K20 Driveshaft Question

[Chaparralman1974]

Hi all,

I just finished installing a 4” lift in my ‘67 K20 and I noticed that there is a noticeable angle in my 2 piece driveshaft at the carrier bearing. Is this ok, or do I need to shim the carrier bearing down? I don’t notice any vibrations but after about a 25 mile test drive my pinion seal is now leaking. Any thoughts or advice?

Thanks, Clay

[57taskforce]

Did the 67-69 t221 trucks have carriers? Both of mine have NP205’s and 1 piece driveshafts. For what it’s worth My K2500 has a carrier and with a 6” lift it has a drop bracket to lower the carrier a couple inches. It probably wouldn’t hurt to lower it some. The drop on my truck is a couple smaller pieces of C channel bolted together.
Got any pics of the truck together after the lift? I bet it looks killer!

[Chaparralman1974]

Originally Posted by 57taskforce

Did the 67-69 t221 trucks have carriers? Both of mine have NP205’s and 1 piece driveshafts. For what it’s worth My K2500 has a carrier and with a 6” lift it has a drop bracket to lower the carrier a couple inches. It probably wouldn’t hurt to lower it some. The drop on my truck is a couple smaller pieces of C channel bolted together.
Got any pics of the truck together after the lift? I bet it looks killer!

Hey Tyler!

Yeah, it came from the factory with the 2 piece driveshaft and carrier bearing. I have read that it should be lowered 1/4" per 1" of lift....but not sure how accurate that is.

Here is a quick picture of it lifted and in the garage. I still need to get her all dolled up and take some pictures outdoors. She is now sporting a 4" lift and 295/75/R16 Nitto Ridge Grapplers.


Clay

[LONGHAIR]

That certainly doesn't look bad. As long as everything is good lengthwise, and no vibration, it will be fine. You don't want the driveline to be straight anyway.
If there is no movement in the joint, the needles just beat against the same place, wearing into the surfaces of the cross.
The tapered blocks have tilted the pinion up, be sure there is some angularity there too. The point of the joints is to make up for movement of the suspension and misalignment, straight is not good there either.
The pinion seal leak is a conundrum. It could be entirely coincidental.
Has the fluid level changed as a result of this? Possibly blocked vent during the process?

[Chaparralman1974]

Originally Posted by LONGHAIR

That certainly doesn't look bad. As long as everything is good lengthwise, and no vibration, it will be fine. You don't want the driveline to be straight anyway.
If there is no movement in the joint, the needles just beat against the same place, wearing into the surfaces of the cross.
The tapered blocks have tilted the pinion up, be sure there is some angularity there too. The point of the joints is to make up for movement of the suspension and misalignment, straight is not good there either.
The pinion seal leak is a conundrum. It could be entirely coincidental.
Has the fluid level changed as a result of this? Possibly blocked vent during the process?

I am hoping that the pinion seal leak is just a coincidence...the entire thing was just rebuilt and only has about 200 miles on it, if that. I just replaced the seal in it so we will see if it holds up.

Regarding the driveline angles, it would appear that there is ~ 3.5* difference between the pinion angle and the angle of the yoke on the transfer case. Do you think this is a cause for concern?

Lastly, when I installed the lift blocks, I put them on top of what appears to be factory shims. I have no idea what degree they are, but they are about 1/4" high on the side facing the transfer case and about 1/8" or so thick on the side facing the rear of the truck. These were original to the truck, so I put them back on, but are they supposed to be there with the lift blocks?

Clay

[57taskforce]

If the factory shims are thinner to the back than they should be pushing the pinion down and making your angles worse. I would remove them and re check the angles. Normally the lift blocks are cut the opposite way and will bring the pinion up. You want it to basically point at the output yoke on the transfer case. It shouldn’t be noticeably up or down.

Your truck is beautiful by the way! Really nice work!

[Southcity]

Originally Posted by 57taskforce

Your truck is beautiful by the way! Really nice work!

^X2^ the lift and your wheel/tire combo look great!