E4OD Torque Converter Slipping?
 

My 1990 f150 302/e4od recently had the famous torque converter shudder, so i changed the fluid and filter with a ford filter and dextron III/mercron fluid. The shudder then went away and I thought I had the problems with the transmission taken care of...... wrong. Now, after about 3500 kilometers, the thing is slipping quite bad. I can haul a decent sized load at 90km/h with O/D off with no problems, but when I come to a hill after about half way up it starts to slip. After some more hills i think its the torque converter because I tried tapping the brakes to make the converter come unlocked and that is when the slipping starts. It also slips bad about 10 seconds after shifting into second gear while going up a hill (also more reason i think its the converter because it wouldn't be locked then either). The transmission shifts perfect, the fluid level is correct, smells and looks perfect.... so I'm thinking I need a new torque converter? does this sound correct? i wanna make sure because i'd rather replace the converter than the whole trans, thanks in advance !

The converter is supposed to "slip" when it is unlocked. The only thing in the converter that can slip that is not supposed to slip is the lockup clutch. You tell us it is slipping when the converter is unlocked, that sounds like the trans itself slipping, not the converter.

it could be the tranny, but say its slipping in second, it'll slip right up until WOT then it takes right off, it sort of feels like someone bumped you from behind then you take off like normal under wide open throttle (still in second gear), shifts into third and keeps pulling. its seems to only do it the most under 1/2 to 3/4 throttle. and i know there is some slipping when the converter is unlocked, but this is way worse, because sometimes it decides to work perfectly.

When you changed the fluid was it all 16-18 quarts?

should that read 16-18 pints?

Nope, quarts. A complete fluid change (pan and converter) will take about 16 quarts.

yes, i drained the converter and the pan, took about 15-16 liters to re-fill.

Then I would say the clutches in the transmission are slipping from what you are describing.

Any codes?

My 1990 did the same thing when I bought it. Full fluid change to Mercon V which has an anti-shudder component and a bottle of Lucas Transmission fix solved the problem.

Hunt4Fun

so today i take the truck and get a load of wood, just about as much as it will haul and the thing works perfect on the drive home which is about an hour of country road with hills and what not. i unload the truck, let it sit for about an hour, jump back in it to head to town and the thing is slipping in first, real bad in second, and also in third. i don't understand why it can haul a load of wood great, then barely haul itself along a flat road. I did not check the codes, I thought if i had codes the engine light would be on? but if thats not the case then i may have a code. and also, should i have used mercon V instead of just plain mercon/dextron III?

You can have codes without a Check Engine Light on. I have used Dexron III/Mercon in all my 90's vintage E4OD equipped F-series trucks.

so i think the thing is completely toast now, slipping in every gear all the time, today after an hour of idling through the woods i come back out on the road and i only had first and second, i could let of the gas and it seemed like it went into neutral, then when i applied the throttle it went right back into second gear. ANYWAYS.... i got a whole C6 swap for free today. the donor truck drives and shifts properly, fluid looks clean, and i know how it was drivin because it was my grandfathers truck, the only problem is the transmission has between 400,000 and 500,000 kilometers ( ~ 300,000 miles) on it, and has never been rebuilt. what kind of hazards am i looking at here? should i just put it in with some new fluid and call it good or should i spend a little money and time on it and give it a fresh rebuild? i hear its easy to do with a good manual and some mechanical know how. but what about the torque converter, is that fine to just leave alone? or should i dump this deal and look for another C6 with lower miles. thanks

I don't understand why you didn't check for codes, often the problem with these trucks and the E4OD is simple wiring connection/sensor type problems and are fairly easily corrected.

If its not overheating, dumping fluid out the pump seal, the fluids not burnt up its probably salvageable or at least might have been when you first started this thread. However avoiding driving it, hauling loads with it until some simple tests were done would have been prudent.

Still might not be to late but surely some damage has been done now, how much? hard to say.

First thing check it for trouble codes, the light won't necessary be on for it to have trans codes stored. If you find any and want to work with it before changing it out drain pan and TC and fill Mercon V, it has the friction modifiers needed, the fluid you used might not be right.

Some mercon/dextron is compatible but would need to know exactly what you used to say for sure. Not sure of the number off the top of my head, I get it at napa.

Myself I'd try save it first before I'd put in a C6 with 300,000 miles on it....

okay, i haven't driven the truck far, idle back and forth school taking it easy on it. ill pull the codes in the next few days if i can figure that out. is it okay to leave my new filter in it? i mean it only has 3500 kilometers on it, ill just change the fluid after i pull the codes. the fluid i bought was "shell" brand fluid from napa. ummm... also, first gear seems a lot better when its in first gear on the column, not in drive. maybe i should do more testing on this before i get into more trouble with a different tranny, ill try and pull the codes and post what i get. i agree with getting a tranny with that many miles, it made me uneasy thinking about it.