5R55S Transmission Solenoid Failures

Has anyone experienced a failure of one of the solenoids in the solenoid pack?

I had an issue on Saturday. Transmission completely lost 4th speed and reverse. Shut the vehicle off. No DTCs. Restarted the vehicle and went for a 45 minute drive with about 50 upshift/downshift complete sequences and the transmission shifted perfectly. Went for another drive on Sunday and transmission shifted perfectly.

This morning I called Tony @ Larry Transmissions and after a lengthy question & answer discussion, he suggested replacing the solenoid pack as he has seen them fail. Reverse and 4th speed also use the same solenoid.

Called Ford next and it would seem that Ford has just released a brand new part number for the solenoid pack - 9L2Z-7G391-A (2009 part #). Oddly enough, my dealer had one on the shelf.

This Saturday I will be dropping the pan to check for any abnormal debris. If all looks good, I will install the new solenoid pack.

Today I got off work a little early so I:

• Drained the fluid from the pan - 3 qts.
• Dropped the pan - drained another 1 qt. that remained in the pan
• Removed the filter - drained about 1 pt.
• Removed the solenoid pack - drained about 1 pt.
• Installed the new solenoid pack
• Installed a new filter
• Drilled the pan for a 1/8" weld in bung to relocate the transmission temp sensor to the pan

The transmission pan was absolutely spotless inside, magnet was clean - no abnormal debris whatsoever. Total fluid loss was about 5 qts. I'm welding the bung in the transmission pan tomorrow. Will be out of town until late Friday. Finish reassembling and road test on Saturday.

Here are some pictures of the old solenoid pack - already removed and the new solenoid pack already installed.

I haven't heard of them failing, but oddly enough since I read your initial post I have seen several solenoids on ebay.

Just out of curiosity was it the old 4L part# or the new 9L part#? Ford sent out a confidential broadcast message to discontinue installing the 4L part number and install only the new 9L part number. Most stealerships have to old part# on hand and will most likely try to deplete their old inventory before selling the new part#. I'm sure everyone is going to try to purge their inventory of the old part#s as soon as possible. The new part# retails $454.00. I suspect a TSB will follow.

I spoke to Tony @ Larry's Transmissions earlier today and he said he would chime in later tonight with his thoughts on this solenoid problem.

this thread reminds me of the autozone commercial where the guy finds out that "it was just the solenoid!" lol

tmcolegr said:

Just out of curiosity was it the old 4L part# or the new 9L part#? Ford sent out a confidential broadcast message to discontinue installing the 4L part number and install only the new 9L part number.

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I didn't have any reason to read the description so I can't tell you. And it isn't important enough for me to go searching for one to look. But I agree, if Ford has updated the part, it is probably the older part

tmcolegr said:

Most stealerships have to old part# on hand and will most likely try to deplete their old inventory before selling the new part#. I'm sure everyone is going to try to purge their inventory of the old part#s as soon as possible. The new part# retails $454.00. I suspect a TSB will follow.

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That's no different than any other company with any other product. Can't fault them for that.

As for a TSB to follow, not really see any reason to issue a TSB if there is an entirely new part number now for the part. And it's not like we are seeing multiple threads from multiple people talking about the part going out.

I spoke to Tony @ Larry's Transmissions earlier today and he said he would chime in later tonight with his thoughts on this solenoid problem.[/quote]

FWIW - as I recall Roper roasted his solenoids - though he appeared to have cooked the fluid all around, so it may not have been a solenoid failure per se, but rather a total weenie roast in the gear box...

What was most impressive was he did that with a basically stock motor...

Hey Roper - did you ever get more info on your trans failure or was it just ruled "FUBAR" and you called it a day?

Lost the solenoids at 30,000 miles.
It took out the converter, a band and a couple of clutch packs. fourteen days to repair at the dealership on warranty.
I wish I had a stick now.

cekim said:

FWIW - as I recall Roper roasted his solenoids - though he appeared to have cooked the fluid all around, so it may not have been a solenoid failure per se, but rather a total weenie roast in the gear box...

What was most impressive was he did that with a basically stock motor...

Hey Roper - did you ever get more info on your trans failure or was it just ruled "FUBAR" and you called it a day?

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Yup, cooked to roasty perfection. Burnt fluid/failing solenoids/failing clutches, in any combination. Once one starts to go, the problem starts to feed on itself and spread the love through the rest of the transmission, or at least that's how I understood it.

06blugt said:

Lost the solenoids at 30,000 miles.
It took out the converter, a band and a couple of clutch packs. fourteen days to repair at the dealership on warranty.
I wish I had a stick now.

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Mister Roper said:

Yup, cooked to roasty perfection. Burnt fluid/failing solenoids/failing clutches, in any combination. Once one starts to go, the problem starts to feed on itself and spread the love through the rest of the transmission, or at least that's how I understood it.

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When your failures occurred, did you get a CEL, flashing OD light or were there any DTCs?

What were the operational symptoms?

tmcolegr said:

When your failures occurred, did you get a CEL, flashing OD light or were there any DTCs?

What were the operational symptoms?

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No CELs, it started "hanging" on the shift to 3rd, the rest reads like a novel...