Old t-case + newer tranny?

[DallasFJ40]

My transfer case exploded last week while pulling out of the drive way. It had been making a loud whining noise , but thought that may have just been normal.

Anyway, I have a spare tranny and transfer case from an older rig (don't know year). Will the t-case mate up with the newer tranny without issue? When trying to swap the front drive assemblies (the older tcase has some issues with that area), I noticed the different spline counts. I know the older one still needs some work, but the gears look ok.

 

[Poser]

What EXACTLY are you working on and with?


Older?

Newer?


Than what?

 

[DallasFJ40]

Sorry for the vagueness. I have a 79 with stock 4 speed tranny. The spare transfer case is older, but I have no idea how much older. The main difference i havenoticed between the 79 t-case and this other one is that the older one has course splines in output shaft (I think that is what it is called) going to drive the front axle.

I have dropped the tranny and t-case out of the truck and was just hoping it may be plug and play by just attaching the older t-case to my 79 tranny.

 

[bustanutley]

I believe a 79 will have a split-case which is 19 spline. My guess is you have a one piece case laying around. This will either be 16 or 10 spline, everything is different, you will need a different tranny to use the 19 one piece case. I would find a new split case if I were you, they are superior.

 

[mustardfj40]

I thought '79 still have the one piece transfer case since I bought one a long time ago:

Yes, the front output flange is fine-splined (one on top):

 

[Downey]

Your 1979 T.C. has the 1974-newer four bolt pattern, but fine spline at the front output shaft. A 1974-78 T.C. has the same 1974-newer bolt pattern, so your drive shaft should bolt-up no sweat. If you are talking about using a 1973-older 3 Spd. T.C., then a bunch of stuff has to fall into place??

 

[DallasFJ40]

It is a one piece case. I think the split case came 8/80. I just found out the older t-case is from a 74. Is it possible to swap the finer splined output shaft from the 79 to the 74 t-case? From the picture above, it looks like the rest of the shaft that goes into the main part of the case is the same.

I guess the case saver I bought from Poser a while back will be installed once we finish the swap...

 

[Poser]

It is a one piece case. I think the split case came 8/80.

Correct. 07/80 was the last of the one-piece Land Cruiser transfer cases in USA.

Is it possible to swap the finer splined output shaft from the 79 to the 74 t-case?

Not without changing the whole main shaft....


The 1974 case will have the coarse splined front drive coupler and you can see the that the fine spline front output shaft uses a fine spline coupler and main shaft. Thank you for the picture.

 

[DallasFJ40]

Carnage

 

[pbgbottle]

i think you need to look at what spline count you have on your input gear also in your spare 1974 t-case .
if it is a 4spd case you might be able to swap the nose cones and make it work see pic also showing the other front output shaft. option

both have the 27 spline on the shift collor

 

[Poser]

Just like many things found in print in major publications, here is another fine example of miss-information.



The main shaft and front drive coupler did not change until 04/75 on the four speed, one-piece Land Cruiser transfer case.

 

[pbgbottle]

AH! good to know . how about the front output on the 3spd case ,
I have one that uses a cotterpin to retain the nut and one that doesn't when did they go away from the cotterpin. i never have read anything about this either on the 3spd case ,,see pic

Just like many things found in print in major publications, here is another fine example of miss-information.



The main shaft and front drive coupler did not change until 04/75 on the four speed, one-piece Land Cruiser transfer case.

 

[Poser]

The other possible hitch in the giddy up will be if the 1974 four speed transfer case does not have the original four speed input gear, as the 1974 transfer case was a transition year case and the input gear from your broken 1979 is not compatible with the 1974.

Low range was 2.3 instead of 1.9 and the gears were narrow, just like the three speed transfer cases, not wide, like what is in the later four speed transfer case.

 

[Poser]

AH! good to know . how about the front output on the 3spd case ,
I have one that uses a cotterpin to retain the nut and one that doesn't when did they go away from the cotterpin. i never have read anything about this either on the 3spd case ,,see pic

The cotter pin locking mechanism changed to a stake nut in 1974, iirc....

 

[Coolerman]

Great swap information, but back up a sec. You said you busted the case "pulling out of the driveway" ?

Exactly what were you doing?

Great pics...

 

[DallasFJ40]

Great swap information, but back up a sec. You said you busted the case "pulling out of the driveway" ?

Exactly what were you doing?

Great pics...

It was actually my brother, but he said it was just at normal speed. Luckily, it was just in the drive way...

The cruiser had a high pitched whine whenever under accceleration that would go away as you let off the accelerator. We assumed it was the tcase (hence the spare already) and we were looking at rebuild or a swap.

 

[dgangle]

Another option for you to consider........

Since the Orion came out, it has made used one-piece TC housings very affordable. I bought my spare for $40 including shipping to me. Buy a used case of the correct vintage and install your guts, parking brake, nose cone with a reputable rebuild kit & a case saver and you should be good for a number of years.

Jim C (fj40jim) posted up the way to decipher the date codes on the cases some time ago here. Look for the thread or PM him and he may be able to tell you exactly the month and year of production of the case you have.