rear axle size difference confusion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

FirstGen · 02-14-2004, 01:09 AM

Ok, I'm alittle confused. I've heard that the 5 lug axles are only 3/8 inch longer than the older 6 lug. However, this thread says that the rear end is 1.25 inches larger? Which is it?
http://67-72chevytrucks.com/vboard/s...threadid=79939
What years have the larger rear and which have the smaller one?
Lastly, what is the benefit to switching to 5 lug besides being able to use a 5 lug wheel design?
Thanks.

Longhorn Man · 02-14-2004, 01:16 AM

5 lug has disc brakes up front, and that is the main reason for getting them. You can get 6 lug rotors, but they are not cheap.
The '70 rear may or may not be wide or narrow, that was the conversion rear end, later ones were wide and 5 lug axle shafts slide right in.
The 3/8 measurement is per side, still doesn't explain the 1 1/4 inch deal, but I have heard from amny people on the 3/8 deal, and a few of them made spacers off that measurement and it worked, so I'll go by that.

FirstGen · 02-14-2004, 01:28 AM

so it's cheaper to get the whole 5 lug disk setup and rear axle swap than buying front 6 lug rotors/calipers? What all do you need to do this conversion? Any tips?

SS55 · 02-14-2004, 01:40 AM

You could have your rear axles re-done for 5 lug. I had a pair done a few years ago. I think I sent them to Moser Engineering. Seems like it was $75 for the pair back about 10-12 years ago.

Darrell

Longhorn Man · 02-14-2004, 01:43 AM

I don't know if it would be cheaper to do the 5 lug than the 6 lug rotors...I highly doubt it actually.
The 6 lug rotors go on just like the 5 lug ones. I don't think they are way over priced, just more expensive (Since they are aftermarket only) than the 5 lug counterparts that you can pick up at any parts store in america.

MOTHERTRUCKERS · 02-14-2004, 08:55 AM

Anybody try 6 lug 89-90 3/4 ton light duty rotors? same inner/outer bearing and seal part numbers as 71-2 rotors.

Bowtie67 · 02-14-2004, 05:38 PM

Actually the only 1 reason I would swap out front rotor to a 5 lug setup would be for better availability, you cant walk into an autoparts place say you have a 69 with 6 liug rotors on it they don't make them. but you caan get 5 lug rotors a lot cheaper because they are more common unless you end up ordering from a specialty place like ECE, CPP, etc.

02-14-2004, 01:09 AM	#1
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	rear axle size difference confusion Ok, I'm alittle confused. I've heard that the 5 lug axles are only 3/8 inch longer than the older 6 lug. However, this thread says that the rear end is 1.25 inches larger? Which is it? http://67-72chevytrucks.com/vboard/s...threadid=79939 What years have the larger rear and which have the smaller one? Lastly, what is the benefit to switching to 5 lug besides being able to use a 5 lug wheel design? Thanks. __________________ 1968 C10 build in process TT LSA/6L90e/9" Last edited by FirstGen; 02-14-2004 at 01:12 AM.

02-14-2004, 01:28 AM	#3
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	so it's cheaper to get the whole 5 lug disk setup and rear axle swap than buying front 6 lug rotors/calipers? What all do you need to do this conversion? Any tips? __________________ 1968 C10 build in process TT LSA/6L90e/9"

02-14-2004, 01:40 AM	#4
SS55 Registered User Join Date: Nov 2003 Location: San Diego, CA Posts: 62	You could have your rear axles re-done for 5 lug. I had a pair done a few years ago. I think I sent them to Moser Engineering. Seems like it was $75 for the pair back about 10-12 years ago. Darrell __________________ Be wary of the light at the end of the tunnel....It might be a gorilla holding a flashlight! 71 Blazer, ex-4WD...Bought it that way 55 GMC 55 Belair 2dr HT 67 El Camino

02-14-2004, 08:55 AM	#6
MOTHERTRUCKERS Registered User Join Date: Dec 1999 Location: BRADENTON FLA Posts: 3,269	Anybody try 6 lug 89-90 3/4 ton light duty rotors? same inner/outer bearing and seal part numbers as 71-2 rotors. __________________ Rest in Peace Ed. Thanks for all the good times.

02-14-2004, 01:16 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	5 lug has disc brakes up front, and that is the main reason for getting them. You can get 6 lug rotors, but they are not cheap. The '70 rear may or may not be wide or narrow, that was the conversion rear end, later ones were wide and 5 lug axle shafts slide right in. The 3/8 measurement is per side, still doesn't explain the 1 1/4 inch deal, but I have heard from amny people on the 3/8 deal, and a few of them made spacers off that measurement and it worked, so I'll go by that.

02-14-2004, 01:43 AM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I don't know if it would be cheaper to do the 5 lug than the 6 lug rotors...I highly doubt it actually. The 6 lug rotors go on just like the 5 lug ones. I don't think they are way over priced, just more expensive (Since they are aftermarket only) than the 5 lug counterparts that you can pick up at any parts store in america.

02-14-2004, 05:38 PM	#7
Bowtie67 Registered User Join Date: Jan 2004 Location: NH Posts: 2,266	Actually the only 1 reason I would swap out front rotor to a 5 lug setup would be for better availability, you cant walk into an autoparts place say you have a 69 with 6 liug rotors on it they don't make them. but you caan get 5 lug rotors a lot cheaper because they are more common unless you end up ordering from a specialty place like ECE, CPP, etc.



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