14 bolt swap question

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Polloso

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I know this has been covered a thousand times however before I purchase this rear end assembly I would like to make sure my scheme will work. I have an 89 K1500 RCSB with a stock 8.5" 10 bolt. I found a 9.5" 14 bolt SF rear end but with the 8 lug axles from an 88-98 3/4 IIRC. I should be able to put 6 lug axles in and probably have to change the drum brake backing plates. Does this sound right or do I need to find a unit that came with the 6 lug axles. Thanks fellas
 

JOHNGAAA1

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It will be a little work hunting, there are 14 bolt rears with 6 lug axles. Why go through the trouble. I have one in mine. 1998 k1500 z71 gmc sierra. They do exist. You need to make sure the ratio is the same in the front and the back.
 

Polloso

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Yeah I have 4.10 in the front and rear. The one I found is a 3.73. I also have another spare 8.25 front diff with a 3.73. As far as the rear assembly I found it seems to me from what I've read is to get 6 lug 33 spline axles. The only thing I'm hung up on is the 6 lug axles are like 32.5" and the 8 lug are something like 31". I would think the difference would be with the drums somehow
 

ShadowRejects

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I bought a 14 bolt 9.5 semi float from a 87 Suburban squarebody. Had to reweld the shock tabs and spring perches, so you're already one step closer than I am.Mine was 8 lug. Wish I would've kept it being I went 8 lug about 2 years later and had to run adapters, which I still have with zero issues.
When I converted it to 6 lug, I swapped to 6 lug 10 Factory axle shafts, and tossed on a Lugnut4x4 disk brake conversion kit. If you plan on keeping the keeping the truck, I'd consider looking into it. It's relatively cheap. The Eldorado calipers are a pain in the butt, but there are many reputable kits out there that utilize different types of e-brake disk brake conversions. Many of which are direct bolt on
 
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Polloso

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Yeah the rear disc's are cool but I'll stay with the 11" duo servo drums that come on the larger rear ends as they are pretty good. Maybe disc's down the road if I keep it. Right now I just wanna make sure a rear end with 8 lug axles can have 6 lug axles swapped in without any issues with the factory 16" wheels or brake issues.
 

Supercharged111

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If the axles are a different length, then maybe the housings are all the same? This came up very recently in another thread and I want to say someone claimed the housings are the same, but don't quote me. If so, don't forget backing plates. I have no idea where to find those new. Also, did you find a 2wd or 4wd? Those are different for sure.
 

Polloso

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I think the housings are all the same and it's the axles that are different lengths but that is what I'm going to be gambling on. Not sure if it's a 2 or 4wd. I think as long as the spring perches are 47" center to center all is good as far as it bolting up and the axles will make up the width difference. I have a 67.5" width on wheel mounting surface to WMS. If the 6 lug axles are the same width in the larger rear end then its just the brakes that are the variable hence the different backing plates. We will see. Wanted to check here first before taking the plunge!
 

Schurkey

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Are you looking at a C2500 axle, or a K2500 axle? Far as I know, the C and K axles are different widths. Which maybe explains the axle-shaft length problem.

I'm prepared to learn something...but...I have NO idea how the rear wheel track widths can be different, the axle shaft lengths can be different, and the axle housings be the same width. Look at where the bearings ride on the axle shaft--if the axle tube isn't longer for the longer axle shafts, the bearing wouldn't be in the right location.

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Aside from the 6-lug axle shafts, you'd also need 6-lug brake drums. I don't know why the backing plates would be different. By the time you buy new axle shafts, and new brake drums...maybe it'd be better to just get the 6-lug axle assembly to begin with. Kinda depends on the condition of the axle assembly--are the axle shafts or drums worn-out? If so, you need to buy those parts anyway.

When it was me, I got a "K2500" 6-lug axle for my K1500 6-lug truck. Bolts right in. No wheel hassles, no brake drum or axle-shaft hassles. Needed four U-bolts, the U-bolt plates from the donor vehicle to match the axle, and a conversion U-joint (#441, I think) for the rear of the driveshaft.

In my case, I also needed to swap shoes around on the rear brakes because the previous owner of the axle did his own "brake job" when he was clearly unqualified.
 
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TSALI137

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I know this has been covered a thousand times however before I purchase this rear end assembly I would like to make sure my scheme will work. I have an 89 K1500 RCSB with a stock 8.5" 10 bolt. I found a 9.5" 14 bolt SF rear end but with the 8 lug axles from an 88-98 3/4 IIRC. I should be able to put 6 lug axles in and probably have to change the drum brake backing plates. Does this sound right or do I need to find a unit that came with the 6 lug axles. Thanks fellas
I read through this and I know it's an old post but maybe this will help someone else. Yes they can have LSD'S in the K2500/K1500 9.5 14bolts, and just to clarify yes it's the wider 4x4 axle. I'm installing one from a 1998 k2500. Also be aware that it's not just a simple 8 lug shaft to 6lug shaft and a new drum hub swap conversion. You WILL HAVE TO CHANGE EVERYTHING! 8lug 9.5 14bolts have 13in brakes and drums. You have to change the backing plate as well as all the brake hardware and drums to 11.15x2.75 brakes. These are the parts you will need:

Yukon Gear & Axle (YA G15521928) 6-Lug Rear Axle for GM 9.5 Differential.

Dorman HW2324 Rear Drum Brake Hardware Kit w/Self Adjusters; 11.15 In. x 2.75 In. Brakes. OEM parts numbers 2324K; H2324.

ACDelco Gold 17473R Riveted Rear Drum Brake Shoe Set w/6lug wheels.

ACDelco Professional 18E292 Rear Drum Brake Wheel Cylinder w/7200lb GVW or 1500 with 11-5/32in Brakes.

Dorman 924-658 Rear Brake Dust Shield - 1 Pair. Quantity: 1; 11.15In. x 2.75 In. Brakes; Includes Both Sides; wo/Wheel Cylinder OEM numbers 15650129; 15650130.

Raybestos 2169R Professional Grade Brake Drum w/ 6 Lug Wheels 11 5/32" X 2 3/4" Brake Shoe.

ACDelco Professional 18E292 Rear Drum Brake Wheel Cylinder w/ 11 5/32" X 2 3/4" Brake Shoe, W/ 6 lug wheels or 7200lb GVW.


CTB95R42 1995-1998 Chevrolet/GMC Pickup Truck 3/4 Ton 4wd Factory Rear Axle Lines 2pc.OE Steel for Factory Brakes Only. Factory preformed Brake Line Set.

Dorman 919-225 Stainless Steel Brake Line Kit Compatible with Select Chevrolet / GMC Models (OE FIX) FITS 1997 CHEVY K1500 EXTENDED CAB 6.5' BED 141.5WB


*****ALSO BE PREPARED TO NOT HAVE AN EMERGENCY PARKING BRAKE! The powers to be, aka idiots at GM discontinued the 1500 6lug or 7200lb 6lug 2500 parking brake strut , lever and washer, OEM parts numbers 15704004, 15704003, 15154260, 15154259, and 5454797. They discontinued them here in the U.S. in 2010 and Canada in 2009.


The following is for a 97/98 to 2013 9.5 14bolt complete rebuild after purchasing everything listed above for 6lug conversion and with 3.73gears. I have also included some older axle parts numbers too.

Yukon (YG GM9.5-373) High Performance Ring and Pinion Gear Set for GM 9.5" Differential

Yukon Gear & Axle (YSPPN-033) Pinion Nut Washer for GM 7.2″ IFS, 7.5″, 7.625″, 7.6″ IFS, 8.5″, 8.6″ & 9.5″

Yukon Gear & Axle (YSPPN-018) Pinion Nut For GM 7.2" Ifs, 7.5", 7.6", 7.6" Ifs, 8.0", 8.25", 8.5", 8.6", 9.25" Ifs, 9.5" & Oldsmobile Dropouts. 1 1/4" Socket, 7/8" X 14 Thread.

Yukon Gear & Axle (YY STR-007) U-Joint Strap for GM 14-Bolt Truck Differential.. You will need to order 2 or use the OEM AC Delco kit that includes the bolts.

AC Delco Universal Joint Strap Kit 45U0508 1975 - 2010 Chevy GMC Truck.

Yukon Gear & Axle (YSPCC-008) C-Clip for GM 9.5 Differential.

Yukon Gear & Axle (YY GM15579602) Yoke for GM 9.5 Differential with a 1350 U/joint size. 3.625" snap ring span, 1.188" cap diameter.

FEL-PRO RDS 55387 Axle Hsg. Cover or Diff. Seal.

GM Genuine Parts 12471479 Rear Axle Housing Drain Plug, Black.

Yukon Gear & Axle (YP C5-GM9.5) Steel Cover for GM 9.5 Differential.

You will need a m20x1. 5 drain plug such as Mishimoto MMODP Magnetic Oil Drain Plug M20 x 1.5, Black.

Eaton eat914a538 9.5 in. detroit truetrac with 33 spline for gm.

Yukon Gear & Axle (SK SSGM9.5) Super Carrier Shim Kit for 9.5 Differential.

Yukon Gear & Axle (YK GM9.5-B) Master Overhaul Kit for GM 9.5 Semi-Float Differential with Triple Lip Seal.

79-97 9.5 you will need (YK GM9.5-A).

National R-1561-TV Wheel Bearing, 2ea.

National 710105 Wheel Seal, 2ea.

Dorman 610-325 Rear M14-1.50 Serrated Wheel Stud - 15.88mm Knurl, 49mm Length for Select Chevrolet/GMC Models - 12ea.

Set of 24, 14mmx1.5 OEM Factory Wheel Lug Nuts Replacement for Sliverado Sierra 1500 Yukon Avalanche Suburban Express 1500 C1500 K1500 Escalade Traverse Yukon M14x1.5 Studs 6 Lug Wheel.

ATS SPRINGS BT8-227CKChevy Leaf Spring Upper and Lower Saddle & Ubolt Kit - 5/8" x 12-1/2"
ATS SPRINGS BT-DN5/8Leaf Spring U-Bolt Deep Nut Kit 5/8"-18, Grade 8.


Make your own dummy pinion set up bearings:

ACDelco Gold / Timken HM88649 Pinion Bearing Tapered Roller Bearing outer pinion.

Timken Tapered Roller Bearing Cone - HM804846, inner pinion bearings.

I know this is long, but hopefully it will help someone else in the future.
 
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BOTTLEDZ28

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I am currently on the hunt for a 6 lug 14 bolt. Is the Dorman backing plate listed above the direct replacement for the GMT400 6 lug 14 bolts? What about axle seals? Id like to get all the parts I need locked down prior to pulling the trigger on a junkyard rear.
 
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