12-bolt u-joint size

[Mastiff]

I'm swapping a 14-bolt into my K5, but it previously had a 12-bolt swapped in place of the original 10-bolt... I read that the 10-bolt used 1310 u-joints, would that be the same for 12-bolt? How can I tell for sure? I want to get the correct conversion u-joint for my swap.

 

[tRustyK5]

Well, my '90 originally came with a 10 rear, but had a 12 when I bought it. It had a conversion U-joint as the 12 has an S-33 yoke. My driveshaft itself was unaltered...and I'm guessing they did the same for yours. So, your driveshaft should have a 1310 yoke at both ends, and you'll need the 1310 to 1350 conversion joint to make your 14 bolt swap happen. Clear as mud?

 

[Mastiff]

Hmmm. Weird thing is, I myself bought a CV driveshaft for it since the 12 was installed. I ordered it over the phone, took a few measurements, etc. I don't remember any special U-joint being involved. But maybe I told him it was a 12-bolt and he put S33 on the driveshaft?

Can I look at it or caliper something and know for sure?

 

[dremu]

Hmmm. Weird thing is, I myself bought a CV driveshaft for it since the 12 was installed. I ordered it over the phone, took a few measurements, etc. I don't remember any special U-joint being involved. But maybe I told him it was a 12-bolt and he put S33 on the driveshaft?

Can I look at it or caliper something and know for sure?

Yep, sure can.

 

[Deuling]

I thought 12 bolts had 1330 yokes

 

[6.2Blazer]

First of all I will make the following comments:
- GM used different configurations over years
- you are dealing with trucks 20+ years old and therefore a good possibility that stuff has been swapped around

Most 12-bolts in factory applications I have seen used a 1310 u-joint, but just about any aftermarket yoke is available.

My '90 with factory 10-bolt axles had S44 u-joints in the rear, and of course the 1310 front. Most factory rear 10-bolts I have seen were S44, but have seen a 1350 in the fairly rare late model K5 with manual transmission.

Quickest way to narrow it down is whether the u-joints have the internal c-clip or external lock ring retaining method.

 

[Mastiff]

Checked it out with the data above and it looks like S44. I was prepared to order a Moog 1310-1350. Anyone know if Moog has an s44-1350 conversion joint? I surfed up this one:

http://www.oreillyauto.com/site/c/detail/PRE0/447.oap?ck=Search_447_-1_2009&keyword=447\

Not sure if it's a quality part. Any thoughts?

 

[max 02]

Yep, sure can.

Sweet!! Just blew up the joint on my 12 bolt...thanks to your guide looks like I need a 1310.

Thanks DREMU.

 

[maxgforce]

The 12 bolt should use a spicer 5-153x, the 10 bolt should use a spicer 5-3147x, and the 14 bolt should use a spicer 5-178x. ( 10 bolt to 14 bolt conversion 2-1153 Neapco or 5-3205x Spicer ), ( 12 bolt to 14 bolt conversion 3-3140 Neapco or 5-460x Spicer ), ( 12 bolt to 10 bolt conversion 3-3130 Neapco or 5-3022x Spicer ), might write this down for your records.

 

[ccarley]

The 12 bolt should use a spicer 5-153x, the 10 bolt should use a spicer 5-3147x, and the 14 bolt should use a spicer 5-178x. ( 10 bolt to 14 bolt conversion 2-1153 Neapco or 5-3205x Spicer ), ( 12 bolt to 14 bolt conversion 3-3140 Neapco or 5-460x Spicer ), ( 12 bolt to 10 bolt conversion 3-3130 Neapco or 5-3022x Spicer ), might write this down for your records.

Super awesome reference right there! I think that info is going into my manuals.

Clay