Centered rear axle & t-case in FJ80? (1 Viewer)

[Greg@RME]

Figured I'd post this in the Hardcore Corner, since it seems fitting.

I'm working on a GM 5.3l engine swap into my '92 FJ80 using a 5.3l, 4L60E and a NP241. I would like to use a Tacoma rear axle to keep the 6 lug pattern, matching 4.10 gear ratio, etc. My reason to do this is to skirt around paying for an expensive $800 adapter that would go between the FJ60 t-case and the 4L60E.

I've heard that using a centered t-case output and centered rear axle, the driveline might not clear the fuel tank. Anyone else done this or something similar? How did it go?

I need to spend some time climbing under the 80 with a tape measure and seeing how things fit up. My 80 is still in running & driving shape, so it's hard to get an exact idea with all the stock drivetrain parts in place.

 

[megolfer]

Have you checked all the options for the 4l60 to the splitcase, $800 sounds lit way to much. Also I would not go with the Taco axle, stay with the full float fj80. I dont think the Taco axle will hold up very well with the weight of the FJ80

 

[Greg@RME]

Have you checked all the options for the 4l60 to the splitcase, $800 sounds lit way to much. Also I would not go with the Taco axle, stay with the full float fj80. I dont think the Taco axle will hold up very well with the weight of the FJ80

The price from Advanced Adapters for the 4L60E to FJ60 split-case is just shy of $800. Even buying it thru a AA vendor, the price is still $700+. That's way too much, IMO. I have searched around and haven't found another 4L60E to Split-case adapter.

My '92 FJ80 axle already has semi-float shafts, I realize the full-float axle from an FZJ is a better option but I don't think the Tacoma rear axle is a bad option. I think it would work just as well as the stock axle would.

The big question is still if a centered t-case output and centered axle will allow the driveshaft to clear.

 

[bustanutley]

gonna need to put chromo shafts in that axle. They are $425

 

[Greg@RME]

gonna need to put chromo shafts in that axle. They are $425

With 33's? I doubt it. 30 spline shafts are 30 spline shafts, regardless of what housing they are in, FZJ or Tacoma. I could see needing aftermarket shafts running 35's or 37's, but for a mild offroad-expedition rig running 33's I think the Tacoma axle will be fine.

I ran 38" SX's on a rear Tacoma axle with dual t-cases in a mini-truck and it's still going strong today. Obviously the weight is different, but with the gearing the torque was there. Never had shaft problems with that setup.

 

[bustanutley]

pretty nasty neckdown on the shafts, i have that axle, I'm waiting to break a few shafts before I upgrade. So far, so good

 

[Letsgomoreplaces]

axle

Adapter still sounds cheaper and better to me

Figured I'd post this in the Hardcore Corner, since it seems fitting.

I'm working on a GM 5.3l engine swap into my '92 FJ80 using a 5.3l, 4L60E and a NP241. I would like to use a Tacoma rear axle to keep the 6 lug pattern, matching 4.10 gear ratio, etc. My reason to do this is to skirt around paying for an expensive $800 adapter that would go between the FJ60 t-case and the 4L60E.

I've heard that using a centered t-case output and centered rear axle, the driveline might not clear the fuel tank. Anyone else done this or something similar? How did it go?

I need to spend some time climbing under the 80 with a tape measure and seeing how things fit up. My 80 is still in running & driving shape, so it's hard to get an exact idea with all the stock drivetrain parts in place.

 

[Greg@RME]

Adapter still sounds cheaper and better to me

Why? Just curious if you'd explain your reasoning. Why put $800 more into a drivetrain swap when that expense can be skirted around, while gaining a stronger t-case with deeper gearing?

If the NP241 and Tacoma rear axle will fit, why not? I have no problem with welding on the suspension mounts to the axle. If it saves me $800 and I can gain strength and gearing, why not do it?

 

[mwdubs]

does $400 for the adapter sound better. I made mine minus the spud shaft, which can be purchased from AA for around $200, and $200 for my end of it, im not attempting to pedal my stuff here just wanting to save a fellow LC junkie some dough, look at post #25 in my build (ELSIE gets GM power......) to get a rough idea of what it is. thinking of making a clamp style tcase/crossmember mount so it can be configured for whatever/however you want to mount it. Just a thought

 

[Greg@RME]

does $400 for the adapter sound better. I made mine minus the spud shaft, which can be purchased from AA for around $200, and $200 for my end of it, im not attempting to pedal my stuff here just wanting to save a fellow LC junkie some dough, look at post #25 in my build (ELSIE gets GM power......) to get a rough idea of what it is. thinking of making a clamp style tcase/crossmember mount so it can be configured for whatever/however you want to mount it. Just a thought

That does sound better, cuts the cost in half. You do some great work, that adapter looks amazing. I really want to try something different with the NP241 and Tacoma rear axle, thought it would be neat to do something different and save $800.

The engine swap is up in the air currently, but if I decide to go thru with it and keep the Toyota split-case, I will contact you for an adapter.

 

[bustanutley]

Do you really think a 241 is stronger than a split case? The lower gear is great however.

 

[Greg@RME]

Do you really think a 241 is stronger than a split case? The lower gear is great however.

I realize the split-case is very strong itself, but I do think the 241 is stronger. The Dodge Cummins trucks come with a 241HD and they stand up to all kinds of stupid abuse.

 

[Dusty]

im running a centered 14b in the back with the 80 series tcase (pass drop) and there isn't much room between the dshaft and gas tank. if you run a centered diff and a centered tcase you will run into trouble. I dont think you can run a centered tcase in any case and keep the 80 tank.

But id do it anyway and get a new tank. the np241 can be had with a 4:1 in the rubicon and is probably plenty strong.

the tacoma rear is kinda wimpy for the 80 weight and the 5.3 power. why have all that power if you cant wheel it?

 

[Greg@RME]

im running a centered 14b in the back with the 80 series tcase (pass drop) and there isn't much room between the dshaft and gas tank. if you run a centered diff and a centered tcase you will run into trouble. I dont think you can run a centered tcase in any case and keep the 80 tank.

But id do it anyway and get a new tank. the np241 can be had with a 4:1 in the rubicon and is probably plenty strong.

the tacoma rear is kinda wimpy for the 80 weight and the 5.3 power. why have all that power if you cant wheel it?

Thanks for posting up, sounds like a centered t-case and centered axle just aren't going to happen with the stock tank. I'd prefer to keep the factory tank, don't really want to get into it that deep.

I think the Tacoma rear would be fine with the V8 and 33's. My first choice would be a Ford 9", but then I'd need a 6 lug pattern, which means custom shafts, = $$$$. A 14 Bolt or a Dana 60 would be overkill for 33's.