91 Explorer Transmission Advice please
What do you think the likely causes are? I checked the fluid, and it is clean, and full. Can this tranny be adjusted at a shop for low cost for this kind of problem or do you think it's on it's way out?
Also anyone that has had success with these transmissions, what kind of maintainence did you do on them? I have a 02 Explorer, and want to treat the transmission with the best of care, since it appears to be a weak link in my 91.
Thanks!
I bought another 1991 Explorer w/ 70,000 miles on it, from a dealer going out of business. I loveit!! The older syles 1991- 1994 are much better looking Trucks. I have never heard of anyone having problems with the transmissions in the older syle Explorer's.
Torque converter: Early ones weren't brazed and the TC clutch wears out. If clutch goes, engine rpm 300-500 higher than before.
Overdrive parts: Drop transmission, unbolt the bellhousing and these parts are the first parts out. No special tools needed. About as hard to replace as a starter once the transmission is out.
Low/Reverse servo: If it is slow to back up or if you drive it down hill in 1 and there is no engine breaking, you can fix this (change two easy O-rings)for under $50. Almost everyone needs this and doesn't know it. Takes as much skill as replacing the filter. Just drop the pan to get at it.
Clogged filter: Hard to shift when it's cold. Change filter and fluid. It will buy you some time but you got something grinding and clogging the filter.
Speed govenor: These start sticking at about 150K. Cause late shifts from 1 to 2. The tail end of the transmission unbolts and you polish the piston. Not a tough job. If you have the skill to do brakes you can do this. Late shifts can also be caused by the vacuum modulator, another external device. Check vacuum tree on engine for signs of oil.
So what exactly is this slop and what is the color of the fluid?
Thanks for the good info. You make it sound so easy that I would be tempted to try
Although I haven't done anything that complicated before. I've only worked on things like oil pan replacement, starter, alternator etc. The easy external stuff. Never even done breaks, but would be interested in learning how to do that if it's relatively easy to do. My wife burns up break pads pretty quick.>So what exactly is this slop and what is the color of the
>fluid?
The color is red, and clear. The slop in the tranny occurs first thing in the morning, the RPMS need to rev around 500 higher than I would expect so there isn't as much torque or power to the road. This lasts for about a block or two, and then things start tightening up.
This car has been a late shifter for awhile and I think that might be a vacuum problem because when it won't shift from 1st to 2nd, I will rev it then let off the gas quick and then that usually makes it shift. Does this sound like vacuum to you?
I guess I will take off the pan off the tranny to replace the filter. What should I look for once I have the cover off? Any other suggestions are greatly appreciated.
Thanks!
Rick
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 the 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.bulkparts.com and comes with a new bolt and spacer. 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 has the patent on this filter design #D422600 and many others.
1) How can I tell which pan I have, and therefore which filter I need? I have the 4WD, so I guess the part number you gave me is correct.
2) Since it doesn't come with gaskets and O-Rings, which ones do I need? I found # 23270 on bulkparts that looks like it might be what I need.
3) Besides magnets, are there any other parts that I need?
4) Can you give me the steps to dropping the pan and replacing the filter/O-rings? I don't even know what the O-rings are for.
5) Do I need a torque wrench for tightening the pan bolts? Is there a specific order to tightening them, or for that matter, loosening them?
Sorry if the answers are obvious, but having never done this before, I want to be prepared when the time comes. Nothing worse than dropping the pan and missing parts that need to be ordered.
Thanks again!
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Also for the pan gasket, bulkparts lists two, one that is listed as cork and rubber, and the other is "Farpak black gasket". The latter is more than 2x expensive. Is this a case of you get what you pay for or is the cork and rubber good enough?
Here's my list of things I'm purchasing (all from bulkparts.com):
1) Filtran Filter (item #23921)
2) Two Pan Gaskets so I can decide later which to use (Item #'s 32141D, 23141)
3) Small and large Filter O Rings Item #'s 23270, 23271.
4) O Ring for the filler tube, item 25266.
Am I missing anything here?
Thanks for your advice thus far, it has been invaluable for someone like me who has the desire to do it, but not the know-how!
I probably didn't need the Filler tube O-ring but it was so cheap, I figured it was easier to have too many rings than not enough. Can you tell me what the gasket kit part number is on bulkparts.com so I am looking at the correct one?
What kind of things would you expect me to see when I drop the pan if there is something wrong with the clutches or overdrive? Can I inspect most of what I need by just removing the pan and filter? My current plan was to just replace the oil and filter, on the chance that it was contaminated with radiator fluid with the bad radiator, but I would like to look for obvious things. Would I need that book to know precisely what to look for?
Don't remember seeing the "Earth transmissions are easy" thread.
I'd be happy to go wherever you are, just need a pointer.
Thanks
On the internal clutches, the snap ring is retained by a metal lip or posts on the spring retainer. It is necessary to push the outer edge of the spring retainer down about 1/4 inch to remove the snap ring. The ATSG manual shows a nifty tool to do this but a variety of home made devices could do this. It could be as simple as using a nearly empty mylar shipping tape spool, as I did one night. Or a small board with 4 or 6 long screws paced in a circle. I fabricated one out of a 4 inch diameter thin wall steel tube that was 2 ½ inches tall. A section of the sidewall was cut out so the tube could be bent to 3 ½ inch diameter. Basically, ovals were cut out of each side for viewing and tool access. That left nearly a complete ring on the top, so the device stayed in one piece, and two half moons on the bottom. A vertical column on each side supported these wide feet, much like the one pictured in the manual. This design is easily bendable to fit different diameters. The compressive force is supplied with two bars pulled together with a long bolt. The top bar is 5 inch and threaded for the long bolt. The bottom bar is 3 1/4 inch with a clearance hole for the bolt.. It takes very little effort then to remove the snap ring. Once you have removed the ring, the need for the retainer becomes obvious. Care should be taken when the rubber sealing rings are removed to note the direction of the sealing lip. Put them in backwards and you won't have much of a seal. Great care must be taken when reinstalling the snap ring. Visually inspect that it is properly seated. Push down on the edges of the retainer and the snap ring to see that it is all the way in. This was considered such a problem that they redesigned the retainer into a continuous lip instead of the posts in later versions.
The clutch plates, friction and steel are easily removed prior to the piston removal. The snap ring has a small lip on one end which can be caught with a small screwdriver. This is followed by a thick pressure plate and the alternating friction and steel plates. There is usually the same number of each but if the transmission has been rebuilt before, there may be an extra plate (.070 inch) to take up some slack. A clear sign to install new friction plates. This is the poor boys adjustment instead of installing a thicker snap ring. When the clutches are installed, you are looking for a clearance of about 70 thousandths (.055-.079 inch) between the snap ring and the pressure plate for all three clutch packs. You not only have to push down on the clutch pack to make this measurement but lift up on the snap ring New friction plates should be soaked in transmission fluid at least an hour before assembly to insure proper thickness.
Overdrive clutch had a retaining ring thickness of 0.0681and I had about 40 thousandths clearance with all used plates. Installed three new steel clutch plates (which were slightly thinner, Allomatic) with the old friction plates and got the required minimum clearance. This was the rebuilt drum from Transtar Industries and doesn't use a full complement of springs (install three springs and skip a spring) . One down, two to go.
Reverse-high clutch had a retaining thickness of 0.0681and I had less than 40 thousandths clearance with all used plates. Again, installed six new steel clutch plates (which were slightly thinner, Allomatic) with the old friction plates and got the required minimum. This was from the transmission rebuild in 96 and wasn't checked too closely. Two down, one to go.
Forward clutch, the one with the rubber cushion, had a retaining ring thickness of 0.0819 and had more than 110 thousandths clearance on all used plates. But then, just how do you measure that when you are gauging against rubber. The interesting part was that this clutch had 5 friction plates and 6 steel plates. Although the friction plates showed no more wear than the others, this drum had the most friction material sediment. All friction and steel plates were all replaced. This time I was able to install six of each and still have the minimum clearance. This piston has the largest surface area of all the clutches and uses the flat sealing rings that don't have any install direction. For this piston, only the two bars and the screw were needed of my home made tool for removal.
The tightness of two of these clutches were probably the cause of the fluid blackening the first six months of operation after the rebuild in 96. Glad I found a use for the steel clutch plates, though it was never the purpose I imagined.


