80 axle with centered t-case output?

[1974FJ]

I know that the 80 series axle doesn't have a completely centered 3rd. But in a fj40, how wrong would it be to run a 80 series rear axle with a centered t-case output? Just trying to weigh some options.

[theyis]

Do you have some other t-case in there with a centered out and are wondering if you can run the 80 rear? IIRC the 80 rear is 5 inches off center. I've been told that it would be okay from Jeremiah at Proffitt's but a driveline guy told me don't do it. I know that isn't any help but that is as far as I got on the same question. If you were going to stretch the wheelbase a bit I would think it would be okay.

Kyon

[1974FJ]

Plan is to run a NP205(centered output) and was wondering if a 80s rear would be ok. It is stretched a tad, but with a nv4500, its more like stock drive shaft length for a 40 series.

[alkaline747trio]

Trail or DD? DD, might not work so well....trail, should be fine strength wise.

[John Smith]

My friend runs a 80 series rear axle on his 4Runner buggy with a centered transfer case with zero driveline issues and the small offset.

[theyis]

Originally Posted by 1974FJ

Plan is to run a NP205(centered output) and was wondering if a 80s rear would be ok. It is stretched a tad, but with a nv4500, its more like stock drive shaft length for a 40 series.

Sounds very similar to what I was originally planning for my 40 until I got the 80. I was going to run an NV4500 with a Klune to a split t-case with 80 axles front and rear. Anyways, the thing I don't quite know/understand is what the compound angles would do to the drive shaft. Seems to me that it would be okay. The drive shaft is designed to flex in any direction... I have been trying to picture the movement in my mind's eye and I think I can see it. Imagine one end of the shaft stationary the other end of the shaft is rigged to make a 3' circle around the stationary end. Now spin the shaft and put the circle end in motion. I think it would do it no problem. Not sure if that is a good example but I have to "see" things to understand them.

Originally Posted by alkaline747trio

Trail or DD? DD, might not work so well....trail, should be fine strength wise.

Alk, not sure I get the logic. Seems to me that on the road you would be facing a much more static environment. i.e. the compound angles would be much less in play, albeit at a much faster driveshaft rotation. On the trail, you would see the angles changing all over the place. Slower rotation speed, yes, but angles would be changing quick.

I still think the drive shaft would be okay...

[1974FJ]

Originally Posted by alkaline747trio

Trail or DD? DD, might not work so well....trail, should be fine strength wise.

Mostly a DD.

Originally Posted by John Smith

My friend runs a 80 series rear axle on his 4Runner buggy with a centered transfer case with zero driveline issues and the small offset.

Difference here is the length in drive shafts. His 4runner, i would imagine, would have a longer rear drive shaft to decrease the offset over a given amount of space. And i guess not knowing what the length will be from my t-case output flange to the rear axle flange makes this a dumb question. Just looking for ideas so i can start getting parts together.

[theyis]

Originally Posted by 1974FJ

Difference here is the length in drive shafts. His 4runner, i would imagine, would have a longer rear drive shaft to decrease the offset over a given amount of space. And i guess not knowing what the length will be from my t-case output flange to the rear axle flange makes this a dumb question. Just looking for ideas so i can start getting parts together.

I would plan or running a double cardon shaft. Stretching to 110" will help too. Gives a great departure angle .

[Isotel]

there is always the Hybrid Centered Cruiser Diff Option.. if you use Tacoma Shafts your Width would be about 60"..

My Driveshaft is 24" long in my cruiser, and the t-case is offset by about 2.5" from the Diff FLange, i have no driveline vibrations with a Toy CV Shaft from an IFS Minitruck

[bustanutley]

you will need to run u-joints on both end of the shaft and you will not be able to rotate your pinion up. U-joint angles on either end of the shaft need to be = within 2-3 deg to not get vibs. As long as the flanges are in parallel plains and you don't exceed the u-joints operation angle you'll be okay.

[alkaline747trio]

Originally Posted by theyis

Alk, not sure I get the logic. Seems to me that on the road you would be facing a much more static environment. i.e. the compound angles would be much less in play, albeit at a much faster driveshaft rotation. On the trail, you would see the angles changing all over the place. Slower rotation speed, yes, but angles would be changing quick.

I still think the drive shaft would be okay...

It would be structurally sound, as in it's not going to grenade from being spun, but it could probably cause terrible vibrations that could cause things to come loose.

[scouthead]

This is how I've always understood things:

Originally Posted by bustanutley

you will need to run u-joints on both end of the shaft and you will not be able to rotate your pinion up. U-joint angles on either end of the shaft need to be = within 2-3 deg to not get vibs. As long as the flanges are in parallel plains and you don't exceed the u-joints operation angle you'll be okay.

(u-joints on both ends of the shaft mean no C.V.s, just a plain old U-joint)

My Scout came factory equipped with Dana 18(offset transfer like a cruiser), and centered rear diff(Dana 27-yikes!). Granted the driveshaft was quite a bit longer than a cruiser's, but it worked just fine.

Never really looked right though!

[Eskimo]

My rear diff is offset and it drives fine on the street, up to about 55 is the highest I've had it, but with my gearing, that's about 75 in a rig with 4.11's and a 35" tire.

[crusier72]

Hijack
I'm going to put a d300 in my cruiser and will be running the stock rear end for a while has anyone run 3sp joints at 20 degrees. I'm probably just going to try it and deal with some vibes. Mine is only a weekend warrior.

[IPOR]

Originally Posted by bustanutley

you will need to run u-joints on both end of the shaft and you will not be able to rotate your pinion up. U-joint angles on either end of the shaft need to be = within 2-3 deg to not get vibs. As long as the flanges are in parallel plains and you don't exceed the u-joints operation angle you'll be okay.

Ditto. You won't be able to run a double cardan joint, or rotate the pinion, but provided you stay within the operating range of the u-joint it doesn't care whether you're down... or out!

Lance
Iron Pig Off Road : Toyota 4WD experts

[jcj_78FJ40]

Wouldn't the gas tank on an 80 series interfere with a centered output?

[1974FJ]

Originally Posted by jcj_78FJ40

Wouldn't the gas tank on an 80 series interfere with a centered output?

Its not going on a 80, Its going under my 74 fj40.

Whats the width of a toyota mini rear axle(V6)?
And whats the width of a fj40 rear axle? and the width of a fj80 rear axle?

[Sputnik40]

Originally Posted by Isotel

there is always the Hybrid Centered Cruiser Diff Option.. if you use Tacoma Shafts your Width would be about 60"..

Any more info on this? Are you running one, have you seen one, build threads?

[bustanutley]

Originally Posted by 1974FJ

Its not going on a 80, Its going under my 74 fj40.

Whats the width of a toyota mini rear axle(V6)?
And whats the width of a fj40 rear axle? and the width of a fj80 rear axle?

fj40 = 55"wms
ifs rear ~ 58"
taco rear = 60"
fj80 = 62"?

[bustanutley]

Originally Posted by Sputnik40

Any more info on this? Are you running one, have you seen one, build threads?

It is detailed well in dhondagod's thread

Dhondagods Fj40 Build - Pirate4x4.Com Bulletin Board

[1974FJ]

Thanks, is this IFS mini rear as strong as the taco rear? and whats the difference?

[bustanutley]

Originally Posted by 1974FJ

Thanks, is this IFS mini rear as strong as the taco rear? and whats the difference?

No, well, the shafts are stronger stock. But the ring and pinion setup is not as strong. The taco third is much stronger. It has bracing that keeps the ring gear from defecting. With cromo shafts the taco rear makes for a very stout axle.

[88chevota]

I did this similar hybrid build. I think I detailed it pretty well. I went with 58" wide, because that is the stock width of 60 series. I used axle shafts from a 90's 4runner and my LC third There is a link to the build in my signature. The minitruck ring and pinion is only an 8". The Landcruiser is like a 9.5" from what I've read.