10 bolt to 14 bolt swap

[ATB1998]

I am currently ordering the last of the parts for my 14 bolt swap and was wondering if there was a certain yoke I need in order to run the same driveshaft or do i need a special U joint?
Thanks in advance for any info!

 

[Schurkey]

WHAT VEHICLE? WHICH "14-Bolt"?

If this is a K1500 and you're removing the 8.5" ring-gear 6-lug axle assembly, then installing a 9.5" semi-float "14-bolt" axle assembly from a 6-lug K2500, you need a conversion U-joint (Precision 447 or similar.) Polish the rust and dirt off the trans yoke, because the yoke will be sliding into the transmission about 1/4--3/8 inches further. You shouldn't have to have the driveshaft shortened, but it does slide farther into the trans tail housing.

As usual, new U-bolts, torque to spec, and enjoy the better, 11.130 rear brakes, too.

 

[Nad_Yvalhosert]

Spot on @Schurkey. I did that swap on my '88 GMC 1500 18 years ago. Best brake upgrade ever!
Conversion U-joint Moog 447

 

[ATB1998]

WHAT VEHICLE? WHICH "14-Bolt"?

If this is a K1500 and you're removing the 8.5" ring-gear 6-lug axle assembly, then installing a 9.5" semi-float "14-bolt" axle assembly from a 6-lug K2500, you need a conversion U-joint (Precision 447 or similar.) Polish the rust and dirt off the trans yoke, because the yoke will be sliding into the transmission about 1/4--3/8 inches further. You shouldn't have to have the driveshaft shortened, but it does slide farther into the trans tail housing.

As usual, new U-bolts, torque to spec, and enjoy the better, 11.130 rear brakes, too.

 

[ATB1998]

@Schurkey my apologies on lack of info, it is a 1998 GMC k1500 single cab shortbed. The axle is a 9.5” out of a 96’. Both have 3.73 gears.
The 477 ujoint, I assume that is the ujoint that allows me to use the stock drive shaft with the new rearend? I apologize if this is a dumb question! This is all new to me.

 

[Nad_Yvalhosert]

Yup, it is a dumb question, and it's been answered twice. The Moog or Precision # 447 is a u-joint that has 2 different size caps. One set fits the OE shaft, the other fits the 9.5's 3/4 ton yoke.

 

[DamHoodlum]

You can transfer the 10 Bolt Yoke on your 14 Bolt without changing anything on your drive shaft.
I did this and everything works flawless, USE GOOD U JOINTS not some amazon brand

OR
Keep the 14 bolt yoke if you have/want to use a 1350 U joint style driveshaft
1350 style on both ends could require 1350 front yoke as well, but will be the strongest
USE GOOD U JOINTS

OR
Do the conversion U joint, my driveshaft guy told be the conversion U joint is weaker.
Unless you do 1350 on both ends which could require 1350 front yoke as well

That should get your driveshaft hooked up, Just do it the best way you can

Oh yea, Put you some disc brakes on it for Shurkey........................

 

[Supercharged111]

You can transfer the 10 Bolt Yoke on your 14 Bolt without changing anything on your drive shaft.
I did this and everything works flawless, USE GOOD U JOINTS not some amazon brand

OR
Keep the 14 bolt yoke if you have/want to use a 1350 U joint style driveshaft
1350 style on both ends could require 1350 front yoke as well, but will be the strongest
USE GOOD U JOINTS

OR
Do the conversion U joint, my driveshaft guy told be the conversion U joint is weaker.
Unless you do 1350 on both ends which could require 1350 front yoke as well

That should get your driveshaft hooked up, Just do it the best way you can

Oh yea, Put you some disc brakes on it for Shurkey........................

If I understand correctly, the conversion joint is weaker, if nothing else, because it is greasable (greasable are softer metal than non).

 

[Schurkey]

Greasable U-joints are hollow, so that there's a drilled channel for the grease to flow through.

 

[Supercharged111]

Greasable U-joints are hollow, so that there's a drilled channel for the grease to flow through.

They seem to list the non-greasable as forged and the greasable as not. I wasted a Precision conversion joint in about 6 years. Seemed a bit premature compared to the originals. Unaware of an alternative, I put another one in. Keeping my eye on it.