Vehicle Information
===============
1993 F150 XLT Long Bed
Mileage: 85,000
5.0L-302ci
AOD Transmission
Stock Transmission Cooler
All Stock Parts, no aftermarket add-ons

What's been done
================
Flush and Fill transmission (2 months ago)
New Tranny Filter (2 months ago)
Correct Torque settings applied (2 months ago)

Problem
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When accelerating normally from a dead stop (e.g. at a stoplight), the transmission 'slips', causing the engine to rev slightly for about a second or two before engaging. The truck runs fine at highway speeds, but I do experience 'clunks' while shifting at both highway and street speeds.

I'm not a senior mechanic nor do I do work on vehicles for a living, but I suspect, through reading various posts here, that the symptoms I'm experiencing suggest a worn clutch (internal? or torque converter clutch?) and possibly other worn internal components.

Recommendations/Suggestions
=========================
I'm asking all veterans/seniors out there for your advice on this particular transmission problem. I'm not a seasoned mechanic, but I learn very quickly. If you have any suggestions and/or can help me breakdown the problem in laymen terms and the steps/warnings you recommend that should be taken to fix, I would be a very happy person who can drive himself to and from work in his own vehicle.

Michael

 

Ahh, The Great Transmission Woes. Seems To Be A Weak Point All The Time. It Will Only Get Worse And A Complete Transmission Rebuild Is In Your Future. I Would Not Attempt This Task On My Own, Instead, Take It To A Reputable Transmission Shop. If You Want To Remove It And Swap It For Another Rebuilt Unit That Would Save Some Money, But It Will Cost Quite A Bit None The Less. Some Say To Get A Trans From A Junker But All You Ever Really Get Is Another Used Trans With Problems In The Near Future. Some Lucas Will Help In The Meantime. I Have A Similar Problem And Plan To Drive It Till' It Croaks.

 

BSHORT, what's Lucas?

I'll definitely keep the rebuild by an autoshop in mind, but I'd like to at least know before I go. Besides, I'm curious as to learning more about my AOD transmission. Thanks a lot.

 

Lucas is a brandname for this transmission stuff that you can mix into your transmission fluid. It's pretty good stuff for 10 bucks, but it won't fix the problem, it will only prolong the tranny's life until it dies.

 

Once upon a time I had a tranny leak, front seal. I took it to a shop , they said $400. 10 days later they still hadn't touched it. Furious, I took my truck back after a verbal thrashing, bought a $75 tranny jack, $30 in. lb. torque wrench, $160 rebuild kit, $50 B&M shift kit, and 40 hours of work later I had a rebuilt tranny, W/ shift kit & new filter for less than they wanted to install a $9 SEAL!!!!??? My point is this, maybe you don't know about trannys, maybe you don't want to, but if you do,... READ! The general concensus is OOOO!! TRANSMISSION! in reality an automatic is a bunch of seals & sealed valves, some with springs to be a check valve.blah..blah any way try a basic Haynes techbook ($16). Read about your AOD and then form your own EDUCATED opinion on whether or not you'll try it yourself. PS- those clunks might be U-joints, check for any slop in your shafts.

 

Now after all that said,..3 primary things make a transmission slip. But 1st, is this a 4x4? W/ a Borg Warner T case? Any how, slippage from a dead stop is a sign of possible Torque converter failure, in which case buy a new one for around $100-150, replace the front pump seal at the same time. Also the internal clearances between your steel plates & friction disks may be too much and instead of grabbing when the piston is applied they "slip". This creates heat, fast. If you'd like to check this yourself rig up an in line temp gague to your " fluid out " line on the way to the cooler. Run the vehicle for 10 - 15 min. and check the temp anything over 190 indicates slippage. And yes this means complete rebuild, but it was designed to be repaired like this, these parts should wear. Less common, but not unheard of is a stuck valve in the valve body. It may only actuate part way. A removal & flushing of the valve body can help this in most cases. Finally, & don't get offended, but did you repeatedly check your fluid level after you changed it? Sometimes pockets, including in the T/C, become filled with air when the fluid is drained & instead of immediately filling back up with fluid they reain trapped for a while, then the fluid squeezes them out only to leave you LOW. I bet you checked it, but ya never know. PS (again)- here's the way to add fluid after you've drained it all: 1.add 4qt.s, 2.start the engine, 3.immediately add 3 more, shift through the gears allowing each to engage briefly, and check and fill to correct level. + keep on checking it

 

I have an 83 F100, 2wd, 302 with AOD and pretty much the same problem. When your tranny fluid was changed, what was the condition of the fluid? and were there any signs of metal flakes?

I changed my fluid, but didn't drain the torque converter. My fluid was clean, and no signs of metal. I also used the Lucas and my shifting has improved for the most part ( it was shifting hard prior to fluid change, but engine tuneup was done as well.)

If I let me truck sit in gear, it'll catch if I wait long enough or if I shift gears ( no revving of engine) it'll also catch. Tranny seems to slip sometimes but is fine after it gets into 2nd. Revving the engine will also get it to catch, but I that that was a little harsh on the tranny.

Problems are USUALLY worse when the truck is cold.

Thoughts anyone?

Sorry Micheal, didn't mean to hijack your post, but it seems like much the same trouble.

 

When I flushed and filled the tranny, the fluid was smelled bad and there was a metal residue at the bottom of the pan. I did not flush the torque converter. What I probably should do is flush the stock tranny cooler. I spoke to a TCI tech services support person and he recommended a tranny cooler flush kit for around $30.00. I have a strong suspicion that the slipping is coming from a bad internal clutch on the AOD transmission.

Thanks a lot 69 and 85.

 

Sorry folks for not responding promptly to your replies, but thank you for the tips and words of advice. I'm definitely learning a lot more about the problem and future potential problem areas since my original post. In the meantime, I'm going to continue to research a viable tranny rebuild kit, oil seals, and a tranny cooler flush kit. I have a digital camera and I'm possibly thinking about documenting the whole process for this forum to reference. In any case, subscribers to the forum can learn what works and what not to do.

Thanks again Jamiesan, Andyman8282, 69 & 85, and BSHORT,

Michael

 

Kalamazoo, I am rebuilding my E40D for the 3rd time.. last time my forward sprag clutch gave out. This time I am getting no OD light and my tranny slips after it gets hot and periodically slams hard into 2nd and 3rd. I just updated it with all the hard parts upgrade but did not replace any clutches or the band which may be the problem this time ( although I put new ones in 2 years ago). Much like you I am shooting from the hip and if I discover anything enlightening this time I will let you know. I will either get it right or explode the thing.

 

Hey Kalamazoo....

I'm considering an AOD rebuild this summer... just wondered where you're at with your problem. I'm living with mine at this point. Not exactly a daily driver, but not getting any worse.

Any new info would be appreciated. thx

 

testing with at least 10 characters in string.

 

69 and 85 and everyone else who posted a response to my transmission thread, I apologize for not responding immediately and regularly--I've been occuppied with work over the winter. Plus, the forum wouldn't let me post any responses to my thread. I emailed tech support and Eric M. offered some suggestions but they did not resolve the issue. This also explains my 'test' message I sent....which finally went through. Message finally went through.

UPDATE: After working out in the cold, I finally gave up working on the truck's transmission for the winter. There's nothing more uncomfortable than wrenching in January (Southwest Michigan's coldest month of the year). As soon as your feet get cold....that's it man....you're going to be cold.

So what I ended up doing was buying a cheap car to drive during the winter. When spring comes along, I'll post updates. Thanks guys/gals for your tips and suggestions. Much appreciated!

 

one thing to check for on an AOD is the TV cable adjustment. if it is out of adjustment line pressure will start to fall off. someone here has posted excellent instructions on how to do this,can't remember who but do some searching regarding AOD and TV cable adjustment. ya never know it may help a little on your slippage.
Mike

 

Mike93,

Thanks for the tip. I'll submit a few keywords to the site's search engine and review the material found.

--Michael