Recently, my 93 Explorer started having problems shifting out of first gear when cold. After the engine reaches operating temp., normal shifting occures. The fluid and filter were just changed, along with the vacumn shift servo; no luck. Any ideas?
Also, a code scan generated no trans codes.
MK

 

This problem is usually the result of a sticking speed governor. This controls the shift from 1>2. This is located in the extension housing just behind the transmission. No need to remove the transmission The steel valve spool gets chatter marks on it and can be easily polished with fine sand paper and oil. No need to buy anything although there are sleeve/spring kits that are more trouble than they are worth. You can likely even patch the old extension gasket with a VERY small amount of silicone.

 

Yeah, I've sort of narrowed it down to the govenor (after talking to several trans specilaists). Unfortunatly, it looks like I'll have to remove the transfer case to get at it and am now wondering if it wouldn't be better to replace the entire trans (160K) if I'm going to go through the trouble of pulling the transfer case?

MK

 

The only other thing I would do is replace the low/reverse servo O ring which is certainly leaking by this age. There is a new improved double lip seal seal that is available.. Unfortunately, I only know of this available in the $30 seal kit. Replacing the transmission is a bad bad bad idea. A lot of rebuilds are poorly done and unless something snaps, these don't wear out. Removing the transfer case isn't hard, but it really takes two people to put it back in cramped conditions. If carefull, it can be reached by the transfer case opening. Observe part order as servo falls apart. You should have replaced the filter with the newer Microfelt type and not the metal screen.

 

I totally agree with you re: taking a chance on letting some knucklhead try to rebuild my trans. Isn't the govenor a relativly cheap bolt-on part? As for the 1st. gear seals: Is that fairly straight forward and accessable through the rear of the trans (without having to remove anything except the t-case?)

MK

 

A4LD LOW/REVERSE SERVO IMPROVEMENT
Some A4LD, 4R44E, and 4R55E transmissions have a problem with no or delayed reverse engagement, reverse shudder/chatter, and/or no engine braking in manual low (1). Some symptoms are not very obvious but can lead to the early failure of the reverse band. Some have reported that this gets rid of the "clunk" when you go into reverse. This is the result of the O-ring on the Low-Reverse Servo developing a heat set and failing to make a complete seal. The low/reverse servo has the largest surface area in the transmission, except for the Torque converter clutch, is a double wrap design and located at he output end of the transmission . These all imply that it sees a lot of torque and could be one of the first components to fail from age. Every A4LD should probably have these O-rings replaced. My 92 transmission was rebuilt in 96 and it did not get this improved seal at that time. There is an updated "double lip" style seal made out of a polyacyrlic rubber instead of the nitrile rubber compound O-ring.. This solution was first borrowed from the C6 transmission and is now included as part of the O-ring kit from the better suppliers.

WARNING: This is a blind procedure and there is no practical way of knowing if the reverse band is seated properly. Unlike single bands, the reverse/low band is a double wrap band and this limits major movement. Frictional and. viscous forces will tend to keep the band where it is. The servo rod is rounded at the end and fits into a well on the band as well as the two housing pins. This serves to self align the band. Obviously for manufacturing purposes, when the transmission is stood vertically on the output end, movement of the band to the rear is restricted and is in position to accept the servo rod. Forward movement of the band, however, is not restricted. Rotation of the output shaft, large vibrations and the transmission pointing down toward the front could cause the band to move forward. The ATSG A4LD manual lists the Low/Reverse Servo as a separate repair procedure on page 47 that can be performed without removal of the transmission. This is not just something I made up. Like any transmission procedure, flushing, pump out, or new fluid has the potential to cause new problems. If you are not currently experiencing delayed reverse or loss of low braking, the risk/benefit of this procedure may not be appropriate. Every effort was made to insure this information is accurate with a transmission in a vehicle and by viewing operation of a disassembled transmission on a stand. This should not be considered professional advice and unknown manufacturing changes could cause an unforseen problem.

I used the overhaul kit from bulkparts.com for the 85-95 A4LD #23031 which is approximately $30. This is the Toledo Trans-Kit from SPX/FILTRAN. The two O-rings that you will need are packaged separately in the kit and will be easy to find. Replacement is no more difficult than changing the filter.

This technical bulletin can be viewed on www.atcdg.com by clicking on tech and looking for A4LD.

Another improvement is the American made glass fiber MicroFelt filter from SPX/FILTRAN.. This is also the same filter that is used in the 5R55E (#23921 for 4WD). If you have shopped for filters previously, you will remember that some 2WD versions got the filter element and the 4WD versions got just a metal screen. Evidently 4WD vehicles needed a higher flow for better cooling/shifting. The new filter is physically much larger than the old filter. There is even more filter area because the filter is folded over and welded inside to create twice the surface area. Flow restriction is no longer a problem with this filter. Be sure you order the correct long or short tube version depending on your pan design. This filter is only about $10 from www.bulkpart.com and comes with a new bolt and spacer. THE FILTER MUST BE SEATED PROPERLY OR THE TRANSMISSION WILL SUCK IN AIR. The bolt sits in a well and it is not obvious if the bolt bottoms out. If the filter is ordered separately, it does not come with replacement O-rings or a pan gasket. These seals are included in the overhaul kit. SPX/FILTRAN .technical details can be viewed on www.bryco.com. SPX , an OEM supplier, has the patent on this filter design #D422600 and many others.

Working on a transmission only seems a like a formidable task. Replacement of these items is easy for anyone to do without removal of the transmission. I have removed and installed the reverse servo several times and there is nothing tricky about it. The center shaft eases the alignment of the piston. The spring only requires moderate effort to compress. The only item to pay attention to is the cover which has a tilted mounting surface and mounts only in one direction. Mark the rear section of the cover before removal. Before installation, the walls on the valve body should be lightly cleaned with a crocus cloth. Remove any sediment from the housing, piston and cover with brake cleaner prior to installation of the new O-rings. Lubricate parts with transmission fluid before installation.

While the pan and filter are off, the torque on the valve body bolts should be checked. When I changed the filter on my 97 5R55E, I found all the valve body bolts were all loose. This could be the problem with many transmissions as they age. Be sure to use the correct torque. Too much is as bad as too little and will cause the plate to warp. Seven foot-pounds is not much of a twist. Transtec has a optional double thick valve body gasket kit to correct more difficult sealing problems.

The steps are as follows:
1. Place vehicle in PARK and leave it in that position for the entire procedure.
2. Make sure that after the vehicle has been jacked up that the front of the vehicle is higher than the rear.
3. Remove pan
4. Remove transmission filter
5. Mark the back edge of the reverse servo cover. Remove four retaining screws on the servo cover. Hold the cover as the screws are removed. The spring between the piston and the valve body will push the piston and cover down. Note the cover surface is slanted and note the position.
6. Inspect for excessive wear. Lightly clean surfaces with a crocus cloth and install the two new O-rings. Lubricate piston with transmission fluid.
7. Replace ( new gasket if available), cover, piston and spring. Torque bolts to specification.
8. Replace filter, old O-rings may need to be transferred from old filter
9. Replace pan gasket and install pan.
10. Fill with 3 quarts of fluid. Start engine and cycle from forward to reverse. Recheck fluid levels when warm.

You might be able to get these O-rings individually at a large distributor like transtarindustries.com if you go to their online catalog.


TORQUE SPECIFICATIONS:
Oil Pan to Case 8-10 Ft-Lbs
Reverse Servo to Case 80-115 Inch-Lbs, 6.7-9.6 Ft-Lbs
Main Control (valve body) to Case 71-97 Inch-Lbs, 5.9 -8.0 Ft-Lbs

REFERENCES:
SPX/FILTRAN, Technical Bulletin No. 124,
C3, A4LD, 4R44E, 4R55E Delayed Reverse Engagement
ATSG, Ford A4LD Techtran Manual Pages 22, 23, 24, 31, 36, 47, 62, 111

www.atcdg.com (View tech bulletins, A4LD
www.bulkpart.com

 

Thanks a million Opera House!! I really appreaciate all of the info. The concensus on my problem (stuck in 1st gear until trans is warm) seems to be a sticky govenor. Once again, how nasty is it to pull the transfer case, and is the govenor accessible and easily replacable (through the rear of the trans) after that is done?? Is this basically an afternoon project??

MK

 

Never tried it, but you should be able to remove the speed governor without removing the extension housing if you are carefull about not dropping any pieces.

Speed Governor and Transfer Case Removal
This is a separate procedure because some A4LD transmissions exhibit problems with a late shift from first to second. This problem is associated with a sticking speed governor valve located in the extension housing. This extension housing can be removed to work on the governor while the transmission it is still in the car. If the transmission is being dropped, this will lower the weight, length, and removing the governor will protect it from damage. The transfer case must be removed if the vehicle is 4WD.
WARNING: The vehicle should be safely supported on jack stands with the wheels blocked on a level surface. Chock the wheels to prevent movement of the vehicle. The automatic transmission PARK will be disabled and the rear wheels may need to be rotated.
Unbolting both drive shafts should be mundane but sometimes these bolts can be hard to remove. A good twelve point socket and penetrant should remove these bolts but sometimes it is best to buy some good Torx sockets. Support the transmission with a jack and remove all the 18mm cross member nuts holding the transmission.
After removing the bolts to the transfer case, pull the transfer case out about a half inch. There is a pin that locks the case into the horizontal position. When this pin is cleared, the transfer case will still be supported by the shaft and will swing down by gravity. Then pull it out more and slowly let it drop down to some folded carpets. Now remove the bolts on the extension housing. The transmission rubber mount must also be removed to get at a couple of the transmission extension bolts. Put the transmission in los (1). Carefully pull off the extension housing. The parking pawl is located between the main transmission case and the extension The pawl should stay with the extension and note the position of the small spring on it. The governor valve is then just mounted with two bolts.
Remove the governor carefully, all the pieces will easily fall out. There is the outer weight, close to the shaft. followed by a spring, then the primary valve that goes into the governor body. The valve should move freely from its own weight Although mine worked, it was very sticky. You could see wear marks on the steel piston. I polished it by hand with some very fine wet or dry paper with oil on it. Roll the paper into a tube with the abrasive side out. Insert this into the aluminum valve body and slowly rotate to clean the surface. It doesn't take much and be sure plenty of oil is on it. The piston should now operate freely. If yours is sticking, it is because of wear and not contamination. I have seen these valves new for about $30, but they are easy enough to clean up.

Not a hard job at all. I think a lot of these are on the brink of failing. The only tricky part is getting the parking rod back into the extension housing. Put in park to extend rod, then shift into low to bolt on the housing. The gasket on the transmission end comes in a standard rebuild kit, the transfer gasket must be ordered separately. If you are doing a repair, you can probably get away with using the old gaskets if they aren't damaged.

 

Thanks for the info. I guess I'll tackle it this weekend. I'll let you know the outcome.

MK

 

Well, I pulled the transfer case, removed the govenor, polished it as recommended (I noticed that it wasn't sticking at all before I pulled it, but it did have a few minor score marks on it), put it all back together---and nothing. Same problem: no shift out of first when cold. When warm, trans works normally in all respects. Now what??

MK