230SL Auto transmission - lost gears and whining noise - Help Please :-)

[Nikolaj]

Hi Pagoda friends


After an engine bay overhaul https://gofile.io/?c=0MtPRm this winter I ran into a major issues with my gearbox. The engine and transmission were out and an engine overhaul were done. No work was done to the transmission itself but the radiator was overhauled (with auto trans cooler). New hoses and the cooling pipes were zinc plated. New filter and oil on the gearbox. The gearbox type GA 230SL-E. The car has not been driving for 15 months.

After assembly the car was driving fine for the first 100km. Gear shifting was perfect, sharp and precise - no noises.

While driving I lost 4th then, 3rd, 2nd and now only have 1st gear and sometimes reverse gear is working. I hear a whining noise from the gearbox. It’s more significant when in reverse gear.

I have checked the functionality of the double acting solenoid and it seems to be working fine - idle, light throttle and full throttle (kick down). I measured the pressure switches and they give a ground signal at idle - right side at Drive and Left at Reverse.

I have attached a video where I measure pressure at what I call Test Port “A"

Video with Idle, Drive and Reverse gear and pressure measurement at Test Port “A":
https://gofile.io/?c=a4mSnE

Picture of Test Port A:
https://gofile.io/?c=ffaBU8


Test Ports: (I assume these are Test Ports - am I right? are there more?)

Test Port A, B: https://gofile.io/?c=t6Io54

Test Port C, D: https://gofile.io/?c=IZgNiM

Test Port E, F: https://gofile.io/?c=Sp74Io

Any thoughts on what the issue could be?

Do you know where I can find information about Test Ports and pressure levels?
Any guides to measurement procedures, pressure levels in N, D, R @ xxx RPM?


All help is appreciated !

Thanks in advance
Nikolaj
Copenhagen, Denmark

[ja17]

Was your transmission and engine separated or left together? The first thing I would do is remove the transmission pan and check for any debris.

[WRe]

Hi Nikolaj,
attached some information from the workshop manual for a K4A025 transmission which are - more or less - all the same for all Pagodas, maybe it helps, sorry in German.
- 27-0: basic adjusting values
- 27-25: test and measure procedures
Btw, your engine bay looks great!
...WRe

[Nikolaj]

Thanks Joe

The engine and tranmission was separated during the project and assembled before installing in the car again.
The oil is clean and clear.

I will remove the oil pan during the weekend and look for any debris.

Thanks WRe for the manuals - I have to refresh my German :-)

/Nikolaj

[ja17]

The biggest and most common mistake made is not engaging the front pump and torque converter correctly during re-assembly. The front pump is damaged and metal debris is usually present in the oil pan.

[Nikolaj]

Hi again

I removed the oil pan and found this -> see pictures

After cleaning the oil filter and re-fill with oil the gearbox worked again.
Both R and D are shifting. One thing I noticed was a sliding shift to 4th gear - any thoughts on why ?

What could be the root cause for the debris in the filter ? it looks like brake band / friction disks debris.

Thanks
Nikolaj

[ja17]

Sorry to say it looks like clutch material. Hope the slipping clears-up.

[WRe]

Hi,
the clutch lining is very thin, more or less painted on material only. If the gears go through/slip the clutch material wears off very fast or is worn already.  You could increase the modulation pressure to avoid slipping but this can cause further damage.
https://www.sls-hh-shop.de/main/en/27-automatic-gearbox-27-i-info-belagzustand-c-3_2333_3614.
...WRe

[Alex e]

Hi All,
 Not wishing to hijack this thread but I would be interested to know if anyone else has experienced the same problem that I have. I bought a `67 230 SL last year which had been sitting for several decades. I will eventually restore it but wanted to establish condition of mechanicals while I can still drive it. On my first test drive the car was OK in lower gears but when changing into third would slip and lose drive, which would return if the throttle was lifted.... Because of this it was very difficult to go up hills !
 I removed the sump pan which all looked very clean, fitted new filter etc.....next test drive it would not go beyond first and second gears, after driving for approx 2 miles from cold it started to try and go into third and soon after started to behave normally but not changing perfectly. Having left the gearbox draining for a week due to lack of parts I thought maybe the valve block needed some time to dispel the air. A couple of days later I drove exactly the same route with the same results, the improvement occurred at exactly the same distance ! I can only assume this improvement is related to temperature. Anybody have any ideas.....Alex

[Garry]

There are several write  ups on waking up a Pagoda from a long sleep in the Technical Manual as it sounds like you may have not gone through the steps necessary to avoid some of the problems you describe. Did you drain and replace all fuel and fluids in the vehicle and replace all filters?


Garry

[Alex e]

Hi Garry,
 Yes I have done all of the basics but not yet attempted to check all of the gearbox, throttle etc..adjustments. Just seems like a very odd problem. Looks like I need to go through all that stuff and see where it leads. Alex

[Alex e]

Interestingly I have now discovered that if I leave my car idling for 15 minutes before driving it the gearbox works fine, which points to it being temperature related. So I have no idea where to start resolving this one.......does anyone else.....Alex