FJ40 for mostly highway driving recommendation.

[Larr75fj40]

I've put 15k miles on mine the last 7 yrs. Filling my tank on my Matrix is more of a concern then my fj40. Like a previous member wrote earlier. " Just buy an old civic". You'll have to drive the 40 a decade before you recover the couple of miles per gallon you will gain with a swap.

 

[duffontap]

Not a 4 wheeling person but I just love the shape of Fj40 so much that I have to have this.

Just kidding. They do look sweet.

My DD (stock front Toyota disk, 2F, 4-sp, 31" tires, 4:11) gets driven on the highway every day it gets driven, but I've had to adapt my driving style quite a bit and I'm talking about uncrowded 45-55mph. max highways. If you're talking about regular busy freeway commuting, I'd say you just might be out of your mind--and that's coming from a guy who drives his daughter to preschool in a '40.

Welcome to MUD.

 

[Oso Flaco]

Zafar,

Try this post - https://forum.ih8mud.com/40-55-series-tech/75467-three-speed-case-four-speed-tranny.html#post884223 Has several posts to read on 3-4speed swap

I'd recommend that when you have an hour or two free, you should grab a cup of coffee, find a comfortable recliner and read the FAQ section https://forum.ih8mud.com/40-55-seri...-asked-questions-f-q-updated-04-jan-11-a.html

The information in the FAQ section really is priceless and a testiment to how many truly great people own FJ's!

 

[zafar11]

Thanks for the reply.

I'm not worried about gas mileage, I only care if I can drive around 65 on a highway without a top.

WIth all the recommendation on V8 conversions (Thanks to everyone) If I keep the F engine and just replace the transmission with 4 speed , Would that let me drive at around 65 mph ? ( My FJ40 is not currently running because if few things)

For getting a civic,Not a car person. I already have a 100 series land cruiser and 2005 lx470 for daily driving

 

[zafar11]

Thanks Oso, Let me read a little. Thanks

 

[BB]

Third gear on a 3 speed is 1:1, as is fourth gear on a 4 speed. A 4 speed swap will not net you a higher top speed. It will result in better driveability (better ratios for real-world driving, plus a syncro first gear). If you are set on going 65 in a topless FJ40, it can be done. I recommend bigger tires, 3.70 gears and a well tuned F or 2F engine. Even so, 65 is pushing it in a 40, especially on Bay Area freeways. To each his own...

 

[zafar11]

BB, Thanks for the reply, I can get the tires

What is 3.70 Gear means ? (Sorry ... I'm a rookie at these things.. Everyone is at one point)

 

[alberta mac]

#9
platypusREX
250+ Club

Join Date: Mar 2011
Location: Dallas Texas
Posts: 369
Garage
A highway 40 is like having a off road Corvette. Wrong base for the job. I am not saying it cant be done.


I'm with him ! good call and that reality !

 

[pc4400]

Thanks for the reply.

I'm not worried about gas mileage, I only care if I can drive around 65 on a highway without a top.

WIth all the recommendation on V8 conversions (Thanks to everyone) If I keep the F engine and just replace the transmission with 4 speed , Would that let me drive at around 65 mph ? ( My FJ40 is not currently running because if few things)

For getting a civic,Not a car person. I already have a 100 series land cruiser and 2005 lx470 for daily driving

I drove 65-70 on the freeway with my 72 (F engine, 3 speed tranny) and that was with it on it's last leg. I'm finishing up a total rebuild and dont see any reason why a properly tuned F or 2F couldn't go 65mph. Maybe you should start by doing a tune up?

 

[platypusREX]

I have heard of these magical 40s that people on this board that go 75-90. Never seen one though. I am burning hard at 55 mph with sails at full and my foot kicking along out the door to assist pushing.

 

[DougAustinTx]

My '79 FJ40 has a 2F with a 2bbl Holley, an H55 5 speed, a splitcase transfer unit, the complete 3.70 rear end out of an FJ60 (and the 3.70's in the front diff). It is all stock on the suspension (no lift) and runs 31" Michelin tires. Disc brakes at the front and the 60 drums on the back. Stops great when you step on the brakes. It has a combo FJ60 power steering box with a Saginaw pump, steers with one finger and has a very small turning radius. It is reasonably quiet and will get up to 85 on the highway with no effort and comfortably cruises at 75 on our Texas interstates and gets about 15 mpg (depending on headwinds). I haven't checked out it's top speed yet, so let's not say that a 40 CAN'T be a reasonable highway cruiser,

 

[pc4400]

I have heard of these magical 40s that people on this board that go 75-90. Never seen one though. I am burning hard at 55 mph with sails at full and my foot kicking along out the door to assist pushing.

Really? Check your compression, timing and fuel delivery. I will admit going 70mph was crazy loud, we wore headphones just to put up with the super loud glowing engine and drivetrain. I tracked my speed with gps just to be accurate. But seriously we did 80 back in the day it is possible.

 

[Moriarty]

Hi i have an 82 FJ40. Last year I swapped my 2F for a 3F on the stock 4 Speed transmission. The fuel economy is much better and the engine feels a lot smoother than the 2F. I haven't tested it out on the highway but i am getting better mileage in the city. I do not live in the U.S so not sure if such a swap would be possible there but i think its worth considering. I am also planning on swapping the transmission for a 5 speed which should further improve the fuel economy and make it pretty good for highway driving.

 

[Eshu Elegua]

...9
platypusREX
250+ Club

Join Date: Mar 2011
Location: Dallas Texas
Posts: 369
Garage
A highway 40 is like having a off road Corvette. Wrong base for the job. I am not saying it cant be done.<<<< Proof here..

 

[1911]

I recommend bigger tires, 3.70 gears and a well tuned F or 2F engine.

+1

I run (stock for my 40) 3.7 diffs, 33" tires, a de-smogged 2F and an H41 transmission and it will go 65 mph all day long at 2500 rpm. It will go 70-75 if I really wind it up, but it is definitely more comfortable at 60-65 mph. I've driven it to southern Utah and back, Colorado and back, numerous over 2,000 - 3,000 mile trips. The seat time is the only limiting factor.

 

[msapers]

I have a 72 with an F and a 3 speed and a 76 with a 2F and a 4 speed. Both have 33's and 4:11's They are both driven regularly on the freeway (I'm talking about L.A. freeways), at 65-70mph with no problems. Both will go much faster if pushed. Drove the 72 to Arizone last year and cruised at 75 the whole way. Anybody who can't get over 50 mph has something wrong with their truck.

Your main focus should be your suspension, steering and brakes. If you have sloppy steering, poorly adjusted brakes and worn out suspension, it will be unsafe on the freeway. My 72 was a handful until I rebuilt the stock steering and brakes, now it's a pleasure.

You'll notice that there are three catagories of FJ40 owners here: 1. Those of us who drive our Cruisers regularly and use them as a primary, all purpose vehicle. 2. Those that mainly drive them off road and rarely if ever use them on the highway. 3. Those that don't really drive them at all (This seems to be the most opinionated group.)

Best of luck with your truck. How about some pictures?

 

[JasonH]

I have heard of these magical 40s that people on this board that go 75-90. Never seen one though. I am burning hard at 55 mph with sails at full and my foot kicking along out the door to assist pushing.

Come to a Lone Star Land Cruiser meeting sometime and I'll give you a 75mph ride in a 2F FJ40.

 

[cryoguy6075]

How far, how fast, how often?

1) Keep your F, add 33x10.50 BFG ATs, stock Toyota 4 speed, possibly 3.70 gears.

2) 350, 33s, Toy 4speed, 3.70 gears.

3) Vortec, OD trans, 33s.

I agree with the 1st one. I just drove my 74 FJ40 from Yuma,AZ to Temecula area last weekend and I have the 1F 4speed with 33x12.5x15 and it drove just fine. I averaged 65 mph and I could have done 70 but didn't want to push it. As far as fuel mileage.... Mine could use a serious tune up! I think I was getting close to 10mpg. If your 1F is done right it should suffice and you can put all that extra money into other goodies! Good luck to you!

 

[cryoguy6075]

Thanks Guys. I really appreciate all the response. I wanted to have open fj40 and go cruising. Not a 4 wheeling person but I just love the shape of Fj40 so much that I have to have this.

One question, Since I'm brand new to FJ40, Mine in 72 with a three speed transmission and stock TC. . Can I just get a 4 speed transmission from a 76 or above and will it bolt write in to F engine and Transfer case ?

Thanks

The final gears are the same 1:1 so 3speed 3rd is the same as 4speed 4th

 

[cryoguy6075]

Thanks Guys. I really appreciate all the response. I wanted to have open fj40 and go cruising. Not a 4 wheeling person but I just love the shape of Fj40 so much that I have to have this.

Here are some pics of my road trip to Cali from AZ