New Tranny or Fixable?

[Broosedamoose]

2007 4.0 Auto 4x4. On my way home tonight, I came to a stop sign and when I went to go it was like the truck was in Neutral. I put it in Park and back to Drive but no difference. When I pulled it down to 1 the truck moved as it should. Once I got up to speed and shifted into Drive, it was like it was in Neutral again. So I was only able to go about 35 mph. Thankfully it was all back roads home. When I got home and went to back in, I had no Reverse. I gave it some throttle and it barely crawled into my driveway. Do you think this is something that can be fixed or is it time for a new tranny? It has 250k on it so it owes me nothing! I'm guessing it would probably cost just as much to fix (if not more) as it would to replace it.

 

[RonD]

Its a classic symptom of failed one-way clutch(sprag), which requires a full tear down to replace, so full rebuild

The one-way clutch is used to "engage" D, when you manually shift to 1st the coast clutch is then used as well so you can move forward without the one-way clutch
Its only a $40 part but at 250k you would want to do a full rebuild

Google: Ford Ranger No Forward or Reverse (Broken Sprag)

You will see a 1min video of where it is inside the transmission

Its a known issue/symptom on all automatics but not a common issue on the 5R55E, at least for the number of these out on the road since 1986, lol

2007 4.0l 4x4, can use a trans from a 2001 to 2011 4.0l 4x4 Ranger or Mazda B4000 4x4
Must be 4x4 no conversion is possible

There will be metal bits in the pan if you want to check
And be sure to flush trans cooler(s) as they will have metal bits as well
And always use a new torque converter, not just because of the metal bits but thats a good enough reason, lol

Used automatic trans is a roll of the dice

 

[Broosedamoose]

Well, you just popped my balloon! LOL I just talked to my mechanic and he said it could just be a bad solenoid but after doing your Google search it appears that's not it. I didn't think it could be that simple. Unfortunately he has never rebuilt a 5R55E so I have to either find a used one or go to a Transmission shop. I'm leaning more towards a used one just because the truck has 250k miles on it. I'm always afraid when I start it that the timing chains are going to explode! It doesn't rattle at all but that's a lot of miles! Oh well, so much for getting out of it cheap.

 

[RonD]

Yes, the solenoids are just there to shift to 2, 3, 4, and 5, they are not used to engage transmission into D or R, that's a mechanical process

But that being said, all automatics run on ATF pressure, pressure holds the clutches and bands open(disengaged) or closed(engaged), this is what the solenoids control, the valves that route pressure to the clutches and bands

The 5R55E does use an EPC(electronic pressure control) solenoid
This can be the issue if you just lose Reverse, because Revese requires the highest pressure to engage, but still a longshot
Haven't read if it could effect Drive, and if it did then 1st wouldn't work because of the low pressure for the coast clutch

 

[Broosedamoose]

I called around and it's gonna cost around $3k to rebuild it. Every shop I called said they are 3-4 weeks out! I called a few junkyards and they are just as expensive! I found one with 45k for $2100, one with 103k for $1800 and one with 145k for $300. They said the tranny is hard to come by these days. Do you think the one with 145k is worth it? I plan on keeping the truck for another year or two and I drive less than 10k miles a year. Even if it had 50k left in it that would be fine. Problem with junkyard parts is you don't know anything about them. What would you do?

 

[RonD]

Try car-part.com

2007
Ford Ranger
Transmission
Your zipcode
SEARCH

It will then ask which transmission, AT, 5R55E 4.0l 4x4

Got alot of hits in my area, most list miles

Lower miles would be better but not TOO LOW, lol, if its very low for the year of vehicle that means it SAT for long periods so seals can dry out and harden
Around 125k would be OK in my opinion

 

[superj]

i would be fine with the 145k one. 300 bucks is still high (to me) but its not a pull a part so thats probably a decent price

 

[Broosedamoose]

I ended up with the one that has 45k. The one with 103k was gone when I called back and the other one with 154k is still in a 2005 so it's probably been sitting. I had the tranny installed and it seems to have an issue. I'm not sure what it is. It has two symptoms: 1) When I'm cruising on the freeway, sometimes the RPM's will suddenly ease up about 500 RPM's and then ease right back down. It's very subtle. Maybe like two seconds. Sort of like a very gentle slip. It's not shifting out of OD because when I push the OD button to turn it off, I can feel it shift and the RPM's climb a lot higher. 2) Twice now when getting on the freeway, it wouldn't drop into OD. The first time I eased off the throttle a little and when I got back on it, it shifted. The second time I just held the throttle steady for about ten seconds waiting for it to shift but then I had to eased off and it shifted. I wasn't still gaining speed. I held it steady the whole time.

 

[19Walt93]

What you're describing sounds like the convertor unlocking and locking back up. Before you get too involved talk to the installer to make sure he cleared the PCM memory, if not you can do that by disconnecting the battery for a few minutes. You'll then need to do a drive cycle for the PCM to relearn. Before even doing that, check the fluid level, it's the cheapest and easiest thing to do.

 

[Broosedamoose]

Ok, I'll give that a try tomorrow and get back on here with the results.

 

[RonD]

Test the built-in stall speed of torque converter
When I was a kid it was called power braking, lol

Engine running
Nothing in front of you
Put trans in D
Leave foot on the brake to hold the front brakes locked
Press gas pedal to the floor but only for 2 or 3 seconds
Engine RPMs will only go up so far, that's the stall speed, the point at which torque convert no longer slips, it locks and rear tires can break loose, lol, for a smoke show , the "power braking"

Stall speed is for the engine being used, it is set for the torque/power for that engine, not horse power, torque power
2,000-2,300 is average
2,500-2,800rpm is fairly common stall speed for high power engines

In 1985 the A4LD came out and had a TCC solenoid, torque converter control, it could lock the torque converter manually if speed and gas pedal were stable, i.e. cruising, this increase MPG quite alot in automatics, also reduced ATF heat generated by torque converter "slipping" when its not locked

Your description of the issue could be the TCC is not holding the torque converter locked when cruising
But could be torque converter can't lock fully as well
The test will tell you if it can
You will see a max RPM as torque converter locks, don't hold gas pedal down longer than 5 seconds UNLESS the rear wheel(s) are now spinning as that can damage the transmission, that energy has to go somewhere

 

[Broosedamoose]

I tried the "Power Brake" method and the stall speed was 2,600 RPM's all three times I did it. On the third try the tires started to slip.

 

[RonD]

So when you are driving and RPM starts to wander what RPM are you at?
If its under 2,600 then the TCC solenoid is probably the issue its not locking torque converter like it should when cruising
Generally above 35MPH TCC should on/locked

If its the solenoid itself that should set a code instantly as an electrical fault
So could be the valve it operates to lock converter, leaking seal maybe
Next fluid/filter change you may want to give that a look

Or there may be a totally different reason, lol
Just guessing

 

[Broosedamoose]

The RPM's are around 2,200-2,300 on the freeway going 70-75 mph. So the torque converter should be locking up at a much lower RPM? I took it in an he said there are no codes. I hate to have to bring it in again and drain all the fluid to change out the TCC Solenoid only to find it wasn't the problem. I think I'm going to go to a transmission shop and talk to them about it. Maybe because it was sitting for a while there is something funked up inside. I can try running it hard a few times by flooring it while getting on the freeway and let it run through the gears. Just don't want to get too crazy doing 100 mph in a 4WD truck! I could also use my tuner to increase the shift pressure and change the shift point to a higher value. IDK. This is just frustrating after spending $3k to have it replaced! Maybe I should've just had the original rebuilt. I just need to get another 10k-15k miles out of it. By then my 2003 5.0 swap/rebuild should be done. I try to baby it so the engine will last but who knows. With 250k miles on it I'm sure it's tired!

 

[RonD]

Transmission shop can run pressure tests to see if there is an internal issue as well