| |
Click on image for the lowdown. 
====
| | |
1 members (baldeagle),
87
guests, and
3
robots. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,037 Posts1,055,467 Members48,424 | | 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 2010 Posts: 384 Shop Shark | | Shop Shark Joined: Jun 2010 Posts: 384 | I removed the speedo gear behind the speedometer because it was jammed completely and ate speedo cables for breakfast. The vacuum hose is plugged in the cab and the speedo cable mounts directly to the speedometer without the vacuumgear in between.
Can someone help me to think here. Even though the vacuum speedo gear is not there the speedo needle DROPS in speed when I go into high gear mode, how the heck can that be ?!?!? If I go low 4 and it shows , let's say 40 mph and go inte high it drops to 30 !?!?!
Of course I am missing something here, but I thought all the high /low gear did was with vacuum to change the rear axle ratio, nothing in the gearbox, right ?
Confused
My Chevy Viking 1959Ulf Hedlund. Eskilstuna. Sweden [email protected]Also: Ford Galaxie 4 dr 1959 Ford Custom 4 dr 1964 Ford Mustang GT 2005
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | The gearbox in the cable changes the speedo speed when you shift the 2 speed rear end. When rear end ratios change the speedo is not right. This gear box compensates for it.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy lastchancetowing, when you shift the rear axle from low range to high range the driveshaft turns at lower rpm to maintain the same speed you were doing in low range, hence without the ratio adapter the speedometer will read slower, reflecting the lower driveshaft rpm in high range, hope that helps. | | | | | Joined: Jun 2010 Posts: 384 Shop Shark | | Shop Shark Joined: Jun 2010 Posts: 384 | Thanks 3B, that explains it. Easy as hell  The vacuum part is okay and works fine. It was just messy and stuck. Have it running freely now, so I will just put it back in again and see if it works fine then.
My Chevy Viking 1959Ulf Hedlund. Eskilstuna. Sweden [email protected]Also: Ford Galaxie 4 dr 1959 Ford Custom 4 dr 1964 Ford Mustang GT 2005
| | | | | Joined: Nov 2010 Posts: 1,159 Shop Shark | | Shop Shark Joined: Nov 2010 Posts: 1,159 | Hey,Ulf! Off topic,but how did the exhaust manifold work out? Glad you posted this,because I have a plugged vacuum line,(under the dash), in my truck,too! I couldn't think of where the thing went,since it has electric wipers. Never even thought about the 2-speed! My speedo. doesn't work. I "gauge",by the "lines" on the road. Too many years driving over-the-road,I guess. I would still like to get mine fixed,but have no idea who may have working parts for the T.F. 2-tons. Nice to "hear" from you,again! Take care! | | |
|
|
| |
