The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1969 - 1972 Blazers and Jimmys Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-04-2006, 03:04 PM   #1
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
1970 4x4 Blazer Disc brake conversion

I have a 70 4x Blazer and looking to install disc brakes on the front. I was told that a 1977 front axle parts will swap over. Not the whole axle because it's slightly wider, but from the knuckles out will work.

Has anyone tried it? Or is there a better way?
(thanks!)


Last edited by HvyChevy; 08-04-2006 at 03:09 PM.
HvyChevy is offline   Reply With Quote
Old 08-04-2006, 03:17 PM   #2
Yukon Jack
Mechanically Challenged
 
Yukon Jack's Avatar
 
Join Date: Feb 2000
Location: Rose Hill, KS, USA
Posts: 12,439
Re: 1970 4x4 Blazer Disc brake conversion

Just swap over the whole axle assuming the gear ratio is correct. Width is the same and spring perches are placed correctly. I'm putting a 78 3/4 ton front axle under my K5 for the same reason.

Oh, welcome to the board and that is one sweet K5!
__________________
1970 Blazer with a 400 sbc and 4" lift Roadworthy!
1969 K20 with a 454, a bit of lift and 35's
1980 Pontiac Trans Am, 455 Oldsmobile

Yukon Jack's Web Pages

Last edited by Yukon Jack; 08-04-2006 at 03:18 PM.
Yukon Jack is offline   Reply With Quote
Old 08-04-2006, 03:24 PM   #3
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
Re: 1970 4x4 Blazer Disc brake conversion

Thanks YJ, that sounds easier.

Thanks for the compliments, it needs a little work. I just bought it a few weeks ago. The front springs are way too stiff (don't know what brand), it has a Mark IV a/c unit that I'm trying to get working, maybe a cross over steering set up in the future? Needs a roll cage too. A little rust on the bottom of the doors.....what fun would it be if it was perfect, right?

I guess there's always going to be a list of things to do to it...

Your truck looks cool...
HvyChevy is offline   Reply With Quote
Old 08-04-2006, 03:59 PM   #4
Jason915
Registered User
 
Join Date: Jan 2005
Location: Colorado Springs
Posts: 693
Re: 1970 4x4 Blazer Disc brake conversion

Sweet 70K5, I too am getting ready for the disc brake conversion on mine. I have a 1975 D44 from a 75K5 with 3.73's ready to go into my K5. The cool thing about the newer D44 is that it has a factory sterring stablizer. My question is what brake lines will work. I know I have to change my master cylinder out.
__________________
1971 GMC K1500 SWB Fleetside, 4" skyjacker softride and, 14 Bolt FF, HD Dana 44 4.10's

1970 K5 TBI conversion lifted etc SOLD
1968 C20 camper truck SOLD


“To ban guns because criminals use them is to tell the innocent and law-abiding that their rights and liberties depend not on their own conduct, but on the conduct of the guilty and the lawless.” Jeff Snyder
Jason915 is offline   Reply With Quote
Old 08-04-2006, 04:09 PM   #5
meathead95
computer illiterate
 
meathead95's Avatar
 
Join Date: Jan 2001
Location: Des Moines, IA
Posts: 6,449
Re: 1970 4x4 Blazer Disc brake conversion

welcome from nashville! that is one awesome rig
__________________
72 2wd blazer
72 swb 4x4
meathead95 is offline   Reply With Quote
Old 08-04-2006, 04:12 PM   #6
Jason915
Registered User
 
Join Date: Jan 2005
Location: Colorado Springs
Posts: 693
Re: 1970 4x4 Blazer Disc brake conversion

Oh yeah for your suspension I would suggest Skyjacker Softride they kick butt in overall ride quility.
__________________
1971 GMC K1500 SWB Fleetside, 4" skyjacker softride and, 14 Bolt FF, HD Dana 44 4.10's

1970 K5 TBI conversion lifted etc SOLD
1968 C20 camper truck SOLD


“To ban guns because criminals use them is to tell the innocent and law-abiding that their rights and liberties depend not on their own conduct, but on the conduct of the guilty and the lawless.” Jeff Snyder
Jason915 is offline   Reply With Quote
Old 08-04-2006, 04:25 PM   #7
bouncytruck
SKINNY TIRES RULE!
 
bouncytruck's Avatar
 
Join Date: Sep 2001
Location: Bothell, WA
Posts: 10,930
Re: 1970 4x4 Blazer Disc brake conversion

Welcome from the Pacific NW. Nice lookin' rig (I'm partial to Orange with a white top!). I've heard the Rough Country is one of the stiffest lifted springs. I've had Rancho Lifts on three of my Blazers and it was stiff, but driveable. The tires make a huge difference too.
__________________
bouncytruck 1972 K5
bouncytruck is online now   Reply With Quote
Old 08-04-2006, 04:49 PM   #8
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
Re: 1970 4x4 Blazer Disc brake conversion

thanks guys!!! I look forward to working on it.
I'll be sure to take pics and keep ya'll posted with the results.
HvyChevy is offline   Reply With Quote
Old 08-05-2006, 04:45 PM   #9
pound41
Registered User
 
Join Date: Dec 2002
Location: Northern Virginia
Posts: 988
Re: 1970 4x4 Blazer Disc brake conversion

I have a 70 that I bought that has a newer disk front swapped in it. It was a factory power drum. To me it didn't stop as well as I would like with the old master and prop valve. I got the correct master and valve but had to do some engineering. Different size threads etc. You might want to consider the whole 3/4 booster swap. That is what I am doing.
pound41 is offline   Reply With Quote
Old 08-05-2006, 05:18 PM   #10
LUV2XCLR8
"Square Corvette"
 
LUV2XCLR8's Avatar
 
Join Date: Jan 2004
Location: West TN
Posts: 30,277
Re: 1970 4x4 Blazer Disc brake conversion

From West TN
__________________
The Toy:"Square Vette" 72 C5 Blazer
Toy Puller: "Burakkubyūtī" 12 Tundra
Toy Hauler: "Feathers" Aluma 8218T
New Toy:"Not Named" 67 GMC Dually
Owner/Admin "TN Classic Truck Club"
LUV2XCLR8 is offline   Reply With Quote
Old 08-05-2006, 05:21 PM   #11
krue
Designated A-hole!
 
krue's Avatar
 
Join Date: Mar 2003
Location: South Mississippi
Posts: 36,150
Re: 1970 4x4 Blazer Disc brake conversion

Welcome to the board from South Mississippi! That's a very nice Blazer you have!
__________________
"If it ain't broke, fix it 'til it is!"
Being stupid ain't illegal.

We're Debt Free Except for the House!!!
www.daveramsey.com

70 GMC SWB Stepside project "Green Booger"
93 S-10 "PawPaw's Truck"
99 Suburban donor for the Green Booger
krue is offline   Reply With Quote
Old 08-05-2006, 07:36 PM   #12
Chevyman63
Can't wait to retire!!
 
Chevyman63's Avatar
 
Join Date: Feb 2003
Location: Corunna, MI
Posts: 1,571
Re: 1970 4x4 Blazer Disc brake conversion

Welcome from Michigan, the home of rust. Nice looking ride.

__________________

2009 4x4 Chevy Crew Cab 6.0
1989 4x4 Siverado (270,000 miles)
1972 4x4 Blazer
2007 Chevy Cutaway 1 ton
1970 Corvette (sons project)

RIP
- CLR 10/11/09
Chevyman63 is offline   Reply With Quote
Old 08-05-2006, 08:45 PM   #13
Southedisto
River life......
 
Southedisto's Avatar
 
Join Date: Oct 2005
Location: Orangeburg SC
Posts: 1,078
Re: 1970 4x4 Blazer Disc brake conversion

Welcome to the board, and I would go with a complete axle swap instead of the knuckles out swap.
__________________
Southedisto is offline   Reply With Quote
Old 08-05-2006, 09:05 PM   #14
Livrat
Member #1049
 
Livrat's Avatar
 
Join Date: Jun 2000
Location: 25 miles east of Arlington, Wa. 4 miles west of Darrington, Wa.
Posts: 3,649
Re: 1970 4x4 Blazer Disc brake conversion

Welcome to the board!!
Since 1970 is the first of the open knuckle dana 44's and the last of the drum brakes.. All you need to do is change from the spindles out... just pull off the calipers, remove the rotors.. then remove the spindles, pull out the axles from the 77.. and put it all in yours... Thats the easy part.. next is the brake lines.. the 77 stuff is not compatible... the easy way is to find a 71 or 72 chev 4X4 and use the brake lines.. the 70 lines drum brake lines come thru the frame behind the axle and the 71/72 comes out in front of the axle and uses different hoses.. you will need to drill the holes in the frame for the lines to come thru.. and use the hoses from a 71 to 80 4X4.. You will also need to change the master cylinder and booster to a "disc brake" one.. it does not matter if its from 2WD or a 4X4 as long as its from a 71/72 1/2 ton...
Hope that was not too confusing.. if you have questions.. feel free to PM me or email me directly.. Livrat@aol.com
Livrat is offline   Reply With Quote
Old 08-14-2006, 09:50 PM   #15
69TowRig
Senior Member
 
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 882
Re: 1970 4x4 Blazer Disc brake conversion

'69 and '70 Blazers had open knuckle D44s. My '69 was not closed knuckle like everyone says it should have been, and I have not seen a '69 K5 with closed knuckles.

The problem with a spindle swap is that drum-brake knuckles have the six bolt holes clocked differently than the disc knuckles do, so a straight spindle swap is not quite so simple. The disc-brake backing plate will put the caliper in contact with the knuckle itself. You *could* grind away a lot of material and make the caliper fit, or swap the entire knuckle off.

If you do the knuckle swap, you can use any 1971-later D44 or Coporate 10-bolt for donor parts. It is closest to "bolt-on" if you use the matching outer axleshafts from the donor axle.

I did the knuckle swap last year on mine. I pulled the knuckles from an '84 K5, bought reman calipers and paid up for a set of Crown brake lines through xtremecrawlers.com. I re-used my original outer axleshafts but was not able to install the retaining clip for the shafts under the lockout. If you go the same route as I did you end up needing 1" long 7/16"-20 bolts with fender washers to retain the axleshaft from moving back and forth (the ends of the shafts are threaded)

The knuckle swap will cost you some $$$, I had to replace the balljoints, an axleshaft u-joint, and a couple wheel bearings too. Lots of time invested. In the end you get disc brakes but still have the smaller u-joints ('73+ have larger axle u-joints). The spring perches are the right distance apart on the '73+ trucks, and it is a straightforward swap if you go that route. A bonus is that you automatically get the lower mounts for a swaybar if you want to add one of those to the truck as well.

Overall, with the power booster and discs up front the thing stops way better than it ever did before, and the effort is worth it.
__________________
-Chris
Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid.
Click HERE for Blazer pics. Click HERE for Nissan Frontier stuff.
69TowRig is offline   Reply With Quote
Old 08-14-2006, 09:56 PM   #16
jakeslim
Premium Level Member
 
jakeslim's Avatar
 
Join Date: Aug 2004
Location: Northern CA
Posts: 829
Re: 1970 4x4 Blazer Disc brake conversion

My drums on front axle will stop on a dime............well maybe 4 dimes Welcome to this habit. Warning we may see ya on that show "Intervention" for a bad parts habit.
__________________
69 K5 CST stock- 350, 4speed

77 K5 - 383, auto, 6" lift, D60 front, 14b rear, 39" tsl's,
jakeslim is offline   Reply With Quote
Old 08-16-2006, 05:14 PM   #17
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
Re: 1970 4x4 Blazer Disc brake conversion

Thanks for the welcome, compliments, and info!!!

I found a 1980 4x4 front axle (well parts of one anyway....lol)

So, I'm going to give it a shot. I guess I need to try and find some beefy axleshaft u-joints.
Off Road Unlimited sells a cross over steering kit comes with a passenger side flat top knuckle, 2 wheel drive steering box, etc.....kinda pricey though. Well see.

Here's some pics of my parts pile.....Oh yeah, best part.. I found a '70 tilt column too...


HvyChevy is offline   Reply With Quote
Old 08-16-2006, 06:13 PM   #18
69TowRig
Senior Member
 
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 882
Re: 1970 4x4 Blazer Disc brake conversion

Good luck, PM me if you need any pointers. Looks like you didn't get the shafts so just "run what you brung". You will need to do the setup with the bolt I was talking about, but you will figure it out when you put it together.

BTW, sweet column, where'd you find that?
__________________
-Chris
Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid.
Click HERE for Blazer pics. Click HERE for Nissan Frontier stuff.
69TowRig is offline   Reply With Quote
Old 08-16-2006, 06:32 PM   #19
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
Re: 1970 4x4 Blazer Disc brake conversion

Quote:
Originally Posted by 69TowRig
Good luck, PM me if you need any pointers. Looks like you didn't get the shafts so just "run what you brung". You will need to do the setup with the bolt I was talking about, but you will figure it out when you put it together.

BTW, sweet column, where'd you find that?
Maybe I can still get the shafts. I picked up the parts before I read your post. I'll probably be pm'n ya. Thanks!

I found the column (after searching a few yards) at Truck Parts Co. a dismantler in Baldwin Park, CA

Last edited by HvyChevy; 08-16-2006 at 06:33 PM.
HvyChevy is offline   Reply With Quote
Old 08-16-2006, 08:18 PM   #20
69TowRig
Senior Member
 
Join Date: Jan 2005
Location: Raleigh, NC
Posts: 882
Re: 1970 4x4 Blazer Disc brake conversion

Hmm, thinking some more if it was from and '80 then it was a Corporate 10-bolt. The inner shafts won't work because they are 19-spline instead of 30-spline like the Dana units. Not sure if there is a conversion joint for the axle u-joints either. You may just have to use what you have.
__________________
-Chris
Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid.
Click HERE for Blazer pics. Click HERE for Nissan Frontier stuff.
69TowRig is offline   Reply With Quote
Old 08-17-2006, 01:17 PM   #21
HvyChevy
Registered User
 
HvyChevy's Avatar
 
Join Date: Aug 2006
Location: So-Cal
Posts: 55
Re: 1970 4x4 Blazer Disc brake conversion

Quote:
Originally Posted by 69TowRig
Hmm, thinking some more if it was from and '80 then it was a Corporate 10-bolt. The inner shafts won't work because they are 19-spline instead of 30-spline like the Dana units. Not sure if there is a conversion joint for the axle u-joints either. You may just have to use what you have.
Hmm....good thing I don't have to drive it everyday...I guess I'll start wrenching and see what happens. (Oh, the fun....lol)
HvyChevy is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:45 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com