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 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-24-2017, 10:29 PM   #1
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
replace 72 rear with a 68 drum to drum on my

I'm going to swap out my complete 72 posi rear thats making a lot of noise with a 68 drum to drum posi i know they are a couple inches shorter end to end than the 72 is there anything besides the brake line plumbing that will be an issue that i should be aware of ....
zicc1835 is offline   Reply With Quote
Old 11-24-2017, 10:32 PM   #2
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

doing this on my 72 c10 rear came out of a 68 burb
zicc1835 is offline   Reply With Quote
Old 11-24-2017, 11:16 PM   #3
leddzepp
Moderator
 
leddzepp's Avatar
 
Join Date: May 2007
Location: Southern Cal
Posts: 20,022
Re: replace 72 rear with a 68 drum to drum on my

The brake lines will plumb right up with a little bending. I did the opposite and put a 72 rear in my 68.
__________________
1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed.

1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck.


RIP ElJay
RIP 67ChevyRedneck
RIP Grumpy Old Man
RIP FleetsidePaul
leddzepp is offline   Reply With Quote
Old 11-24-2017, 11:50 PM   #4
CG
BlahBlahBlah
 
Join Date: Feb 2002
Location: Wa.
Posts: 19,992
Re: replace 72 rear with a 68 drum to drum on my

Maybe I miss understood the process you are going through. To me the obvious difference is 5 lug to 6 lug unless you are doing something with the axels Im not getting.
__________________
… … … … … … … … ... … … … … … … … … … … …
CG is offline   Reply With Quote
Old 11-25-2017, 12:28 AM   #5
randy500
Account Suspended
 
Join Date: Jul 2016
Location: Tacoma, WA
Posts: 6,873
Re: replace 72 rear with a 68 drum to drum on my

Why not sell the 68 posi rear and use the money to fix the one in your truck.

Have you checked the pinion nut? They get loose and make a lot of noise, mostly on decal I believe. Its not the best solution but usually you can tighten the pinion and it will be lots better.
Posi additive, if its a crunching noise.
randy500 is offline   Reply With Quote
Old 11-25-2017, 08:41 AM   #6
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

thanks everyone . Had this used POSI unit ""professionally" installed 3 years ago bearings seals axle seals the whole enchilata , I had 2 i bought from board members, we picked what we thought was the best out of the 2 from the get go iI had the clunking going on pretty significant making the turns felt like the rear was going to jump off the frame . I replaced the gear oil put the additive went with the purple stuff etc. Some improvement was noted but still significant clunking on the turns only, so now i have about 15k on it and i been hearing some different noises and feel i slight vibration coming thru i believe the drive train up to my hands on the steering wheel So i have a few options the easiest is to make the swap Im back on the road again pretty quick ...I have 6 lug rallies so im covered there , I get to clean ,rattlecan rebuild , complete brake job , and test drive the 68 rear this came out of a driver so we have some history. So Like Paul Harvey said....." now you have the rest of the story.".... as usual I appreciate the comments will keep all posted with my results
JZ
zicc1835 is offline   Reply With Quote
Old 12-18-2017, 10:56 PM   #7
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

UPDATE
I decided to use this open rear I was saving for another project cleaned it up new brakes ,lines, Ebrake cables installed under my 72 and very pleased ..now i want to take that 68 posi unit and set that up for my other project (69 short bed fleet) convert to 5 lug axles and i may as well do the disk conversion while Im at it. any recomendations on axles / disc conv.? Im not sure I want to put big brakes on because I would like to stay with 15 inch rallies I know the rear is more narrow so I can put some fatter tires with the right back space without tubbing I already have 5 lug drop spindles for up front ...
Attached Images
   
zicc1835 is offline   Reply With Quote
Old 12-22-2017, 10:32 AM   #8
ScottH
Senior Member
 
ScottH's Avatar
 
Join Date: Sep 2002
Location: Hampstead, NC
Posts: 8,190
Re: replace 72 rear with a 68 drum to drum on my

Hey Jess, if u decide to sell the 68 posi keep me in mind.

A very merry xmas & happy healthy new year to u & urs!

Scott
__________________
1963 C10 swb fleetside
1966 GMC G1000 Handi-bus (future project)
1955 Chevy 2 dr. wagon
ScottH is offline   Reply With Quote
Old 12-22-2017, 11:02 AM   #9
GASoline71
"I ain't nobody, dork."
 
GASoline71's Avatar
 
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,948
Re: replace 72 rear with a 68 drum to drum on my

If you use 71-72 axles in a 67-70 housing you will have problems as the axle shafts are too long.

Gary
__________________
'cuz chicks dig scars...

My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread.

The Rebuild of Creeping Death after the wreck

Quote:
Originally Posted by LONGHAIR View Post
I would never rebuild a 305.
Quote:
Originally Posted by prostreetC-10 View Post
I love using vacuum gauges as part of the carb tuning process. I hook the gauge to the inside of my garbage can and leave it there.
Quote:
Originally Posted by Marv D View Post
Remember Murphys 2nd law of mechanical relationships... "OPPOSING COMPONENTS ATTEMPTING TO OCCUPY THE SAME SPACE, AT THE SAME TIME, GENERALLY END UP OCCUPYING ADJOINING SPACE AT THE BOTTOM OF THE OIL PAN"
Quote:
Originally Posted by cableguy0 View Post
Its cheaper to listen to advice given when you ask for help than it is to ignore everyone and wait for carnage.
GASoline71 is offline   Reply With Quote
Old 12-22-2017, 08:40 PM   #10
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

Quote:
Originally Posted by ScottH View Post
Hey Jess, if u decide to sell the 68 posi keep me in mind.

A very merry xmas & happy healthy new year to u & urs!

Scott
thanks Scott thank you Merry Christmas to you and family too Im gonna hold on to this rear buy 5 lug axles ( the right length ) couple hundred might do the rear disc conv. while Im at it..... ill keep you posted
zicc1835 is offline   Reply With Quote
Old 12-24-2017, 02:33 PM   #11
Average Joe
Registered User
 
Average Joe's Avatar
 
Join Date: Feb 2009
Location: Southern Oregon
Posts: 1,352
Re: replace 72 rear with a 68 drum to drum on my

Quote:
Originally Posted by zicc1835 View Post
thanks Scott thank you Merry Christmas to you and family too Im gonna hold on to this rear buy 5 lug axles ( the right length ) couple hundred might do the rear disc conv. while Im at it..... ill keep you posted
Have you thought about having a good machinist redrill your axles to the bolt pattern you want? A friend did this on his '64. Went from 6 on 5.5 to car pattern 5 on 4.75. It worked great and was cheaper than new axles.
__________________
1967 C10 Suburban 454/TH400/3.07's

An Average Joe and His 'Burb:
http://67-72chevytrucks.com/vboard/s...d.php?t=775843
Average Joe is offline   Reply With Quote
Old 12-26-2017, 11:21 AM   #12
CC69Rat
Registered User
 
CC69Rat's Avatar
 
Join Date: Jan 2011
Location: Chattanooga TN
Posts: 6,210
Re: replace 72 rear with a 68 drum to drum on my

Early axles are 30.5 in long measured from the end of the splines to the wheel mounting surface. Late axles are 31 5/16 in this same spot. Just an easy way to tell if you buy them used, and/or to make sure you buy the right ones.
__________________
Chad

1967 C10 SWB - Project Savannah - 6.0/4L80 *Currently underway*
1968 C10 SWB - TOTY 2018, 50th Anniversary Tribute Project * Sold * Pride and Joy
1986 Silverado Short Fleet - Scarlet *Sold*
1985 Silverado Short Fleet *Sold*
2022 Jeep Gladiator Mojave
2001 Jeep Cherokee XJ 4x4 - Lifted, Built
1992 Jeep Cherokee XJ 4x4 - Lifted
2013 Honda Accord EX-L v6 Coupe 6spd (wife's ride)
CC69Rat is offline   Reply With Quote
Old 12-26-2017, 05:34 PM   #13
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

Quote:
Originally Posted by Average Joe View Post
Have you thought about having a good machinist redrill your axles to the bolt pattern you want? A friend did this on his '64. Went from 6 on 5.5 to car pattern 5 on 4.75. It worked great and was cheaper than new axles.
"key word here is good machinist" im going to see if i can get that done and what the cost is thanks for the info sounds like a good option
zicc1835 is offline   Reply With Quote
Old 12-26-2017, 05:38 PM   #14
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

Quote:
Originally Posted by CC69Rat View Post
Early axles are 30.5 in long measured from the end of the splines to the wheel mounting surface. Late axles are 31 5/16 in this same spot. Just an easy way to tell if you buy them used, and/or to make sure you buy the right ones.
when you say late, you mean 71-72 ? ,I have some options to look at ..before I shop them new im going to pull and measure thanks for that info
zicc1835 is offline   Reply With Quote
Old 12-29-2017, 11:33 PM   #15
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

ACT II
clean this up pull the axels and have it blasted
Attached Images
    
zicc1835 is offline   Reply With Quote
Old 12-29-2017, 11:40 PM   #16
zicc1835
Senior Member
 
zicc1835's Avatar
 
Join Date: Mar 2011
Location: Hanover NJ
Posts: 4,252
Re: replace 72 rear with a 68 drum to drum on my

I need some recomendations on rear disc conversion the truck im going to use this rear on will be an automatic ....but i still want e brakes i like the drum type in the rotor any suggestions would be helpful
zicc1835 is offline   Reply With Quote
Reply

Bookmarks


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 11:25 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com