Fairey overdrive ???

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I have an overdrive that a previous owner installed on my 76 FJ55. I think it is a very rare unit made by Eaton. While it is no Toyota 5-speed it does rock on the highway. Once engaged it will drop the RPM's by almost 600 and the ride is way better. It works with all the gears and is pretty kewl actually...

Max
 
Fairey works off the back of the transfer case. It has two shafts, one inside the other. The inner shaft takes the power from the tranny, brings it into the OD, transfers it across the idler in the lower part of the assembly and returns it to the outer shaft, which has a custom imput gear toothed to match the transfer case. Can be used in any gear, 2 or 4wd. I used to run one on my 3 spd many, many years ago. Second and OD was a nice option for maintaining speed on the hills where 3rd was too tall. !st and LO with OD was nice in the sand off road.

The units are very tempermental. I built up one and installed it a few years ago for a customer who is very happy with it. I wouldn't trust one unless it was recently serviced by someone who knows the unit. Most that I've seen are one small step away from junk.

To run the PTO with the Fairey, you need a special gear. I have 3 NOS gears.

;)
 
Mark,
What I read in your post sounds like I'd need to change the tranny output shaft (I assume the overdrive came/comes with a special one) as well as locate an idler gear to match the 3 speed transfer case to the overdrive. Is that correct?

It sounds like I'd be lucky to get all the stuff I'd need since I have the 4 speed tranny/3 speed transfer case with a PTO.

Are you saying you have the correct gear available for the PTO when running a Fairey overdrive?

If I were to proceed, is it possible to reverse the installation without needing replacement parts to the tranny/transfer (assuming I keep whatever I remove)? ie: Do I need to cut or machine my existing parts to make this fit?
 
You do NOT need a special shaft. The Fairey was engineered to go onto the stock shaft. The unit I installed a few years back was one I had previously been paid to remove from another customer's rig. All that was required to return the truck to stock was: a. stock imput gear; b. stock pto gear; c. stock imput bearing; d. tailshaft spacer sleeve; e. rear pto cone-shaped cover.

Yes I do have the Fairey PTO gear.
 
Mark, do I need parts for both the four speed overdrive and the three speed overdrive when I'm running a 3 speed transfer case and four speed transmission or will an overdrive from a four speed net me all the parts I need short of the PTO gear?

When you call these units "tempermental" what sort of issues should I be looking for to make an informed decision on the suitability/reliability of the unit? I assume that replacing the bearings would be about all that one can do as the remaining parts would be no longer available. This will be on my daughters truck and while she is somewhat handy I don't suspect that she is able to rebuild an overdrive if it should fail.

What would the PTO gear cost me, assuming that the overdrive does not have one already?
 
Cruiser_guy,
Does it look like this...
I've been told that it is not a Fairey, but I don't know who actually manufactured it. I got it and needed some bearings and thrust washers (which I had no problem getting), it worked very well for me for a few years. Anyone have any info on this one would be greatly appreciated.

Regards
Rear Iso View Assembled.webp
 
cruiser_guy said:
Mark, do I need parts for both the four speed overdrive and the three speed overdrive when I'm running a 3 speed transfer case and four speed transmission or will an overdrive from a four speed net me all the parts I need short of the PTO gear?

When you call these units "tempermental" what sort of issues should I be looking for to make an informed decision on the suitability/reliability of the unit? I assume that replacing the bearings would be about all that one can do as the remaining parts would be no longer available. This will be on my daughters truck and while she is somewhat handy I don't suspect that she is able to rebuild an overdrive if it should fail.

What would the PTO gear cost me, assuming that the overdrive does not have one already?

Ahhh. Somehow I missed that part in your original post. Yes there is an issue, and it's a biggie. The Fairey that was made for the three speed would match your imput gear and the support bearing hole in your housing, but would not have the right imput shaft. The 74-only Fairey would have the imput gear AND imput shaft both worked out, but would not work with your housing because of the hole. The 75 and newer would have the wrong gear and the hole problem.

So yes you would need to either: a put your 3 speed guts into a 74 housing and find a 74 only Fairey; b. Find a 4 speed Fairey and swap the imput shaft into a 3 speed Fairey; or c just get a 4speed transfer case to match the 4 speed Fairey.

Actually there is a fourth, really pricey option, and that is to get an H41 tranny with a 3speed tailshaft! That's what my buddy Jeff did. He runs the H41 [5.29:1 1st] with the 3speed case, the Fairey AND the PTO. It's a mutha to get that thing in and out of the truck!
 
Sparky mark,

I doesn't look like that because that one doesn't allow a PTO setup.

Mark,

Sound's to me like I'd best forget the Fairey overdrive as it's going to be VERY HARD to find what I'd need to make it work with the setup we have in the truck right now. We'll stick with the "Poor Boys Overdrive".... larger tires!!
 
cruiser_guy said:
Mark,

Sound's to me like I'd best forget the Fairey overdrive as it's going to be VERY HARD to find what I'd need to make it work with the setup we have in the truck right now. We'll stick with the "Poor Boys Overdrive".... larger tires!!

An excellent choice for your locale! :cheers:
 
I agree the Fairy doesn't sound like what you need. But I need to put in my .02 for Fairy overdrives. I've been using one for almost 3 years and really like it. I hear people put them down, but I wonder if they have driven one themselves. I'm going to be selling mine soon, reluctantly, to go to a sm465. It's been a hard decision to make the swap, because I like the Fairy overdrive so much. But I need the lower gear now more than the higher gear. Wish I could have both!

Troy
 
65swb45 said:
An excellent choice for your locale! :cheers:

Actually Mark, the FJ55 is my daughters truck and is located in British Columbia where our truck is also registered. We are working in Guatemala for at least another year and a half. If the FJ55 makes it down here to Guatemala it would only be for vacation travel not long term.

Troy, is your Fairey a 3 speed model? I've got a lead on the 4 speed Fairey but it sounds like I'd need both 3 speed and 4 speed models to make my setup work. With the low end torque of the diesel I don't anticipate ever needing lower gearing than factory.

I know when my BJ60 still had the four speed it just didn't have what it takes for highway driving that's why I'm looking into the Fairey overdrive for the FJ55. The BJ60 was an excellent candidate for the H55F which it now has.

Installing an H55F into the FJ55 would be significant work as I still need to maintain a parking brake so it's either a special setup on the split case or a different setup on the rear axle, the H55F normally does not have the shifter where it needs to be for a '40/'55, I'd need a split case transfer and different PTO takeoff.
 
My Fairy is mounted to the 3 speed transfer case, with a 3 speed transmission. I found that with the 35" tires I am not geared low enough to do even the moderate rock crawling I would like, even with the 4:88 gears. If I didn't enjoy the rocks I'd never change, for everything else the current setup it great.

Troy
 
FWIW - I had a fairey OD in my BJ60 mated to a 5sd with the 3B engine. Having the OD was pretty good in making it driveable (i.e. splitting gears with the gutless 3B).

It was noisy and like others have said, impossible to get parts for. However in the 14 years I had the truck, I only replaced the output bearing which was easy to source.

Probably better units around though.
 
thats a cool unit , would make nice behind a sm420 , orion combo with 4.88 axle gears and 36 tires .
 
Some parts may be available through super winch in the UK and some of the rover dealers. Super winch was the last owners, unfortnatly I think all the tooling was trashed. If anyone needs a copy of the 4 speed manual, I have a copy of the orignial....I had a "new" one that I sold on e-bay about 3 years ago. Still had orignal window stickers and all.
 
LIVERUST said:
I agree the Fairy doesn't sound like what you need. But I need to put in my .02 for Fairy overdrives. I've been using one for almost 3 years and really like it. I hear people put them down, but I wonder if they have driven one themselves. I'm going to be selling mine soon, reluctantly, to go to a sm465. It's been a hard decision to make the swap, because I like the Fairy overdrive so much. But I need the lower gear now more than the higher gear. Wish I could have both!

Troy


You CAN keep the Fairy OD. You just have to use either an AA 'long' style adapter, toybox, or NP203 reduction unit. all of which retains the long style output shaft thorough the T-case.
 
Fairey will ONLY work with stock Toyota tailshafts. They were machines to the exact specs of the factory tailshafts, and AA will be the first to tell you that their tailshafts are not cut to exactly factory specs.
 
whatever Mr. knowitall , The spare 420 oldschool a/a tailshaft looks and measures damn close to the yota.
 
65swb45 said:
Fairey will ONLY work with stock Toyota tailshafts. They were machines to the exact specs of the factory tailshafts, and AA will be the first to tell you that their tailshafts are not cut to exactly factory specs.

Hrm. This is news. I was under the impression that the important part was that the tailshaft was the same length as the stock tailshaft.

So, if the AA tailshaft isn't cut to factory specs, why do the stock input gears work? There should be enough variation there that it should work with the fairy just as well as with the stock gears.

Or am I totally smoking the proverbial crack?
 
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if so then I'm on the same pipe as you Tiger , cause it sure looks like it is the same. Although the new t-case input gear for the orion did go on the a/a shaft a little stuborn.
 

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