73 fj40 2f conversion

[73landcrusher]

Hi folks,

I'm new to the forum bit am looking for some advice.

I have a stock 73fj40 with f motor and 3 speed tranny/transfer.

I just picked up a 78 fj40 with low miles and am thinking of doing a full drive train swap less diffs.

I was just working on pulling the 78's fits and I see that there are some significant differences around the tranny/transfer. Ie an extra mount etc.

How many mods are required to get the 2f motor and tranny/transfer to fit?

Any advice is greatly appreciated!

Thanks!

 

[shelfboy1]

its a bolt in procedure a search should get you all the details as this has been covered many times on here .welcome to mud

 

[Mace]

Got a pic of the extra mount?

 

[73landcrusher]

Thanks for any tips. I've done a bit of a search and have found some info, but I need some more time to do a good search. Just popping on while at work for a quick second.

The extra mount is on the passenger side by the transfer case. Pretty much the same format as a motor mount. If I remember correct, my 73 has a cross member to support the tranny/transfer instead of a side mount. I'll get a pic of it next time I'm out there (maybe tonight if the kids behave I did notice that it is riveted onto the frame though which is what concerns me. I suppose if I have to I can grind the rivets and bolt onto the 73 frame.

Cheers

 

[Mace]

There are not any other stock motor or tranny mounts other than on the motor and bellhousing on a 73 or 78.

 

[Tigerstripe40]

You'll need to use the 78's diff's as well, due to different bolt patterns for the driveshafts.
the 78's diffs ought to be fine spline pinions, which is a win in either case.

 

[78fj40mg]

BTW ~ Welcome to MUD!

 

[shelfboy1]

the motor mounts are riveted to the frame on all cruisers i have seen unless modified .someone may have added an aftermarket rear mount photos would be your best bet .you dont have to change the diffs for the drive shafts to work we can deal with that later .i prefer to use the early stock parts on my 2 fs that way everything bolts up .but thats just me .using the stock 2 f parts you will have to modify,wiring ,throttle lincage .exhaust and a few other things .the clutch arm and slave can be moved to the other side so you dont have to run new lines .

 

[SouthBostonFJ40]

You could save a lot of time by just striping the 78 front axle from the knuckles out and pull the fine spline birfs and re-install it all on the 73 axle.

 

[73landcrusher]

Sorry for the long time between posts. Two kids under 3 with colds at the same time make for a lack of garage time. But I have had a chance to take another look under the 78 and compare to my 73. Motor mounts do look the same between the two rigs so a relief there. The way the rear passenger mount on 78 connects to the motor looked like it was going to the transfer at 1st glance. My bad. I had only taken a quick look as I hadn't jacked it up yet.

The 78 I picked up is missing the front springs and has the front axle with one broken birf stuffed in the back. Apparently the diff is ok though but I haven't had it apart to confirm.

I'd be interested in hearing more about your idea Shelfboy1 about not having to change the diffs. I have a decent sized mill and lathe so fabricating an adapter plate or modifying parts is always doable.

The exhaust on the 78 looks like it's in good condition all the way to the tail pipe. I was going to take a look at tacking on new hangers and using it. Any thoughts?

How about the speedo cable? Any mods required there? I haven't gotten to the point of pulling the tranny and transfer off yet. Speaking of....I'm assuming it's a lot easier to pull the trany and transfer off prior to pulling the engine? Or has anyone pulled as an entire unit? Keep in mind that as I mentioned there's no front axle so it's not easy to move around right now.

Cheers

 

[Mace]

If you use the entire drivetrain out of the 78 (including driveshafts and axles) it'll be the smoothest.

No lathe needed, do you specifically want to use the diffs you currently have?

2f exhaust should probably work just fine. Speedo from the 73 should screw into the 78 tcase.


Pulling everything at once is not hard at all, you just need to make sure that you have a good engine hoist. It's heavy..