Advice needed on driving a truck with a 2 speed rear axle

[hzl6cm]

I'm going to go look at a 76 Chevy 2 1/2 ton truck in about an hour and plan to drive it the 70 miles back home since it is too long to put on my trailer. Most of this driving is on the Interstate. The truck has a 4-speed transmission with a 2-speed rear axle. I have never driven a truck with a multi-speed rear axle and have some quick questions for anyone who has. Do you shift the axle on the fly or just shift it in high or low range before taking off and leave it in that range? Do you use the clutch when shifting the axle? Thanks!

[ehames005]

Usually when you are shifting a axle you go through the pattern then shift the axle into high range and go through the pattern again. As for using the clutch it is always a safe bet to use it. My Peterbuilt does not need the clutch except for take off but it does have modern air shifters the high/low split.

[PrivatePilot]

My only experience with a 2 speed rear axle is in large equipment, and in this case all that was needed to make the shift was to preselect the shift, and break torque - it does the rest.

(Edit: I missed the "2" before the "1/2" ton. )

[33m racing]

You say 2 1/2 ton like c60? If so, I'd leave the axle in low till you get in high gear, then shift the rear axle. You could use the clutch, or burp the throttle.

[Tanc Crusher]

The only one I ever drove went like this. You shift into 1st and diff in low. Then next shift will be still in first and shift rear end into high. Next shift is 2nd gear and rear end in low. But will all depend on the transmission and gear it has to whether you may be able to start at the bottom again and work through the gears again.

Brian

[wingman98]

have one like this for 30 years leave in low till you get to 4th thenshift to hig on rear xle actually I am wingmans dad> Ehames005 this a two speed rear axle not a trans as you are used to shifting on your large car You will not go back to 1 as this truck will have a muncie 465 trans.wind it up in 4th pull up on the red button on gear shift burp throttle slowly get back in to the gas and you should be inhigh on rear ax.If it is cold out it will take longer to shift.DO NOT RUSH IT

[Dakota Dave]

Just leave it in high and drive home. You should not need Low unless loaded. That should be a syncronised trany. use the clutch to prevent destroying them.

[iceroadman]

A two speed axle is more or less a kind of an overdrive.
Like others have said you only need it in high gear.

[justinsdad]

if you do shift it into high after 4th, dont go back to low until you stop, it can be kinda tricky to hit and the grinding sounds horrible when you miss.

[racer55]

I have found that it takes some experience when deciding to split shift,getting to know the range between the gears will let you know more about when to use hi or low on a given gear and load has a lot to do with it.

As mentioned earlier I ussually would accellerate under load when going from low to high,pull the shifter to high,let off the throttle and wait for the gear to shift and contine my accelleration.

To go from hi to low takes a bit more finness and can be done several ways,deccelerate and drop the switch then slowly rev the engine to try and match the speed(this is tough to do without being harsh on the rear end/drivetrain) or clutch and rev the engine a quick burp and let the clutch out still harsh but less so if you catch it at all.It is easy to miss gears this way and without experience it should not be used for engine braking.