6 bolt to 5 bolt rear axles - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Keith Grizzle · 09-23-2010, 11:27 AM

Hi guys, Say I have a 67 short box with a 69 6 bolt rearend.I want to go to 5 bolt. I have donor axles from a 5 bolt 71. Are they the same length ? I thought I read some were the 71 are a bit longer, and were a guy put a 1/4 inch shim behind the backing plate to get the correct length.Can you guys help me out on what to do ? THANKS

hoss67 · 09-23-2010, 11:45 AM

I just took my 67 axles out and had them redrilled to 5 on 5 lug pattern. We have a local powertrain shop here. Not that expensive.

71meangreenc10 · 09-23-2010, 11:47 AM

71 are longer but you can get custom axles for your application. Check CPP website for axles.

Smitty

raycow · 09-23-2010, 08:22 PM

The 5 lug shafts are about 3/4" longer than the 69. Most people either buy aftermarket shafts or redrill the stock ones. I suppose you could move the backing plates out with some kind of spacer as you describe, but you might have to do something to get the hard lines on the housing to reach.

Ray

Longhorn Man · 09-24-2010, 10:07 PM

if you use a spacer, then the bearings will roll on a part of the shaft not made for bearings. (nonhardened)
I wouldn't do it personally

**67 cst swb** · 09-25-2010, 02:14 AM

Superior Axle Company sells conversion axles.
Part #PA5855
AXLE; GM 12Bolt TRUCK 65-69
Superior Axle PA5855 is manufactured to exacting standards to precisely fit GM Truck 12 Bolt (8.875") axles found on GM Trucks manufactured from 1965 to 1969.
Converts axle to 5 Lug
www.superioraxlegear.com
or
Moser Engineering Sells them also.

**MikeB** · 09-25-2010, 07:54 AM

I had my 69 axles re-drilled many years ago. However, it's not a do-it-at-home job. The guy who did mine used a CNC machine and had to spot weld plugs in some of the old holes.

Your best bet is aftermarket axles. I bought a pair from Moser in September 2008 for a friend's 1966 C-10.

Here's what I paid.

Axles: $235/pr
new lugs installed: $17.50
Timken axle bearings and National seals: $30
Diff cover gasket: $2.50
freight (Indiana to Dallas): $26

And the best part is they built and shipped them in 3 days.

09-23-2010, 11:27 AM	#1
Keith Grizzle Registered User Join Date: Apr 2010 Location: Wright, Wyo Posts: 26	6 bolt to 5 bolt rear axles Hi guys, Say I have a 67 short box with a 69 6 bolt rearend.I want to go to 5 bolt. I have donor axles from a 5 bolt 71. Are they the same length ? I thought I read some were the 71 are a bit longer, and were a guy put a 1/4 inch shim behind the backing plate to get the correct length.Can you guys help me out on what to do ? THANKS

09-23-2010, 11:45 AM	#2
hoss67 Registered User Join Date: Jun 2009 Location: Harrisville, MS Posts: 267	Re: 6 bolt to 5 bolt rear axles I just took my 67 axles out and had them redrilled to 5 on 5 lug pattern. We have a local powertrain shop here. Not that expensive.

09-23-2010, 11:47 AM	#3
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,159	Re: 6 bolt to 5 bolt rear axles 71 are longer but you can get custom axles for your application. Check CPP website for axles. Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 71 C20 Longhorn/Ole Yellor 69 C30 Former Motor Home, Flat Bed time Last edited by 71meangreenc10; 09-23-2010 at 11:48 AM.

09-23-2010, 08:22 PM	#4
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: 6 bolt to 5 bolt rear axles The 5 lug shafts are about 3/4" longer than the 69. Most people either buy aftermarket shafts or redrill the stock ones. I suppose you could move the backing plates out with some kind of spacer as you describe, but you might have to do something to get the hard lines on the housing to reach. Ray

09-24-2010, 10:07 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 6 bolt to 5 bolt rear axles if you use a spacer, then the bearings will roll on a part of the shaft not made for bearings. (nonhardened) I wouldn't do it personally

09-25-2010, 02:14 AM	#6
67 cst swb Senior Member Join Date: Nov 2001 Location: Rapid City, SD Posts: 2,281	Re: 6 bolt to 5 bolt rear axles Superior Axle Company sells conversion axles. Part #PA5855 AXLE; GM 12Bolt TRUCK 65-69 Superior Axle PA5855 is manufactured to exacting standards to precisely fit GM Truck 12 Bolt (8.875") axles found on GM Trucks manufactured from 1965 to 1969. Converts axle to 5 Lug www.superioraxlegear.com or Moser Engineering Sells them also. __________________ My Trucks: 1967 Chevrolet Short Wide Box 327 TH350 9" w/3.90 gears paint will be White - Current Project 1967 Chevrolet Custom LWB 283 TH400 3.73 Posi, no-AC, no-PS, no-PB, bench-seat, small-window - mostly orig driver 1967 Chevrolet CST LWB originally a 327 TH400 3.73 Posi AC PS PB, had Buddy Buckets, Small Window - parts truck 1967 Chevrolet CST LWB, 283 MT 3.73 had Buddy Buckets, Panoramic Window - parts truck 2001 Chevrolet 3500 2WD Crew Cab Dually 8.1L Allison White

09-25-2010, 07:54 AM	#7
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,473	Re: 6 bolt to 5 bolt rear axles I had my 69 axles re-drilled many years ago. However, it's not a do-it-at-home job. The guy who did mine used a CNC machine and had to spot weld plugs in some of the old holes. Your best bet is aftermarket axles. I bought a pair from Moser in September 2008 for a friend's 1966 C-10. Here's what I paid. Axles: $235/pr new lugs installed: $17.50 Timken axle bearings and National seals: $30 Diff cover gasket: $2.50 freight (Indiana to Dallas): $26 And the best part is they built and shipped them in 3 days. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!



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