| |
Click on image for the lowdown. 
====
|
| |
0 members (),
54
guests, and
2
robots. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,049 Posts1,055,743 Members48,426 | | 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: Jun 2009 Posts: 98 'Bolter | | 'Bolter Joined: Jun 2009 Posts: 98 | How do you dissasemble the 2 sp vacuum shifter?
Or better yet, where can I get a rebuilt one or at least parts to rebuild mine?
Most likely the rubber is kaput.
Thanks
I had no luck in the archives even tho It I saw a post about it a year ago
Thank you, John | | | | | Joined: Apr 2007 Posts: 1,038 'Bolter | | 'Bolter Joined: Apr 2007 Posts: 1,038 | The shop manual has a complete description of the repair of these units. The only thing that would wear out, short of being trashed, is that rubber diaphragm. GM used the same diaphragm in later (circa '70-71) vacuum shifters. I was able to get two new ones from a local GMC truck dealer by perusing the old chevy manual site, finding the part number, and going through my local Chevy dealer. If you do that, they may tell you that the part number is obsolete. Ask them to use their parts locater computer which was succesful in my case. The Chevy dealer sent me across town to the GMC dealer.
I don't have the part number where I am now, but can get it for you later this week when I will be at my shop.
Kent | | | | | Joined: Jun 2009 Posts: 98 'Bolter | | 'Bolter Joined: Jun 2009 Posts: 98 | That would be a big help. In the meantime I`ll try to get mine apart.
Thank you Lightholder. | | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | Group 5.635 "Vacuum Shift Diaphragm" part number 3847058. Still a good number. Mike B  | | | | | Joined: Apr 2007 Posts: 1,038 'Bolter | | 'Bolter Joined: Apr 2007 Posts: 1,038 | Mike B has got the right number. The box mine came in also has the same number with a zero in front (03847058) so you might try that if the other doesn't work when you order it.
To dissasemble, remove vacuum hoses, then remove the ten small bolts at the periphery. The outside cover should come off. The diaphragm is between two plates. Put a box wrench on the shaft behind the diagphragm (towards the differential carrier) and one on the outside to remove the plates and diaphragm. Replace the diaphragm with the same orientation as the original and that should do it.
Kent | | | | | Joined: Jun 2009 Posts: 98 'Bolter | | 'Bolter Joined: Jun 2009 Posts: 98 | Mine is different. No bolts, just a crimped rim. Probably not original to the truck but stuck on afterwards.
I talked with my International Harvester navistar parts guy and he said bring it up and maybe he could match up something.
In the meantime I have my trucks rear in perpetual high range and its decently roadable.
If I find a compatible vacuum shifting unit I`ll post the part numbers so it may help others.
Thanks to all
John | | |
|
|
| |
