Fairey Overdrive V8

[Boxoftricks]

Hi,

Where is the stamp on the transfer case so I see what suffix I currently have.

Will Ashcroft build up the kit for you or is it DIY?

Thanks for the kind offer.  I may well take you up.

The number of the transfer case is the gearbox number although of course there is a risk it may have been swapped in the past. You can't easily tell by just looking at it. You would need to take the bottom cover off and count the teeth on the high range gear. The number is stamped on the side of the gearbox top cover on 2, 2A and early S3 vehicles. After that the number was stamped on the top back of the gearbox casing where it joins the transfer box.

Ashcroft will not build it up. It is a DIY job or find somebody who is OK with setting up a transfer box properly. If you need help and want to do this, let me know. I may be able to assist as you aren't too far away from me I guess.

[JonB]

I've just re-read the thread and to try and condense the various thoughts

Ashcroft need your bare case, I don't think an early small shaft case would matter as they're re-drilling the hole to the bigger size anyway. You would need the later gear as DW has said. It is a diy rebuild, they send back the case and three gears.

My thoughts on usage

2.25 + od = ok
2.25 + 7.50 tyres = ok
2.25 + hrt=ok on 6.00/205 tyres
2.25 + 3.54 diffs = ok on 6.00/205 tyres ( roughly the same change as hrt)

First is not too high for a stock petrol with a hrt on small wheels, using 7.50s might well be though


a v8 with 7.50s and 3.54 diffs might struggle with a hrt added as well. An overdrive or 5 speed would probably be the best way here

Jon

[GlenAnderson]

I have 3.54 diffs, 235 tyres and a Roverdrive behind my 200tdi.

I would suggest that a high ratio transfer box, together with basically the same diff/tyre combination will be too high geared. It'd be like driving around with the overdrive permanently engaged, which would be too much for my setup, definitely.

Save for splitting-hairs (if by different means) you've the same grunt and torque at the same rpm as my set-up. I run 7.50 x 16. I see you've 3:54 & your Roverdrive. That seems like it's going to be too tall. Are you saying you wouldn't add a high-ratio box to your set-up - I'd agree - or, that'd it'd be too tall for the OP? With grunt as ours,  I'm thinking we want:

1) Stock + Overdrive
2) Stock + 3.54 (1st a bit high for a 2.25)
3) Stock + HR Transfer (1st a bit high for a 2.25)
4) Stock + 5-cog box.

ie: Overdrive or 3.54, or HR, or 5 cog. Pick any one, not two. Only you appear to have gone for more?

Yes, I have got "two" upgear setups, plus the bigger tyres. The Tdi (and no doubt the V8) will happily pull both the higher ratio diffs and the overdrive, allowing an easy cruise at 60mph at 2000 rpm (or well north of 80 if you're in a hurry). However, it's the overdrive's flexibility that allows this, because it still gives a relatively low first gear when disengaged. However, that first gear is still high enough that when fully loaded I can find it necessary to use low box for pulling away on a steep hill. Fitting a fixed higher ratio transfer case might be cheaper than an overdrive, but it's a fixed ratio, and as I said I suspect it will make first too high for comfort.

The other issue with higher gearing if you have a 2A gearbox is the need to perfect your double-declutch technique as you'll be doing a lot more shifting in and out of the lower gears.

[NoBeardNoTopKnot]

Thanks Glen. That makes sense, thus it's not so much the tall gearing - and yes, whilst you'll use it... ... more it's the real-world utility 'doubling-up' gives.