High ratio transfer case

Hi everyone, does anyone on here have experience of the high ratio transfer box available from Ashcroft transmissions? I have a 200tdi powered 109 series 3 that is very undergeared. It has 235/85 tyres but standard gearing. I want the speedo as accurate as possible (although that is clearly very approximate anyway!), so 3.5 ratio diff are out. Also, I've yet to find a Fairy overdrive that is less noisy than the engine,so really I have three options, the Ashcroft transfer case, the Rocky mountain roamerdrive (£1400ish so not an option) or better ear defenders..... I just wondered about the long term reliability and ratio suitability for normal driving...... thoughts please...

I have the ashcroft Hi ratio conversion fitted to my 72 SWB powered by 200DI and like it , used to have overdrive which worked fine but needed higher ratio for better top speed for engine rev / noise.
Been in about 18 months find local I get into 4th about 28mph can stay there on the flat no problem , hit hills need to drop to third. At speed ie 65/70 will go up most hills , but best not try to accelerate or engine starts smoking , with turbo this would not be a problem. Set up is a lot quieter and less hassle than overdrive , used to always forget to change back out of overdrive when had to slow down / stop. Never had any issue pulling away with extra gearing but 1st gets used now which it rarely did on old setup.

Changing the transfer box is one way of doing it.

I finally got the final drive ration on my 200tdi SIII 'right' when I changed the diffs to those from a 90, and the overdrive that I already had. 80mph on the motorway was comfortable (with headphones) and the steeper hills usually only called for dropping out of o/d. The very steepest would call for third gear, but they'd be 3rd gear (5 speed box) in any modern car too.

Diff changes are cheap, but I do appreciate that an o/d unit is not.

Don't rule out 3.54's they're cheap and Speed Cables will recalibrate your speedo for about £70 + carriage. I've got one ready to send off but keep forgetting to package and post it...I'd be seriously looking at both diffs/transfer and an overdrive if you do any amount of motorway driving - cruising at 70mph goes from a still deafening 3000rpm with 3.54 diffs or high ratio box down to 2300ish with overdrive on top which doesn't seem like much on paper but makes the difference between needing ear defenders or being able to listen to the news on the radio!

D

Ashcrofts have a nice ratio calculator here
Ashcroft Transmissions - Ratio Calculator.
Solemn Warning also has one here
Transmission Calculator - Solemn's site

I think I'm going to put one of these in next summer. Got a 109 200di and going on dual carriageway/motorway isn't a nice experience. Had an o/d but it screamed like hell and just blew up a few months ago...

high ratio should be good as it will be much stronger than the o/d and not whine or anything. At the moment I always wear ear plugs.

I realise its not first hand experience but i spoke to a guy at the classic car show that had fitted one to his S3 lightweight (the S3 LW in last months Classic Land Rover) and he couldn't rate it highly enough, as such I've ordered one and will be fitting it when i do my chassis swap in Jan.

is it an easy job to fit the Ashcroft high ratio transfer box, at £255 plus £75 if you don't exchange your existing box it has to be a serious contender to a 2nd hand od off the bay for £500

When I was looking at different options. I thought of an overdrive prob one of the easiest options the only worry is getting a good one it could be early to spend £500 and end up with a bad or noisey one.

Mick

I have an s1 with an od and an s3 with nothing, so I wanted to try the high ratio box if it was an easy fit probably in the s1 as I doubt that will ever venture off tarmac - I would keep the original tb in case I ever sold the car on - happy to lose the £75 exchange deposit as it is still significantly cheaper than spending £500-£600 on an od that could be a pile of doo doo. My existing od I only paid £250 for in 2008/9 although I only just got round to fitting it , if I had realised what a piece of **** to fit it was I might have done it sooner. The high ratio box route seems more sensible from a price and gearing perspective.

I would then swap the od onto the s3 or sell it if the Ashcroft box was a lot better, I could sell the od as it seems to be in good order and that might more or less cover both Ashcroft boxes.

Wouldn't be bothered about keeping the original tb for the s3.

boguing said:

Changing the transfer box is one way of doing it.

I finally got the final drive ration on my 200tdi SIII 'right' when I changed the diffs to those from a 90, and the overdrive that I already had. 80mph on the motorway was comfortable (with headphones) and the steeper hills usually only called for dropping out of o/d. The very steepest would call for third gear, but they'd be 3rd gear (5 speed box) in any modern car too.

Diff changes are cheap, but I do appreciate that an o/d unit is not.

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Trouble with diff changes, it ruins the low range crawl speed. And one has to say, in a country with a 70mph speed limit, why do you need to cruise at 80mph in a Series Land Rover?

dominicbeesley said:

Don't rule out 3.54's they're cheap and Speed Cables will recalibrate your speedo for about £70 + carriage. I've got one ready to send off but keep forgetting to package and post it...I'd be seriously looking at both diffs/transfer and an overdrive if you do any amount of motorway driving - cruising at 70mph goes from a still deafening 3000rpm with 3.54 diffs or high ratio box down to 2300ish with overdrive on top which doesn't seem like much on paper but makes the difference between needing ear defenders or being able to listen to the news on the radio!

D

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Or just run at 60-65mph. Much cheaper to attain, won't have any real affect on journey times and will offer better mpg.

In all the offroading (real not silly competitions where you are not allowed to touch sticks) I've never used 1st gear/low ratio. Usually 2nd or 3rd even for hill starts the difference between 1mph and 1 1/4mph is quite difficult to spot.

Doesn't sound like you've ever done any proper off roading. Taking a Land rover where you can easily take a normal hatchback seriously doesn't count.

Off roading often requires lots of control and 2nd/3rd simply won't give you that.

Cobblers

Or should I say - depends on what you call serious off roading - if you mean competitions or climbing over rocks then you're maybe right. If you mean dragging trailers full of logs/feed around fields and bumping over the odd bit of rough ground then I just don't see it. The gear ratios have changed over the years for differing compromises I doubt there's more than about 5% of Series owners who have needed 1st / low ratio. There are probably >90% who wish it was a lot quieter at 50/60mph...

according to the Ashcroft site, its much easier to fit their high ratio box into an s3 than an s1 as you need to change a few bits to get it in an s1, but has anyone actually fitted one and can comment on how difficult or big a job it is?