Easy tips

How can I tell if my GMC Jimmy has 4WD?

How can I tell if my GMC Jimmy has 4WD?

Check the front axle coupler sensor (wires to it) by unscrewing and pushing the ball in) which tells the TCCM or 4wd computer that the axle is coupled for all 4wd modes. 4. Check the similar sensor on the transfer case for the encoder motor that engages the low gear for 4LO. 5.

Where is the actuator on a GMC Jimmy 4WD?

1. Check the vac hoses from the untake over to the reservior and T off to the actuator under the battery tray. 2. Chack the actuator (crawl under the pass side front) by looking /listening to see it the cable pulls the axle coupler. 3.

How does transfer case work on GMC Jimmy 4WD?

For 4Lo the transfer case has an encoder motor that is on the transfer case that engages a lower gear when you stop, put trans in neutral and push 4 lo and a clunk is heard. Again a sensor on the transfer case to tell TCCM it is engaged. Hope that wasn’t too confusing.

What to do if your GMC Jimmy has vibration?

Check/change the front and rear differential gear oil and the pinion seals can leak there too. Vibration must be traced to type – tire or drive train. If the U-joints are original and have no zerks on them they may be loose. Check the front wheel bearing and tire balance.

Is there a problem with my GMC Jimmy 4WD?

If you have 4 button Autotrac the transfer cases sometimes have clutch problems and use special blue syn fluid to smooth out. The Bang comes going back to 2WD. When going into 4WD, you hear the clicking of the relays and feel it shift and hear a low whine/rumble. 4LO seems to be working as advertised.

Where are the 4WD lights on a GMC Jimmy?

2.When selecting the Auto 4WD button the Auto light starts blinking and instead of being in the 4WD “on demand” mode it goes directly into 4WD. 3.No code or check 4WD lights appear on the dash.

For 4Lo the transfer case has an encoder motor that is on the transfer case that engages a lower gear when you stop, put trans in neutral and push 4 lo and a clunk is heard. Again a sensor on the transfer case to tell TCCM it is engaged. Hope that wasn’t too confusing.

1. Check the vac hoses from the untake over to the reservior and T off to the actuator under the battery tray. 2. Chack the actuator (crawl under the pass side front) by looking /listening to see it the cable pulls the axle coupler. 3.

Check the front axle coupler sensor (wires to it) by unscrewing and pushing the ball in) which tells the TCCM or 4wd computer that the axle is coupled for all 4wd modes. 4. Check the similar sensor on the transfer case for the encoder motor that engages the low gear for 4LO. 5.

Why does my GMC Jimmy make Rev 2 / 4 noise?

That rev/2/4 thing is caused by an internal broken Sunshell and the neck breaks off all at once usually from drivetrain shock as hard 4wd or towing. Noise could be many things as u-joints, hubs, brakes, tires etc so need to look under it and start checking. Also look at the transfer case fluid and change every 50k as well as trans fluid/filter.

What kind of fluid does a GMC Jimmy use?

Finally, check the front diff fluid and make sure its full and the transfer case requires blue autotrak II GM fluid – this has a GM bulletin on it so do not use Dexron red in it due to the clutch packs in yours.

That rev/2/4 thing is caused by an internal broken Sunshell and the neck breaks off all at once usually from drivetrain shock as hard 4wd or towing. Noise could be many things as u-joints, hubs, brakes, tires etc so need to look under it and start checking. Also look at the transfer case fluid and change every 50k as well as trans fluid/filter.

Where is the VAC line on a GMC Jimmy 4WD?

Vac line runs from the intake by the PCV hose, over to the drivers side fender/firewall where it Ts to the vac reservior can in the fender and to the 4wd and heater (hard plastic one). Then to that switch on the firewall so check all lines and replace 5/32 (and 7/32 for larger line) vac line.

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Ruth Doyle