Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: Thierry du Laos on November 21, 2016, 02:31:54

Title: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Thierry du Laos on November 21, 2016, 02:31:54

Who can give me some investigation direction?
I refurbished the car and re-installed the engine and gear box back as it came with the car.
After the first runs, I had poor power and over heating in the hot city traffic. It seems that this is solved now by adjusting correctly the timing, which was 20 degrees out minimum...!!!! Not less.
But now driving the second gear transition is not smooth, the two others no problem...
So I change the filter and replaced the gear box oil, but not with CASTROL TQ95 that I cannot find...???
Now  driving, the gear changes are perfect, just some time it looks like the gear box is cavitating? And instead of changing the gear, climbing gears, the engine increase regime, like with empty load at out put.
Maybe after the oil replacement, there is some air in the system?
But the main new problem now, that wasn't before is:
When I get out of Neutral, and select Reverse or 4th, the engine cannot hold and stops.
If I adjust the idle (air) screw to increase the RPM, I create an other problem when applying brakes. One side the RPM increase too much or the other side, the engine stops.
So if somebody can give me clues?
One question more:
Is the electrical actuator on the accelerator linkage not suppose to overcome this problem?
Thierry

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: cfm65@me.com on November 21, 2016, 10:48:59

Hi Thierry,
I cant give any advice regarding the settings, but check the gearbox oil level. Remember, it must be checked in P, engine idling, at normal operating temperature. Make sure you use a CLEAN cloth, without any fluffies. Auto trannies do not like dirt or any flaff because it could block small oil channels and galleys.
Regards
Chris

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Thierry du Laos on November 21, 2016, 11:44:03

Thank you Chris, I will check again.
But meanwhile, I found in the Haynes that the problem could be the constant speed actuator.
The item I was wondering what it is for, earlier.
This one could be faulty or not properly adjusted. But I can't find any diagram that indicates from where it gets the signal to work.
How can I test it?

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Thierry du Laos on November 21, 2016, 11:45:06

Chris,
Are you familiar with the aircraft engine CFM????

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Peter van Es on November 21, 2016, 12:19:53

Thierry,

two sections available to full members have a lot of info on the linkage adjustment, and starting aids. They discuss the warm running device, thermo time switches, and cold start valve in a lot of detail.

https://www.sl113.org/wiki/Restricted/Engine-starting-aid-tour
https://www.sl113.org/wiki/Restricted/Linkage-tour

Peter

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Cees Klumper on November 21, 2016, 12:49:43

Thierry: it does sound like you have multiple issues, one being the change in transmission behaviour after the oil change (I would also suspect the oil level may not be proper now as Chris notes), there is a three-way solenoid that affects shifting that could be mis-adjusted, incorrectly wired or otherwise malfunctioning, and lastly the constant speed solenoid, which is designed to increase engine rpm's when you put the car in drive (4) or reverse. Each of these issues is well-described here, and as Peter notes, including in sections of the technical manual that are only accessible to paying members.

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: cfm65@me.com on November 21, 2016, 21:26:30

Hi Thierry,
Yes, I flew quite a few thousand hours on the Boeing 737-800 for South African Airways before retirement, which had CFM56 engines.
However, CFM65 as in my e mail address, was the Somerset West number plate on my 65 230SL, for many years. It is now on my E Type.
Regards
Chris

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Thierry du Laos on November 28, 2016, 04:44:33

For your information,
I removed the CS actuator, because it was not free to play.
Opened it, using my lathe.
(http://img4.hostingpics.net/thumbs/mini_955295IMG3949.jpg) (http://www.hostingpics.net/viewer.php?id=955295IMG3949.jpg)
Pulled carefully the shaft.
(http://img4.hostingpics.net/thumbs/mini_693702IMG3950.jpg) (http://www.hostingpics.net/viewer.php?id=693702IMG3950.jpg)
Dismantled all.
(http://img4.hostingpics.net/thumbs/mini_801991IMG3952.jpg) (http://www.hostingpics.net/viewer.php?id=801991IMG3952.jpg)
Cleaned all, protected and reworked a ring to re-assemble all together like before.
(http://img4.hostingpics.net/thumbs/mini_925470IMG3954.jpg) (http://www.hostingpics.net/viewer.php?id=925470IMG3954.jpg)
Now it is back on the car, and everything works fine and smooth.
Thanks for your support.

Title: Re: 280SL 1968 -- Automatic gear shifting difficult.
Post by: Shvegel on December 27, 2016, 10:55:14

Thierry,
Does the endplate of the actuator unscrew or did you have to cut it off on your lathe?