The Stovebolt Site Forums The Parking Lot Big Bolts 2-speed rear vacuum actuated lever

I'm repairing the vacuum actuation assembly on a 58 Chevy two speed rear (GM, not Eaton). I pulled the entire housing off the axle in order to check that the lever mechanism is operating freely. It is. Could someone who is familiar with this axle tell me if 'lever up' is low or high range? Thanks!

Normally with the lever up you should be in high speed. However if the vacuum hoses get switched around you would be in low. IRONICALLY I have a 1958 C 60 Viking truck and the hoses are switched so I am in low with the lever up.

If it's a timken axle the lever up is high gear on my 1955 first series 6400. Might be different on a 1958 but it's probably the same

Yes, up is High range on the Corporate Chevrolet rears...

You never park a 2-speed in High range because gravity is pulling the shaft down and if it gets half way due to vibrations or whatever the rear can slip into neutral and allow the truck to roll free...not a good thing!

Mike B

Thanks for the great responses....my concern was that the hoses had been switched over time, as there was evidence that someone had fooled with them.... but they are right (up for hi) and I jacked up one side of the rear to check this. Mike B, I discovered that there is indeed a 'neutral' position between hi and low, and I can see how easy it would be to slip into this position. This truck had been in low range for many years because the vacuum diaphram was torn and gravity had brought the lever down to the lower position. Now that I have put the truck on the road for the first time in at least 35 years, I have discovered a new problem (performance in hi range). I'll post on that separately.