'95 460 E4OD Shifts HARD When Warm
 

When it was blazing hot here in Texas I took my truck on a long highway trip in traffic. When getting up to speed I noticed that shift into OD we're very harsh, snap your neck harsh. When I slowed down a bit I noticed it shifted hard in every gear. Then I put it in reverse and the truck died.

Never done this before. It shifted so hard in reverse it killed the engine. I read it could be fluid low or the tranny filter falling out. So I put in a quart of fluid as the tranny pan is slightly leaking.

This seemed to help a hair. But I took it out tonight, nice and cool here, and had zero problems. Shifted in reverse smooth and all shifts we're smooth.

Decided to run engine codes. No KOEO codes :) My KOER codes is the same one code Ive had since Ive owned it. 311. This is a no brainer because the cat has been removed, so the thermatic air system doesnt work.

When I bought the truck I did a FULL fluid flush, including draining the converter.

Not sure what the problem might be. Also Im having a real hard time getting tranny fluid to read correct on the dipstick. I check it when warm and fluid seems WAY over filled, like 6 times over. Have a hard time believing this because I put in the correct amount when it was flushed and it right then. Not to mention my tiny drip from the pan would let it get lower, if anything.

Any clues before I send it to an arse raping tranny mechanic that will tell me the tranny is OUT and needs rebuilding?

Tranny fluid level should be checked warm, with the engine running. Remember the hash-marks on transmission dipsticks typically cover 1 pint, not 1 quart like engine oil.

So you think its a fluid level issue? Always checked level and warm. Again, truck has been fine up until we started to get really hot weather.

Man...Anybody?

Sounds like maybe your torque converter isn't unlocking? It shouldn't stall no matter how hard it shifts.

I'll give it a try, for what it's worth.

I'll approach this with my story and you can decide what may or may not apply to you.

My truck was running lean due to a mis-adjusted idle set screw, bad TPS, and a bad ECT sensor.

Once I corrected those items and got the truck running where it should be, it ran cooler......remember a lean running motor runs hotter then a rich running motor.

What does the above have to do with anything you ask..........

Well, MY transmission cooler is in the radiator, and since my truck was running lean and hot, the radiator was running hot, which in turn wasn't cooling the transmission fluid as well as it should have been.

So, once my truck was up and running as it is suppose to (no longer lean and hot), my transmission was running cooler, and the shifts became very soft like I haven't ever felt in my truck.

If your 460's transmission cooler is in the radiator, you better start checking the coolant system as well as your air/fuel mixture and devices that controll the a/f mixture.

That's just what happened in my case/instance.

As they say, Your Mileage May Vary,

Bob

I have had hard shifting experiences with my '92. At the suggestion of my transmission guy and a few folks on this forum I drained the fluid from the pan and the torque converter completely, installed a new strainer and refilled with Mercon V. Have not had any such symptoms since.

Thanks for all the help, sorry for the late response, been super busy.

Torq Converter not unlocking could be it, but I would think it would stall throughout other gears??

Here is some new info, took it out this weekend to pick up some lumber, and it died in reverse cold. Also truck cranked much longer than usual when starting.

SO in this case the truck was not warm when it happened.

I did the flush on the fluid a year ago, I probably put 2000 miles on it since the fluid flush. I originally flushed the fluid to fix reverse slipping. I read a full flush could fix it...I put in a new filter flushed the tranny and converter and filled it back up. The truck still slipped in reverse so I put in some lucas tranny treatment stuff. Helped a hair...


I thought about it being an issue with a sensor but the KOER and KOEO showed no codes. It has been cranking much longer on starts though. Used to fire up when cold, now a good 2 or 3 seconds or cranking and it will start.

To me, all of this still sounds like a vacuum leak (lean condition) somewhere, and/or an IAC valve problem.

I may be wrong, and heaven knows I've been wrong here LOT'S of times, but it just plane old sounds like a sticking IAC (no codes but the symptoms) or a vacuum leak (no codes but the symptoms) somewhere.

My Take,

Bob

Here is some more information regarding the IAC and transmission problems:
Click this link: E4OD Diagnosis Thread - FSB Forums

Pay special attention to this part:

"My truck wants to stall when put in reverse"
"This may or may not be accompanied by irraddic idle and/or codes. If no codes are found pull the IAC (Idle Air Control) sensor and clean/replace as needed."

Just confirming my huntch, ;)

Bob

My old F350 4x4 w/5.8L engine and E4OD would have a harsh shift from time to time. All KOEO/CM and KOER tests passed. I measured the TPS output with a meter, the output was text book values and very linear with no "dips".

After scratching my head for awhile I went back to the basics....check the connectors. Yep, the TPS connector was filled with green corrosion. I gave it a good soaking with contact cleaner and some scrubbing with a toothbrush until both sides of the connecter were all shiny and new looking. I applied a little dielectric grease before re-assembling. Truck ran great for the next 3 years. Now it has a new owner :-jammin

Much appreciated! I went through the entire link and was able to try some things tonight.

Decided to check IAC valve. Pulled it and cleaned the hell out of it. It was never idling bad, but i thought Id give it a try. No different. Maybe replace the IAC?

This time I noticed something i didnt notice before, shifts we're not all that bad and when I put it in reverse I noticed the rpms dropped more than in a forward gear to around 500rpm and the truck was wanting to lurch in reverse, like the converter was "locked" more in reverse than in a forward gear. It also shuddered in reverse. Maybe the filter dropped off the pan??

It also stalled on me a couple times going in reverse again.

The shuddering seems like a classic converter clutch issue to me. I could see IAC if it just stalled occasionally, but the lurch/shudder along with hard shifts seems to indicate the converter is very hesitant to unlock.

It's probably worth dropping the pan and trying a fluid/filter change. While you're under there check the valve body bolts. They should be snug, but not crazy tight: 80-100 inch-pounds. IF fluid is going/leaking from places it's not supposed to - the transmission can do anything really. Also make sure you drain the converter. You'll need 4 gallons of fluid with a converter + pan drain. Might also be worth trying Mercon V fluid over Mercon.

FOLLOWING THIS ONE!

I've done the Throttle Position Sensor, Neutral Safety Switch/Gear Selector, Speed Sensor in the rear end (1995), cleaned every contact from transmission to computer, filter and fluid..... still no luck

mine only shifts hard in "warm" conditions too now that I have had a change in temps up here, it does fine in the cool mornings but in the 90's in the afternoon it shifts hard right away... hope to pull something from one of these threads, all these people on here have been more than awesome to work with, just wish I could figure it out already...

Do you have a leaking front seal too ????
If you haven't done so yet, pull the MLPS plug and verify you have the correct wiring at the pins(in the plug) to match the MLPS on your transmission.
If you've had the trans rebuilt and the incorrect year MLPS was installed and the plugs were changed to accomidate the "old version" MLPS, chances are the "service person" moved the pins into the wrong position in the plug.

I just checked mine this morning and low and behold, the wiring has been wrong at the plug for 8 years !!!!

We need some help here subford........
Can you post that very nice picture of the pin-outs of the different MLPS plugs and sockets you recently posted in another thread !!!!!!


Bob