Need help with disc brake set up... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JerseyGirl · 07-03-2005, 07:05 PM

I tried looking thru ALL the threads for this & I couldn't find what I needed. I guess if I really searched High & Low..I would have found it..

Are the axles & length & number of splines the same from the 5 lug to 6 lug on the 12 bolt rear?

I am thinking about converting over my 6 lug to 5 lug, I know pretty much all what needs to be done, but needed to ask the above question...has anyone done it & if so, can ya put a link showing what ya did?

Any help would be sooooo much appreciated!

Tree

**hilljob26** · 07-03-2005, 07:56 PM

i converted a 70 w/6 lug to a 72 5 lug a couple of yeras ago,and it worked out just right,i dont think you can swap out a 6 lug 4x4 rear w/ 5 lug,but i am pretty sure you can do a 2wd

JerseyGirl · 07-03-2005, 08:01 PM

Yea they are both 2wd..I appreciate the response!

neonlarry · 07-03-2005, 08:11 PM

Depends on which width rear you have (on your truck). There was a mid year switch to a wider rear, if you have the wider one the 5 lug will go right in. The narrower one will need spacers. The other possibilities are an after market 5 lug axle or have yours filled and redrilled.
Check out this page for measurements:
http://50chevy.freeservers.com/Suspension_Widths.html

Longhorn Man · 07-03-2005, 08:14 PM

Spacers is not a good idea, the portion of the axle shaft that rides on the bearing is hardened...but the rest of the axle shaft isn't. I kn ow it's been done and stuff, but that's a lot of damage if an axle gives out...esp on the freeway.

JerseyGirl · 07-03-2005, 10:50 PM

The donor I am using (or will use) will be coming off a '69.
All I want to do is put disc brakes on the front...I have power drums brakes now on my '70...but would LOVE the disc up front.
Is there any 6 lug trucks that have power brakes that everything will just tranfer onto my truck without any problems?

**GMCPaul** · 07-04-2005, 04:56 AM

1970 6lug rear axles are the same length as 1971 & 72 5lug rear axles so axles and drum brake drums can be swapped, 1969 and earlier rear axles are shorter by approx. 3/4" each and if you try to swap late model 71-72 axles into them they protrude a additional 3/4" further out so you can not do a direct swap on axles and drums only. Spline count on all 1967-72 1/2 ton 12 bolt rearends is the same.
GMCPaul

**GMCPaul** · 07-04-2005, 05:03 AM

You stated the donor truck is a 1969, in 1969 they had 6 lug front & rear and drum brakes front and rear so if your getting a 69 with disc brakes in front & 5 lug front & rear someone has then converted it to disc brakes & 5 lug. If thats the case you need to find out what year group parts were used to convert it.
GMCPaul

JerseyGirl · 07-04-2005, 09:42 AM

Quote:

Originally Posted by GMCPaul

You stated the donor truck is a 1969, in 1969 they had 6 lug front & rear and drum brakes front and rear so if your getting a 69 with disc brakes in front & 5 lug front & rear someone has then converted it to disc brakes & 5 lug. If thats the case you need to find out what year group parts were used to convert it.
GMCPaul

That is what my husband figured! I appreciate your help, the truck had a new master cylinder & booster as well...don't know if it's worth going thru all the trouble to convert it over. Thinking about just putting the front spindles & disc brake assembly on & finding a 5-6 lug adapter for the fronts & keeping my wheels & tires...any suggestions would be appreciated!

**GMCPaul** · 07-04-2005, 09:54 AM

The donor truck your speaking of if it has truck 5on5" bolt pattern with 1 1/4" thick rotors then you can use the standard 6 lug rotors ourselves and most other parts vendors carry to replace the current 5lug rotors on it to keep your 6 on 5.5" bolt pattern you currently have.
If you like the wheels better on the 69 and its got a 71-72 rearend under it then you can pull itsd rear axles and drums and swap with your 1970 axles. If its got a 73 up rear end the axle shafts are wrong length for the swap.
GMCPaul

boraxman · 07-04-2005, 10:03 AM

Hang on JerseyGirl, im on my way to help

**hilljob26** · 07-04-2005, 10:47 AM

they do make a 6 lug rotor for the front of that,try like manestruckparts.com they have the rotors for 100 bucks each i think,which isn't bad if you are really stuck on the 6 lug

**PICKMUP** · 07-04-2005, 12:47 PM

The new 6-lug rotors onto a 5-lug spindle is a "bolt on".
I am sure Manestruck & others may have these, but I would recommend you contact GMC Paul first. He is on the board, giving lots of free information, has the parts in stock and I will bet his prices are better also.

JerseyGirl · 07-04-2005, 02:35 PM

Quote:

Originally Posted by PICKMUP

The new 6-lug rotors onto a 5-lug spindle is a "bolt on".
I am sure Manestruck & others may have these, but I would recommend you contact GMC Paul first. He is on the board, giving lots of free information, has the parts in stock and I will bet his prices are better also.

Did NOT know that..very cool! Thanks for that info...

And thanks guys for the help. GMCPaul you are da man!!! Very helpful info..thanks soooooooooo much!

07-03-2005, 07:05 PM	#1
JerseyGirl American Woman! Join Date: Jan 2005 Location: TN Posts: 1,046	Need help with disc brake set up... I tried looking thru ALL the threads for this & I couldn't find what I needed. I guess if I really searched High & Low..I would have found it.. Are the axles & length & number of splines the same from the 5 lug to 6 lug on the 12 bolt rear? I am thinking about converting over my 6 lug to 5 lug, I know pretty much all what needs to be done, but needed to ask the above question...has anyone done it & if so, can ya put a link showing what ya did? Any help would be sooooo much appreciated! Tree __________________ Tree Was Here! Click here to see pics of my new rig!

07-03-2005, 07:56 PM	#2
hilljob26 Registered User Join Date: Dec 2004 Location: Gypsum Kansas 67448 Posts: 1,681	i converted a 70 w/6 lug to a 72 5 lug a couple of yeras ago,and it worked out just right,i dont think you can swap out a 6 lug 4x4 rear w/ 5 lug,but i am pretty sure you can do a 2wd __________________ 21 2500hd duramax 58 apache HILLJOB GRAPHIX--for all your graphic needs My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=542497 LS ENGINE SWAP INFORMATION THREAD http://67-72chevytrucks.com/vboard/s...d.php?t=377348 4l60 to an NP205 http://67-72chevytrucks.com/vboard/s...43#post3697343

07-03-2005, 08:01 PM	#3
JerseyGirl American Woman! Join Date: Jan 2005 Location: TN Posts: 1,046	Yea they are both 2wd..I appreciate the response! __________________ Tree Was Here! Click here to see pics of my new rig!

07-03-2005, 08:11 PM	#4
neonlarry Registered User Join Date: Feb 2002 Location: Vacaville, CA Posts: 2,745	Depends on which width rear you have (on your truck). There was a mid year switch to a wider rear, if you have the wider one the 5 lug will go right in. The narrower one will need spacers. The other possibilities are an after market 5 lug axle or have yours filled and redrilled. Check out this page for measurements: http://50chevy.freeservers.com/Suspension_Widths.html __________________ 70 C/10 Light Red 350/TH350, HEI, Duals w/40 series Flows, 91 seat, LED taillights 99 Pontiac S/C GTP, SLP Ram Air hood, GMPP Konis & springs 95 Neon ACR, MP PCM, AFX UDP, 3.0 CAI

07-03-2005, 10:50 PM	#6
JerseyGirl American Woman! Join Date: Jan 2005 Location: TN Posts: 1,046	The donor I am using (or will use) will be coming off a '69. All I want to do is put disc brakes on the front...I have power drums brakes now on my '70...but would LOVE the disc up front. Is there any 6 lug trucks that have power brakes that everything will just tranfer onto my truck without any problems? __________________ Tree Was Here! Click here to see pics of my new rig!

07-03-2005, 08:14 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Spacers is not a good idea, the portion of the axle shaft that rides on the bearing is hardened...but the rest of the axle shaft isn't. I kn ow it's been done and stuff, but that's a lot of damage if an axle gives out...esp on the freeway.

07-04-2005, 04:56 AM	#7
GMCPaul Senior Member Join Date: Mar 2000 Location: Rockville,In. USA Posts: 3,721	1970 6lug rear axles are the same length as 1971 & 72 5lug rear axles so axles and drum brake drums can be swapped, 1969 and earlier rear axles are shorter by approx. 3/4" each and if you try to swap late model 71-72 axles into them they protrude a additional 3/4" further out so you can not do a direct swap on axles and drums only. Spline count on all 1967-72 1/2 ton 12 bolt rearends is the same. GMCPaul __________________ Secure Online Catalog for-GMCPauls Truck Parts Email- GMCPAULS@GMAIL.COM

07-04-2005, 05:03 AM	#8
GMCPaul Senior Member Join Date: Mar 2000 Location: Rockville,In. USA Posts: 3,721	You stated the donor truck is a 1969, in 1969 they had 6 lug front & rear and drum brakes front and rear so if your getting a 69 with disc brakes in front & 5 lug front & rear someone has then converted it to disc brakes & 5 lug. If thats the case you need to find out what year group parts were used to convert it. GMCPaul __________________ Secure Online Catalog for-GMCPauls Truck Parts Email- GMCPAULS@GMAIL.COM

07-04-2005, 09:54 AM	#10
GMCPaul Senior Member Join Date: Mar 2000 Location: Rockville,In. USA Posts: 3,721	The donor truck your speaking of if it has truck 5on5" bolt pattern with 1 1/4" thick rotors then you can use the standard 6 lug rotors ourselves and most other parts vendors carry to replace the current 5lug rotors on it to keep your 6 on 5.5" bolt pattern you currently have. If you like the wheels better on the 69 and its got a 71-72 rearend under it then you can pull itsd rear axles and drums and swap with your 1970 axles. If its got a 73 up rear end the axle shafts are wrong length for the swap. GMCPaul __________________ Secure Online Catalog for-GMCPauls Truck Parts Email- GMCPAULS@GMAIL.COM

07-04-2005, 10:03 AM	#11
boraxman Keepin an eye out Join Date: Feb 2003 Location: So.Cal Posts: 3,920	Hang on JerseyGirl, im on my way to help __________________ 1970 Chevy C10 SWB 5.3 1996 Toyota Tacoma SR5 4x4 2007 Vespa GTS 250 Scooter ZIP 91351

07-04-2005, 10:47 AM	#12
hilljob26 Registered User Join Date: Dec 2004 Location: Gypsum Kansas 67448 Posts: 1,681	they do make a 6 lug rotor for the front of that,try like manestruckparts.com they have the rotors for 100 bucks each i think,which isn't bad if you are really stuck on the 6 lug __________________ 21 2500hd duramax 58 apache HILLJOB GRAPHIX--for all your graphic needs My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=542497 LS ENGINE SWAP INFORMATION THREAD http://67-72chevytrucks.com/vboard/s...d.php?t=377348 4l60 to an NP205 http://67-72chevytrucks.com/vboard/s...43#post3697343

07-04-2005, 12:47 PM	#13
PICKMUP "Trucks with Class" Join Date: Jul 2000 Location: OLYMPIA, WA, USA Posts: 8,158	The new 6-lug rotors onto a 5-lug spindle is a "bolt on". I am sure Manestruck & others may have these, but I would recommend you contact GMC Paul first. He is on the board, giving lots of free information, has the parts in stock and I will bet his prices are better also. __________________ Email: frankeham@comcast.net Phone: 360-956-7170



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