Randomly flashing 4wd lights while driving...

[spotdog14]

I posted this in the 95-98 forum, but though i might post a thread here too...

Here is my problem, ever since we got our tranny rebuilt (BTW its a 95 explorer limited) we have had a loud clunk noise coming from under the vehicle when you would accelerate from a dead stop to almost where it would shift to second gear, but would release pressure off the pedal so it does not shift, that is when you would hear the cluck. The tranny place said that it is probibly slack in your t-case/rear diff/rear drive shaft and most likely not the tranny.

My question is now since the new tranny (rebuilt) is in place is this putting more stress on the old t-case and all the slack that is in it, causing it to make those cluncks and flash 4wd lights as us randomly?

Its got 160,000 miles on it, and the 4wd low does not work, i guessing because of it never being used by the previous owner, but from what i can tell (at least last winter) the 4wd auto did work fine, how would i go about testing this without snow on the ground? i dont realy want to get stuck in a field with it not working... lol...

Anyways do you think that the slack in the old t-case and the combination of the 4wd low not working is causing an error in the system to flash the lights at us?

Thanks!

P.S. yes i know someone is going to say "search" but after 50 pages of posts about 95 explorer transfer cases everything seems to say the same thing "you should have searched before you post" and no one actually answering anything....

Thanks for any help you guys can give me... And the fluid from the t-case and rear diff look fine.

 

[NHale623]

You should be fine to use 4WD Auto on pavement. Just go to a parking lot and drive straight and there won't be any worries. You should feel a difference if the clutch in the transfer case is engaging.

I'd also crawl underneath the truck and check the electrical connection on the shift motor mounted on the back of the transfer case. Make sure everything is clean and tight. Dielectric grease is recommended when you put it back together.

Your transfer case is controlled by the GEM, your transmission is controlled by the PCM. I don't think they share anything, except possibly the DTR but I can't say for sure without looking at a wiring diagram. You could scan for codes in both modules, but to get at the GEM codes you'll probably have to go to a dealership. When the 4WD lights flash, there is a code stored in the GEM that could be read.

Regarding the thunking, have you checked your u-joints and slip joint? Granted, it would have been ideal to check, repair and lubricate them while the transmission was out.

 

[KPT]

I would guess the lights are flashing because the contacts that tell the GEM where your shift motor is are not working right. Shift motor is only used to get the t-case in and out of low, thats why auto would work even if the case won't shift to low.

 

[spotdog14]

You should be fine to use 4WD Auto on pavement. Just go to a parking lot and drive straight and there won't be any worries. You should feel a difference if the clutch in the transfer case is engaging.

I'd also crawl underneath the truck and check the electrical connection on the shift motor mounted on the back of the transfer case. Make sure everything is clean and tight. Dielectric grease is recommended when you put it back together.

Your transfer case is controlled by the GEM, your transmission is controlled by the PCM. I don't think they share anything, except possibly the DTR but I can't say for sure without looking at a wiring diagram. You could scan for codes in both modules, but to get at the GEM codes you'll probably have to go to a dealership. When the 4WD lights flash, there is a code stored in the GEM that could be read.

Regarding the thunking, have you checked your u-joints and slip joint? Granted, it would have been ideal to check, repair and lubricate them while the transmission was out.

Thank you for the information. I will have to check under the truck tonight and see how the condition of the shift motor is. By the way how much is a new one from a dealership, arnt they around $300 (at least that is what i thik i remember being quoted for my 01 ranger). Ill have to pick up some of that dielectric grease on my way home as well, i remember the dealership did say that would help again in my old Rangers case.

Now for the u-joints, from what i understand to see if they are in need of replacing, you need to attempt to see if there is any play in the drive shaft, correct? I have done this with the vehicle in park and i cannot get the drive shaft to budge an inch, while the front drive shaft on the other had, while it turns (because its in 2wd mode) it does have a lot of play at both t-case connection and front diff connection. Am i correct in my way to see if they are in need of replacement?

Ahah, i know i really wish i would have remembered to tell them to do what when the tranny was out.. oh well....

I would guess the lights are flashing because the contacts that tell the GEM where your shift motor is are not working right. Shift motor is only used to get the t-case in and out of low, thats why auto would work even if the case won't shift to low.

That is a piece of information that i did not know, i though that since it was AWD the shift motor did have to be engaged in order for the front wheels to get power.

Since we are the third owners of this explorer, and both of the pervious owners lived in Souther California, and i live in Michigan (as does the Explorer) that i am guessing that 4 low was never used, and now the shift motor does not work since it was not used in oh some 11 years or so...

So another question... is the transfer case required to give power to the front wheels in AWD mode? What i am getting at is, would AWD work if the tcase and shift motor were bad? I would really like to get it working so i am considering getting a shift motor, but do not want to spend the money on a new one is the tcase is bad as well...


Thank you guys very much for all your help, this is by far the most information i have gotten on this subject from anyone! I am starting to realize that the 95 explorer is a lot different setup than my 01 Ranger 4x4.

 

[NHale623]

... By the way how much is a new one from a dealership, arnt they around $300 (at least that is what i thik i remember being quoted for my 01 ranger)...

I do not know how much a shift motor costs. I do know that for a '95 with ControlTrac, the shift motor is only used to shift into and out of 4WD Lo. The figure you quoted does not surprise me.

Now for the u-joints, from what i understand to see if they are in need of replacing, you need to attempt to see if there is any play in the drive shaft, correct? I have done this with the vehicle in park and i cannot get the drive shaft to budge an inch, while the front drive shaft on the other had, while it turns (because its in 2wd mode) it does have a lot of play at both t-case connection and front diff connection. Am i correct in my way to see if they are in need of replacement?

Sounds good to me. I have to say though, I find the symptoms regarding the clunking you are experiencing odd. If there was that much "slack" in the drivetrain, I would expect to hear something when shifting from park to to reverse, from reverse to drive, etc.... You said you only experience a clunk when shifting from first to second (if I read you correctly). That does not sound like a problem that can only be attributed to the drivetrain exclusive of the transmission to me.

If it didn't clunk before the rebuild, it shouldn't clunk after.

 

[spotdog14]

I do not know how much a shift motor costs. I do know that for a '95 with ControlTrac, the shift motor is only used to shift into and out of 4WD Lo. The figure you quoted does not surprise me.



Sounds good to me. I have to say though, I find the symptoms regarding the clunking you are experiencing odd. If there was that much "slack" in the drivetrain, I would expect to hear something when shifting from park to to reverse, from reverse to drive, etc.... You said you only experience a clunk when shifting from first to second (if I read you correctly). That does not sound like a problem that can only be attributed to the drivetrain exclusive of the transmission to me.

If it didn't clunk before the rebuild, it shouldn't clunk after.

lol that is true, if it did not make the noise before the rebuild then it should not after, but before the rebuild i didnt have second gear either. haha. It only does it some times, i find it doing it less and less as time goes on, or else i am learning to drive so that it does not make that noise. I have the standred "ford" clunks that i hear in all for trucks from going from park to drive, park to reverse, reverse to drive. But it is no where near as loud or violant (much more shaking of the vehicle in the one fron 1-2nd gears).

But on the good side of things i did get the extended 3 year warrenty with the tranny so if anything should go wrong it will be covered. I already had to take it back because the bands were adjusted incorrectly. The guy said that the rebuilder adjusted them to what he over experiance has found to work best, but it didnt work in my case and had to go back and torque them to ford specs and everything is nice and tight when shifting.

Im really glad to hear that my problem with 4wd low though is probibly going to be sloved with just replacement of the t-case shift motor.

But one question still, the t-case is required for 4wd auto to work correctly right?

 

[NHale623]

Yes.

 

[dreamr]

Don't spend that kind of cash to replace the shift motor, just rebuild it.

It is a very simple mechanism, and typically it fails due to a stopper bushing wearing out. Do a search for the Shift Motor Rebuild thread. You could also find it likely close to the top in the list of useful threads...