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8 to 6 lug pattern wheel spacers on 14 SF

thatK30guy

thatK30guy

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I can get a 14 SF next to nothing here in town and would like to keep my '87 V10 at 6 lugs. Since the rear is narrower than the front, has anyone ever installed a spacer to fit a semi-floater rear from 8 to 6 lugs? How did it fit? How thick of spacers does it take to get the rear track the same as the front?

One other question: has anyone ever done anything about the 7/16" lugs on the 1/2 tons as far as "upgrading" them to at least 1/2" studs?
 
I've seen spacers that go from 8x6.5 to 6x5.5 for 14bff's and the holes get real close to each other. I think a couple of members of this board make them. Another option would be getting some 6 lug shafts from a light duty 14bsf and swapping them in.
 
I knew someone would reply with swapping shafts. Kind of staying away from tearing the rear apart and spending more money than I need to. Spacers are quick, easy and cheaper to install.
 
If you do a search aways back you'll see where a couple of us tried to solve the later 14SF 14MM lugnut problem, but I don't think anyone ever found a stud that was knurled right for the axle, with the 7/16" studs. (mentioned because there is also a link to the dorman catalog IIRC, which has all of the knurl diameter etc)

One thing I've never had apart, the front studs are pressed into the rotor? If so, I'd imagine it would be a real simple process to drill the holes out to the right diameter for the larger stud knurl.

Axle shaft swap adds expense, but if you find a 6 lug axle for more money, you don't have to deal with spacers/8 lug issue at least, just spring perches. It would at least be simpler/cheaper to start out with something like that than "just" swapping axleshafts then having to buy spacers anyways.
 
I've done it...

The narrowest adapter/spacer I could find for that exact purpose was 2.5" wide. Believe me, I looked.

I did a test fit on the truck, it looked stupid. Rear tires stuck out wayyy too far. Ended up selling them for a loss.

I've gone the axleshaft swapping route, it looks better and works much better. IMHO go that route.

John
 
83ZZ502_Jimmy said:
I've done it...

The narrowest adapter/spacer I could find for that exact purpose was 2.5" wide. Believe me, I looked.

I did a test fit on the truck, it looked stupid. Rear tires stuck out wayyy too far. Ended up selling them for a loss.

I've gone the axleshaft swapping route, it looks better and works much better. IMHO go that route.

John
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I personally saw the truck with the adapters it did not look right at all. I went the 6 lug shaft route on my blazer. Defintly worth it!
 
I bought a set of adapters for my 14bff from a guy on this board. I believe it was Tonyp. I had to get the hubs and axle flange turned on a lathe, but all said and done, it went together well, and allowed me to fit my 15x10 M/T classic II's over a 3/4 ton disc brake setup with no clearance issues. If I remember correctly the spacers were only 1-1.5" thick. I have abused the truck thouroughly since the install (about 2 years ago) and have found no strength or reliability issues. I know you are asking for a 14bsf, but this info should apply here as well.
 
I personally saw the truck with the adapters it did not look right at all. I went the 6 lug shaft route on my blazer. Defintly worth it!
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Yep I saw it and boy it looked a bit goofy
 
Bigorange90jimmy said:
you'd need 1.5" spacers as all of GM's SRW (excluding vans) rear axles of that era are 3" narrower than the front.
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What year truck is the axle out of? The 88+(newer body style) trucks had a wider rear.

A while back I checked on 14SF 6 lug shafts. They were aroudn $88 ea from National Drivetrain...
 
Rear is out of an '83 or '84 Sub.

I'm thinking of disc braking it (with 8 lug parts) and the 8-to-6 adaptor, if I can get the proper thickness. I'm still waiting on TONYP for some other parts I've asked to be fabbed.
 
I just swapped the shafts. This gave me the 6 lug pattern and it gave me the right track width without spacers. If your drum brakes are in good shape, the spacers would be more attractive, but I was saving money by doing discs anyway.

I looked pretty hard at adapters too and it really would be a hard piece to build. I never found anyone willing to do it.
 
Swapped shafts...

Narrow 14SF housing and wider shafts, or same width axles and housing?

A bit curious if you could use the longer axles in the narrower housing and still have the bearings ride on the smooth surface of the shaft. Looks like it would be pretty close.
 
dyeager535 said:
Swapped shafts...

Narrow 14SF housing and wider shafts, or same width axles and housing?

A bit curious if you could use the longer axles in the narrower housing and still have the bearings ride on the smooth surface of the shaft. Looks like it would be pretty close.
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I don't think that's a good idea.
 
I am running the later style shafts in an 80-something housing. The bearing surface is in the right place. Different length shafts were available to compensate for different widths of brake drums.
 
So (if you have to) guessing at where the length of the axleshaft is different, is it "outboard" of the wheel bearing then? Meaning the distance from the carrier to the wheel bearing is the same regardless of axle housing width?

Or was there enough bearing surface to make up the 1.5" width even if the distance between carrier and bearing is longer?

I'm assuming the concern about using a longer axle is leverage on the shaft at the bearing, but you are increasing leverage on the thickest part of the axle at least. For ultimate strength I agree that it's not a good setup (nor is a semi floater) but with the weight of a K5, even a bit portly, I don't see it being much of an issue.

Cheap/easy way to have a "bolt up" (early) 14SF with 6 lugs and the wider stance.
 
Dorian-

On the setup that I did, that works....

I got an 8 lug axle, complete from an 80's diesel burb. Its axles are 32-9/16"

The axles I got were from a 88-98 1500HD or LD 2500. They measure 33-1/8" The difference is 7/16" There was enough machined surface on the 6 lug shafts for the bearing to ride on.

Due to the increased length of the shaft, I had to space out the drum brake backing plate. I accomplished this with one nut of the correct thread pitch and size to act as a spacer. It has worked flawlessly for almost 25k miles.

I found this the easiest, best looking solution.

John
 
dyeager535 said:
Swapped shafts...

Narrow 14SF housing and wider shafts, or same width axles and housing?

A bit curious if you could use the longer axles in the narrower housing and still have the bearings ride on the smooth surface of the shaft. Looks like it would be pretty close.
Click to expand...


I know for fact TSM brake company sells 2 different rear disc brake kits for the 14 SF due to 2 different widths of shafts.

Someone on this site a few years ago used an older SF housing and got new, longer shafts to install in place of the 8 lugs. I remember him telling me TSM specifically asked for the length of the 6 lug shafts so they would get him the correct kit. Turns out he had the wider width shafts and last I knew, the TSM kit worked flawlessly.
 
I did my 14SF the same way. An '85 Burban housing which is a bolt in and the longer (newer) 6 lug shafts. The bearing surface is adaquate, however I made myself a .020" spacer to go under the bearing, pushing it outboard. Prolly not nessesary but it made me sleep better at night :wink1: This setup matches the front track width nearly exactly. I went with the TSM brackets with a little extra spacing and it's worked great for about 4 years now but I did have to use the smaller GM caddy caliper. If I did it again now I think I'd just use a generic 14FF bracket and some custom spacers with large GM caddy calipers.
This was all done of course to preserve the 6 lug Centerlines that I already had.

James
 
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