5r55w transmission flawed?--Opinions

[Mrblack07]

Great forum guys! My current explorer (2nd one) is 2003 xlt 4.0 and I love it but last week my turbine speed sensor faulted (po715). At the time there was not any shifting problems with my explorer (a few days later it shifted poorly from 1st to 2nd). When I took it to a transmission shop and they attempted to test the sensor, they found the sensor had melted into the transmission. The cause of the overheating was a broken servo that led to the overdrive band braking and damage to the gears.

Upon further research through this website and other sites I have found these particular transmissions to fail quit often below 100,000 miles. I had my step son's Grandfather, who is an engineer (die cast), inspect my transmission and review the pdf from ratiotek (a link from this site!) and this is what his preliminary conclusions were in an email he sent me:

"Thanks Jeff,

That really helps [ratiotek pdf]. I think I see what the root cause of the piston failure is. On page 51 notice that the “Servo Strut” has an angle to it. This places a side load on the piston and the shaft which I believe causes a bind that eventually fatigues the steel and results in the broken piston. That explains why the bore gets worn and egg shaped like Shawn [transmission mechanic] was pointing out. I had never seen that type of wear before and until I saw the feature on page 51 it didn’t make sense. For years most transmission designers have placed the piston bore on an angle so that it pushes straight against the band rather than at an angle. I believe that we can show that other automobile transmission designs continue to push straight and do not have this failure. We would need to involved Shawn in order to document that but I think we can prove it..."

He believes the transmission design is at fault and there should be a class action law suite to ask Ford to reimburse consumers for the cost of the trasmission failure.

I don't know if I would seriously considered that but I am wondering about his analysis. Does he have a point? Is the servo or piston the main cause for failure in these 5r55w transmissions?

 

[akajammer]

servo bore wear info

it is an issue.
just am finishing my rebuild of the same trans.
I installed the bronze bushing into both bores.
I have the kit still with one bushing set, if anyone is interested.

see attached pdf file
http://www.modularfords.com/forums/showthread.php?t=137247

http://www.explorerforum.com/forums/showthread.php?t=220655

http://www.servobore.com/servobore/5rw.asp

 

[mikeytotka23]

Great forum guys! My current explorer (2nd one) is 2003 xlt 4.0 and I love it but last week my turbine speed sensor faulted (po715). At the time there was not any shifting problems with my explorer (a few days later it shifted poorly from 1st to 2nd). When I took it to a transmission shop and they attempted to test the sensor, they found the sensor had melted into the transmission. The cause of the overheating was a broken servo that led to the overdrive band braking and damage to the gears.

Upon further research through this website and other sites I have found these particular transmissions to fail quit often below 100,000 miles. I had my step son's Grandfather, who is an engineer (die cast), inspect my transmission and review the pdf from ratiotek (a link from this site!) and this is what his preliminary conclusions were in an email he sent me:

"Thanks Jeff,

That really helps [ratiotek pdf]. I think I see what the root cause of the piston failure is. On page 51 notice that the “Servo Strut” has an angle to it. This places a side load on the piston and the shaft which I believe causes a bind that eventually fatigues the steel and results in the broken piston. That explains why the bore gets worn and egg shaped like Shawn [transmission mechanic] was pointing out. I had never seen that type of wear before and until I saw the feature on page 51 it didn’t make sense. For years most transmission designers have placed the piston bore on an angle so that it pushes straight against the band rather than at an angle. I believe that we can show that other automobile transmission designs continue to push straight and do not have this failure. We would need to involved Shawn in order to document that but I think we can prove it..."

He believes the transmission design is at fault and there should be a class action law suite to ask Ford to reimburse consumers for the cost of the trasmission failure.

I don't know if I would seriously considered that but I am wondering about his analysis. Does he have a point? Is the servo or piston the main cause for failure in these 5r55w transmissions?

I have a 2002 XLS with the same transmission and just found out it needs to be rebuilt before it fails completely (quote for rebuild - $2500, quote for new transmission $3500). I believe this is totally unacceptable on a vehicle that just passed 90,000 miles. After I found out about this I did some research online and found out that this is probably the most common mechanical complaint of any vehicle http://www.carcomplaints.com/worst_vehicles.shtml Ford is clearly aware of the problem, and has even issued technical service bulletins regarding the high failure rate of this transmission. I have even read of several of them failing at under 50,000. If I could, I would start a class action lawsuit against them, because it is clearly a problem with the design of the transmission and not the maintenance (which Ford also makes as difficult as possible by not including a dipstick). Also, I have heard about the cylinder being the reason for failure in many of the transmissions, but I am not sure if this is the reason in all of them. If you hear of a recall or lawsuit against Ford, PLEASE let me know. Otherwise, I will be trading this pos in on a 4Runner.

 

[High_Order1]

I'm in.


You find us an attorney, and the retainer, I'll sign my life away. This transmission stuff and the paint stuff is bs.


-Shawn

 

[gijoecam]

You've got to realize that for every failure you read about here, there are literally hundreds of thousands of other identical transmissions that are going about their daily drive with nary an issue. ALL transmissions fail eventually. Some will fail sooner rather than later, and some portion of those failures will have common faults. That doesn't mean it's a 'design flaw' that merits litigation. It simply means it's one of the short-comings of that particular model.

Keep in mind it wasn't that long ago where vehicles didn't even have a sixth digit in the odometer, NO transmission went more then 50,000 miles without a rebuild, you had to adjust carbs and points every Sunday, and engine rebuilds happened LONG before the body rotted or paint faded.

Now, is it a design flaw? IMHO, no. Is it a shortcoming of that particular trans? Possibly. Then again, I didn't design or test that transmission, so I can't really vouch for why they may have designed it that way. Maybe they had a particular reason for it, and it was done that way as a trade-off for some other performance or function? Who knows?

 

[jrford]

to add my .02 worth, when mine went at 60k, I lost third gear. It was not the servo bores but a snap ring holding the planetary that broke. My trans guy stated 'not a bad design but they used really light parts to increase mpg'

 

[Glacier991]

I'll add my 2 cents.

Auto transmissions are always a trade off in design. Ever noticed how few totally new designs come out, merely updates, upgrades and knock offs? That is because it can run upwards of the better part of a billion (yes with a B!) dollars to totally design, tool and bring a new one into production! (true).

In the life cycle of transmission designs then, we see radical changes, and then for a period of years improvements until we have a pretty decent transmission. Then the cycle starts again.

Cost has dictated that the tranny case be everything for every function. Aluminum does not make a good bore under the best of circumstances - and that is why a majority of aftermarket "fixes" involve sleeving a bore... it has ALWAYS been so. (Now an off axis thrust will accelerate bore wear for sure and THAT is NOT a good design in my mind).

Virtually every "step change" (my description) in a transmission has had its share of problems - regardless of manufacturer. For example, the AOD was considered an awful tranny and the 4R70W that grew out of it may be one of the best FORD ever made.

The 5R55W grew out of the A4LD (not a stellar tranny initially) that itself grew out of the C-3. It morfed from the A4LD into the A4LD-E; 4R55E; 5R55E; 5R55W, S and N. Each has had its troubles after introduction, and over time the fixes, both manufacturer and aftermarket have turned it into a "not bad" tranny....

All that said however, FORD has asked a lot of this transmission in terms of its placement in vehicles.

I don't think the W is in many ways any worse than other manufacturer's trannies - it just has its own share of growing pains. I always did worry about the size of the servos in the aluminum case. (Although the GM 700R4 has just as big of ones, as does the 4R70W... its just that somehow I always looked back to the C-3 and though the case, even upgraded was a little small... and in defense of FORD the 5R55W DID get an entirely NEW case.)

Anyway... there's my thoughts.

Glacier