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 1960 - 1966 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-25-2013, 04:43 PM   #1
spudder
Junior Member
 
Join Date: Aug 2012
Location: Central Illinois
Posts: 55
Later, bigger rear drum brakes???

Can the bigger drum brakesfrom later trucks be retro-fitted onto a '63-'66 rearend? What are the options? Can 6 lug 4WD drums be used
I intend to redrill the axles for 5 on 5" and turn down the center register to accept the right drums.
Can anyone share some info this?
spudder is offline   Reply With Quote
Old 01-25-2013, 05:01 PM   #2
luvbowties
Registered User
 
luvbowties's Avatar
 
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
Smile Re: Later, bigger rear drum brakes???

Quote:
Originally Posted by spudder View Post
Can the bigger drum brakesfrom later trucks be retro-fitted onto a '63-'66 rearend? What are the options? Can 6 lug 4WD drums be used
I intend to redrill the axles for 5 on 5" and turn down the center register to accept the right drums.
Can anyone share some info this?
We put a set of later axles w/5 lugs and wider drums in a stock '66 differential. Axles were 3/4" longer. Brakes were wider than 2", but I don't recall just how much. We spaced the orig. '66 backing plates out the needed distance for the wider drums to cover the wider brakes. Been working great for several years. IIRC, the drums and wider shoes came from a G20 van.
HTH,
Sam
luvbowties is offline   Reply With Quote
Old 01-26-2013, 01:38 AM   #3
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 22,378
Re: Later, bigger rear drum brakes???

The '71-'87 trucks were available with optional 2.5" wide brakes on the rear for both the C10 and K10's. These can be swapped onto any year truck 12 bolt from '64-'82 and the 8.5 10 bolt from '80-'86 on the C and K series and '87-'91 for the R and V series. You will need both the backing plates and drums. The shoes and hardware can be sourced from your local auto parts store.

I do not recommend installing the longer 31.25" axles into housings that are designed for the 30.5" axles
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 01-26-2013, 05:54 AM   #4
luvbowties
Registered User
 
luvbowties's Avatar
 
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
Question Re: Later, bigger rear drum brakes???

Quote:
Originally Posted by Captainfab View Post
The '71-'87 trucks were available with optional 2.5" wide brakes on the rear for both the C10 and K10's. These can be swapped onto any year truck 12 bolt from '64-'82 and the 8.5 10 bolt from '80-'86 on the C and K series and '87-'91 for the R and V series. You will need both the backing plates and drums. The shoes and hardware can be sourced from your local auto parts store.

I do not recommend installing the longer 31.25" axles into housings that are designed for the 30.5" axles
Good info, Captain, as usual. One thing arouses my curiosity, and hoping I never get too old to learn: I'm curious why installing the longer 31.25" axles into housings that are designed for the 30.5" axles is a bad idea. Or, does it depend on how it is accomplished? We did one that way, but used the orig. '66 backing plates, and machined a spacer block that fit between housing flange and backing plate. Also, the axles had plenty of length of machined bearing surface('meat')to run inside the bearings.
Hope I don't have to do a 1-vehicle recall!
Thanks a bunch,
Sam
luvbowties is offline   Reply With Quote
Old 01-27-2013, 01:53 AM   #5
Captainfab
60-66 Nut

 
Join Date: Mar 2007
Location: Coeur d'Alene, Idaho
Posts: 22,378
Re: Later, bigger rear drum brakes???

Yes it does depend somewhat on how it is done, as well as how the truck is going to be used.

Most of the ones I have seen done, were nothing more than sliding in the longer axles with all the original brake parts. I don't know if all the axles have a long enough machined area to accomodate the bearing being moved inward 3/4". Most guys doing this aren't going to check that. As for the backing plate spacers, most guys do not have the means to accomplish that them selves. If someone had to pay a machine shop to make those, how much is a guy really saving versus purchasing the correct axles in the first place?

Quote:
Originally Posted by luvbowties View Post
Good info, Captain, as usual. One thing arouses my curiosity, and hoping I never get too old to learn: I'm curious why installing the longer 31.25" axles into housings that are designed for the 30.5" axles is a bad idea. Or, does it depend on how it is accomplished? We did one that way, but used the orig. '66 backing plates, and machined a spacer block that fit between housing flange and backing plate. Also, the axles had plenty of length of machined bearing surface('meat')to run inside the bearings.
Hope I don't have to do a 1-vehicle recall!
Thanks a bunch,
Sam
__________________
Power Steering Box Adapter Plates For Sale HERE
Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE
Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE
Hydroboost Mounting Plates HERE
Captainfab is offline   Reply With Quote
Old 01-27-2013, 05:05 AM   #6
luvbowties
Registered User
 
luvbowties's Avatar
 
Join Date: Feb 2009
Location: southeasternfoothillsofusa
Posts: 1,557
Thumbs up Re: Later, bigger rear drum brakes???

Thanks for the informative reply. Since I see the truck about every week, I dreaded having to face him requesting we lick that calf over.

I tend to forget we don't all have the same means, machinery, and skills. With this particular job, the owner had a gratis set of nice longer axles; and we tried and erred our way thru to using wider drums and shoes. We used some industrial-plant scrap that needed mostly sawing off and drilling to make the spacers, very little precision. A roundabout method I agree, but it seems we determined it was a reproducible job, with used parts, for just over half the cost of new axles.

I agree the simplest way, with NO downsides is to buy new axles. And admittedly not being so cost-conscious today, were I to do my own it would be my 1st choice, with re-drilling my other. Whichever method, I prefer keeping stock width due to otherwise limiting the space & thus choice of wheels.

Thx again for sharing so much with our group.
Sam
luvbowties is offline   Reply With Quote
Old 07-28-2014, 11:25 AM   #7
robber grin
Registered User
 
Join Date: Apr 2012
Location: Sunny Youngwood PA
Posts: 462
Re: Later, bigger rear drum brakes???

Capt. Fab,

Great fan of your work.

Question - With the parts we have on hand we are considering a quick upgrade on a 63 C10 long fleet.

Can we used the 2.5 rear brakes on an 86 5-lug rear in conjunction with the 81 1/2 ton LD front brakes without creating brake-ratio or system balance issues?

If not would an adjustable proportioning valve take up any system balance issue?

Thanks,
Bob
robber grin is offline   Reply With Quote
Old 07-28-2014, 12:18 PM   #8
66Submarine
Registered User
 
66Submarine's Avatar
 
Join Date: Sep 2012
Location: Dallas, GA
Posts: 1,498
Re: Later, bigger rear drum brakes???

Just a note; the later six lug K10 brakes are actually 2-3/4" wide as standard.

FWIW, the GM "info kit" for an '81 lists the same front rotor diameter for the C10 with 2" brakes and the K10 with 2-3/4". http://gmheritagecenter.com/docs/gm-...olet-Truck.pdf
__________________
1965 C30 pickup 350/SM420/4.10's (daily driver) thread
1968 Impala 4 door sedan (future driver project) thread
66Submarine is offline   Reply With Quote
Old 07-28-2014, 01:50 PM   #9
robber grin
Registered User
 
Join Date: Apr 2012
Location: Sunny Youngwood PA
Posts: 462
Re: Later, bigger rear drum brakes???

Quote:
Originally Posted by 66Submarine View Post
the GM "info kit" for an '81 lists the same front rotor diameter for the C10 with 2" brakes and the K10 with 2-3/4".
So my intention of possibly using an 81 2WD 1/2 ton front cross member with it's LD 1" brakes / rotors combined with an 86 2WD 1/2 5-lug rear end may not be a factor for overall brake system balance.

I'd be using a Capt Fab bracket and 88-98 booster/master combination to power things on a 63 C10 long fleet we may be getting.

Thanks!
bob
robber grin 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 -4. The time now is 05:50 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com