14 bolt and driveshaft legnth

[sled_dog]

You sure yours isn't a Semi Floater? The thing that makes the 14bolt long is that it has a bigger ring gear and the axles have to be in the middle of the ring gear so the pinion has to be pushed outwards. I've only really heard of it being long than a 10 bolt not shorter like you are saying.

 

[R72K5]

semi flaoter ? huh ? its a 14 bolt FF

the distance fromt he centerline of the axle tubes up to the end of the pinion yoke is 1.5" or 2" shorter on the 14 than on a 10 and 12 bolt, would need longer shaft when swapping to a 14 bolt FF in a 1/2 ton, and the dana 60 axles have very close to same distance as 10 and 12 bolt, if not exact same, this is what i have found by measuring on axles i have recently





thanks

 

[sled_dog]

sorry I meant are you sure its not a semi floater. hmm interesting thing. Wish I knew why I was being told such conflicting things, its gonna be real important to me real soon.

 

[GMtrucklover]

when i went to my 14bolt ff my drive shaft was about 2" two short. I havent fixed that problem yet it vibrates like a aob on the highy. I have a 87 350/700r4/208. The strange part is i get 16-18 as an average with 33"'s and 4.10 gears. /forums/images/graemlins/thumb.gif

 

[sled_dog]

not liking the conflicting responses, I can lengthen or shorten a driveshaft without worry but I just want to know its coming.

 

[GMtrucklover]

I know how you feel, every body told me the same thing that you are getting, the drive shaft being to short, I was going to put my lift on at that same time. Then i just figures i would install the rear end and go from there. It was a good thing i did, after i got te axle in and i put it up on my lift to bleed the brakes and put the shocks on the shaft poped out of my 208! What a surprize that was. My best advice to you is slide the rear end under the truck and go from there.

 

[R72K5]

yeah id just put it under and go from there, i opted to not do the swap because i dont want ot go throguh driveshaft hassle because i was gonna have to find a longer driveshaft to go from 10 bolt to the 14 ff,

good luck

 

[new2k5]

so basicaly it could be longer,it could be shorter,it could be perfect. wow that really clears things up /forums/images/graemlins/confused.gif /forums/images/graemlins/smile.gif

 

[sled_dog]

ok now that us Pennsyltucky boys are throroughly confused I guess I will just slap the sucker under there and go from there /forums/images/graemlins/smile.gif.

 

[R72K5]

yeah just put it under and go from there, im sure several of us want to kow how it turns out- as far as driveshaft length goes
before i brought out the tape measure i made the assumption that the 14 bolt FF would have to need to have driveshaft shortened- i figured this because its a big axle compared to the 10 bolt it was to replace- but when i measured i found that it would need a longer shaft instead, so i was like, "uhmmmm, ok.... this isnt a good thing, hmmm..." and then i measured on the dana 60 ff i had next to it and it was basicalyl same measurement as the 10 bolt, like maybe 1/4" difference.. wierd..


ive got right about 12.5" on the 14 bolt ff from the centerline of axle tube(leaf pack center pin) up to the yoke where the caps bottom out

good luck

 

[Thumper]

OK, I had to do it. No one seems to know. Is there that many different versions of a 14FF that would account for the different answers?
I have a 12 bolt from a 75 4x4 in my K5. Here is a pic of it with a tape measure.

I will be installing a 14FF from a mid 80s 3/4T 4x4 truck, here is a pic with the same tape measure.

As far as I could see, they are the same (within and inch) from the center(ish) of the tubes to the yoke at the u-joint. This is consistent with what I heard a while ago. I dunno where or how you guys are haveing to lengthen or shorten your driveshafts for this. Unless they are a different version of a 14bolt, or you did a lift at the same time, or you relocated the springs with a zero rate or block.
Beyond me, I dont know whats the right answer... but mine is going to use the same length shaft for sure.

Mike

 

[R72K5]

theres only one version of 14 bolt FF- its the same 14 bolt ff we are all talking about- we all know this so thats not the problem

my problem is that my 10 bolt rear isnt same 12" measurement- its more than 12", its a regular every day normal gm corp 10 bolt 8.5" so i dunno,,, another reason i need to sell or scrap it, i hate it..

i dont know why.,..

 

[new2k5]

well if things go as planned i should be picking my axels up on sunday. so i will let ya'll know what happens sometime next week.

 

[Smurfmobile85]

You know in my earlier reply I didn't even think about it but I lifted my burb when it had a 14SF in it and didn't have any problems with drive shaft length.Now I have a 14FF in it and it seems like it needs to be lengthend a couple of inches.So I am not so sure what is going to be needed for your swap but good luck and let us know. /forums/images/graemlins/confused.gif