Over drive removal

I've found a Series 3 in a scrap yard with over drive, I want the OD for my 200tdi series 3 What tools do I need and how do I go about getting it off in its entireity so it will just slot straight on to mine.


Also anyone know what it alters the ratio to?

Thanks, Adam

In an ideal world you'd have Land Rover special tool 600900(?) or whatever it is to undo the castle nut on the back of the mainshaft. If however the gearbox is a scrapper you can undo the small steel plate on the top of the gearbox (4 bolts) and batter the nut undone with a hammer/drift. Overdrive withdraws as one unit from the back of the box, you need a handful of other bits too ... see the guide for details.

Have a real good look at the overdrive before you part with any money, especially the little splines you can see when the unit is withdrawn. They can wear badly. Make sure it turns over smoothly engaged and disengaged. I think the sump plug on it is magnetic so you could check the condition of the oil in it and how much of the gears have been chewed off inside it at the same time.

When it comes to refitting you might consider making/borrowing a tool to torque the nut up properly, I made one for mine and it looks like the pic below. The nut should be pretty tight.

guide:
Fairey Overdrive by Rovers Down South

Ratio is something like +25% ish, maybe even slightly little more.

I had a look on the net at worked out it would lower my revs down to about 3100 at 70mph which would make it so much nicer to drive with it being a 200tdi


So the unit come off as one and then I need to smack the nut off to enable me to get the drive gear (that goes between OD and Gbox) out the back of the box?

overdrive is 27.5% more efficient. according to Ashcroft transmissions

Ashcroft Transmissions - High Ratio Transfer Case Kit

Yes, it will come off as one unit, take off the final gear on your box and then bolt it on. I used no specal tools for either removal or installation. It did take a bit of jiggering aroud to get it off (and on) but using a bar and wiggling it about. I found rockiing the car in gear, whilst someone on the bar was the way for me!