'97 ControlTrac pops into neutral while driving

[97EB]

ControlTrac transfer case pops into neutral while driving. Am always able to get it into 4wd low, and eventually (knock on wood) into Auto. Shift motor has been replaced, but didn't fixed the issue. Is this a transfer case issue, or a module/ sensor issue? Will disconnecting the shift motor pigtail eliminate the problem until the real issue has been corrected? Have had a couple of transmission shops look at it, and they were stumped...

 

[Turdle]

Hmm, might be a wild hunch but when my manual transfer case did this it was due to the front diff bushings worn, the rear frame bushing allowed play and made the transfer case pop into neutral when it stressed the driveshaft.

Use a prybar to see if you get any up and down movement at the frame mount of the front diff.

 

[97EB]

It's tight...

 

[bigred4x4]

What do you mean pops into nuetral? Is there endplay/run-out in the rear output shaft that you can notice by grabbing the yoke and trying to wiggle it?

 

[boominXplorer]

Body control module behind the radio on the left side is going crazy I bet. Just had a 97 in my shop that would illuminate 4x4 randomly even though the switch was in auto. I threw an extra case I had in there and same deal. Swapped out the bcm and it started working right like it should.

 

[97EB]

What do you mean pops into nuetral? Is there endplay/run-out in the rear output shaft that you can notice by grabbing the yoke and trying to wiggle it?

Neutral. As if the transmission gear shift lever was thrown into neutral while driving. Once pulled over and stopped, engine running, with the transmission in neutral, the dash switch can be put into 4 Low, and the transfer case engages In 4 Low, and the truck drives. Trying to change from 4 Low... truck stopped, trans in neutral, switching dash switch into Auto or 4 High, it will come out of 4 Low, but won't go into the option selected. Also, at that point, (engine running/ transmission in neutral/ attempting to switch from a working 4 Low to Auto or 4 High) the engine must be shut off as the transmission lever won't go from neutral into either park, or drive, without resistance...

 

[97EB]

Body control module behind the radio on the left side is going crazy I bet. Just had a 97 in my shop that would illuminate 4x4 randomly even though the switch was in auto. I threw an extra case I had in there and same deal. Swapped out the bcm and it started working right like it should.

What does the BCM look like? How would I know it if I saw it?

 

[boominXplorer]

Rectangular box behind the radio on the drivers side. Has a few plugs going to it and it's held in by (3) 7mm screws (near positive). I'd grab one out of a junkyard truck and give it a try. I'm pretty sure you can't buy them new anymore.

You need to make sure you get one from a 4x4 truck in 97. I'm pretty sure the ohv and sohc 4.0 engines use the same bcm. All 5.0 v8 trucks have 2wd bcm's.

 

[bigred4x4]

There is a number/letter sequence on it can't miss it it's in bold just make sure the numbers are the same.i got one on eBay for $20 and it cured alot of weird random problems I had but.i would definitely start here since it's cheap.

 

[97EB]

There is a number/letter sequence on it can't miss it it's in bold just make sure the numbers are the same.i got one on eBay for $20 and it cured alot of weird random problems I had but.i would definitely start here since it's cheap.

I found a bone yard not too far from me that says that they have 3. Running by in the morning to make sure the part number matches. Hopefully by this time tomorrow I will have put this issue to bed. Thanks for your input!

 

[97EB]

There is a number/letter sequence on it can't miss it it's in bold just make sure the numbers are the same.i got one on eBay for $20 and it cured alot of weird random problems I had but.i would definitely start here since it's cheap.

Update: No go. Picked up a module yesterday, installed it this morning with no change. Since they said that they had others, swapped with them, installed it, no change. Either all 3 are bad, or it's something else.

Hooked up Auto Enginuity to it and got a p1820 code. Looked the code up online, got a description of sorts, but no definitive answer on what needs to be done to correct the issue. Ideas?

(P1820 Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure)

 

[bigred4x4]

Ok so from what I see online is pointing to the shift relay which is the little square grey box with a plug connection behind the gem towards the firewall that would explain your 4 auto problem but..... The nuetral thing idk I'd try replacing the shift relay next if that doesn't work maybe check all the wiring and worst case take it into Ford for a diagnosis. Absolute worst case senario is a bad t case.

 

[bigred4x4]

On second thought I'm thinking shift relay once again because these t cases have a nuetral tow function that a switch can be installed to activate this feature the t case does actually have a nuetral position between hi and low range so a bad shift relay may be causing the shift motor to do strange things.

 

[97EB]

Ok so from what I see online is pointing to the shift relay which is the little square grey box with a plug connection behind the gem towards the firewall that would explain your 4 auto problem but..... The nuetral thing idk I'd try replacing the shift relay next if that doesn't work maybe check all the wiring and worst case take it into Ford for a diagnosis. Absolute worst case senario is a bad t case.

I noticed that grey box when I replaced the GEM, and wondered what it was. I'll try that & see what happens... Thanks!

 

[97EB]

.

 

[drdoom]

You need to rebuild that t case, with upgrades.

 

[Mbrooks420]

What upgrades?

 

[bigred4x4]

I looked into a rebuild there are some upgrades like a piece that goes into the case shell to reduce wear from shift fork and a few other small items the full rebuild isn't cheap by no means and actually think it's worth it to buy a reman tcase with all the updates done already that certified and warrantied because it's not much more than a full rebuild but depends on what is needed a master overhaul kit isn't that expensive but the new case shell alone is $500 so depends really on how extensive on needed parts for the rebuild.

 

[97EB]

.