13BT into South American '77 BJ40 (1 Viewer)

[Aaroneous]

Hey all,

I'm working on swapping a 13BT into my cousin's '77 BJ40 and I'm at a point where I know there are a couple of different paths that I could go down, and wanted to open it up to this group to see if there are any other options I haven't considered or if there is a strong community preference for one over another. I've made significant progress, but am blocked until we have a plan of attack.

Plan of attack
* 13BT acquired complete accessories through bell housing.
* Retain 4spd trans & solid t-case in the short-term, long-term plan is to go with H55f, split case, rear axle w/ parking brake
* Flip radiator outlet to opposite side for 13BT
* New exhaust

Complete
* Original B diesel removed, engine mount brackets transferred to 13BT
* Bell housing from B retained to provide mounting options (missing lower block -> bell housing brackets)
* B diesel sold
* Converted vacuum shutoff switch, starter, and alternator from 24V to 12V (have not addressed glow screen yet)

Mounting options
This is where I have the most questions and would really love input. The South American BJ40 has the transmission mount on the bell housing that attaches to a crossmember. The 13BT relies on the H55f side-mount transmission mounts. Here are the options I see...

1. Mate the 13BT to the 4spd via the 13BT bell housing, add a rear mount cross-member like this one from Advance Adapters. I've read that the clocking of the 13BT bell housing requires modification to the engine mounts on the frame side, and I'd prefer not to do that because when we go to the H55f we will need to undo whatever we did to support the 4spd.
2. Use the B bell housing to mate the 13BT to the 4spd and utilize the bell housing transmission mount. I've read that there are potentially clutch clearance issues with this approach. This would require sourcing the lower block -> bell housing brackets and dealing with bolt size differences, etc. However, this feels like the simplest solution to support the long-term plan.
3. Go big and get the H55f, split-case, rear axle, and drive shafts now and do it all once. Logically, this feels like the right solution, but time and budget may not allow.
4. ?????

Would love input from anyone who has done this on which approach folks have taken successfully. Need to come up with a plan that will get this sucker back together and back on the road as quickly as possible.

Thanks in advance!

Aaron

 

[jim land]

i never done this swap but i think #3 , go big with h55 and split-case , you can keep the stock rear end if you buy a t-case mounted parking brake

 

[Aaroneous]

Yeah, I think that option #3 is a strong one, good to know you can buy a t-case mounted parking brake. Thank for that suggestion!

Curious if anyone on here has positive or negative experience from going with option #1 or #2?

 

[RAYJON]

Do some digging there was a guy who did this swap on a fj70, he went from a 3fe to 13b, there were some differences in the clutch and etc, he did a good job of detailing the differences..

 

[Brewsterfire]

I used an aluminum bellhousing and H55f with the tranny mount. No clutch problems. Need to shorten rear driveshaft and lengthen front driveshaft.

 

[John in Utah]

What kind of modification are we talking for #1? Can you just source new mounts when you swap to the h55?

If it were me I’d just get the whole thing over with and go #3.

 

[Aaroneous]

Ended up going with option 2 and it seems to be a winner. Got the engine cranked over and everything is turning nicely. I had to grind down the raised edges of the late-model pressure plate to create comfortable tolerance to the bell housing and needed to use a 3B-style throwout bearing spacer with the B-style fork to make it all work. Starter bolt alignment took some elbow grease and creativity, but it's centered on the backing plate so should be good to go. Haven't driven it yet, but the slave cylinder throw looks like it will be good as well. I left the lower brackets for the aluminum bell housing on there to reuse if/when we go to H55f.

Best part about this approach is I didn't have to clock the motor so if we go to H55f later, I can swap bell housings and add side-mounts and not have to undo anything I did.

This thread was very helpful