Swapping in a Dana 60

[J10/J20 Project]

Hey all, I just got my dana 60 out of my 83 J20. I pulled (awhile ago) a set of axle shafts from a 74 T-18 dana 20 Dana 60 (offset alittle). I just pulled the shafts out of my 83 Dana 60 and there the same length. Now will this rear hit the gas tank? Do I need a Dana 60 from a Quadra trac? I'm putting in a TH400/Dana20. Well just posting for info. I'm going to get the J10 ready tomorrow but it is suppost to snow. I will need to clean out the garage more so the hole truck will fit in (warm is good). I thought Jeep had 2 Dana 60's full floater's, the Dana 20/208 which share the shame output and the Quadra trac which is offset to the right. Any info will help. I will post again on how it's going in a couple day's. this is all going into a 78 J10

[ October 28, 2002, 10:14 PM: Message edited by: J10/J20 Project ]

[Sundowner]

if the Dana 60 is a 30 spline full floater, I wouldn't waste your time putting it in your Jeep. your current dana 44 already has 30 spline shafts.

[Frank in Norway]

But the 44 is not a full-floater

[Sundowner]

full floater is for (vertical)weight carrying capability.
spline count is for torque carrying capapbility.

given the same spline count, going to a full floater doesn't increase the axle's ability to resist the twist from big tires or low gears.

[Frank in Norway]

The spline count itself doesn't increase or decrease the axles ability to flex. The dimension of the axle has much more to do with the strength. And if the axle don't have to carry the vehichles weight it will tolerate more force before twisting and snapping.
I've broken a few axle shafts, but never stripped the splines so I don't think having 35 instead of 30 splines does that much difference. I think that going from 1.33" to 1.5" axle shaft is what really makes the 35 splined D60 stronger

[TexasJ10]

I think it is a good swap. Why not let the axle tubes rather than the axle shaft take the shock and the loads. Plus you get larger brake drums. For larger tires I think it is a good move.

[Sundowner]

the axle will tolerate MARGINALLY more force if it is a full floater. the difference is negligable unless there is a lot of vertical load over the axle. if you have a 1 ton truck loaded with a cord of wood and towing an 18000 lb trailer, then you need a full floater. going from sf to ff in an axle that sees MAYBE 3k lb of vertical load is relatively nothing.

spline count is a bit of a misnomer.
as far as dana and ford are concerned (not really the big GM axles) there is a standard spline size. to put 30 splines around the outside of an axle shaft, you need to have the shaft be 1.31" in dia. if you want to have 35 splines around the shaft, it has to be 1.50" in dia. the most common exception to this is the 14 bolt ff, whih has 1.50" shafts and 30 splines.

dana 44's and MOSt dana 60's have 30 spline, 1.31" dia shafts. swapping in a 30 spline dana 60 for a 30 spline dana 44 is useless and costs ground clearance.

[ October 29, 2002, 06:57 AM: Message edited by: Sundowner ]

[J10/J20 Project]

ok all, I didn't mean to start a, which axle is going in my Jeep. I just wanted info on the different Dana 60 Full floaters?

[Hump]

RustyJeep has a centered D60 in his truck. I forget what kind of tranny he is running, but he doesn't have any issues with hitting the gas tank and he doesn't have a ton of lift. It's a direct swap in, so I would recommend the 60 swap just to have it. Good luck!

[J10/J20 Project]

Hump, Thanks, now i need to figure out the axle shaft thing.

[Panther]

j10/j20,
I could be wrong (and probably am if the shafts are the same as you say) but I thought that all 80+ axles had a centered diff? If so then the 83 should have equal length shafts and the 74 offset with drivers side about 6" longer than the pass side.

I think the debate over the FF D60 and semi-float D44 is a good one. I have yet to see the cold hard facts on semi vs. full float and which is better and why? There are other factors to consider like gear ratio, axle width and bolt pattern when considering the swap. But, aside from the 60 carrier being significantly larger than the 44, how much of a benefit is the FF with 30 splines over the SF?

I would agree that the diameter of the axle shaft 1 1/2" vs 1 5/16" is more significant than the spline count but is the splines and diameter are the same how much stronger is a full floater than a semi floater?

SWB guys take no thought to dropping a grand to upgrade an axle to a full-floater, is the benefit more the aftermarket shaft that the FF design?

Lee

[J10/J20 Project]

Hello Panther, I was told that the output of the 208 and the Dana 20 t-cases where the same out. So when I saw a 74 J20 with a T-18 Dana 20 I grabbed the axle shafts. Thinking they where the same but there not. The one's that came out of the 83 are the same size.

[ October 29, 2002, 05:00 PM: Message edited by: J10/J20 Project ]

[scotty]

thats easy. full floating is better. even if all other things are equal,if a shaft in a full floating axle breaks you can drive/pull it home with no worries of the wheel falling off. i have driven as far as 75 miles with broken semi-floating shafts,and its no fun. full loating is well worth the piece of mind.

also keep in mind that the 60 will have a stronger diff,bigger R&P,and a beefier housing. i have only broken 1 rear 44 shaft,but i have completely bent/destroyed my rear 44 housing,and broken spider gears twice. you can shave enuff off a 60 to not lose much ground clearance. i have alittle less than 1/2" difference in ground clearance under my front 44 and rear 14 bolt. you can get a 60 real close to what a stock 44 is.

i definately would not say sapping in a 30 spline 60 is "useless". it is undebatably stronger than a rear 44,and you have the option of upgrading to larger shafts later if you have a prollem with the 1.31 inchers.

sundowner,you got to remember that our FSJs are alot heavier than a cj.verticle weight carring ability is appreciated in a heavy fsj with 35"+ tires.

[Sundowner]

ff's provide more strength for the axle at the flange, not at the splines. the shaft, itself, is fully supported betweel the pressed-on bearing and the carrier. where did your 44 shaft break? if you drove it home, I'd guess you twisted it off at the splines.
and yeah, you have the option to upgrade to 35 spline shafts, but you have to bore out the spindles to get the bigger shafts to fit. they're like 1.45" on the inside dia. 35 spline shafts + machining the spindles will cost about $400. add to this that if you have a 30 spline locker, now you need a new one.

[scotty]

the one i broke was about 6" from the flange onthe short side of a WT 44. it broke in a very bizare place.

my whole point is that i broke other stuff alot more than i actually broke shafts. the 30 splie 60 is equal in axleshaft stenght,stronger in all others. hows that? ;)

they are real easy to find in 2wd/4wd 3/4 ton ford and dodge trucks and vans. you could find a rear 30 spline for next to nothing,weld it,and see how it holds up. extra sahfts are real east to find,and if the shafts turn out to be a prollem,youre not out much,swap in a 70 or 14 bolt.

if you want my opinion on rear axles,id say the 14 bolt in a hearbeat. you can find em cheap,theyre allready beefy(shafts,R&P,housing)detroits are only $350,and theyre easy as pie to work on.

but not everyone has the same needs as me. many ways to skin the cat smile.gif

[Sundowner]

extra shafts?
who needs extra shafts?
(pic borrowed from a friend)
20 yr old dana 60 30 sp, next to new Dutchman 35 sp

http://www.dana60.com/images/dutch2.jpg

[burlyj10]

Hey guys, i feel like an idiot for asking this in a thread that is so technical, but ive never read or had anyone explain what a "full floating" axel is. what does FF mean, whats teh difference from a SF? thanks , ryan

[Bob Barry]

On Full-floater axles, there is a spindle on the end of the axle housing that supports the wheel hub. The wheel bearings (usually two) ride on that spindle, all the weight of the truck rests on that spindle. The axle-shaft slides in to the housing and bolts to the hub, but does not support the weight of the truck, and does not have a bearing riding on it at one point. If an axle-shaft breaks, then the weight of the truck is still carried by those bearings.

On a semi-floater axle, however, the weight of the truck rests on a single bearing that fits between the axle-shaft and the end of the axle-housing, though some weight is also borne by the carrier. If you break an axle, then the weight of the truck still rests on that bearing, but is exerting leverage on the broken end of the shaft within the housing. So, if you try to drive on it, one part of the axle is flopping around inside the housing while the wheel is flopping around out there. Not pretty.

[Rande]

FF=Full Floating, SF= Semi-floating. You can remove the axle shaft on a full-floater and still drive the truck via the front axle. On a Semi-floater, if you remove the axle, the wheel mounting surface comes out with it.
The SF axle is what you see in rear wheel drive cars and 1/2 ton trucks.
The FF is what you see in 3/4 ton and up trucks, it has a hub that sticks out through the center of the wheel. This hub has a plate on the end that is attached with about 6 bolts. If you remove that plate, you can pull the axle out there.
You could also install locking hubs there, disengage them and flat-tow the truck.

[J10/J20 Project]

Bob, that's putting it in english. Thanks

[scotty]

yup,on a FF rear axle,you can pull the shafts and take the carrier and pinion out and have an empty housing without even jacking up the truck or taking off the wheels :D

ive got a set of block-off plates that i bolt onto my rear hubs so i can flat tow it with no rear shafts.

FF is the way to go with sometin you intend to use hard! ;)

[Panther]

Also front axles are basically full floaters too. Good description Bob.

[Sundowner]

Also front axles are basically full floaters too. Good description Bob.not always true.
most newer axles such as the yj/xj/tj/wj fronts and the dodges have pressed-in stub shafts that locate the front hubs. these are technically defined as semi-floating axles.

[fsj1978]

I'll add my 2c worth here. We're eventually going to upgrade to a D60 or 14 bolt. Part of the reason is wieght carrying ability since we've added a very heavy hitch to the back, a winch, a 2nd gas tank, etc, etc. Add to that towing a boat/trailer that weighs in around 8-10K and we're pusing GAW (Gross Axle Weight) ratings on both front and rear axles. The other 1/2 of the reason is for BRAKES!!! The stock brakes are fine with stock tires. We're up to 35s now. We've replaced the master cylinder with a dual diaphram(sp?) unit from an 80s FSJ and now the brakes are acceptable as long as I keep the rears adjusted up. But I'd like 'good' brakes so I'd like the MUCH larger brakes from the above mentioned axles. Oh, and I'll add that for another 25% (makeing a grand total of 125%) I like the safety factor of the FF axles. Break an axle and you keep your tire! I like that. smile.gif

[Bob Barry]

The extra benefit is the distribution of the load in the rear over two large wheel bearings, rather than on a single medium-sized wheel bearing.

The other difference is axle-tube diameter and thickness. Todd did in his rear D44 axle by bending the housing where the tubes entered the pumpkin. A problem encountered with AMC20 axles in extreme situations is the center-section spinning in the tubes. There is much less of a danger of doing that with a 3/4-ton or 1-ton full-floater rear axle.

With 14-bolts going in the $100-$200 range for a full-floating axle with 1.5" shafts, they're your best bet for 37"+ tires. Much cheaper than trying to upgrade a D44.

And if you're a farmer, they're your best bet for laying down furrows, if you run some 30" tires... ;)

<JK!> I'll be trimming mine down quite a bit.

[Sundowner]

I think I can carve about 150lbs off of my 14 bolt just by converting to discs. those drums are HE-UGE.
I will be shaving mine, too.
I'm just not sureif I'm going to cut and weld a new plate or just take off the bottom lip.

[burlyj10]

Hey thanks guys, there was a lot of good info. i appreciate it.

ya ive seen/heard a broken axel and it wasnt pretty , nor did it sound too healthy...

thanks again, ryan

[scotty]

Originally posted by Bob Barry:

And if you're a farmer, they're your best bet for laying down furrows, if you run some 30" tires... ;)

<JK!> I'll be trimming mine down quite a bit.lol,thats a good one. :D i cut about an inch off the bottom of mine. with a 17" radius on my worn out 38" hawgs ive got allmost 11.5" under my front 44 and about 11" under the 14 bolt. i know it still drags,all the paint is gone from the bottom tongue.gif