Thread: FAIREY OVERDRIVE MODIFICATION

Originally Posted by Michael2

That's a great idea.

I found that the breather hole, which is a pin size hole with a split pin in it to prevent blockage, was a major source of oil loss on the Fairey OD. The lost oil could be found as a mist around that hole. I drilled and tapped the hole and fitted a brass hose fitting, then put a large breather hose on it. I routed the hose to the t/case, but should have routed it to the top of the firewall with a filter on the end, so that the oil would just condense and run back down. Fitting a larger breather did keep the oil level up for longer though.

Have a look at the breather set up as well.

Mine has a short piece of hose (approx. 2'') with an inline fuel filter attached as a breather. It works fine, no oil loss. It is probably the only thing on the vehicle that doesn't leak oil.

Hey folks,

I thought I might reply to some of the queries and observations on this job. Originally, I had been waiting to finish the project and then post on it, but Hodgo asked if he might post my pics now and it's good to see that it's of interest to some people.

Firstly, the volume as I measure it (without internals refitted) is approximately four times the original oil volume. With gears and shafts back in, the relative increase will be greater.

I know that the side cooling fins would be better if run lengthwise, but the fellow who did the welding forgot to add them at first, and when he did I was not so bothered by the direction to ask him to change it. As it is, I am sure that the whole thing will be a lot cooler anyway.

It's a good point that once the oil level drops, the gears will not pick up all that extra oil anyway. I'm putting in new bearings and seals, and will keep an eye on levels and see how it all goes. If it holds its oil alright, I will be happy to leave it without any further modifications like reticulation systems or anything.

The sump plug is lower than I wanted it, but it still sits well above the level of the handbrake drum. My vehicle is a short wheelbase IIA, so hopefully I will never run aground on the overdrive anyway. When I fit it, I might put a small skidplate in front of it to eliminate any possibility of snagging the extension on rocks or logs or whatever. There is no room for cooling fins between the housing and the handbrake. I guess some could go on the bottom.....

I have an enlarged breather on the top plate to reduce case pressures.

Some time back, somebody on this forum suggested increasing the oil volume as a solution to Fairey woes (I seem to remember being told about somebody called Ian doing something like this in West Australia in the past), so I have mulled on it for a while, took a design to a workshop with a template and left them to it.

I have not sourced all bearings yet (trying to do cheaper than just buying from Rovers Down South), and will hopefully do so soon. On that note, I have found a supplier in the UK who provides the output shaft bearing for about a third of the price at RDS or from Australian suppliers. If anybody wants details on the supplier, just get in touch with me.

It will be quite a few months before the overdrive (in fact, the whole Landy) is back together. Once it is running, I will definitely give everybody a full report. Meanwhile, anybody who is interested can get in touch.

Cheers,

John

Well some good replys guys. I am a bit reluctant to go the Hodgo Mod as i am worried it may distort the housing and add more problems with bearings out of alignment. I am looking at a unit on Ebay at the moment and will probably go down the remote resiviour route with an electric pump that i can engage via a swith on the od lever.
Mike

By the way - my vehicle is still not back on the road, but the overdrive is rebuilt.

When I finish the thread on the vehicle's rebuild and I am driving the Landy again, I will post some stuff on the overdrive modification. The point about possible distortion of the housing is a good one and has occurred to me before. Hopefully this one is OK.....

Why bother,just buy a high speed Tcase from the UK and all the problems are gone. Pat

Might be worth considering fitting a finned transfer case sump base too!
Alluminium ones are available from Roverdrive at a reasonable price, or alternatively you could make one.


Cheers, Mick.

Yep, I've seen them. I wonder how much difference they make.