AW55-50SN attempt at repair (with pics)

[oragex]

There is also a video on Youtube to show how to open up a solenoid using some sort of a special key.

Not sure if it works for Volvo's

[precopster]

You can't open S1 through S5. You can open and service the SLS, SLT and SLU solenoids which are the most common failure points in these valve bodies.

You can buy S1 through S5 at any dealer or as a set from eBay.

EDIT: I found a friend here in Adelaide who happens to have a valve body lying around. He's sending me the S4 solenoid this week. Looks like I'll be stitching up the casing tonight.

When the Transgo kit arrives I'll fit the kit to the valve body and stitch it all back up.

[DGM]

Mike it is good to see that you make progress to fix this issue. The shift solenoids states aren't always the same depending on which document we read. Most likely it is related to the various issues of valve bodies for different car manufacturers over the years.

Hiram Guteirrez in its video often mentioned the band anchor bolt as a potential suspect for no reverse and also a missing seal behind the valve body. It may not apply to you but it is always good to keep it in mind. He has a nice video on how to adjust the SLT line pressure.

You may have already seen them but for future reference I include the links to the different topics.

Transmission tear down & Inspection


Solenoids repair



Most common mistakes


Diagnostic/repair/ pressure adjustment - Valve body

[DGM]

I posted twice by mistake. I don't know how to remove it.

[precopster]

Thanks DGM Hiram's work is already very familiar to me. In fact I wouldn't have ventured near a transmission without his videos.

Band anchor is checked and in place as are the seals behind the valve body.

He does have style when it comes to his work!!

Last night I noticed a crack in the rear drum. I'll post some pics before I have it repaired.

20140211_123537 (Custom).jpg (98.54 KiB) Viewed 4021 times

[jimmy57]

I think that is the prize. Isn't there a piston bore on the inside of that drum where crack is located?

[precopster]

I'll check that out Jimmy.

I pulled down the drum and have arrived at an alloy casing inside the drum.

It has clutch packs inside and is called the Forward (C1) and direct (C2) clutch assembly.

I don't yet understand why the car drove so well in D when this drum retains hydraulic pressure for both reverse and 1st gear.

The S4 solenoid is on its way so I should be able to compare it with mine.

[precopster]

The used S4 solenoid arrived and it too has no return actuation spring (is this a common fault or normal?).

It seems that the return for S4 is hydraulically actuated or I have another faulty solenoid.

Only way to find out is buy a new one.

I haven't had the drum repaired yet.

[precopster]

I attempted a valve body refurb on a different car today and compared the S4 solenoid.

All S4 solenoids have no auto return actuation unlike the other 4 solenoids.

So now the blame for no reverse lies squarely on the cracked rear drum casing.

[xHeart]

Dr. Mike,
Learning is a joy, but you are killing me.
Would you continue to include photos of your findings?