How to: Rebuild 4X4 Shift Motor

[glfredrick]

I have no high or low, switch and lights work and seems to be in lower gear but no 4 wheel drive! Damn aggravating get stuck in my driveway every night after this record snow fall!

HELP!!

It almost sounds like you are a victim of bad automatic hubs...

Try putting the truck into neutral when you shift into 4 low and see if that makes a difference. Otherwise, do you hear any popping or grinding noises coming from the front axle area? If so, then your hubs are most likely not working. I recommend manual hubs (Warns).

 

[DeRocha]

I have no high or low, switch and lights work and seems to be in lower gear but no 4 wheel drive! Damn aggravating get stuck in my driveway every night after this record snow fall!

HELP!!

If the switch works and the 4x4 lights on the dash and button come on then your shift motor is working. Unfortunately this means your HUBS are not. If you have autohubs you should replace them with manuals as the autos are more than twice the cost of manuals (even though manuals are stronger).

 

[Linkster]

Hubs

Well that was a fast reply for sure!

Maybe I will just drive to Brockton and have you check them to be sure..LOL


Will check on hubs for sure, had manuals on my old Blaser which was a beast to be sure! I know I put new rotors on recently and put a lot of grease in there so maybe that is the issue. Kinda nasty out to be doing that now, another 9 inches we really need, but tired of getting stuck in my semi-cleaned path to the yard!


Thanks again guys!

 

[glfredrick]

I know I put new rotors on recently and put a lot of grease in there so maybe that is the issue.

If the auto hubs are full of grease, they will almost certainly fail - and/or "freeze up" and be unable to engage.

I'd pull the wheels and hubs and clean out all but the thinest film of grease and see if they work. That should take less than an hour counting the time spent jacking up the truck...

Clean them out with mineral spirits. Just fill them - and use an ond tooth brush to get all the grease out - then try them again. Oh - and if your hubs still have the factory clip on one of the studs, just dump it and forget it. It isn't needed.

 

[3spd on floor]

Another Method

First of all, I would like to say thanks to Brain for this writeup. I took my malfunctioning shift motor off today and replaced the bushing that was broken into 5 pieces with a piece of rubber hose, as was mentioned above. (also thanks to whomever mentioned that)


Additionally, I would like to add to the procedure another method for alligning the shift motor servo. It was friggin freezing here today and I didnt want to spend time under the truck putting the drive gear back in and then putting the cover back on.

What I thought of, and then did, was to make a match mark on the housing, as Brain mentioned in the first write-up. This allows the cover to be put back on in the factory alligned position. Next, I simply placed the large drive gear in the housing in a position that was obviously between the 2HI and 4HI positions. After this I just replaced the cover, alliging the marks I made, all in the comfort of my warm basement. The trick to this method is to let the computer and servo automatically allign the gear to where its supposed to be. To do this, I simply set the assembly under the truck, plugged in the wiring connector, started the truck and pushed the 4x4 button on the dash. Sure enough, the motor rotated to the 4x4 position, so I pushed it again to let it rotate back and it will automatically stop at the correct 2HI position when it gets there. Dont you just love servos? Then just bolt it on and go wheelin'!

 

[DeRocha]

That is a great idea 3spd on floor!. I fiddled with my sensor alignment for 2 hours getting it dialed in with a multi meter. I assumed the 4x4 computer would do nothing if the sensor wasn't in its 2H starting position. I will have to try this out next time I tear into a shift motor.

 

[blkman9]

How difficult is it to add a body lift and suspenstion lift to my 91 explorer.I,d like to run some 35"s...Hello....anyone?

 

[jaxon1174]

Thanx for the great thread

I just wanted to say that is an awesome thread. I realized my 4x4 was out on my 93 XLT a month ago when we had a big snow and decided 400 bucks for a new shift motor wasnt worth the trouble. When the weather man predicted another snow storm I was determined to find a cheaper way to fix my explorer. I found your thread through a search engine... I couldnt believe how easy it was to fix that motor. I spent less than 10 bucks on the torx bit and some new RTV sealant... you saved me 400 bucks and a lot of trouble from the next snow storm which accumulated 14 inches. Thanx again

 

[Glacier991]

Blkman9, I see you are somewhat new here. You might want to start your own thread on your question... this thread is about:

"This is a general how-to thread for fixing the transfer case shift motor for the 4X4 models."

Your question is:

Q>" How difficult is it to add a body lift and suspenstion lift to my 91 explorer.I,d like to run some 35"s...Hello....anyone?"

NOT A MATCH. Yours is an excellent Q... but you might want to post a new thread with that Q here or in the Modified Explorers Forum.

It is best when the people reading your Q are in the same frame of mind. Your own thread will probably get your lots of answers ! Good luck! And welcome to the site. And you are excused, we all had to start somewhere! This is not a flame or anything!

 

[Linkster]

Took off my hubs and cleaned all the grease out but the rear wheels still and nothing from the front wheels it seems. Has anyone ever taken apart the hubs or could explain to me how they work? Hate to replace it if it is repairable!

 

[Glacier991]

Gee! and this thread is about rebuilding the SHIFT MOTOR???? Get a clue guys... start new threads and someone will notice! (sorry - just a pet peeve.. post in appropriate places if you want someone to answer you.... post in a thread (or make one) about what it is you are asking about!)

hint: new thread... "Cleaning Auto Hubs"... post your Q there and the answers will come rolling in.. here you will get zero because anyone reading the title assumes (correctly) that this thread is about the shift motor rebuild, NOT AUTO HUBS!!! (or raising an Explorer!)

 

[TPLYNCH]

Took off my hubs and cleaned all the grease out but the rear wheels still and nothing from the front wheels it seems. Has anyone ever taken apart the hubs or could explain to me how they work? Hate to replace it if it is repairable!

(step onto soapbox)

Search for How Auto Hubs work. There are probably 500 posts about how hubs work, how to clean, how to replace, etc. How do you know the hubs are not working? You sure the t/fcase is working? What tests have you run? Research your issue, follow the diagnostics that have been written up, read thru all the info on the Singleton Maintenance site, and if after doing all that has been described you still can't get your 4x4 to work, then post a new thread.

(step off of soap box)

 

[EMG7895]

I just finished fixing mine and heres some things that helped:
1.Instead of marking the gear that turns the shifter, I installed the shift motor on the case without the gear, after everything was tightened i just pushed the gear into the proper spot.

2.The pins in the wiring harness are extremely easy to remove with a paper clip. Just unfold a small paper clip and using very small needle nose pliers make a small hook on the end, then pull out the red piece in the connecter. After that you use a very small screwdriver to release each pin and pull it out the back.

3.When I had the motor taken apart I hooked it up to a battery and cycled it back and forth without the gear while adding oil, to lube and free up eveything.

4.The lightbulb that illuminates the 4x4 buttons on the dash(when tha headlights are on) can be replaced by pulling out the vent and buttons and removing the white plug on the back.

5.4x4/low range can be engaged without the engine running.

Maybe later if I have a chance I will post the wiring/computer tests and wiring harness pinouts.

 

[TooL]

This is a GREAT thread!

Now.. where can i get the plastic gasket? Should I just use a rubber vacuum hose thats used for air? Fish tank line cut? The ford dealership did not help me at all (non servicable part, pfft), napa helped me out and gave me a piece of vacuum hose to try out for free (<3 napa). Mine was dry and cracked (fell off in 2 pieces before I did anything, when I picked it up it broke apart even more).

Its this gasket im talking aobut:

 

[EMG7895]

When i took mine apart and it was completely gone, i just used a piece of vacum hose. Read my post above for some things that helped me.(I had it on and off the truck 4 times)

 

[99stocksport]

im not sure if this question has been asked yet, but how to you get the screws out with those little pins?

 

[glfredrick]

im not sure if this question has been asked yet, but how to you get the screws out with those little pins?

Those screws are called tamper proof torx, and you can get bits to fit them at most auto parts, Sears, Snap On, etc. They are standard torx bits that have a hole drilled in the center of the bit to make them supposedly tamper proof - except that anyone can buy the bits these days.


http://buy1.snapon.com/catalog/tools.asp?tool=all&Group_ID=159&store=snapon-store

http://buy1.snapon.com/catalog/tools.asp?tool=all&Group_ID=13238&store=snapon-store

http://buy1.snapon.com/catalog/item...8&group_ID=716&store=snapon-store&dir=catalog

 

[DeRocha]

This is the set I picked up from Sears. Craftsman: Security bit set

 

[shak]

Shift Motor Rebuild

This is a great thread...thanks Brain...you spent a lot of time and effort with the pix and write-up...and it sure helped me a bunch...here's a few things I experienced as an amateur:
1. The three Tamper-proof torx screw heads on the gear reduction/controller end of the shift motor assembly broke off...leaving me with a drill and easy out procedure...which I promptly screwed up by not correctly center punching the remainder of the screw buried in the housing...bad deal...busted the casting in the screw holes to the outside...recovered nicely with epoxy though...the screws must be held with lock-tite...wonder if mild heat applied to the outside of the housing along the screw area would help before attempting to turn them.
2. The Match mark procedure described and emphasized several times in your write-up bears repeating again...It is a must do!
3. More Grease is not better...I used moderate amount of lithium on all bearing points and it worked fine. Taking a little extra time here is a good idea, as is keeping the grease away from the electrical contact side of the big gear and the inside of the cover. If you "over-grease" the motor shaft and the teeth on the big gear...it will eventually leech onto the electrical contact surface of the assembly.
4. After getting it all back together and installed...it was still stuck in 4-wheel high...as it had been before I started...my heart sunk! In neutral it would shift into 4-wheel low and back out again with no trouble. The 4-wheel low light on the dash would come on and go off and the controller was clicking...but nothing from the 4-wheel high button push attempts, except a steady light on the button and it was still in 4-wheel high of course. I removed the button assembly from the dash with a small screw driver...it comes right out. Guess what? The housing on the back of the button assembly at the top of the connector had popped off in a manner that allowed contact for the "4-wheel Low" button but not the "4-wheel High" button. My Daughter admitted that she started pushing the button progessively harder in an attempt to disengage the 4-wheel drive...eventually her efforts resulted in the "disconnect". Snapped the connector back on the button assembly and all was right with the world again...Wow...was I a happy camper!
5. For those who cut the brown wire and use a butt connector..(cut it half way between motor and transfer case housing). My stripper was set to 12 Gauge and that worked. Installed the butt connector on the brown wire at the motor end first... while on the bench and slipped a 4" piece of shrink tubing over it...then once the motor was back in...crimped the connection to the other end and slid the shrink tubing over the connector and shrunk it with a Bic lighter.

 

[zensius]

Here's what I just learned. When you re-assemble the motor make sure you line up the nicks in the motor case. There's one for the magnet tube to the brush base and another on the end cover. They are very small but there for a reason. Not lining those up will bind the motor and prevent it from turning. I learned that the hard way. Silicone was hiding them.
Also, don't use fuel line to replace the bushing. It's too large and won't allow the gear to rotate far enough to put the whole apparatus back on the transfer case.
All that said. It took me about three hours. That's three removals and three installs. Thanks for all the help on this thread guys.