Hello,

2000 F-150 4x4 SCREW with 5.4L 2v, 4R70W, and 44-06 ESOF. 245,000mi

Apologies for the novel. I want to preemptively answer a lot of basic questions as to what I've done/tried.


A while back I "lost" reverse. At first it started shuddering but still worked, then it only would clunk into gear, and just rev like it's in neutral.

Recently tore everything apart that I could get to from underneath the pickup. Dropped the pan. found a fair amount of magnetic material and sludge, some chips, etc.
Figured might as well investigate further and see if I lost a band/servo/something.
Found a broken snap ring and its pieces from the OD servo.
All solenoids ohm'd out within spec. Solid harness also tested good. Case connector was leaking fluid.
The reverse band appeared to be present, when I removed the servo and checked it with a screw driver. I had constant and even spring pressure as I pressed in.
I completely and meticulously cleaned every part of this system I could, and relubed with fresh ATF. Blew out all the cooler lines, installed a see-through filter on the return end, and refilled the system with fresh fluid.
New check ***** and three gaskets on the valve body, new case connector, overdrive servo pin, new pan filter, new gasket, etc

I went from having no reverse, to sort of having reverse. At idle, I'm getting about 90psi line pressure in reverse. If I rev it up, pressure increases. All other gears are within spec, in terms of idle line pressure.
While there was some wear on the main regulator in the VB, it is my understanding that if it was too far gone, I wouldn't have consistent pressure, and it would dump to EPC exhaust and not engage the band.
EPC voltage is around 10.48v idle, and increases with RPM. All shift positions register correctly between the dash and the computer running FORScan.

I have engine braking if I manually shift into first gear while driving, with no interruption in braking from 2 to 1.

At this point, it's sounding like the reverse clutch pack and/or drum might be the issue/source of the chips and sludge, and reason for weak reverse gear engagement.

I noticed with the rear end off the ground and transmission in neutral, that the wheels spun fairly easily forwards, but took a very significant amount of effort to spin them backwards.
I disconnected the drive line from the rear, and the rear spun freely both ways. Reconnected after, seeing how it wasn't the diff.
From there, I pulled the motor off of the tcase, and set it to neutral (between 4hi and 4lo). The drive shafts and wheels spun freely both directions, with no noise or binding.

Then, when I put it back to 2hi, and spun the drive shaft, I noticed a sound coming from the output of the trans, or input to the tcase. Somewhere in that cylindrical section.
It is absolutely positively in that area, and it can't be u-joints as I'm able to spin the tcase in neutral and listen to both drive shafts turn without so much as a whisper.
It's a high pitched rotational squeal combined with some low level grinding, about every half revolution.
I can only really get this sound when spinning the wheels forwards, as I physically can't turn the wheels backwards just by grabbing onto the driveshaft from underneath with one hand.
It sounds like a bearing that is either gone, or on its way out. No real grinding so to speak, just a squalling sort of sound.
Transfer case has a fresh two or so quarts of mercon fluid in, with no miles on it.

I'm guessing that there is a bearing that lost/shredded a roller/needle, forcing the others to become pitched at an angle, and only really allow forward movement without binding.
I'm also guessing that this bearing/mystery thing started going out first, and the reverse clutches started wearing/slipping as a result of having to fight against the bind.

My question is, am I close?
Is it more likely to be a tcase or transmission bearing?
Can either of these be replaced if I drop the tcase?
What else could it be?

Thank you in advance, let me know what I can clarify/answer.

 

Well, got the transfer case removed finally, after fighting torsion bars.
Hope this helps someone: make sure the vehicle has jack stands under the front, as those bars are all thats holding you up besides bump stops.
Had to remove the torsion bar keys completely with a two jaw puller on the second dimple, and 2x2 piece of square tubing above the crossmember so the jaws could catch onto something.
Looks like Amazon has a torsion key puller as well

Even with the transfer case out, it still sounds like the noise is coming from within the transmission. I'll pop off the extension housing just to make sure it's not the bushing, but otherwise it is looking like swap/rebuild time.

 

Did you ever find out what was wrong with your truck. I have exact same truck and exact same problem

 

Hi, no I did not. Judging from stuff found in the fluid and filter, I'm guessing that the reverse clutch material got shaved / shredded off, which is why it still kinda works.

Seems worse when the transmission is warm. I have had some luck actually moving backwards on flat ground by going into neutral, then 4 low, then reverse.

Still just driving around without a reverse gear! Been meaning to try and find a junkyard transmission, but not much free time.