TXFER Case Question - Engine/tranny/txfer case compatibility for FJ55 (1 Viewer)

[logic2]

I have a running/driving 72 FJ55 with the original F motor and 3-speed tranny.
I plan to continue using this drivetrain as long as I can (don't fix it if it ain't broke) but I have access to a very low mile 6.0 with a 4L80e Tranny and the NP246 Transfer Case to go with it. The new drivetrain is (2004 with 80k miles). So I need to consider this for future planning.

Question: I've done several 4.8 & 5.3 Vortec swaps in FJ40s so I'm sure the (6.0) Engine & (4L80e) Tranny will work like a charm, but will the NP246 transfer case clear and line up nicely with the front & rear FJ55 differentials or do I need to go with another Toyota txfer case, etc.. ?

If I eventually upgrade my driveline, I'd like to keep it all together (engine/tranny/txfer case) but I'm open to feedback from those that have tried it before.

Thanks for any feedback,
Mike

 

[reddingcruiser]

Are you changing to a centered rear diff? Is the t-case a right hand drop?

 

[logic2]

Good question and the reason for my post. I wanted to make sure they line up.

I do not plan on changing anything except my engine/tranny/txfer case.
I plan on keeping the original FJ55 front axle assemblies (offset diff)

I'm still researching the 4L80e & NP246 to make sure it will line up with the FJ Diffs.

 

[reddingcruiser]

IIRC, the rear output on the NP246 is straight out the back, which will not line up with the offset rear diff. The NP205 is a passenger side drop, but I'm not sure what you would need to get it to work properly with the 4L60E, (i.e., VSS)

 

[Rock40]

Get an adapter for the auto trans to mate a passenger side drop NP205. Off Road Design can mill/machine the factory NP205 output housing (the cast part which contains the speedo cable) for a VSS which you will need to talk to the 6.0L. I just had them do one for me related to an upcoming 8.1 Vortec/SM465/Magnum/NP205 build. Off Road Design charges about $200 for the service and that includes the VSS, reluctor ring and wiring. Other than that, your swap idea will work great, just ditch the factory transfer case from the 04' donor

 

[logic2]

Good Info Thanks

 

[Rock40]

Keep in mind the NP205 does have a centered rear output that will result in a rear driveshaft with a compound angle. HOWEVER, I have been running a compound angle in the rear of my 40 for years (3 speed transfer case/FZJ80 rear axle) without issue. You'll likely need a CV shaft though. Tom Woods makes some very good stuff and he stands behind his work too. Far easier to run a quality shaft with a compound angle than making some kind of centered diff Toyota axle hybrid.

 

[logic2]

Sorry, I'm confused (nothing new...)

1.) Do (BOTH) the NP205 (AND) the NP246 have centered output shaft ?
I'm reading above that the NP205 "could be adapted to have" a (Right Hand - Passenger Side) output shaft with some minor machine work.
Is this correct ?

If they (both) have a centered output shaft, is there a preference to use one over the other ?
Regarding the NP205 with a centered output shaft (IF I were to go that route)....
It sounds like it it being run on FJ40s with severe driveshaft angles but without issue as long as it's a quality driveshaft.

2.) Observation: Since I would be running this 4l80e/NP246 or NP205 txfer case, in a FJ55 (much longer drivetrain), the angle of the centered driveshaft should not cause much of a problem (Since they are being ran in 40s without issue).

3.) More Important Question: Rather than trying to do it the hard way...(force a modern GM transfer case work), Should I use a (Adapt) a Toyota transfer case to the 4L80e tranny that already has an offset transfer case ?

I'm just trying to collect the experiences and headaches form those that have done it before me.

I appreciate all the feedback !

 

[reddingcruiser]

1. Yes, both are. Compound drive line angles will "work" but not normally recommended. Early FJ40'S had centered rear diff and eventually Toyota saw the error of their ways.
2. See 1
3. This keeps the drive lines in their OEM orientation, you don't have to install a centered rear diff and you still have a parking brake.

 

[logic2]

Thanks !
I know there is more than one Toyota txfer case with an offset driveshaft, but for reliability & strength (including highway speeds, etc..) Is there one that is highly recommended for my 4L80e setup (FJ55) ?

Assuming that I keep the 4L80e transmission because it's already connected to my engine setup, and assuming I use Advanced Adapters to mate up to a Toyota Transfer Case, which one would be the best option and has proven to work ?

Thanks

 

[Rock40]

You could easily use your stock FJ55 "3 speed" transfer case with an AA adapter. Mine (braced all over) has survived the Vortec engine, lockers and 37's. I have a very light right foot however. The NP205 regardless, is WAY stronger than the FJ55 transfer case you now have. BUT, the NP205 cannot be machined to have an offset rear output as you mentioned above. It will always be a centered output.

If it was me, I'd likely run an NP205 and a rear shaft with a compound angle as I mentioned above. I have discussed this with Tom Woods (Tom Woods Driveshafts) and he doesn't see an issue with it. But, I like to wheel things and not worry about them.

For you, assuming you are not going to wheel the snot out of this and you already have an FJ55 3 speed transfer case, it may make more sense to source the correct AA adapter and run the Toyota case. Rebuild the case, brace the front output and over the top of the case and you'll likely be good for a long while. You'll have a "normal" driveshaft angle at least.