Bj 70 5spd into my BJ 42

[The Glowplug]

Just thought I'd throw this out there (I've searched till I'm cross eyed).I have a 85 Bj 70 (rolling parts truck)with a 5 speed and want to replace the 4speed in the Bj 42 (tranny and transfer case) with the 5 speed ,the wheel base is about the same in both trucks ,can i just take the driveshafts outta the 70 and put them in the 42 or will driveshaft mods be in order . wanted to make it a weekend deal and go to work on monday,if I have to lengthen (shorten) the shafts it will be more than a weekend affair.. Are the transfer case ratios the same ?? Both are split cases . How about crossmember mods.any input would be apprecated.

 

[Combat Chuck]

Do you know what tranny the 70's got? If it's an H55, the axles and shafts should be fine, but you'll have to move the tranny rear crossmember back to adapt. I'm not so familiar with the B series engines, but as I understand, any "H" tranny will mate up to any "F" engine, and I don't see why not for the B. Dan, who haunts the diesel board would know more, that's really his field. He's the guy with the cool Five Iron Frenzy avatar.

 

[The Glowplug]

Not sure on the tranny I think its a 55 and the transfer cases look identical ..stupid question but how do you tell if it is a h55?

 

[Combat Chuck]

this is the best I can do, you can also check out the cruiserfaq page here on Mud to see if there's anything.
Australian H55 5-speed Overdrive Transmission

I'm sure there are all kinds of folks here on Mud who are about a billion times more in the know than I am, so just keep your fingers crossed in the hope that someone will visit this.

 

[Combat Chuck]

I alos found this on Mud.
https://forum.ih8mud.com/40-55-series-tech/45269-how-do-i-identify-h55-transmission.html
I decided to be dumb and not search the forum at first.

 

[The Glowplug]

Thanks combat im still researching this and will post anything I find out

 

[Dieseler]

I believe the 5 spd tranny is longer than the 4spd which you would have to shorten your shaft or find a shaft from a 5spd BJ4*
I assume the 70 has a 3B motor if that is the case it should have the H55 tranny which is a direct bolt up

 

[The Glowplug]

I was thinking the shafts outta the Bj 70 would be the proper lengths since it had the 5 speed.Yes the 70 has a 3b.

 

[The Glowplug]

would the transfer cases have the same gears or should I take the low side gears from the 42 transfer case and put them in the 5 speed transfer case.

 

[Combat Chuck]

TCase should bolt right up, according to my intel.

 

[Dieseler]

The input would be the same I am refering to the tail end which houses the 5th gear or OD of the trany if I'm not mistaken,measure the two if you have both trany's.

 

[Josie'sLandCruiser]

Hi All:

You should really post this question in the "Diesel & 24 Volt" section - there are some very experienced folks hanging out there who have done swaps like this.

From my limited knowledge of the BJ42 & 70 yes the BJ70 will have a 3B and the H55F.

This tranny will bolt-up to the 3B in the '42. Like has been mentioned, the tranny crossmember will have to be moved (the H55F is longer than the H42.)

Regarding the drive shafts, the '70's might work, length-wise; you will have to wait until the tranny is installed in the '42 to find out. Also, compare the drive shaft yoke patterns on the BJ42 to those on the BJ70 to see if they are the same or not.

That BJ70 parts truck has other good stuff to use on your BJ42, like the suspension seats, longer rear springs, etc.

Be sure to post-up pics of the project!

Regards,

Alan

 

[mano002]

The 5 speed is about 3" longer than the 4 speed, but you could m,easure both drive shafts and see if the one fromt eh 70 is 3" shorter than the one in your 42. Its cheap to have a driveshaft shortened though, less than $100, so I think you should do it! Then you can DD your 42 and put the 4 speed in yout 70 and sell it.

 

[The Glowplug]

Thanks for all the input and suggestions,It might be a little more than a weekend project with the turn around time on the driveshafts.Yes I will be putting the 4 spd back into the 70 and use it as a winter beater 400,000 km still runs like a top..

 

[Zekester]

I just swapped an H55 into my 40, and did not have to move my crossmember, it sits under the bellhousing, not the transmission...I did have to notch it to provide clearance for the front shaft...

I don't know how close the 70 shafts are in length, I got both two shafts shortened for $35....one was from a 60 and long, the other was my 40 shaft, also too long, easier to shorten them than lengthen one of them...

 

[The Glowplug]

My crossmember sits under the tranny,But thanks for the info.

 

[Josie'sLandCruiser]

Hi All:

Ah, on later model 40 Series, and the 60 Series there is a crossmember supporting the transmission (unlike the early 40 Series that had the tranny mount at the bellhousing.) One will need to use this to support the H55F and t-case (a rather long assembly!)

Regards,

Alan



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I just swapped an H55 into my 40, and did not have to move my crossmember, it sits under the bellhousing, not the transmission...I did have to notch it to provide clearance for the front shaft...

I don't know how close the 70 shafts are in length, I got both two shafts shortened for $35....one was from a 60 and long, the other was my 40 shaft, also too long, easier to shorten them than lengthen one of them...

 

[Zekester]

there is a crossmember supporting the transmission (unlike the early 40 Series that had the tranny mount at the bellhousing.) One will need to use this to support the H55F and t-case (a rather long assembly!)

I have the H55 supported by the crossmember that supported my four speed, under the bellhousing...I posed the question in the diesel section as to how safe that was, and was assured that it would be ok....I know it does seem like a lot hanging off the bellhousing, but is it that much different than a 4 speed hanging of it?

 

[DanS HJ-45]

He's the guy with the cool Five Iron Frenzy avatar.

Go! Go!

Pick it up! Pick it up!

Real quick bit on the H55f crossmember question though. This is all on here (including Josie's LC post a few above this), but in different places. So I'll quickly summarize it...

Early 5 speeds in the 40 used the bellhousing for the rear motor mount.
Later models (yes of the 40) used a crossmember under the 5-speed for the rear motor mount (they don't have the bellhousing mounts)
60 and 70 series trucks used the transmission style crossmember like the later 40s.

Here's what the 40 series/H55f crossmember looks like (along with the two mounting tabs that are attached to the frame)


BUT, the rubber isolator between that crossmember and the transmission is CRAZY hard to get. I finally got one from RADD Cruisers, but it took a while. If I was doing it again (like I will on my 45) I will use a 60 series crossmember modified to fit the 40 series frame (or just keep the bellhousing motor mounts alone). That isolator is easy to find.

There's pics of a later 3B/H55f in my 3B into FJ-40 thread (in the diesel section), and many more pics to come. Including mounting the engine/transmission into the frame very, very soon (like next week--hopefully).

Hope that clears it up a bit.

Dan

 

[Zekester]

that.....looks exactly like the mount I pulled out of my 60, under the H55...I modified the original 4 speed one in my 40...the one I have like above...is in the for sale section...