1.003 or 1.211 ?

Trying to decide between the ratios for my defender 90 td5 transfer box. i have read that people think the 1.003 is to much. in what way?
I wont be towing and only doing the odd green lane nothing serious.
What are your thoughts?

Thanks in advance

Unless you have serious power you won't be able to hold higher gears, although the engine would turn over slower it wouldn't generate sufficient torque to keep you moving so you'd end up in a lower gear which kind of defeats the reasoning for the 1.003 - if that makes any sense. That diff ratio is better suited to V8's and auto's.

Beyond that with what you reckon you will be doing I see no issue - depends on your truck and what lies under the bonnet - and what it can deliver.

1.22 transfer box high range ratio is fine

Depending on tyre size if your running 235 750s ect low range the lt230s are all the same.

I run a 1.003 but have 4.7 diffs and tall tyres

1:003 is for big boy diesels

sounds like the 1.22 is the one. I just want it so that when i have to use a motorway i can sit at 70 and not have it sounding like the engine is going to explode. I am doing it up at the moment and have a hybrid turbo ready to go on just need new intercooler and re map but dont think that will make enough power to keep it going with a 1.003. i have 235/70/16. i just liked the idea of sitting at 70 at 2500rpm with a 1.003. i need to look in to the revs at 70 in 5th with a 1.211.

i have a 300 tdi auto with a1.2 in my 90 on 265/75r16 bfg mt and solo its very good on the motorway , quite frelaxed at 65mph , but towing is not so good as it has a job holding top. So you need to consdider what you intend doing most with it and gear to suit that. HTSH

If you want 70 at 2500 rpm you need to change your diffs too I think - check out Ashcroft transmissions calculator but you need to know your own starting numbers before you start playing. 70 in 5th on the Disco I have is a shade over 2600rpm from memory.

BenKenobi said:

If you want 70 at 2500 rpm you need to change your diffs too I think - check out Ashcroft transmissions calculator but you need to know your own starting numbers before you start playing. 70 in 5th on the Disco I have is a shade over 2600rpm from memory.

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Expensive! any way I dont think you would want or physically be able fit a higher ratio than 3.5:1 in a diff anyway!(pinion size)

I've not long changed my 1.41 for a disco 1.22, and was impressed at the results as soon as I got 100 yards down the road (ie I wasn't in 3rd yet!) and 70 on the motorway was now ok.
I've just fitted a set of General Grabber New A/Ts 235/85 16 that are quite a bit taller than the ones that came off, so 70 should now bee even better, but ive not been on the motorway since fitting yesterday.
So my advise is if you've all ready got the 'right' tyres, just go for the transfer box.

Thanks for all your opinions and info. I am going with a 1.2 70 at 2500 was just a rough finger I just want it to be easer and less noise at 70. I will let you know how I get on
Thanks

Has anyone got any further experience on a 1.003 transfer box? I’ve got a 300TDI which I heavily suspect has been breathed on - I’ve had it up to 85 on the GPS on 235/85 AT’s and not far on slightly larger muds - 285/75’s I think. I’m planning on using it for commuting so wouldn’t mind some longer gearing as I think my transfer box is bust (currently a 1.2). I also live in Norfolk so not too many hills!

Does the 1.003 affect the low range at all?

Generally speaking the higher geared options are all on the high range geartrain. I can't rule out the possibility that someone is making options for the low range gears too, but it's usually left alone.

With very high gearset the engine might labour a little at most UK road speeds. It's not quite the same thing but I was using a Roamerdrive overdrive unit for a number of years and it was fine for steady cruising at 70 on a flat motorway, but you had very little flexibility for easing in and out of the faster moving traffic in lane 3, and speed dropped going uphill. I now have a high top gear optioned R380 gearbox and no overdrive and it's not quite as high geared. It's an easier drive on motorways now as I can ease in and out of lane 3 traffic without getting in anybody's way and I can keep the needle on 70 on hills. It's revving slightly higher, but doesn't appear to be appreciably more thirsty.

I see Ashcroft's have a variety of ratio options available. I'm wondering whether to go a little higher next time I have my transfer box apart, or whether to stay where I am . . .

pressbrake said:

1:003 is for big boy diesels

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Or a standard V8 Range Rover classic with the 3 speed auto.

tom.brandford said:

Has anyone got any further experience on a 1.003 transfer box? I’ve got a 300TDI which I heavily suspect has been breathed on - I’ve had it up to 85 on the GPS on 235/85 AT’s and not far on slightly larger muds - 285/75’s I think. I’m planning on using it for commuting so wouldn’t mind some longer gearing as I think my transfer box is bust (currently a 1.2). I also live in Norfolk so not too many hills!

Does the 1.003 affect the low range at all?

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The 1:1 transfer box would massively over gear most 5 speed vehicles. Let alone a Tdi. Suspect it would be most undriveable in 4th or 5th and slower than a glacier away from the lights. Constant labouring likely to increase egr’s and make the engine run hot too.

1st gear would be terrible pulling away and likely require clutch slip.

300bhp/ton said:

Or a standard V8 Range Rover classic with the 3 speed auto.

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I’d seen a few of those boxes about and wasn’t sure if they’d fit the 300tdi

300bhp/ton said:

The 1:1 transfer box would massively over gear most 5 speed vehicles. Let alone a Tdi. Suspect it would be most undriveable in 4th or 5th and slower than a glacier away from the lights. Constant labouring likely to increase egr’s and make the engine run hot too.

1st gear would be terrible pulling away and likely require clutch slip.

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Ah, perhaps stick to the 1.2 - I’ll admit that off boost on the steeper hills in wales it struggled in 1st! I’m going to try and turn the off boost fuelling up when I have a chance