3spd to 4spd (1 Viewer)

[Ethan]

First off sorry because I know this has been talked about to death but when I search all I get are crazy conversions not all toyota parts. So my question is simple. If I have a 72 FJ40 with a F motor and I get a 76 Fj40 TC, trans, and bell housing what will I need to do to make this fit? Will it fit no problem?

 

[lc69hunter]

I haven't done it myself yet, but I know you need either to shorten your driveshaft or replace it.

 

[alkarich]

You'll need the kit if you don't already have that. Then it is swapping parts that you have and shortening you driveshaft.

 

[Ethan]

Both drive shafts change or just one? What about the clutch?

 

[Ethan]

whats in the kit?

 

[alkarich]

I believe it is just the rear driveshaft. My buddy did this swap in his 40. Clutch should be okay.

 

[alkarich]

Sorry I missed your next post. In the kit are some bearings and I believe 1 gear to mate the two together. Some of the vendors have them. I know Proffitt's used to carry them as well as Mark's Off-Road. A call to either of these shops will give you all the info.

 

[Bret]

You may be referring to using the 3spd transfer with the 4 speed tranny, that requires the "transition gear"

 

[Jakes40]

the bolt patern on the 4 speed is biger or smaller not sure but you have to change the end that bolts to the tranfer case flange on the frount and rear.

Chris

 

[Pin_Head]

Get everything on the '76 from the flywheel to the differential flanges. That's the EZ way. It is also acceptable to use the 3sp slip yokes on the 4sp drive shafts and bolt the slip yoke to the differential (eg flip the driveshaft end to end).

 

[Ethan]

Ok so if I get the newer bell housing and trans AND TC then all im looking at is drive line issues?

 

[bsmith123]

4 spd

https://forum.ih8mud.com/40-55-series-tech/245021-pics-oem-p-ns-rear-main-clutch-change.html


I just did mine except for actually mating the trans, so have a look at the post--- I hope it helps I listed all the p/ns I got from Cruiser Dan and took pics of the difference between the 3 and 4 spd parts


For the 4 spd make sure the bell housing has the little pivot for the fork I am not sure if the 3 speed one fork along with the longer pivot would work with the 4 speed or not

I know you can use your 3 clutch stuff if you swap it all over but you cant mix and match parts according to most of the advice I got. They say the diaphragm style clutch is better and it is used on the later models so I decided to swap. I am not sure about that I mean if the clutch works?


Its a good time to do the rear main seal too, this requires removing the oil pan and 4 bolts on the rear bearing cap but is easy to do and well worth the peace of mind

I also swapped the pilot bearing but I don't think I needed too mine was in good shape but if I mess up installing the trans I have the old one as a spare.


I know I didnt want to run it for 6 mos and then have to buy a new clutch so you may want to think about that

I originally thought of the 4 spd to 3 spd T/C too but in the end I went the easy route and went all 4 speed and later model clutch

If you dont read the post then make sure you pre-fit your pilot bearing on the trans shaft other wise you may not get your tranny to slide in. You can use emery cloth on the shaft until the bearing slides on--about 5 min work on mine

Whole job cost me around $350