2001 4.0 4x4 possible trans problem?

[Bird76Mojo]

On the way to work the other day, I started to get a pretty major shudder in the driveline. I've since noticed that it will only do it right after it has shifted gears and it's low in the RPM range, while you're applying more throttle to try to accelerate. It's a major shudder and will rock you back-n-forth in the seat a little bit. I'm thinking it's the OD band or OD apply servo piston is worn. The truck is high mileage at nearly 200,000 miles. It only does it when it's in 5th gear...

So far it hasn't throw any codes. I've done a fair bit of reading and some people have had the same symptoms with a weak coil. It will misfire when under load and at low RPM. I may go ahead and throw a new coil on it to see what happens. The coil is the original unit to the truck right now.. I've also read up on torque converter shudder, but am unsure if that's what it may be. It's never done this before.

I changed the trans filter today with a Motorcraft 4x4 unit and 4 quarts of Motorcraft Mercon V. No change, even after warmed up.

Anyone here with a good bit of insight in these transmissions have any thoughts?



GB

 

[RonD]

In a 5R55E transmission OD is also used with 1st gear to get a "Faux" 2nd gear, i.e. 1st, turn on OD, now in 2nd, turn off OD, shift to 3rd
That's how the 4R(4-speed) became the 5R(5-speed)

Unrelated issue but shows whats activating and when in the 5R55E: https://atracom.blob.core.windows.net/gears/2003/2003-05/2003_5_50.pdf

 

[Bird76Mojo]

I've never had a 2-3 flare before but a long time ago I was getting an occasional 1-2 flare, but not recently..

I'm going to throw a different coil on it tomorrow, from a parts truck I have sitting around.

 

[MikeG]

I had ignition coils do that once, was sure the tranny was going out.... but replacing the coils (per the advice of a mechanic) solved the problem. So.... that is a maybe.

 

[Bird76Mojo]

Fingers crossed!!!

But on the other hand, I did find a somewhat local shop that seems to specialize in the 5R55 transmissions, and they perform all of the upgrades to the valve body and servo bores, all for around $1650 and $150 for a rebuilt torque converter.. so there's that...

 

[DILLARD000]

A possibilty.
ThrottlePositionSensor\TPS mounted on left end of ThrottleBody,
was failing\erratic a few years ago on my 2001 v6~4.0L~SOHC, caused symptoms like your describing.
PCM forced transmission into limp mode; had to drive in 2ndGear 10 miles home.
Thought I had a tranny problem; turned out to be the TPS; it's a 3wire pot that gets burnt spots in the wiper.
Several hours to figure it out, 15min & $25 to fix it.

Are you using an OBD2 scanner that will read both StandardSAE & ProprietaryFord codes?
Hope this helps.

PS: Putting basic vehicle specs in your profile+signature will help folks answer questions faster.

 

[Bird76Mojo]

I only have a cheap 2-button code reader. If the coil swap doesn't change anything then I'll look in to swapping out the TPS.

Do you have to verify TPS voltage on these when swapping them out by checking the voltage at zero throttle and watch for a smooth voltage sweep when opening the throttle?

 

[DILLARD000]

The transmission codes are all Proprietary Ford codes, maybe why you are not seeing any trouble codes. Make sure your OD OFF lamp bulb is not burnt out, so you can at least tell if any tranny codes are stored in PCM. You really need a better scanner. Their is a spec voltage range for the TPS signal, dont recall what that is though for your engine/year.

 

[DILLARD000]

Dug out my maintenance records.
For my 2001 SOHC, the TPS signal wire should read approximately 1.0v @Idle ~ 5.0v WideOpenThrottle.
The bad TPS was erratic & roughly reading 4.7v Idle ~ 5.0v WOT; so the pot was burnt thru in the lower range.
About that same time, I discovered I also had a cooked DPFE sensor on the EGR tube, so I also replaced that.

 

[Bird76Mojo]

The O/D light is working and hasn't remained on. When I was road testing the truck, I pushed the switch and saw the light on the dash illuminate. The truck drives fine with O/D turned off. No shudder while shifting, which makes me think something is wrong with the torque converter lockup when the truck hits 5th gear.

 

[DILLARD000]

Good the OD OFF bulb is working;
it will blink several times when a Transmission trouble code happens.

 

[Bird76Mojo]

I took it out for a test drive today, and I had read previously about someone not getting it to throw a code unless they gave it a full throttle run. So I drove it like I stole it. Sure enough, it started flashing the check engine light. Then it went out. Then on the way back home I stomped it some more because angry Hulk smash, and it flashed some more.. I hooked up the code reader and got a code for misfire cylinder 4... hmmm...

Before all of this, I had disabled the EGR temporarily with no improvement. I'd also changed the trans filter and fluid with no change. I also checked the TPS voltage and it was a normal, smooth voltage sweep and in spec. I removed and cleaned the MAF, and discovered it needs a new air filter..

After seeing the code for cylinder 4 I thought I'd pull that plug and sho nuff, it had the porcelain cracked. So I went to the parts store and bought a single plug. Installed it and still had a misfire. When I removed the plug wire, it must have broken internally, because it had zero continuity when checked with a meter. So a quick trip to my parts truck to grab a spare plug wire, and she's running like a scalded dog now.

Next project is to install new rear leaf spring bushings in the junk FR34 Softride leaf springs..