1970 '40 3-speed swap options (1 Viewer)

[Scota4570]

Related to my other recent thread on a possibly ruined transmission.....

The 3-speed has a maximum comfortable speed of about 50 MPH. After that it get loud and shaky. I have a PTO winch that I want to keep.

Are there any options to get a lower cruise RPM? Different transmission? Different gears??? For reference I have never needed the low range first gear in the hills.

 

[Living in the Past]

Four speed fourth gear is one to one same as a three speed. Idea is to reduce RPM. Tire size, diff gearing and Overdrive will help with that. All except overdrive you have to give up low end gearing.

 

[Scota4570]

Four speed fourth gear is one to one same as a three speed. Idea is to reduce RPM. Tire size, diff gearing and Overdrive will help with that. All except overdrive you have to give up low end gearing.

Never needed the low range first gear. It is not a sacrifice. Is there an overdrive option today? The only one I am aware of is no longer in production. It seems that a spit rear axle would be perfect. I never heard of one for this vehicle though. Can the transmission gears be changed to different ratios?

 

[red66toy]

Mine is loud from 1mph to 60mph. After that everything gets eerily quite because I think my auditory neurons have called it quits.
What size tires are you running? I used to run 33" tires, hope to again soon, and it really helped with highway cruising speeds.

 

[Scota4570]

235/75 R15 I measure 28" They are off road but not super aggressive. See avatar photo.
I am concerned about drive train noise.

 

[Living in the Past]

The only one I am aware of is no longer in production. It seems that a spit rear axle would be perfect. I never heard of one for this vehicle though. Can the transmission gears be changed to different ratios?

Hone was one OD made for the 40 series. Those would be close to the two speed rear axle since it's mounted to the back of the transfer. Fairey was another more popular when they were available. Had a few of them.

You can still buy a H55F five speed from Toyota. Price is really not too bad. It everything else that needs to be done that really add the close.

Made my living thru the seventies driving trucks with two speed rear axles. I agree it be difficult finding one small enough for an FJ40 but would be fun.

I know of no gearing for transmissions used in the 40 series would would increase the final gear. Only the H55F has an overdrive the rest are all one to one in the top gear.

 

[70fj40]

My 1970 40 is 3 on the tree and factory tranny/transfer case. It was also happy at 50, seemed like 55 was barely in reach and loud even with a rebuilt motor. I finally had the transfer case rebuilt and immediately noticed that 60 - 65 was now easy to cruise at and although I would not say it is anything resembling quiet it certainly is quieter than before. A factory 40 doesn’t have to sound like it’s coming apart at 50 and perfectly capable of 65 miles per hour in stock form.

 

[B y r o n]

Maybe this information may help.