Marlin knew that you guys wanted more parts then he would probably make them..

Additionally, the Dana knuckled mini axles are a novelty only. There are much better systems (longfields come to mind) out there for upgrading the mini/rover stuff.

There is a lot available for the rover crowd. They just have not gotten into the major mods as much as the Toy guys have. I think it is more a matter of rover owners diehard loyalty to the rover line. I mean, how many mods can you do to a Rover before it is no longer a rover???


Personaly, a set of Volvo portals under a D110 would be the cats ass IMHO.

:D

I haven't been posting or giving opinions on this topic as I am convinced on the crawler box - at first I was shying away from the $ and the added weight/parts in the belly, but I cannot deny the 3 gearing option available...

This or an Atlas that can fit our patterns...

Saving up for them BIG TIME.

Nadim

I haven't been posting or giving opinions on this topic as I am convinced on the crawler box - at first I was shying away from the $ and the added weight/parts in the belly, but I cannot deny the 3 gearing option available...

This or an Atlas that can fit our patterns...

Saving up for them BIG TIME.

Nadim

I still think the $ for the crawler box is way too steep and does not make sense only for three additional gears....
TOY crawler boxes are half this price

I haven't been posting or giving opinions on this topic as I am convinced on the crawler box - at first I was shying away from the $ and the added weight/parts in the belly, but I cannot deny the 3 gearing option available...

This or an Atlas that can fit our patterns...

Saving up for them BIG TIME.

Nadim

I agree with this.

best bang for bucks and bolts straight in. (small mod to floor area)

Michael.