94' Bronco. 351w/E4OD, When i go on long drives, or any highway with a steep grade,(up hill usually), The tranny starts shifting very hard, like there is a serious shift kit, or like older trannies, the accumulator spring is blocked off, (poor mans dragster(. That lasts for a few days then goes back to normal. Ive been told a few different things, there is a solenoid thats sticking, the cooler isnt working properly, even that there is a problem in the rearend, or the motor mounts are broken. I changed the motor mounts, because one was broken, but didnt affect anything. I had a new axle and spider gear put in, cuz it was in a wreck, flushed the tranny,it has an external cooler, not sure of the quality or age. Ive heard theres alot of problems with these trannies. Can anyone help?

 

My 94 Bronco with a 302/E4OD had a simular "problem" It seemed to have a sticking valve. It would shift really hard about 2/3 of the time. So hard I thought something was gonna break!

I'm putting duals on the truck so I thought before I go running pipes under the tranny pan I should pull it off and have a look. Well I dropped the pan and found things in pretty good shape for 125000 miles. The fluid didn't smell burnt at all, and there was only the typical sludge on the magnet. Overall I was happy the way things looked. So I put on a new filter and filled it back up with Valvoline synth blend ATF. I also added just for #####s and giggles a bottle of Lucas Oil trans fix. Well at first thing were pretty much the same. The tranny may have even hitting a little harder.

The next morning I take off for work and the same old hard shifts are there, but by the time I got to work thing started to feel better. Things improved on the way home even more. By the time I got home (total of 55 miles) the tranny was shifting like a brand new truck.

the only problem I have with it now is it feels like it needs a shift kit.

So you may want to give that a try.

 

The later E4OD trannies are quite durable. I have close to 150k on mine, and it still feels smooth and shifts well. I did have a hard shift problem one time, but it was the PCM that caused it.

There is a solenoid pack inside the pan, and the PCM sends a signal to control the line pressure of the tranny. The higher the RPM's of the motor, the higher the line pressure for a faster shift.

If the solenoid gets clogged, then you can experience hard shift problems. It could also be the PCM loosing it's mine, but mine set a code and the hard shifting was there all the time.

I just changed my filter, drained the torque converter, installed a B&M Shift Improver, and refilled with B&M Syntehtic Trick Shift fluid (~16 qts.). It is awesome now. Fast, firm shifts, but not harsh.

First thing I would do is pull the codes. There may be one to lead you down a path. If not, try the previously posted trick to see if there's a sticking solenoid. You should also change the fluid/filter for good measure, especially if it's due.

 

I'll toss this out here on your post just cause it seems kind of related even though I hate to cross post but I have been told that if your not sure of how many miles are actually on the fluid in the trans that you can actually do more harm by changing it. My 91 has 144,000 and one of the first things I was going to do was drop the pan and change the filter and fluid and I was told that unless I was having a problem to leave it alone, something about varnish or particles building up and then you change the fluid and it has a tendency to free things up and clog passageways in the trans. (Please no shooting the messenger just posting what I was told) I checked with someone else and they said they would recommend dropping the pan to see what kind of condition the fluid was in and if there was varnish to change the gasket and leave it alone. Anyone have any input on this.

 

Hmm, I don't agree with that statement of not changing the fluid. If you don't know what condition the fluid is in, I would definitely change it, mainly because you don't know how long its been in there. If your fluid is brown, dark, or smells burnt, definitely change it right away. Flushing the old fluild will remove some varnish buildup and deposits, but in an auto tranny, thats exactly what you want.

The entire theory of the automatic transmission is based on hydraulic fluid and its flow. If you have severe enough build up in the lines of the fluid flow, your tranny can start to show problems due to this. Also, the fluid is the life of the tranny. If you let the fluid go too long and don't change it, then it breaks down (unless you have syntehtic), and parts start wearing faster. Heat is hard on all oils, and auto tranny fluid get more abuse from heat than any other part of the car. Torque converters and clutches depend on the fluid, and can be really harsh on it at the same time.

In my opinion, changing the fluid is always the better alternative.

 

Let me add my successful experience. I had the same issue. I first un-did the electrical connections to the tranny and filled them with di-electric grease. Plugged them back in. Also heard that if the TPS (throttle position sensor) is on the blink and gives erronious readings, the tranny defaults to a "failsafe" mode which makes it shift like it's under a real heavy load to prevent slipping. Changing out the TPS and greasing the tranny connections did wonders for me. So much, that I un-did every electrical connection under the hood as well and greased them as well. This included the mass air flow sensor, all compter connections, every fuse in the fuse block, including relays, the coolant and air temp sensors for the PCM. Anything I could find. WOW!! Like a brand new truck. I bought my Bronco (1994) in Tennessee with 101,000 miles on it and I'm also coming to the conclusion that many of these sensors are slowly wearing out due to the heat imposed to the vehicle over the 6 years the truck was in Memphis, TN (I'm in Maine now) and I'm changing them out one by one. The E4OD tranny relies on many of these sensors to operate properly. For those of you in hot climates, I would consider changing out the cheap sensors up to the expensive ones at a time and experience the results. Especially if you are past the 100,000 mile mark. I, so far have paid between $20.00 and $50.00 for each. Use OEM where possible. Some have had 4 revisions since truck manufacture which tells me they found some things along the way.

 

You ain't joking about the TPS messing stuff up. I bought my Bronco last year with a blown motor in it. After putting my spare 302 in it the thing would not shift or start with out pouring gas down the intake. Once it was running it would stay running but once it was shut off you'd would have to dump gas down it again to get it to fire. After alot of messing around swapping stuff back and forth from another truck we swapped the TPS and all was well the sucker started right up, and shifted just like it should. I'd bet the TPS went out and they blew it up because it would shift. Oh well I now have less than 6000 into a truck that is worth 9000. Gotta love that for couple weekends work.

 

I recently had some E4OD issues where I was getting the Overdrive OFF button flashing and hard shifting. Reading the post on here only added my fear of having the possibility of having to rebuild the transmission. Luckily, it was nothing major and I agree on changing out the trans fluid. Most people agree on the 30k mark to flush out old trans fluid. Hey, paying to get it flushed every 30k to me is better than having to rebuild it. However I know that day will eventually come. However my E40D issues started with 2 months ago.

About 2 months ago, my brake lights went out. They would not turn on, nada which is almost like driving with a death sentence here on busy Dallas Streets. So I had it looked at it what they found was they brake switch on the Master Cynlinder had leaked and shorted. I repaired the switch, but also found that my cruise control did not work because it had also shorted since it is all on the same wire bracket. No biggie, I can live without cruise control for a while since the cruise control servo was not a cheap part. Well fast forward to about a week ago, when I was driving home and my Bronco hard shifted into 2nd and the check engine light came on. I was like...Profanity Removed? and my Overdrive button light was going off and on. I followed some tips on the board and checked all wires under the dash and fuses, even disconnected the battery to correct it. The problem still lingered and I bit the bullet and took the Bronco in to get it checked out. Turned out the faulty cruise control servo was still causing a short on the wire bracket cause not only was I have the overdrive shift button issues, my horn was not working. You could temporarily correct the problem by jiggling the wires and it would shift smooth and the horn worked. I just ended up getting the cruise control servo replaced and now the problem should not come back anymore and my cruise control works. I guess I had to get it fixed some time. I just thought I would share this with the board in case anyone might have a similar issue.

 

I just have to add this... HOLY CRAP!

I added the Lucas transmission stuff that was mentioned here, and the difference is incredible. After about 10 miles, I couldn't believe it was the same truck. Apparently it had been slipping the whole time I have had it. (About 1,500 miles. This is my first Bronco, so I never knew how bad it was.) Once I put that stuff in, I had the full power of the engine finally getting to the wheels. Suddenly I could accellerate on the freeway without it kicking out of overdrive. There is a slight hill on the way to work that always used to bog me down, and today I just flew right up it with no problems.

I can't wait to see how this will improve my gas mileage too!

I'm sure the transmission has been fairly well toasted by now, so I'm going to change the fluid & filter, add a bottle of this transmission goo and save my pennies for the day it gives out.

All I can say is: Buy this stuff!!

 

Truley, hit your connections for the tranny too....Just unplug and grease them..See what you get..

 

I had the same type of problem, and it ended up blowing up the tranny, on the way to the transmission shop.
My mech. said this was the 3rd truck in with the same problem and everyone is right it was the PCM module.
It cost about 80.00 through ford, thats the only place to get replacement, there is no codes for the problem ether
i believe if i remember correctly. Also check the cooling lines to the transmission. they both should be hot, in and out.
My radiator was bad and didn't know it, fluid was coming in but wasn't returning. Ended up cracking the rebuilt trany.
After the last rebuild i had gone back to same hard shifting 2/3. I thought all that money wasted. But i found out
that its the computer calibrating itself. Some say about 150 miles others say 600 miles for it to reset. mine took
a little over 500 to reset. Now i dont even feel it shift, the only way i know its shifted is by the sound of the flowmasters
changing tones.

95 bronco EB, redneck hi pro POS, 302
94 bronco xlt, Its the wife's
65 monarch
73 challenger, 340 six pac

 

 

Don't know if anyone mentioned this but after you do anything in the way of electronics with the E4OD remember it may take a few miles of driving for the computer to adjust or "relearn" the shift points and compensate for new compontents or clean strong connections and corrected voltages.