has anybody used this system? i don't think the price is too bad at $150.00. the thing i am curious about is the 2-lo feature. it will give you 4-lo torque with bind-free steering. i know that running in 4-lo on the road is hard on the drivetrain, but what about 2-lo? am i right in assuming it is ok since the axles wont be fighting each other?


i am curious because i pull grain wagons with my truck at low speeds, 20-25 mph, 30,000+ pounds. what is harder on the tranny and drivetrain, running in 2-hi, 2nd or 3rd gear, or put it in 2-lo and get it into fourth gear and maybe even lock the torque converter up?


i know hundreds of farmers that pull wagons with there trucks and dont ever have problems, im just curious if this 2-lo concept would work.

The short answer is yes. 2-lo will work, but in 4th you're overdriven .25 , thrid would be 1:1 drive.


Remember that in 4wd, the rear get's 50% input, front 25% input and 25% dissapears into the transfercase, drivelineand tires.Edited by: quantum mechanic

so third would be good? is it good to get the coverter to lockup or does it not matter at that speed? if i use 2 hi i wont ever get it lockedup.

If you have a TCC locker go for it above 1800 rpm, right?

Why not just put a switch in series with one of the wires to the electric actuator? Then it is still automatic unless you don't want the front locked.


It would be cheaper too.

The actuator wears out eventually. There's also a stepper gear actuator replacement from GM.

Didn't the 97's come with the stepper motor?


Even if the old thermal actuator is still working, it is well worth the money to replace it.


They are only about $100 including the harness. When upgrading, would be the perfect time to install a lockout switch. Just put it in series with the brown wire that needs to be connected.

Posi Lok 4x4 is a step up in my book for the front axle problem that GM has produced for themselves, the electric Thermal Solenoid is a delayed device that works from 11 seconds to never and you never know when it is not going to work again, Electrics have there place and this is not one of them, Having the capability to use 2-lo in your case would be nice. Just a small story about GM's great solenoid,
have a customer here in PA, his GM truck was in 4x4 and it was working, he parked on ice, shut the truck off, and guess what, the solenoid disengaged, he came back out to move his truck and he sat and spun the rear tires, he had to be pushed off the spot to get the front end solenoid to reengage itself. He got Posi Lok 4x4 the next day.
Brakeshoe

I have a short article on replacing the heater one with the servo style....


88-UP C/K ACTUATOR UPGRADE (http://www.uscom.com/~hoot/cars/actuator_upgrade/GM_TRUCK_4X4_ACTUATOR_UPGRADE.html)

Any idea why he had to splice the brown wire into the cab? We were talikng about a switch, the switch would go on the brown wire connection in the cab, yes?

The new actuator has the extra wire that needs to pick up the signal from the brown wire. I chose inside because it runs up in there... I'd rather have a splice in the cab than underneath exposed to weather.

The replacement servo actuator uses no switch. It engages like the old one. This is not the Posi-Lok setup.Edited by: hoot