| |
Click on image for the lowdown. 
====
| | | Forums66 Topics128,165 Posts1,056,987 Members48,458 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Jan 2000 Posts: 734 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 734 | Saw it done years ago during my 3.55 installation (by a seasoned old car mechanic). Ran a piece of brown paper bag through the ring and pinion to check how things meshed. Must've been good, because I've got many thousands of reliable miles on that diff. Anyone know the details on that procedure? Is it the magic thickness for proper backlash or something?
Matthew 6:33 1952 Chevy 1/2-ton 3100 Late '55 235/SM420/torque tube 3.55 Dalton Highway survivor (using original 216) www.truckwithaheart.com | | | | | Joined: Feb 2004 Posts: 29,866 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,866 | A $25.00 magnetic base dial indicator from Ebay or Harbor Freight Tools is a much better and more accurate way to check gear backlash. I usually try to get to .010"-.015" if possible. The tooth contact pattern, checked with white lead paste or Prussian Blue is at least as important as backlash, maybe more so.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Aug 2004 Posts: 1,418 ODSS Lawman | | ODSS Lawman Joined: Aug 2004 Posts: 1,418 | I agree with both of Jerry's comments. Not sure what the bag can do other than make a mess. Gear lash is important but a central gear contact pattern even more important.
SWEET Sergeant At Arms: Old Dominion Stovebolt Society BUNS?!?!?!Where we're going, we don't need no buns.....1950 GMC 450 1951 Chevy 1/2-TonThe GreenMachineIn the Stovebolt Gallery | | | | | Joined: Jan 2000 Posts: 734 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 734 | Any idea why the manual recommends such a tight spec at .005-.008? Even Patrick's old instructions say no tighter than .008-.012.
Matthew 6:33 1952 Chevy 1/2-ton 3100 Late '55 235/SM420/torque tube 3.55 Dalton Highway survivor (using original 216) www.truckwithaheart.com | | | | | Joined: Feb 2004 Posts: 29,866 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,866 | New gears in the 40's and 50's had a habit of "wearing in" a little, so the factory setup took that into account. Newer production items probably have the benefit of a little more accurate manufacturing, plus better heat-treating, so they can be set up to the tolerances the gears ended up with after a run-in period.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Mar 2008 Posts: 374 'Bolter | | 'Bolter Joined: Mar 2008 Posts: 374 | I know my grandfather talked about doing it this way with newspaper(20s, 30s and 40s). Old timers could set the lash by reviewing the prints on the newspaper. | | |
|
|
| |
