What Tranny Setup ?

[Stroker]

I have a 75 FJ40 SB Turbo400 tranny . I would like to shift my motor back because the fan is right up against the radiator and I over heat to the extreme on the trails. Now I know what some of you are thinking and I'm sure I tried it. I'm sure I need to slide my motor back and I have about 7" betwwen the distributor and the firewall. I'm looking to put in an electric fan. I would like to keep my rig setup as an auto. Part 2 of my ? is I would like to gear down, I'm thinking 5.38 What do you think and where can I find them? Thanks
Stroker

 

[Rice]

I know this isn't what you were asking but it sure sounds like it would be less problematic to move the radiator forward a bit or switch to a short water pump if you're not running one already. The short pump will yield you a little less than two inches and moving up the radiator another 1 inch. In the pick below my engine is 8 inches forward of stock.

 

[Jetboy]

not sure about the engine, but as for the gears, the lowest gear you should run is 5.29. if you have a shoparround that you can look at a set of 5.38's you'll see why. the pinion gets too small!!! minitrucks with 4cyl.s break them and they are not much different the LC diffs. the 5.29 pinion is considerably stronger.

 

[65swb45]

With a TH400, you aint got SH*t for a rear driveshaft now. Try to move it back and you significantly decrease the life expectancy of EVERYTHING back there. So Part 1 and Part 2 are related: if you move it back, you'd better stay with 4:11s, cause you're gonna be buying spares sooner than you'd like.

 

[TJDIV]

With a TH400, you aint got SH*t for a rear driveshaft now. Try to move it back and you significantly decrease the life expectancy of EVERYTHING back there. So Part 1 and Part 2 are related: if you move it back, you'd better stay with 4:11s, cause you're gonna be buying spares sooner than you'd like.

And that's considering you get the pinion angles right. I had a helluva time doing it when I put a 700R4 in my 40.

I too vote for Rice's option (which is what I eventually had to do). Move it forward and make EVERY change possible before you crunch down your driveshaft lengths even more.

 

[albee]

Switch to a fan with a different pitch on the blade. It worked for me.

 

[Stroker]

I'll look at the pump, fan and radiator positions first. The way it stands now my fan is 1/2" away from the radiator. Concerning moving the engine I was thinking of putting in a TH350 in place of the 400 and sliding the motor back seeing how the 350 is shorter. The point of this excercise is to install an electric pusher fan between the bezel and radiator. What are the thoughts?

 

[VTFJ40]

The pusher doesn't work as well as the puller.

 

[Ponce]

Stroker. I have an electric pusher fan on my 40. I have had no problems over heating. I'm running a 283 with the stock radiator and a short water pump. I usually run about 200-210. Thats both city and freeway driving even in high 90* temp days. My fan is rated at 3300 cfm. I wired it in with a themostat. It comes on at 190*. I had to move my radiator back about 1" to get the fan to fit between the radiator and bezel. When I finished my SBC I had no room for a mech. fan. so I had to go electric. You will need to fab up a shroud. I went to Lowes and bought a piece for sheet metal and copied a pattern I made out of cardboard.
HTH

 

[Stroker]

Ponce What about when your wheelin? how hot are getting at a crawl, Here in eastern washington It can be over 100 on a given summer day and it's crawlin where I get hot.

 

[HI^C]

toreass fan, mild 406 SBC, seen 210 twice this yr (but it was 95+ outside), stock rad, longpump barely misses the fan.

toreass needs like 4.5" i believe.

most th400 adapters are shorter then the other auto trans adapters that i have seen.