New owner ... looking to learn : transmission

[Por911t4]

Hi folks, having introduced myself in the new members section, I have purchased a '66 Pagoda 230SL that belonged to the late Mike Rutledge - seemingly a very well respected and active member here on the forum. Im a 20+ year Porsche guy so please go easy on me as I'm just building my Pagoda knowledge....

I understand that a characteristic of auto box is that its fairly clunky when shifting up and down the gears and I fully understand the car is 53 years old. But just how clunky should it be and would an old and filter change on the box improve matters ? Solenoid adjustment help ? In addition it seems to hang onto the gears until quite high up the revs (?) Is this all normal ?   

Any feed back would be appreciated … remember Im a newbie !!

Kind regards
Barry Clarkson
Glasgow Scotland UK

[JamesL]

Barry
Clunky as in audibly clunks, or is not a smooth transition? The latter sounds wrong to me but it's not a seamless transition

They start in 2nd - unless you're trying really hard - so you really have three gears working. So yes, they do hold revs to higher than you'd expect, and they run at higher revs. Give or take, in top, you're at 500rpm per 10mph (so I am at ~3k at 60mph). The max torque is quite high up the rev range so they hold the gears

[Por911t4]

Many thanks James , I appreciate all the advise I can get being a new owner. The change between gears is clunky ( certainly not smooth feeling and you can hear the thump if under load) however if I anticipate the next gear change and lift off the throttle its a lot smoother. Just doesn't seem right . I'm going to take her out again this afternoon. I'm also going to monitor the rev on the motorway.

Many thanks
Barry

[kampala]

Barry,

Congrats on your entry to Pagodas!   

I would say that the Auto box should not be rough.  In fact, when all things are "tuned" I find it surprisingly smooth for a design from 50 years ago.  I am in no way an expert at these but have done a couple things that changed the shifting.

1. you must make certain that your fuel/air linkages are correct - this is very important and makes a significant difference in shifting due to item 3.

2. you need to make sure that the motor timing and such are correct.

3.  there is a little solenoid switch on the throttle body (air intake) with a couple of wires on it.  If items 1 & 2 are adjusted correctly and the transmission still shifts rough, you can adjust the position of this switch as it will adjust when the trans will shift.  A very tiny (hair) movement makes a change in shift timing. Don't do this until you have done items 1 & 2.

4. If shifting has improved with the above crucial items, BUT you still hear a slight clunk, check the rubber differential mount that comes up into the trunk.  When this mount is metal to metal, you could get a clunk. 

you will also read about checking the solenoid on the trans - I will not comment on that as I have not had to do this.   The above 4 items were enough to get smooth shifting.

Some links that will help:

https://www.sl113.org/wiki/Restricted/Linkage-tour   (must be a "full member" to access)

https://www.sl113.org/wiki/Automatic/Start#SmoothShifting

https://www.sl113.org/forums/index.php?topic=806.msg3842#msg3842  (for the Diff Mount)

There is more than this, but this will get you started and all of the above is easy to check.

[ja17]

Good advice from kampala. You can also view the operation of the linkage on the transmission by removing the access panel under the carpet on the tunnel (right side). The solenoid and its linkage should move to the back position at rest (idle) middle position when the accelerator is moved off idle and forward position at full throttle (kickdown button on floor depressed). If the linkage is stuck or the switch on the intake venturi is not adjusted correctly, all sorts of transmission shift problems occur.

[Pawel66]

Do you have records on gearbox oil change? I would also check on the oil level and condition and replace it all together with the filter if in slightest doubt.

Then all written in previous post applies - thoroughly and systematically, no shortcuts, no bypassing (I am talking from my experience). Yes, you should start from adjusting ignition timing and fuel/air mixture adjustment at idle - it is all interconnected with gear changes (through vacuum).

All the adjustment jobs described are not that difficult, including adjustment of modulator pressure - if it comes to this, which is not for sure.

Gear changes are soft and there are no clunks. It just takes some patience usually to get there.

[Por911t4]

All great advise gents and much appreciated. The level of knowledge here on the site never fails to amaze me . Kampala thanks for the highly detailed reply. Ill give all this some deep though before getting in around the box … I don't want to dabble and make the situation worse ! Ill check to see if its had a recent oil change and start there . Ill maybe have a natter with a local automatic transmission company that I know . It helps that were in the motor trade.

Ill keep you posted of developments

Many thanks gents

Barry

[Peter h]

Hello
I change the transmission Öl on my 280sl. The only reason was, I don't don't know how old it was. Some weeks later the transmission leaks hard. The same happened to a friend's pagoda. I think the new öl wash the dirt out and the transmission leaks. Maybe....
Is some one there happened the same. 
It may don't happened to you Barry, but it's interesting if someone else.
Peter

[Por911t4]

Many thanks Peter , interesting but sorry to hear of your oil leaks … especially when you were trying to make things better !

kind regards
Barry