automatic transmission - rebuild, upgrade or fix?

[userzweig]

Hi,

Recently, the automatic transmission in my 1971 280sl (150,000 mi) has been acting up.  I was driving in the city, and all of a sudden the car stopped.  It seemed to be stuck in some gear that just let it inch along slowly on level ground, no matter if it was N, R, or a forward gear.  I called AAA, turned it off, popped the hood (I was actually in a traffic lane, pointed slightly uphill, and it wouldn't roll back or go forward!).  AAA took forever, of course, and after 10 minutes I started it up, shifted a few times, and it worked again, but it felt weak.

Mechanic started a simple service, removed the fluid pan, and found 'significant' metal shavings there -- not giant, but big.  He says I should get a rebuilt one - about $3,000 installed, although Sun Valley can bring that cost down about $500 (I'm in San Francisco).

Any advice on whether I should have it towed to a transmission specialist ($100 towing fee to a good one 15 miles away) who 'might' be able to repair it, or should I just bite the bullet and get the rebuild?

Bruce

[TheEngineer]

Now is your chance to really fix your transmission: The KA025 you have in your car is not the best the world has ever seen. Later models Mercedes had much better ones. I bought a 1979 transmission from Benz Friendz here in Seattle for $250 and plan to install it. If you must, they probably have KA025 transmissions as well; they were used in the sedans also. But the KA025 transmission (marked:"Getriebe Typ GA280SE") on the tag affixed to the left side, has no torque converter, only a slip clutch. All later transmissions have a torque converter which multiplies the engine torque about two times and they also sense throttle position. Do some research.

[userzweig]

Thanks for the suggestion.  I've added the word 'upgrade' to this topic title as a result.  I spoke with the guy at Sun Valley (www.mercedesdismantlers.com) and he thought that the loss in resale value (plus the effort of refitting) made the upgrade a bad idea.

Bruce

quote:Originally posted by theengineer

Now is your chance to really fix your transmission: The KA025 you have in your car is not the best the world has ever seen. Later models Mercedes had much better ones. I bought a 1979 transmission from Benz Friendz here in Seattle for $250 and plan to install it. If you must, they probably have KA025 transmissions as well; they were used in the sedans also. But the KA025 transmission (marked:"Getriebe Typ GA280SE") on the tag affixed to the left side, has no torque converter, only a slip clutch. All later transmissions have a torque converter which multiplies the engine torque about two times and they also sense throttle position. Do some research.

'69 280SL,Signal Red,113044-12-007537,tired engineer, West-Seattle,WA

[RBurg]

Dear userzweig:
When I took my 280Sl out for a test drive (prior to purchase)and at the second light I drop the tranny. The owner was in the passanger seat next to me. Purchased  the O GIGI with 1/3 off the price because he did not want toi mess with a tranny proble.
 Lake Country Classic in Minneapolis  put a new tranny in  and we used EUROPEN TRANSMISSIONS. 201 489 7770. 240 Lodi Street, Hackensack, NJ. Did a great job and the one they sent use was perfect.About $1800.00 installed. We sent the old one back for them to handle, took about 4 days for the tranny to arrive.  They have adversited in the STAR for as long as I can remember Besure to put a new flex joint in when you do the tranny, no sense doing the job twice.

Ron - Minnesota
71 280SL Tobacco "O GIGI"
97 E420 Silver Mist

[69280sl]

I/m facing some auto trans issues on my 68' 280sl and find theEngineer's idea for an upgrade to a later (and presumeably better) transmission of interest. Somehow the idea of a transmission that starts in second never made a lot of sense to me. To say nothing of the hard shifts with the fluid coupling.
The question is,Would this be a direct, drop in replacement?

inspectorgm

[TheEngineer]

To 69280SL: No, it would not be a "drop-in". You must select an automatic that has a matching bolt hole pattern with the engine. There is also a pilot hole in the flywheel and newer transmissions have a smaller pilot: you have to make a bushing. There is no relative motion, it is for centering only. I found the newer transmissions are longer by about 3 inches and you have to shorten the drive shaft. You want to keep the shift lever the same. The newer transmissions have the "P" forward. So you have to make an extension to the lever on the gearbox and attach the existing shift lever there. This way, no one can tell that you have a modern automatic in there. You also need to modify one bellcrank on your trottle linkage to provide another ball joint. This is to attach the throttle position control lever of the transmission. You can find parts from sedans starting mid 1969 because they had a newer transmission. That "starting in second gear" was retained by Mercedes for many years and you may not be able to find a transmission that does not have that set-up. But it works just fine because the torque converter multiplies your engine torque two fold, the fluid coupling does not. It really depends what you can find at a junk yard. Your MB mechanic has a small book that gives all the tech. info by year and transmission number. I got a 1979 transmission (p/n 722.112) used by 280E/CE from 1977 to 1981 It is a W4B 025 and has 'bout the same gear ratios as my K4A 025. It helps if you can do the engineering. Me, I have a machine shop and am making parts for a 1937 540K

[n/a]

I had my automatic in a '69 280SL rebuilt shortly after I bought it...key is find a known good repair shop or you'll waste your money. Even if you have to ship out of state to have the rebuild done and have someone else install, it's worth it, as taking these things out due to the cramped quarters, not something you want to keep repeating. I used a firm in Milford, Connecticut by the name of Brangaccio's and the cost 2 years ago was $2,200...a real deal for a total rebuild and installation. Never a problem since, and I am hard on it with manual upshifts.

I too find the starting out in 2nd a real drag...anyone consider swapping out the fluid coupling for a torque converter with a slightly lower stall speed? It would be good to upgrade the existing tranny rather than altering linkages for a later box. Any comments?
Thanks.
Regards,
Joe Bango

[cth350]

the way you bypass the "start in 2nd" feature is to manually shift down while the car is sitting still.  Then punch the gas.  1st gear is only good to 22 mph or so. -cth

[psmith]

I have heard good things about Peter Schmid (no relation!) Transmissions in Burlingame.  They specializes in german transmissions.  There's some good info on his website as well, but mostly for newer cars. http://www.peterschmid.com/

Pete S.

[userzweig]

I called Peter Schmid (Wolfgang actually owns it now), and I told them I have a '71 280SL.  They wanted to know the number on the side of the transmission before they could tell me if they had a rebuild in stock.  

Sun Valley told me that all of the 280 SL's use the exact same transmission, and they could ship me one without any additional info.

Does anyone know which of these two informed opinions is correct (i.e., is there more than one transmission model for the '71 280SL)?

Sun Valley even says that all of the 230 250 280 SL automatic transmissions are the same -- same gear ratios, etc.  

Bruce

quote:Originally posted by psmith

I have heard good things about Peter Schmid (no relation!) Transmissions in Burlingame.  They specializes in german transmissions.  There's some good info on his website as well, but mostly for newer cars. http://www.peterschmid.com/

Pete S.

[ja17]

Hello Bruce,
Any W113 transmission is correct. There is an early version (GA 230SL-E) and a late version (GA 280SE) both of these are the type K4A 025. The two versions are virtually the same and completely interchangeable. They are also identical in appearance also. Some very minor internal changes are the only difference.

Joe Alexander
Blacklick, Ohio

[n/a]

I also have a 280SE Convertible that uses the same transmission as my 69 280SL. In late 1969 MBZ changed the trans to one that starts in first gear. I was going to install this later trans and asked the guys at the MBZ Classic Center and they said to maintain the value leave the numbers matching the original data card. And, there are other parts (down shift, shift lever and drive shaft) that all must be changed. So I kept the original. I am in Los Angeles and took the car to Sun Valley and had a GREAT experience. Work was clean, on time and on price. The owner knows these cars in and out. Runs like a top now. The even delivered it back to my house at no addtl cost.

[joelj]

Hi Bruce,

How's your transmission?

did you buy the tranny?

Keep us posted.

Joel

[userzweig]

I finally bit the bullet and bought a Peter Schmid, installed by Pete's Mercedes in San Francisco.  This is the most expensive way to go (sigh), but I'd heard that the Peter Schmid transmissions were going to go up in price a lot in the near future, so I figured that I'd better just get one while I could.  Also, they're totally guaranteed, and this turned out to be a good thing.

Incidentally, several other good shops in SF could have put in the tranny, and would have saved me $300 or more, but the car ended up at Pete's when died, so I figured what the heck.

I thought about having Sun Valley send one up, but no one could tell me what would happen if there was something not right with it.  SV would fix it for free, of course, but somehow the car and/or tranny would need to get to So California, where they are located.  I suppose that if I'd been willing to drive the car down there in the off chance there was a problem, then I could have saved some big $$ with SV.  However, I didn't really have that option.

Turned out, finally, that Pete's put in the Peter Schmid transmission, and they didn't like the way that it felt, so I had to wait a couple of days while they took the car down to Burlingame, where they tried to correct the problem, gave up, and then put in an entirely different rebuilt transmission, which needless to say really feels good.  So, all in all, I think that I'm better off with the way I did it, though a little on the minus side financially.

Also, I had to buy a new thing that couples the transmission to the drive shaft, another $240 or so.  Someone else might have let me buy the part myself.

Anyhow, the shifting is much smoother than before, and the car no longer seems to knock ever, which is nice.  Looks like this transmission should go until 2050 or so with proper maintenance, which is probably longer than I will

Bruce

quote:Originally posted by joelj

Hi Bruce,

How's your transmission?

did you buy the tranny?

Keep us posted.

Joel

1971 Copper 280SL Automatic

[joelj]

Hi Bruce,

sounds like the money you spent, maybe a lot up front is well worth it due to the service you got from Pete's mercedes.

I too have an automatic with the fluid coupling that is starting to leak. I'll be sedning the unit to The converter Shop to have them weld the rivets.

I'm glad to hear that your car is running smooth. Keep us posted as you run up the miles. One of these days if my car would ever need a new/rebuilt transmission i'll make sure and go back on your thread.

Cheers and good luck.

Joel-j

[Fintail]

Dear Sirs

May I ask which is the better the aluminium coulping or the all steel coupling from a later year. Are they interchangable. its a 280se engine onto a 250se box

Many thanks

John

[ja17]

Hello John,

In rare occasions I have seen the aluminum converters split at the weld seam and fail.  I have also seen the steel and aluminum  converters begin to leak at the riveted hubs. The steel converters with the welded hubs seem to be the best. But you must pay attention to whether your original  converter has the four or six hole attachment pattern to your flywheel also.  I believe that the steel welded converters use only the six bolt attachment configuration.

To summarize.....
Converter failures are rare.  Price may be the deciding factor.  If you use a riveted hub converter, pressure check it for leaks ahead of time. If a steel converter with a welded hub is available, it is the most robust. .

[ptooner]

Hello Bruce,
Any W113 transmission is correct. There is an early version (GA 230SL-E) and a late version (GA 280SE) both of these are the type K4A 025. The two versions are virtually the same and completely interchangeable. They are also identical in appearance also. Some very minor internal changes are the only difference.

Joe Alexander
Blacklick, Ohio

Well, I can tell you that one difference is that the later transmissions don't have the pressure switch that controls the high idle solenoid when the car is in gear.
(Ask me how I know 

Gerry
65 230sl

[Fintail]

Thank you Gerry and ja17

Noted the point on 4 and 6 pin location, so still use the kickdown solonoid (3 way) but no need for micro switch on the venturer. I see steel is more robust is there better hp transfer efficiency.

So many Thanks and Merry Christmas to all members

John

[naniroma0]

Hello John,

In rare occasions I have seen the aluminum converters split at the weld seam and fail.  I have also seen the steel and aluminum  converters begin to leak at the riveted hubs. The steel converters with the welded hubs seem to be the best. But you must pay attention to whether your original  converter has the four or six hole attachment pattern to your flywheel also.  I believe that the steel welded converters use only the six bolt attachment configuration.

To summarize.....
Converter failures are rare.  Price may be the deciding factor.  If you use a riveted hub converter, pressure check it for leaks ahead of time. If a steel converter with a welded hub is available, it is the most robust. .

Hello,
converter is problem, y
pak disc 3ª default

[TheEngineer]

As you can see, in my earlier posts I have been unhappy with the shifting of my automatic transmission. I bought a newer model transmission and was prepared to install it. My old 1986 Toyota truck shifts so much better and every time I used the Mercedes I thought: Why can my Mercedes not shift so nice? I have several friends who have Pagodas just like me and we have traded cars just to compare: They all say, my car shifts smoother than theirs. But one day I test-drove a dark red Pagoda that was for sale at the local Jaguar dealer. It shifted very smooth, smoother than my car. I tried to find out who had worked on the car, but no luck. The one thing I got out of it was, that the transmission could shift properly. Talking to local mechanics was of no help: They all said, your car shifts just fine. But the up-shift from 2nd to 3rd was often rough, especially when the car had been driven a while. That went on for a decade. Then, last year, I noticed white smoke from the exhaust after the car had not been used for a week. The smoke would disappear quickly. It occurred to me that the diaphragm in the modulator was 40 years old and could be cracked. I found that someone had been tampering with the adjustment because the seal was gone. I removed the diaphragm. It was difficult because the shield for the exhaust pipe is close, visibility is poor and working room restricted. I inspected the diaphragm on the bench: It is small: 40mm diameter. It looked fine and I pulled a vacuum on it over night. But I noticed that it had been installed not quite properly inserted into the cover. I re-installed it and checked for proper operation by the book. I found that the switch adjacent to the throttle flap was misadjusted. The instructions are to connect a test light and it must go out before engine rpm reaches 1600. (Leergasschalter prüfen 27-23/4) Time for a test drive: Surprise: The car shifts just fine! It had been smooth before, as long as it was cold, but now it shifts so smooth all the time! Just as good as the Toyota! That was last year and it still shifts very nice. I’m still suspicious of course: When rpm reaches about 2500, I wait for the jerk. But it doesn’t happen. It shifts smoothly into 3rd. I’m very happy!