No 4x4 '95 Chevy 2500(LD)

Caver Dave

Caver Dave

Just holdin' it down here in BFV
Moderator
Joined
Mar 10, 2005
Location
Hooterville (24171)
A coworkers says his P/U isn't engaging in 4x4, which is very obvious in wet grass with (6-lug) SF "14B" w/ G80... :rolleyes:

He says the lever does move into the 4x4 positions, but gets NO orange light (near shifter), indicator (dash), & no engagement of the front axle. He indicates it hasn't been worked on since working correctly... several years ago.

I have limited knowledge of these trucks, but figure it's got to be a linkage related(?) since there's no solenoid/actuator involved, the driveshaft is there, & the front diff isn't exploded (seems that'd be obvious, even for a PhD? :lol: )

What to look for?
 
The actuator in the front diff is bad. I've had several of these trucks. If his has the thermo actuator it's worth the extra $ to upgrade to teh electric one.
 
barnee said:
The actuator in the front diff is bad. I've had several of these trucks. If his has the thermo actuator it's worth the extra $ to upgrade to teh electric one.
Click to expand...

An actuator in the front diff of a manually engaged transfer cased truck?
What purpose does it serve?
Hows does (assuming thermo =) temperature affect it's operation?

What kinda coin is he looking at for the upgrade?

:beer:
 
If the 4wd fuse is blown, it is more than likely the actuator. It engages the passenger axle to the rest of the diff.
The thermo actuator has nothing to do with the temp. When it is engaged it heats up and expands, pushing a collar on the axle to engage the diff. There is a newer style, that is a small electric motor that does the same thing. You could also go with a "posi-lock" manual cable system.

The thermo replacement is normally $80 to $100 at Auto Zone.
 
Blue CJ said:
If the 4wd fuse is blown, it is more than likely the actuator
Click to expand...

And if the fuse isn't blown? Prone to still being a crapped actuator?

Blue CJ said:
It engages the passenger axle to the rest of the diff.
The thermo actuator has nothing to do with the temp. When it is engaged it heats up and expands, pushing a collar on the axle to engage the diff.
Click to expand...

No surprised they'd use a system like this... smells of a "trip to the stealership"! :lol:
Guessing it's insurance against having it locked and driving down the (dry asphalt) street?

Blue CJ said:
There is a newer style, that is a small electric motor that does the same thing. You could also go with a "posi-lock" manual cable system.
The thermo replacement is normally $80 to $100 at Auto Zone.
Click to expand...

Any guesstimation on the cost of the electric actuator?
How hard is the "posi-lock" mod & cost?

Thanks guys! :beer:
 
I've never seen a bad thermo actuator that didn't blow the fuse, but anything is possible.

All of the parts you would need are available without going to a dealership.

The system came about so the auto manufacturers could have on the fly 4x4 and not have to deal with manual locking hubs. It lets the front diff disengage (spider gears are still turning in 2wd) without turning the front driveshaft and t-case. The vacuum operated system (central axle disconnect) on Dodge, Jeep, etc. is essentially the same thing.

The electric actuator is about $100 to $120, but you will also need a conversion wiring harness, about $35 to $45.

The Posi-Lok complete kit is about $160 to $180. It is a simple install. Routing the cable into the cab is the most aggravating part.

The cheapest and easiest fix is to replace with another new thermo actuator, also the most unreliable.

All of these parts are available on the internet.
 
Back
Top