Kind of dumb NP241-related questions

patooyee · Oct 20, 2015

I am considering using an NP241c front output flange on a project but have no experience with the Chevies that these things came in to know what was going on with their front driveshafts. The flange I am considering is the one on the left in this pic:

(random internet photo I found.)

The bolt pattern is 3"x3" square which matches Ford Superduty front 1350 CV shafts, which is coincidentally the shaft I am hoping to use. As far as I can tell there is only one Spicer 1350 CV flange pattern anyway. Which is surprising to me because I doubt the Chevies these came in used 1350 CV front shafts, did they?

So I guess my main questions are:
1. What front drive shafts did Chevies use that came with the NP241?
2. Does anyone know for sure if the Chevy flange fits the Ford 1350 CV?

fl-krawler · Oct 20, 2015

Its my understanding there are 2 ford CV's, and one chevy (saginaw) . I believe the only difference is the pilot diameter... I'm in the same boat with running CV's and I just started looking into it, because both of my axles will need double CV's on the driveshafts due to compound angles. I know the older fords had a 2" pilot, and the newer superduty's use a 2.6" i think. Dont quote me on that number, but I know its larger and requires a different flange

RustyC · Oct 20, 2015

What size is the pilot on the 241 front flange? Is it male or female?

patooyee · Oct 20, 2015

RustyC said:
What size is the pilot on the 241 front flange? Is it male or female?

3.125 male.

TBItoy · Oct 20, 2015

The chevy's use a 3R series CV.

As for the pilot, I've seen it mentioned when referring to swapping 1350 CVs in place of 3Rs in K5 Blazers and such. Not sure what it entails, but the way it was discussed it seemed simple. In fact I remember some people talking about just grinding the male pilot off with a hand grinder and bolting the 1350 shaft up.

looks like some early super duty's had 3r cv shafts also.

patooyee · Oct 20, 2015

TBItoy said:
I remember some people talking about just grinding the male pilot off with a hand grinder and bolting the 1350 shaft up.

That's basically how most rockwell shafts with pinion brakes on them are run and I've never once heard of anyone having an issue. Kind of what I had planned if the pilot registers didn't work out as well since the bolt patterns match.

I'm pretty clueless when it comes to drive shaft nomenclature, such as "3R."

TBItoy · Oct 20, 2015

apparently the 3r Saginaw cvs are weak "according to the internet".

I somehow acquired 4 or 5 K5 blazer front shafts at one time, so I can measure one if need something in particular

patooyee · Oct 20, 2015

TBItoy said:
apparently the 3r Saginaw cvs are weak "according to the internet".

I somehow acquired 4 or 5 K5 blazer front shafts at one time, so I can measure one if need something in particular

Are you saying that because that's what an NP241c comes in ... because I don't even know?

TBItoy · Oct 20, 2015

patooyee said:
Are you saying that because that's what an NP241c comes in ... because I don't even know?

Yes, the later k5 (actually after they went to V/R designation) had NP241s.

Actually most 90s chevys 1500 or larger had NP241s (or the electric shift 243s)

Hell, I had a 95 3500 dually with a 454, NV4500, and a fixed yoke NP241, and a 89 K5 with a 350, 700r4, and NP241, and a 04 1500 with a 5.3, 4L65e, and NP241...

check out this site I just ran across http://quad4x4.com/

Lots of info and parts that *looks* accurate (at least it's stated with confidence...).

patooyee · Oct 20, 2015

Well I think if you are saying that it is common for people to just cut the center journal off and run whatever bolts up I think that's really all I needed to know. Because I've already confirmed that the pattern on the Chevy yoke and the Ford drive shaft is 3x3.

TBItoy · Oct 20, 2015

patooyee said:
Well I think if you are saying that it is common for people to just cut the center journal off and run whatever bolts up I think that's really all I needed to know. Because I've already confirmed that the pattern on the Chevy yoke and the Ford drive shaft is 3x3.

patooyee · Oct 20, 2015

TBItoy said:

Haha, nice MEEM.

onepieceatatime · Oct 20, 2015

Re:

I don't know what all that technical stuff is yall are talking about but I run a 241c in my jeep and will try and remember to get ya some pictures of the cv stuff on my spare shaft when I get home. Glad to see someone else using one. I just used it because it came with my drive train but I've been really happy with it for the past 5 years.

Sent from my SM-G900V using Tapatalk

RustyC · Oct 20, 2015

The 3.125 pilot looks to be a 3r. from what I found here. (http://www.northerndrivetrain.com/category/cat_driveshaftcomp_cvsocketyokes_3R.html)

Click on the part # for part dimensions.

patooyee · Oct 20, 2015

Re:

onepieceatatime said:
Glad to see someone else using one.

They're decent cases from what I've heard but I'm not using one, just the flange.

LightBnDr · Oct 20, 2015

onepieceatatime said:
I don't know what all that technical stuff is yall are talking about but I run a 241c in my jeep and will try and remember to get ya some pictures of the cv stuff on my spare shaft when I get home. Glad to see someone else using one. I just used it because it came with my drive train but I've been really happy with it for the past 5 years.

Sent from my SM-G900V using Tapatalk

One Piece at a Time

Is your jeep only offroad under crazy D shaft angles or is it highway driver as well?