4x4 will not engage

[Boosted6.4]

Not sure if this is the right area or not, if not could a mod please move?

Truck is a 2008 F350, with just the basic stuff, Tune, Intake, Exhaust. Lately the truck will not engage 4WD, it is not the hubs because there is no light coming on indicating the transfer case has shifted and locking them in manual doesn't change a thing. My problem is the transfer case not shifting. I have checked the switch with a multimeter for resistance and it all checks out. Checked all fuses related to the 4x4 system, along with both relays (Hi to Low, and Low to HI) With the key on engine off, I can turn the switch to 4HI and I hear the shift motor make noise on and off. It will hum for 3 seconds, stop, then hum again, it does this probably 3-4 times and won't shift the transfer case. If I try to shift it back to 2HI and then 4HI again, it will not try and shift again. Do I replace the shift motor? Where do I go from here?

Thanks, as always, all help is appreciated!

 

[Atsah]

When you lock them manually, you are over riding the switch so I would think it would be in 4x4 if you lock them by hand.. It sounds like the system is working but you have a vaccum leak somewhere that is not letting the hubs lock.. That would be my guess..

 

[Boosted6.4]

When you lock them manually, you are over riding the switch so I would think it would be in 4x4 if you lock them by hand.. It sounds like the system is working but you have a vaccum leak somewhere that is not letting the hubs lock.. That would be my guess..

Manually locked or not, the transfer case is not shifting to 4WD. Leaving them in auto or turning to manual doesn't engage it so I know it is not my hubs having a problem.

 

[Atsah]

If no lights come on then I would say you have a bad shift motor or other wiring problem..

 

[Stroked777]

i see your from Chicago, possibility could be that the shift motor is frozen up from water getting into it, what i would do is take the shift motor off and see if you can manually put it in 4x4 by turning the shifting shaft, if you can do it by hand then the shift motor is bad, if you cant do it by hand then something is wrong in the transfer case

 

[Boosted6.4]

i see your from Chicago, possibility could be that the shift motor is frozen up from water getting into it, what i would do is take the shift motor off and see if you can manually put it in 4x4 by turning the shifting shaft, if you can do it by hand then the shift motor is bad, if you cant do it by hand then something is wrong in the transfer case

I cannot shift the transfer case by hand, I can with a pair of big vise grips on it but it is still not easy. What could be wrong with the transfer case because it does go in and out of 4wd but it's not as easy as you say it is lol. FWIW, these issues came about in the -20 degree days we had a couple weeks ago so it very we'll could be a junk motor.


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[Stroked777]

When I said by hand I mean using a wrench lol. I should have specified. Just want to make sure it will engage manually. If it didn't then it would be an issue internally in the t case

 

[Boosted6.4]

When I said by hand I mean using a wrench lol. I should have specified. Just want to make sure it will engage manually. If it didn't then it would be an issue internally in the t case

Yup, with some visegrips it will go in and out of 4x4. Gonna pull the shift motor off tomorrow and check the hearing in it and go from there. Now I do not even hear the vacuum pump, running to lock the hubs. Grrr, very frustrating. Thank you for the help!


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[Stroked777]

Yup, with some visegrips it will go in and out of 4x4. Gonna pull the shift motor off tomorrow and check the hearing in it and go from there. Now I do not even hear the vacuum pump, running to lock the hubs. Grrr, very frustrating. Thank you for the help!


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No problem man. Hope it all works out, remember test stuff to see if it's actually the problem, don't throw parts at it

 

[GatorBaitR6]

Not trying to be a smart ass... but find the solenoid and hit it with a hammer... not to hard but enough to jar things... seen this happen multiple times in New England... Damn things just get frozen... Saved many guys lots of money lol...

 

[Boosted6.4]

Not trying to be a smart ass... but find the solenoid and hit it with a hammer... not to hard but enough to jar things... seen this happen multiple times in New England... Damn things just get frozen... Saved many guys lots of money lol...

If I take it off and try and spin the motor by hand, will that damage things? I will try giving it a whack or too to loosen things up before I tear into this truck after class. Thanks for the help!