2002 Sportange No 4WD Troubleshooting

Hi! I've had trouble with the vacuum hoses before and replaced one.

Now there is no 4wd and I've started to troubleshoot with these symptoms:

1. Each front side when jacked up with the motor running and in 4WD (manual transmission in neutral!) locks up when in 4wd and free wheels when in 2wd; ie vacuum system seems to be working.

2. Still no 4wd when actually driving

What could be wrong. 45K mi, no odd noises, car generally in great shape.

Mike

...well I'm not convinced....and it is better that way, cause if hubs work properly, then what is left is much more complicated....T-case (?)...and I do not think this would have been broken without you being aware of it....
Hubs can apply while car idles and throttle is almost closed, providing high manifold vacuum but as you drive and depress throttle, vacuum lessens and may be then the hubs disengage, so, as this is a very common scenario, I still suspect you have a vacuum leak at the hubs/bearing .

ONe definite way to test this option would be to do what KIA did to activate failed hubs: remove and dismantle the hubs by removing the clip and remove all parts keeping them in proper order...then reposition the spring on the other side of the piston:NOrmally the piston spring returns the hub to unlock, but then it will keep it engaged instead; this will positively keep the hubs locked and then you still have 2wd or 4wd through the T-case, but the shafts will rotate all the time and of course, this uses more fuel, but you will have a definite idea on the matter.

....another test, may be before the one above, would be to unplug the vacuum to hubs www.geocities.com/lmp4203/kiasport/vacsol.jpg ,(hubs will not engage) ; block car from moving at both front wheels, jack one or both rear wheels, run the negine, engage 4wd, shift in 1st gear, release clutch...and of course, rear wheels rotate and the front driving shaft between T-case and front differential should rotate; try 2wd and 4wd just to be sure....this gives another view of the situation

thanks for the quick reply i sense you know what you say!

will ponder/test this. while also pondering warn manual hubs!

mike

Yeah I have the Warn automechanical...I like them.
IN case you lock the front hubs as an interim solution and you live in snow area, avoid driving in 2wd in slippery condition as the drive train drag from undriven front wheels is a high risk of loss of control. I talk of experience....and this applies to manual hubs too....

Thanks for the "WARN"ing, I was going to go with the Warn Manual because someone said they are more reliable.

I'm going to replace the vacuum tubes with urethane tubing today to give it one more chance, if that doesn't work, Warn Auto.

Mike

OK mike..installation instructions for the autos: : www.geocities.com/lmp4203/kiasport/hubinstall.pdf
..also there are special precautions using the automechanical. Takes some time to explain...come back when ready...

Well the urethane tubing did it! Thanks for the reference, I might need it.

Best,

Mike