Chevy IFS questions

[BBsound]

I have a 96 Tahoe that does not see too much off road, but hopefully that will change:jumping:

Anyway my question pertains to the front axle engagement. The few times I have put it in 4x it has worked fine, sand on the outer banks, some mud etc. But I was playing with it tonight climbing a bank from the street to my backyard. I was crawling up at an angle until the right rear tire started slipping (no G80). The left rear was compressed and both the front tires were solidly on the ground (partially up the bank). So I put it in 4lo, because I wanted to see if it would idle up. I could not get the front end to pull the truck up!! all the truck would do is spin the right rear. I believe that means the front end was not engaging, because neither front was turning.

Do I need to upgrade my actuator, or get a cable actuator kit?

 

[DaveInDenver]

I'm far from a Chevy IFS person, but it's pretty basic. There's some sort of actuator that engages the front axle and another that shifts the transfer case front drive output. In the case of old trucks those were locking hubs and a shifter. Now it's usually a vacuum solenoid and an electric motor. From your post I'd gather that you probably know this, though. My point is that the reason this stuff often fails is actually lack of use as often as anything. My first step would be to check fuses, wires, hoses, motors and solenoids, clean and lube as necessary. Then if that does not fix it, like Shovel says, replace what might be bad and then remember to once a month engage 4WD to keep things from freezing up.

 

[ujoint]

Does it work normal on flat ground? It may have been because the truck was already in a "bind" that everything wouldn't engage properly. Try putting it in 4low before you climb the hill.

oh yea, and it's time for a solid axle swap!!!

 

[BBsound]

I will have to play with it some more

Dave it is a manual case and has some type of thermal axle engagement. I have heard of the thermal system having problems, and chevy does offer an upgrade.

as far as the binding, I did play with it some, hitting neutral, rolling back etc.

 

[DaveInDenver]

Dave it is a manual case and has some type of thermal axle engagement. I have heard of the thermal system having problems, and chevy does offer an upgrade.

Gotcha. I notice that there's this thing called a posi-lock that replaces it, too. I would think the factory electric shift might be preferred to a exposed linkage and cable. Seems that a little cable like that might have rust and mud issues, but then again so would an electric motor.

What was so wrong with manual hubs, anyway? ;-)

 

[njtaco]

IIRC, I paid less than $100 for the actuator from the dealer...and it failed again 2 years later.

It is easy to diagnose the electrical side, just check for 12V at the connector, in 4wd, ignition on, but not running.

I think (not sure) you can check the actuator out of the truck with 12V, and measure the distance the piston travels as it heats up.

If that checks out, check them together, corrosion in the wiring may drop the voltage too much to heat the actuator. Check every connection, and follow the wiring with a digital VOM (both + and -).

I considered the "cable upgrade" but returned it before I installed it, as I had concerns about it surviving the salt here on the shore, and salt on the roads in the winter. It was about $40 more than the dealer part, plus shipping, less sales tax.

Let us know how you do, and good luck.

 

[BBsound]

thanks, that cable setup does look a little hokey.

after all, a solid axle would have good ole' manual hubs......

:Mechanic:

 

[TheRoadie]

What was so wrong with manual hubs, anyway? ;-)

Soccer moms hate manual hubs. Break fingernails.

 

[big sky trapper]

After owning 5 of these trucks in the last 12 years, plus a few suburbans. The front axel actuater is a PITA, even the updated quick engage one. If you wish to keep it more OEM when yours does go completly out, spend the few extra bucks for it. I think there still a dealer only item, and around 180.00 and require a little extra wiring mods to install (the quick engage actuater bypasses the the time delay relay and is powdered from the T case sensor direct).

The posilock cable converter is an outstanding conversion for the chevys. I've installed two of them myself, and looking at a third, very well thought out. Theres no worries about it getting hit by anything. If something where to get that far up under the axel theres going to be more damage than just the conversion cable parts. (If your really concerned about front parts damage check the salvage yards for the full aluminum front skid plates from an earlier Z71...later models went plastic)

I kinda perfer the posi lock, one added benifit is it will allow 2W low. if ever needed. They retail around 140.00 and take about an hour and half to install.


Convert to a solid axel.....yeah right...might as well buy a rig with one allready under it....