Semi-Floating Dana 60 in 68’ GMC C1500
 

I got my 1968 GMC C1500 back in 1987 when I as only 15. After spending every dime I had on it throughout high school and college painting it and creating a monster out of the 396 I managed to wipe 4 teeth of the ring gear on the factory Dana 60 rear axle one night when I was racing. The axle broke around 1993 and I didn’t have enough money to put the Dana 60 back together so I swapped in a Dana 44 out of one of my parts trucks that we had lying around my dads shop at the time.

Fast forward 10 years to today…..I really want to rebuild the original Dana 60 which never gotten rid of…(thank god!) and was wondering if any of you have every seen one of these rare rear axles?

I have worked on many GM trucks while I was growing up at the dads shop and still play with them today….But, I have never seen another semi-floating (6 lug) Dana 60 in the rear of any other halfton GMC of that era. I know the axle was original as I bought the truck from the original owner and he said he ordered with a heavy-duty suspension package.

I have seen semi-floating Dana 60’s (5 lug) in the rear of old Mopar muscle cars and mid to late 80’s Ford F250 trucks (8 lug) but no other GMC’s.

For those of you that do not know the difference between semi-floating axles and full-floating axles…..the axle shaft itself is supports the weight of the truck on a semi-floater whereas a full-floater axle shaft is supported by two huge bearings in the hub. In the 67-72 trucks full floaters had 8 lugs and semi-floaters had 6 lugs.

Not very common
 

I have two of them right now. One is a coil sprung. The leaf is a posi to boot. The 4X4 guys love them to beef up their 1/2Ts and keep 6-lug.

I thought the 6 lug dana's came behind bbc's with sticks. Is Your th400 original?

So you guys have seen them….I did not know a coil sprung semi-floating Chevrolet variant existed. I have seen coil sprung full-floating Dana 60’s before but no semi-floater.

Yup, she is an original 396, TH400, factory tach, factory bucket seats, A/C, ridicules power steering assist rather than real powersteering, which I have converted to real powersteering. The Dana 44 that I put in it when the 60 broke came out of a 68’ GMC C1500 with a 305 V6 and a SM435 4-speed manual.

I am going to start gathering parts to put the Dana 60 back together. I will most likely use National Drivetrain for the parts. Will also be adding a Detroit locker or limited slip so I can ruin both tires instead of just one at a time.

The real difficult thing to find for these old GMC ½ ton rear axles are new brake drums. The drums are much different than a Chevrolet drum as the GMC drum is more bowl shaped. If you put a Chevrolet drum on the back of a GMC axle about a quarter inch of brake shoe is exposed on the backing plate side.

even though GMC and Chevy of this era are basically the same, there are still a few little differences floating around. i have noticed that GMC's tend to have dana rearends, as opposed to corporate units. this applies to 3/4 tons like mine, too. originally a 4.10 or 4.11 , now 3.73. but the dana is the rarer of the 2 rearends. maybe i am smoking crack but i dont think so.

Dirty Larry
Do you still have that 305V6 by any chance? Send me a PM if you do.
Erl

Sorry Erl….All I have left of that truck is the cab, front clip and frame. I sold the engine many years ago. My god are those old V6's heavy! :eek:

The cab is for sale though…..it is 100% rust free :)