Control Trac : Normal Operation (Grabbing)?

[stilbo]

Been away for awhile. The Xplors have been all waxed up and waitin for winter.. Summertime '70 Mustang project been keeping me away. Great new format! Haven't gotten used to it yet though! I searched topics for this (problem?) but didn't come up with much.
Just bought my Sweetie a '97 XLT with Control Trac, 4.0 OHV in dark metallic grey. 101k and very clean. Bought it from a dealer on eBay for $3300! I've changed/flushed all fluids and did major tune up and it runs out great but I have a question.
This scared the hell out of me at first but I think (hope) it may just be normal Control Trac operation....
When in "AUTO" I can feel some grabbing in the drive train during acceleration from a stop. It's kinda like clutch slipping but not that severe. Very slight and no real loss of torque to the wheels. All of this is on dry pavement. The reason I think it is related to the Control Trac is that when I switch to 4WD High I can't feel any of the aforementioned symptoms. Am I just feeling the system looking for wheel slippage and the quick engagement and disengagement of the Control Trac system?
Is this NORMAL?
If not I'd like to get some feedback as to what may be going on. Cheap stuff like ABS pick ups would be ok. Normal would be better! My old pre '95 manual lockers and my Limited 4x4 are no doubt different from the Control Trac system, right?
Thanks....

 

[TPLYNCH]

As you mentioned changed of fluids, I'll assume the t/fcase fluid is new and at the proper level. There was a tendency in the '97's for the engagement to be a bit harsh if I recall. Ford did do a reprogramming of the GEM's to alleviate it I believe. If it gets to harsh, you may want to consider having it checked.

 

[gijoecam]

Completely normal and quite common. The brown wire mod will disable the automatic 4wd and eliminate the clunking should you choose to do so. Mine has done it since new with no ill effects. It took a lot of getting used to it, but I never did. I recently did the brown wire mod and love it, but I'm a control freak too....

In short, nothing to worry about, unless it starts doing it when making a tight corner like in a parking lot at low speeds.


-Joe

 

[jayhawkexplorer]

I've got the exact same truck as you just bought, with 107,000 miles, and mine does the same thing, but only if I try to spin the tires. Driving normally, it doesn't do that. If you're having that happen driving normally, it may be a problem. Give some more info and maybe we can figure it out.

 

[stilbo]

Thanks for all the input!

"Fluids" I'm assuming that the Valvoline shop got the transfer case level correct... The T/C case uses Mercon same as transmission, right?

"GEMS reprogram"... Is there a TSB from Ford on this? Does Ford offer the reprogramming for FREE? (har har har...)

"Brown Wire" Hmmm this sounds interesting. I bought this with the thought that with Control Trac, my wife wouldn't have to mess with switching to 4x4 high unless the going got really rough (we got 14" of snow last Thanksgiving for our first snow of the year!). I guess that if it (grabby feeling) isn't apparent to her, I'll just leave things as they are. She hasn't driven my Explorers very much so she may not even notice this Control Trac trait. It's nice to know though that I can deactivate the system if need be by just disconnecting a wire. Are there any fault codes once the wire is disconnected?

All in all I'm glad and relieved to hear that others have noticed this behaviour!

Where is this "brown wire" and it's connector?

Thanks again !

stilbo

 

[gijoecam]

Thanks for all the input!

"Fluids" I'm assuming that the Valvoline shop got the transfer case level correct... The T/C case uses Mercon same as transmission, right?

"GEMS reprogram"... Is there a TSB from Ford on this? Does Ford offer the reprogramming for FREE? (har har har...)

"Brown Wire" Hmmm this sounds interesting. I bought this with the thought that with Control Trac, my wife wouldn't have to mess with switching to 4x4 high unless the going got really rough (we got 14" of snow last Thanksgiving for our first snow of the year!). I guess that if it (grabby feeling) isn't apparent to her, I'll just leave things as they are. She hasn't driven my Explorers very much so she may not even notice this Control Trac trait. It's nice to know though that I can deactivate the system if need be by just disconnecting a wire. Are there any fault codes once the wire is disconnected?

All in all I'm glad and relieved to hear that others have noticed this behaviour!

Where is this "brown wire" and it's connector?

Thanks again !

stilbo

No, the reprogramming was only free if it was under warranty, if and ONLY if the transfer case was engaging during parking lot maneuvers. I don't recall there being a TSB on the issue for the '97.... I think it was an '00-up issue IIRC.

For all your brown wire questions, read the 13-pages of the brown wire thread in the list of useful threads. Read the ENTIRE thing, and ignore everything to do with the YELLOW wire.

The short version is that no, it will not hurt anything, not throw any codes, and simply cut the power to the transfer case clutch coil, thereby preventing the front and rear driveshafts from locking together.

If I was in your shoes, and it was the wife's car, I would do as you suggested and leave the system the way it is, unless she's 4-wheel-drive-savvy and would prefer to have complete control over the 4 wheel drive system. There's no performance advantage for the daily driver, other than eliminating the slight clunking you felt as the system cycled.

Hope that helps!

-Joe

 

[Lee S.]

To save you some time with the brown wire mod (way way too much reading) agarbs87 just did the mod. His thread may help you out:

http://www.explorerforum.com/forums/showthread.php?t=143353

 

[white95explorer]

Mine 95 does the same thing, you ever figure it out?

 

[stilbo]

Back again...
I didn't do anything to the '97. I took it for a test drive to evaluate brake condition (needed pads and replaced) and noticed that the grabbin/thumpkin has gotten more pronounced. I'm gonna crawl under it this weekend and 1: Change transfer case fluid 2: Do the brown wire mod. Thanks for the SIMPLE version !!!