4X4 will not engage

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Jan 7, 2002 | 07:01 AM

mjkindler

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Joined: Jan 2002

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From: Arona USA

4X4 will not engage

My friend has a 1997 F150 Extended Cab, 4.6L, 4 Wheel Drive. This morning his 4WD would not work. There were no lights or noises indicating that his transfer case had engaged. I suspect whatever controlls the transfer case is not working. Is this done through vacuume or electric motors. What might be the best way to troubleshoot this problem. Any help is greatly appreciated.

Jan 8, 2002 | 01:41 AM

knuckles

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4X4 will not engage

It's probably the shift motor. They're usually repairable. See the link below for more info. The link is to an Explorer site, but your truck uses a similar system & suffers from the same problems.

http://www.glue.umd.edu/~singletn/web/pages/tcase.html

Jan 19, 2002 | 06:54 AM

mfaphoto

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4X4 will not engage

Did your friend get this fixed yet? Anyway, I have had the problem of not engaging or not going out of 4X4 occassionally. I've found that stopping and putting it in reverse sometimes gets it to change.

Jan 19, 2002 | 11:15 AM

mjkindler

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From: Arona USA

4X4 will not engage

We finally got around to looking at it yesterday. He was convinced the it was the shift motor but i had my doubts. We only tore the motor down and checked the brushes/armature. They were dirty so we cleaned them and put the motor back in. It still didn't work! we couldnt find a decent schematic in Haynes or Chiltons but Haynes did mention that the 4WD was controlled electronically throught the GEM (Generic Electronic Module). Ten minutes od a disconected battery and the problem was solved. I never had this problem with my '79. My advice to everyone is don't overlook resetting the computer.

Jan 20, 2002 | 10:28 PM

Ultramagdan

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Joined: Feb 2000

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From: Kansas

4X4 will not engage

I lost my 4WD! And I was not happy.

But I know there are 2 places for it to mess up. I knew the transfer case motor was working by the clunk I got and the power I had in 4 low.

So that left the front dif.

I got the chance to crawl under the thing (while it was in 4WD) and checked the front drive shaft. Yup it was engaged. So I looked at the front dif. I could see the servo for the dif and simply moved it a little - a quiet SNICK was heard

.

Got back in the truck and Holy Moly I had my truck back!

Jan 21, 2002 | 03:02 PM

TEEJAY

Mountain Pass

Joined: Nov 2001

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From: NE PA

4X4 will not engage

Could you please give some more details about what you did after you found the driveshaft was moving but no 4wheel drive. I have the same problem on a 1997 LD f-250. Thank you.

Jan 21, 2002 | 04:39 PM

Ultramagdan

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From: Kansas

4X4 will not engage

With the truck in 4 Low, I put it in park. Crawled underneath and since the driveshaft did not move I knew that the transfer case motor was ok. But, there is a little servo on your front differential (top -right side) that is supposed to engage the axle. I assume the contacts were dirty or something and when I moved it by rotating it, I could hear the device engage the axle. It's easy to spot and has wires going to it. It was easy to rotate and didn't take much - maybe an 1/8 of inch.