Conversion joints needed?

[sope]

Mabey this is a nube question but I often see advice on when conversion joints are needed and when spring perches need to be moved to go with a one ton drive train in a half ton. I have only done this once but I have an 87 V1500 shortbox and I upgraded to a 14 bolt ff and a D60. I didn't have to move spring perches or use conversion joints. I don't need this information for my build. I'm just currious and I'm sure other guys that are upgrading are too. I can't remember what years my one ton's came from but everything bolted in. I have 1350 rear joints that were for my 10 bolt and my 14 bolt. I check some vender web sights like Summit and the U joints seem to usually be 1350's in both 1/2 ton and 1 ton trucks.

I guess I was lucky and I'm sure conversion joints and spring perches have to be moved often but when?

 

[Hossbaby50]

Napa #447 ujoint is to convert from a 10 bolt rear axle to a 14bff rear axle. Front ujoint should still be the same on the front driveshaft.

Harley

 

[Hossbaby50]

Oops, I just noticed you have an SM465 which means you already should have a 1350 ujoint on the rear driveshaft so you should not need a conversion ujoint to attach your rear driveshaft to a 14bff.

Harley

 

[goldwing2000]

Most 10-bolts come with S44 joints and 12 bolts come with 1310 joints, unless (as Hossbaby said) you have the SM465. And even that's not guaranteed. I had a 12-bolt behind an SM465 that had 1310 joints. It all just depends on year and equipment.

Also, the 14bff you got must have been off a 3/4-ton and not a 1-ton, since the 3/4 and 1/2 ton share the same spring spacing. The 1-ton axles have narrower spring perches to accommodate the DRW option.

It's also possible that your p.o. changed things around.
All in all, you just got lucky with your upgrades!

 

[Hossbaby50]

The SM465's with the 1350 ujoint are from the 208/241 era trucks with 10 bolt axles. The older Sm465's had different joints like you mentioned.

Harley

 

[goldwing2000]

Mine was in the transition period. It was an '80 with a 205 case, 10-bolt front, 12-bolt rear and 1310 joints throughout.

I never broke anything on that thing but wore out my share of u-joints.

 

[sope]

Thanks for the info.
I got it now. The SM465 208 is the difference and a bolt up. The duall rear wheel diffs have the different spring spacing.
I've been wondering about this for a while.

 

[dremu]

Thanks for the info.
I got it now. The SM465 208 is the difference and a bolt up. The duall rear wheel diffs have the different spring spacing.
I've been wondering about this for a while.

Uhh, not quite.

1-ton frame are narrower, so any 1-ton rear axle, whether SRW or DRW, would have the funny perches.

Some people think one tons are always dually, and in 73-87 this ain't the case -- lots of C/K30 SRW's out there.

-- A

 

[goldwing2000]

Uhh, not quite.

1-ton frame are narrower, so any 1-ton rear axle, whether SRW or DRW, would have the funny perches.

Some people think one tons are always dually, and in 73-87 this ain't the case -- lots of C/K30 SRW's out there.

-- A

Yep. That's pretty much what I said back on post #4. All 1-ton axles have narrower perches to accommodate the ones that have the DRW option.

 

[dremu]

Yep. That's pretty much what I said back on post #4. All 1-ton axles have narrower perches to accommodate the ones that have the DRW option.

Yep. Just trying to be extra precise, for future generations of people reading this

-- A

 

[sope]

Thanks.