FJ40 overdrive unit (1 Viewer)

[John Greene]

I would drive my 1978 FJ40 more (don't have 40,00 miles on it yet) if it wasn't so wound up at 50 mph. I have thought about installing one of the "overdrive units" available on the aftermarket. Has anyone done this that could give me some results they realized? What does it do to rpm's at 50-55 mph. Has anyone checked miles per gallon on the road with one of these units?

 

[CruisinGA]

The overdrive units are not worth pursuing. Do a search for "fairey od" or some variation.

You have three viable options- larger tires, smaller (numerical) ring and pinion ratio, or an overdrive transmission. In your case the H55 from Toyota would be the easiest to install. It is still available new from Toyota.

Many people would be willing to trade their 3.70 ratio third members out of 79-83 FJ40's and all FJ60's for the desirable fine spline 4.11 ratio gears in your truck.

 

[CruisinGA]

3.70 gear ratio would drop your RPM's from about 2900 @ 65 mph to about 2600, assuming 31" tires.

 

[Fast Eddy]

Stock sized tires? How about some rubber overdrive? 10% is easy.

 

[Jetboy]

I'd vote for tires too. Something like a 33/9.5 can make a pretty significand difference in cruising ability. I'd probably go with a h41 and taller tires rather than an h55. That's just my opinion though, because I'd use the low gearing as much or more than the 5th gear. I'd guess either tranny is cheaper than an old bolt on over drive and probably more efficient. Less gears to spin before you get to the ground.

THink about it this way; the slower you drive, the more time you get to enjoy driving a cruiser...

 

[DiHrdBowTi]

I have the Ranger overdrive in front of my stock toy 4 speed but then I'm also running a 350. I like it.

 

[Advent]

I've actually got a Fairey overdrive that supposedly only has 15,000 miles on it that came out of a '78 (supposedly) FJ55 that I'm not using. Plans changed, but it appears to be fine.

I think a lot of people's problem with them relates to not keeping them properly lubricated and tightened.

They're sure as heck a lot cheaper than new gears or an H55F. For that matter, cheaper than a new set of tires. Not hard to install at all.

 

[brider]

I just installed a Fairey on my Pig that came off a '78 FJ40. Works great.

Taller tires is easy, but affects your crawl ratio. So do 3.70 axles.

 

[Living in the Past]

Taller tires is easy, but affects your crawl ratio. So do 3.70 axles.

X2 you have to loss something to gain something. The H55F is a good tranny but longer than the H42 making a short rear drive line even shorter. With an overdrive you don't loss anything but your four speed now gives a overdrive plus eight forward gears in both high and low ranges.


Jim

 

[Hltoppr]

My troopy has a fairey overdrive in it, and it really makes a difference in town. The original H41 (5:1 1st) is pretty low and even starting in second runs through the gears pretty fast when not in overdrive....

The overdrive just makes it much more comfortable on the street...

-H-

 

[1962fj40]

Just caught this older post. Does anyone now where I may find a Fairey OD??


Robert

 

[Degnol]

Just caught this older post. Does anyone now where I may find a Fairey OD??


Robert

There is a Mudder that posted that he had eight Fairey OD units. I'm sorry that I don't remember who it was, but maybe they'll chime in.


Ed

 

[grant5127]

Nice novlety....

Has not been made for what, almost twenty years??

Not aware of anyone providing product support for this toy...

Save your money and purchase a Toyota five speed transmission...

 

[Combat Chuck]

H55 will mate up niecely to an F engie, and save you money on adapters. If you go aftermarket OD, or get a new tranny you'll have to move the T-case bracket back, and have the drive shafts adjusted.

 

[ranger]

I believe they still make them for Rovers under Superwinch. Not for TLC though.
Finding parts is not easy as well.