Rear axle width

[Mario]

I recently purchased a used 10.5" 14 bolt axle from a 1994 van.  The WMS to WMS width is 70" with a pinion offset of 1-1/2".  My truck is a '81 K20 Silverado with 9.5" 14 bolt, and WMS to WMS width of 67".  As you all know the front axle WMS to WMS is wider by 2" on each side.  I have a plan to cut both tubes on the 10.5" full floater, remove a 1/2" from both sides, and swap the left to the right and vice versa.  This plan would center the pinion, and create a WMS to WMS of 69".  I use my truck as a daily driver, I occasionally haul with it, and rarely take it off road.  It has a 4" lift so I don't take turns fast, but I do drive it fast down the interstate.  I know there are some former GM guys on here.  Are there any handling type issues with making the rear end closer in width to the front end?

[VileZambonie]

The only thing I ever noticed from increasing the rear track width was less body roll and improved handling. It doesn't hurt that it looks much better too. I've always just used staggered wheels with 2WD's or 2" adapters on 1/2 ton 4x4's. 3/4 and upis a non-issue. I don't buy the better handling narrow rear track stories, more like production cost savings.

So I'm not understanding what exactly you are trying to accomplish with cutting up this rear end you bought. Seems like a lot of time effort and costs. What's wrong with the 14 bolt that's in there?

[1967KaiserM715]

So I'm not understanding what exactly you are trying to accomplish with cutting up this rear end you bought. Seems like a lot of time effort and costs. What's wrong with the 14 bolt that's in there?

Sounds like he got a semi float 14 bolt, and he wishes to replace it with a full float.

I see no reason to cut an axle to center the pinion, at that point  now the whole diff is offcenter, plus now you'll run into issues of being straight after welding, and I don't think the axle shafts are a different length either. The carrier should be centered, just because of the size, the pinion is off set.

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[Mario]

Vile, thank you for you response!  I've been happy with my semi float, but I've chased a high speed vibration down to the pinion bearings.  If I swap in the full floater, I'll have everything rebuilt with new bearings, seals, and a TrueTrac.  Later on I can rebuild the semi float and install it my 1/2 ton '72.

I've done a lot of research to develop a plan that makes sense.  All 10.5" 14 bolts have the housing off center.  One tube is always longer than the other, and same for the axles.  Recall that I said "from a van".  I didn't know what that meant either when I purchased this rear end.  Pinion is offset 1-1/2" from center of WMS to WMS width (and with respect to the frame), and of course off center in the housing too.  Probably designed that way in a van to make room for a larger/flatter fuel tank.

I spent a lot of years just accepting a high speed vibration.  My current driveshaft uses a double cardon joint at the transfer case, and has about 1 degree down angle at the pinion.  When it gets some torque it might operate at close to 0 angle.  I see no reason to add horizontal angles (with an offset pinion) to my near vibration free set up.  I think it's worth the extra effort to have a nicer rear view.  I'm the guy that takes lemons (van rear end), and makes lemon aid.  Hahaha 

[Irish_Alley]

im sure you have read this but just in case

"Notes:

The SRW and C&C axles use the same housings and shafts, with the difference in width being in the hubs. The housings are actuallly identical except for the location of the backing plate flange. Drums & hubs are different, but backing plates, shoes, and wheel cylinders are the same) * The SRW and Van axles use the same hubs, the C&C and DRW axles use the same hubs; Though different, the SRW/Van hubs and the C&C/DRW hubs can be interchanged causing a change to the axles WMS (see pics below) SRW and C&C axle shafts are the same ** Van, DRW, and SRW/C&C axle shafts are all different lengths as follows (long/right side / short/left side):
Type 1 - SRW/C&C - 37-5/8" / 31-5/8"Type 2 - DRW - ??
Type 3 - Van - 39-3/8" / 33-3/8"
C&C and dually brakes are the same.In all cases one side axleshaft is shorter than the other; pinions are centered. 1350 appears to be the only available stock pinion yoke.1-tons feature 40.5" perch spacing - whether C&C or pickup, whether SRW or DRW. 3/4-ton is 42.5" spacing. (COUNTER) - The perchs on my C&C measure 36"Wheel studs went metric for the 88-up C/K trucks, and 96-up vans
Front 60 and rear 14b spindles have the same bearing spacing and same bearing journal sizes. Seal journal is different
The following pics, courtesy of Brawler from the PBB, illustrate the differences between the 2 types of hubs."


http://www.pirate4x4.com/tech/billavista/14b_bible/

[Mario]

Yeah, when I said "research" that bible written by Billavista was one of the first.  I have a strong feeling that his data is incomplete in regards to late model vans using the 2nd generation 14 bolts.  I mean I can't blame him.  Why would anyone research van axle data?  All the rest of his data is awesome!  He states that all 14 bolts have the pinion centered between the WMS to WMS wdith, but I can say without of doubt the one I have is offset by 1-1/2".  That's why his axle lengths for the vans are TYPE 3 (they don't match any other vehicle), but I think he has the lengths wrong.  Mine are LT 34-1/4" and RT 38-1/4".  Most everyone goes shopping for theirs out of junked trucks not vans.  Right?  Honestly, I'm only sharing my plan for fabrication because at some point people will start using the van axles.  I was just concerned about the driving characteristics with a slightly wider rear end.  Thanks for your response though!