1988 F-250 AOD shifting way too late

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Old 12-05-10, 11:14 AM
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1988 F-250 AOD shifting way too late

I have a 1988 F-250 with a 302 and an AOD transmission. For a couple of days I’v noticed it has been taking longer and longer to shift. Yesterday it wouldn’t shift until the RPMs were very high and then when it did finally shift the transition was very abrupt. I decided to park it until I found out what was going on. One other symptom that may or may not have anything to do with it was that when I started the truck for the first time of the day and stopped at the gate keypad to enter the code to leave (the truck is on a slight incline at that point), I would have to step on the gas a bit to get the truck to go into gear again.
Any ideas?
 
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Old 12-05-10, 11:20 AM
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2 things....

Check Fluid level......

AND...

Under the hood, at the throttle body, you will see a a rod, or cable running down to the transmission.....Make sure the mounting "Grommets" have not broken off. This was very common with AOD's back in the day, and would take less than 50 miles to eat up your trans.....Dont drive it until the situation is corrected.
 
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Old 12-05-10, 12:44 PM
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I checked the fluid level yesterday before I left and it was just at the crosshatched area. The dipstick says not to add fluid if the level is in the crosshatched area. I'll add fluid if you say I should but it doesn't seem to me that a half pint or so could make that much difference. But then again, what I know about automatic transmissions could fit on the head of a pin.
Concerning the "mounting grommet", would that be the grommet the cable runs through on the bracket? It looks like it is intact but if there was something missing, I wouldn't know. I'll look it up and see what it is supposed to look like.
Thanks for getting back so quickly. I really don't want to go poking around the tranny until I have some guidance.
 
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Old 12-05-10, 02:41 PM
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The point where the cable attaches to the throttle lever
 
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Old 12-05-10, 04:29 PM
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I checked it against pictures and it appears to be intact. You also mentioned check the fluid. It seemed lower than I remember and the fluid was pretty dark. Someone suggested I change the fluid and filter which I am in the process of doing now.
When I removed the pan, there was a white plastic piece inside. It resembles a child's toy top roughly 3/4" in diameter and about an inch high with a stem about 2" long.
I have no idea where it came from. I don't see any depressions or holes it might fit into but I only looked a couple of minutes before I decided I would go back to the house and medicate myself (kidding). Any idea what it is and where it goes?
 
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Old 12-05-10, 05:40 PM
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The thing you found is just the plug for the dipstick tube on assy of the new tranny.. It gets pushed into the trans on assy of the dipstick tube & removed on the 1st service.. If it's still there, the trans has never been serviced... Make sure you check the fluid level with the engine @ hot idle in park,,.. Roger
 
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Old 12-05-10, 05:57 PM
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You have got to be kidding me. I had just decided to reassemble and wait to see what happened. Mentally I had earmarked $1500 for another transmission. Thank you!
As I was comparing the old filter with the new one, I noticed how enlarged the round hole in the old filter was. I slipped it back into place and the fit was very, very loose. The new filter had to be worked on. I can't imagine that must slop in the fit can be a good thing, can it?
 
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Old 12-05-10, 09:46 PM
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Well, it's a LOT better thanks to you. You think I should get some more ATF and replace ALL of the fluid soon as possible? Saw a way to get all of it out on line somewhere. Drain the pan, bolt it back up and fill it with new. Disconnect the return line from the radiator, put some tubing on the fitting, put the tube into a milk jug and start the engine. Soon as it changes colors from old to new stop the engine.
I'll do it if you think it will help.
 
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Old 12-06-10, 01:29 PM
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I only got to drive the truck for a few minutes last night when I got done and it did seem better. Today I had to run some errands and though it does seem better, it is still shifting too late for me. I noticed that when it was overdue to shift, if I let up on the gas a bit, it would shift. I haven't changed my driving habits any. I'm not bearing down on the gas or anything. Just normal acceleration. It made me think of your suggestion about the cable. Or maybe I need to finish changing all the fluid rather than just what was in the pan. The old fluid was very dark.
 
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Old 12-22-10, 11:27 PM
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With a 1988 aod with the lollypop still in the pan I would keep that 1500 handy. Its not unheard of for aod to go that long but at the first sign of problems you ought to go ahead and get it rebuilt before it fails catastrophically. ( more $$$)

That new fluid may just push it over the edge. The new fluid will have new additives that will clean and condition valves and seals and change the balance of how everything was working. You can drain the converter if you still want to do an almost complete flush. Turn the flywheel by hand until the find the drainplug on the outside edge of the converter. You may get more time and miles out of it but I wouldnt go on any long trips with it.

You may want to add the number of a tow service to your cell phone also.

Good luck
 
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Old 07-15-11, 01:13 PM
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I find this hard to believe my own self but the truck is now running better than ever. I did two things. The first problem was the radiator fan clutch was jammed. The fan was the thing making the roaring noise I could never pin down. Sounds stupid but I am very, very hard of hearing so simple things like that are very difficult to trouble shoot for me. First, I can't really describe the noise accurately because things sound differently to me and secondly, with only one ear performing, no matter where I point that ear, that's where the sound is coming from. I can have squealing brake shoes but if I point my ear at the rear view mirror, that's where the sound is coming from.
Now, I know the jammed fan probably didn't fix my problem but it is nice not to hear that roaring anymore.
Next, there were two blank holders in the fuse box. Not knowing what they did, I put a 5amp fuse in each. After that the truck started running differently. The next morning it started running much better and by the end of the day was running like a brand new truck. It is shifting flawlessly, the engine sounds better, I have bunches of power and the mileage went through the roof (11.5 mpg to 18 mpg).
I still haven't bothered to find out what the fuses did but I'm assuming one of them had something to do with the OBD or computer.
A damn fuse after all this time. I had pretty much given up and was resigned to the fact that I'd better start shopping for a new truck.
 
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