1978 Chevrolet pickup won't go into 4 low Used to be full time four wheel drive

SOURCE: heater core on a 2003 Chevrolet pickup 4 wheel drive crew cab

if you have air conditioning you will need to take it to a garage and recover the r134, you will need to remove the dash to allow you to remove the heater box, it's an ugly job, I've done a dozen or so and can do it in about 6 hours now, the first time it was closer to 11 hrs, good luck

SOURCE: part time four wheel drive

This is due to the type of differential used.

I suspect this is a limited-slip differential, which locks up when one set of wheels starts to spin.

You can get problems with these when they age. The simplest fix is to change to a lighter fluid, as this will reduce the friction effect - thus giving you lighter steering and saving tyre wear.

You may as well change fluids in all diffs.

Marvin

• 85242 Answers
• Posted on Nov 20, 2009

SOURCE: I have a 1988 chevrolet cheyenne 1500 pickup with

this can be cuased by a stuck transfer case, this can be cuased by dirty worn out fluid, has the transfer case ever been serviced? if not change the fluid and drive it for a day ofr so this will free up the transfer case clutch. It uses DEXRON 6 ATF

Dennis Mulford

• 1055 Answers
• Posted on Feb 24, 2010

SOURCE: 1978 Chevy pickup four wheel drive shifter will

linkage is bent or fork is broke in transfer case