V8 Defender 90 ratio query

Hi all - been viewing this site for a while but not posted before. Its informative and amusing!

I have a 1995 V8 90 (orginally 3.5 now 4.6). I want to raise the gearing to make motorway cruising more comfortable and economical. I know the usual story is to change out the 1.41 defender box for a 1.222 from a Disco. Well this was my plan until this morning when I crawled under me vehicle and found that I already have a 1.211 fitted which should be making the gearing nice an low no??

@ 60 mph in 5th I'm pulling 3,100 revs and 70 is around 3,800 revs which to me feels quite high revving - especially for a 4.6 and is similar to me 110 td5 which has a 1.41.

So - I'm confused. As far as I know diffs, t box, and gearbox are all as original and tyres are big ish (275/75/16). so why is it revving so high? Could my landie have different ratio diffs, or I suppose someone could have messed with the t box gearing but I don't think so.

My mate has a NAS 90 v8 with a 1.211 box and thats pulling 2800 @ 70 which would be ideal for me.

Anyone on here got a v8 90 and what revs are ya getting?

Any help greatly appreciated cause I'm at a bit of a loss.

Cheers

Could be your gearbox ratios. My old V8 had the engine, gearbox and all running gear taken straight off the same Rangie. 4 speed Auto, cruising at 70 was very pleasant with revs about 2500. Blip the throttle, kicked down into 3rd and you were approaching 90 very quickly with not too much control over direction

If your T-box is correct, I would point the finger at the gearbox. LT77 or LT85?

Thanks - gearbox is R380 and as far as I was aware they are all the same?

70 @ 2,500 rpm sounds great and what I was hoping to achieve by swapping for a Disco t box ........

DubaiLandy said:

Thanks - gearbox is R380 and as far as I was aware they are all the same?

70 @ 2,500 rpm sounds great and what I was hoping to achieve by swapping for a Disco t box ........

Click to expand...

Have you considered fitting one or other of the overdrives?
Just the job for what you want to do, and doesn't affect your gears at the bottom end, so towing would be as normal.

CharlesY

CharlesY - yes had considered that but thanks for suggesting.

Which one would you go for - don't particularly want more levers in the cab.

Plus - I'm in Dubai and can't get one localy whereas ther are loads of old disco's knocking around here and I could have just banged a recon disco box on but now i've seen mine says its a 1.211 I'm confused.

Don't tow - car is desert toy

cheers

Could I suggest an email to Dave Ashcroft of Ashcroft Transmissions, Luton, the acknowledged Landy after-market gearbox expert. He might be able to put you on the right track and send whatever's necessary. Another option is KAM diffs (crownwheels & pinions) which you would need to change yourself, just not available for 6 months, though. There's also the 1.1003 ratio for the transfer box, which is a RR item. Ashcroft Transmissions