Thread: Fairey overdrive

The Fairey overdrive is, in my view, not necessary behind any Rover engine. While in theory they reduce engine wear and noise, you need to realise that all of these engines were designed to operate at high rpm, and operating at lower rpm but full throttle is not going to be good for them, especially the six.

As for noise, your money is much better spent on ensuring there are no holes in the firewall and floor, and on sound proofing. Especially since most Fairey overdrives are noisy to very noisy - and parts to quieten them are hard to find and very expensive. (Some other overdrives are better, but even more expensive and harder to find parts for.)

I accept that they are almost essential for Landrovers fitted with most Holden engines, and probably for some other engines, but that was not your question!

Disclaimer - I have an overdrive on my 2a, but mainly because I have not got round to removing it yet. I spent a fair bit on overhauling it, and it still howls (I probably should have replaced more gears, but could not afford it) and every long trip I worry about a possible failure. I rarely actually use it.

Thanks for the reply the reason i asked is that i may be purchasing a Series 2 with a Holden engine and Fairy overdrive, but i want to restore it to original, which was a six cylinder land rover engine i have one of those already. I will probably install a Series 3 standard transmission or restore the Series 2 box thanks for your advice. I had heard the overdrive units were noisy my only experience with early land rovers was a Series 1 with a Slant 6 Chrysler motor and 3.54 diffs and i could beat any standard HQ at the time but bloody scary.
Gippy

I fitted a new Fairey overdrive to a 1976 SIII LWB 2.25 petrol. The motor ran quite well so the overdrive was handy on the highway as a fifth gear. It was also handy on hilly winding roads when you could leave it in overdrive and shift to third and if revs looked like dropping, simply shift out of overdrive to third normal. I also used it in low range on occasions where the half gear between third and fourth was just right. I had no problems with noise and made sure the oil level was always spot on. From memory, I used to check the transfer case level, too as I think the oil used to overflow into it. I wasn't interested in speed so much (I didn't fit free wheel hubs for reliability and lubrication reasons) but overall the car ran just that little bit quieter and faster on the highway.
But if I was going to the trouble of restoring a car, I wouldn't bother with one. But as you have one in the car, I'd probably keep it in if it was in good condition.

These are the major roads we've traveled in a series 1 LWB with 2.25 l engine between 2003 and 2018 in Qld We've also crossed the Snowy Mountains three times and visited the Flinders Ranges, Birdsville and Strzelecki tracks. There is no way we would have done those trips without an overdrive.
.W.

My Series III shorty has a high ratio transfer box.
I was told early on that I'd be slipping the clutch to get away from a standstill but this hasn't proved to be true.
The only 'problem' I've found is that in a built up area at low speed you often have to drop into 3rd. Low range is only altered by a couple of percent.
A couple of pictures in this thread show the modification to move the intermediate shaft Isuzu C240 powered Series 3

Ashcroft were doing a kit but you had to get the machining done locally or you could send them your transfer box casing for modification.

I currently have four Fairey overdrives, every one is damaged and needs money spending on parts (if you can find them). I've now learnt that buying a parts car to score the overdrive is a waste of money !


Colin