My truck (90 F150 5.8L) was parked in the yard and the dogs lay under it in the shade for a couple of days. Next time I drove it, the E4OD upshifted with a terrible shock every time. Felt like a Toyota hit my rear bumper. Scan codes galore, long story short: the wire harness was chewed off the transmission. Repaired the harness and it still shifted hard. Had trans Ohauled, shift kit, reman TC, etc. Still banged the gears sometimes, not always, hard to predict (that is a clue). Long periods of good smooth shifts punctuated by driveshaft twisting jolts. Obvious suspect is TC lockup clutch. Much driving with logic probes connected to TCC sol ckt and shift sol ckt, etc. showed the signal for "unlock" when lifting off throttle and when upshift occured whether the shift was good or bad. Not a control problem. Inspection of TC shows it was indeed replaced but maybe the core was previously damaged? First question for AT gurus: Might there be some sort of mechanical damage inside the TC that prevents the clutch from disengaging or delays the disengagement? I'm replacing it just in case while the motor is out. In the end I may cut the thing open and look. What am I looking for? Next question to hopefully be pondered in this string: For general farm and town use with occasional pulling of ridiculously overloaded trailers, what sort of TC should I buy and why? I see that I can spend from $200 to maybe $600 without even going hotrod so what do I need?

 

Did you replace that section of harness, solder connections, or just twist and tape the connections?

 

It is properly soldered and heat shrinked, no bad connections. The dogs ate about ten inches of wire that I never found!

 

Try looking on the front lawn tomorrow morning....won't be pretty, though.
Roger

 

Are you still getting any codes? And I mean any codes not just transmission codes because all sensor inputs affect transmission operation. Fix all code related issues and when you are back to the "all clear" status code 111 for stored and constant memory if the transmission is still acting you have a mechanical problem.

 

That reminds me of Cheet and Chongs movie where the dog ate his stash..... thats alot of "fiber" there!

You may have a crossed wire thats causing the problem. I have repaired harnes's before and everyso often I cross a wire. Drove me nuts till I reverified connections. Also check the connectors on the tranny and other end, as the harness was being munched on it could have pull some of the connectors loose inside them. Years ago I had a cat under the hood and when I went to work, the fun began! Had to reseat just about all the connectors and repair few mung up wires on my car and that took two weeks as it was intermittant to find!

 

To clarify my symptoms: Not setting codes, just occasional hard upshifts as if not disengaging clutch on a manual. Never ever on decel. Signal on TCC ckt verified good under road test conditions from a tap near the brake booster. Signal is good whether or not the symptom occurs. Undervehicle harness integrity verified with "wiggle test" using digital graphing scope. It must almost certainly be a mechanical problem rather than a control one. Time to "substitute a known good part and retest". I gotta throw a new TC in there while I can and see what happens. Important question to me as I look at options is Which One?

 

Have heard good thing about hugesperformance.com converters, might be worth checking out. Have a look at tciauto.com as well.

 

Did you check to see if they ate the vss wires going to that sensor on the rearend? Im sure it would throw a code but im unsure

 

I am very curious as to what you find out it is because that is exactly what my tranny is doing (1992 5.8L E4OD 4X4). I did not have dogs eating my harness, just occasional hard upshifts and jumping and "shifting" too soon, slamming into gear, etc. The only code I got that could have been it was 122 (TPS) and that was only once recently, but I have replaced it 4 times over the last couple of years and it still does it. I finally took some dielectric grease and put on the two tranny connectors then pulled them in and out trying to make good contact (sort of rubbing off any corrosion). That seemed to help everything except the torque converter locking too soon and also unlocking sometimes at highway speeds. I am going crazy with this E4OD. If it did it all the time, I should have been able to find something by now, but it happens intermidately.

Good luck, I cant wait to see what it turns out to be.

 

OK, this is coming down to the wire. I picked up the engine parts at the machine shop today. The naked block is on the stand in my barn with fresh Ford Gray outside and oil wiped on the inside. All the stuff is here to build a motor (.040 over for an honest 5.824L, Hypereutectic large relief pistons to burn regular, RV grind computer compatible cam and adjustable fuel pressure regulator) and when it is ready to go in I need to have a torque converter to put behind it. Here is what I have found out so far without mentioning brand names: A "reconditioned" OEM can be had for between $140 and $300; One with a billet front cover goes for $3xx to $4xx, while adding triple plates to the lockup clutch and upgraded thrust bearings makes it a $500+ deal. Any of these would be suitable for towing service.The high stall hotrod stuff for upwards of a grand is not suitable for my purposes. Anybody had an experience with one of the rebuilt OEMs? Is there a good one? Comments and suggestion welcomed.

 

OK, since I seem to be on my own here I am proceeding as follows: I have ordered a F55HSP from torqueconverter1.com. It is supposed to be std. stall speed with beefed up internals (single clutch plate). We shall see how it goes. Engine will be 355.4cid., 8.6:1 mathematical compression ratio (I measured the chamber volume at 94 to 96 cc). The cam lobes look very narrow and pointy compared to the old cam. New one has about .020" more lift than stock. I can't find duration specs for stock cam but I think new one may be somewhat shorter. Supposed to provide "a noticeable improvement" in performance while being compatible with EFI. Hope I am not building a "peaky" motor with a TC that squeals the tires every time. I expect to see a drop in fuel economy, because all I can do to feed the beast is turn up the fuel pressure. If this combination turns out to require an aftermarket computer system, I will have built the most expensive truck I ever didn't need, because if I had known how this job would escalate I would have poured the old motor full of SAE50 and traded the truck for a 4WD.

 

(with dramatic fanfare, the barn doors open. the truck rolls out into the sunlight, a subdued rumble emanating from the dual exhaust pipes) I fired it up Sunday. The new engine and torque converter now have about 30 miles on them. All is well. The F55HSP seems to engage at low rpm with just about the same feel as the original one, so that is good so far. I am not giving it much throttle yet so can't say about the intermittent hard shifting issues previously mentioned, but no problems noted as yet. A visit to the machine shop today got me a chat with a tech familiar with the cam they sold me. He says it is "a flat lifter version of the 303 mustang cam". It is .303 lift on the ex lobes, so ??? The lobes looked much "pointier" than the OEM cam. Hot cams usually have big old goose egg lobes, so the quick duration profile surprised me. It looks to me like they are using a greater lift for a shorter duration to get some high end power without screwing up the EFI calibration at low and mid range. The EFI is programmed for a certain volume/rpm ratio. Almost makes me miss carburetors, but it sure seems to work. I know already that it is hard to remember to keep it under 3000 rpm because that is right where it wants to take off. I think I may like this new motor.