Please Help - w107 280sl transmission fluid leak from torque converter grate??

[body_infinity]

Hi again, helping a friend get his w107 280sl (M110) 1975 back on the road. We want to get the transmission leak fixed as its getting bigger so started working on it trying to find a leak cleaned it up and found drops of ATF fluid from the grate where the torque converter is.

Q1. Could the plug be the cause and need a new washer? or is there another place here where it could leak from? It seems to leak the most when starting from cold then slows but will continue to leak.

Q2. Also when measuring the AT fluid when hot what should the reading be? When we did this it is well below the bottom line on the dip stick and when cold all the way up well past the top line??

Any tips would be fantastic


-------------------------------
W107 280sl (M110) 1975

[body_infinity]

Ok we had a look for the drain plug at th TC but could not see anything, anyone know where to look for the drain plug? Anyway I thought some pics might help explain the prob...





Any tips ...

[Gurunutkins]

looking at the pics, the torque converter is dry which would suggest that the fluid is leaking out around the shaft seal running down the back plate and dripping out of the grate which is a much more likely scenario than the plug in the TC leaking.

if you look through the hole on the bottom grating and turn the TC then you will see the drain plug in the TC its a small screw with an allan key (or hex key) hole in it.

[deanyel]

The prescribed method for turning the torque converter is to turn the engine with the crankshaft bolt, probably a 27 mm. The fluid level would be higher when warm so you are not getting good readings. The fluid level is to be checked on a level surface, car at operating temperature, in park, engine running, using a clean cloth.

[body_infinity]

Originally Posted by deanyel

The prescribed method for turning the torque converter is to turn the engine with the crankshaft bolt, probably a 27 mm. The fluid level would be higher when warm so you are not getting good readings. The fluid level is to be checked on a level surface, car at operating temperature, in park, engine running, using a clean cloth.

Hi deanyel & thanks for the response, just to clarify I am getting a low reading at operating temp (about 1.2 inch below the min line) which I think is ok?

Re the drain plug, I will double check but I think I did notice fluid on the flywheel hence my thinking it may be the drain plug? It has occurred before on my w114 where for whatever reason the crush washer was not replaced but I am sure the grill was removable anyway will take another look and report back once I find the drain plug...thanks for the info so far any more tips are very welcome...

[deanyel]

Originally Posted by body_infinity

Hi deanyel & thanks for the response, just to clarify I am getting a low reading at operating temp (about 1.2 inch below the min line) which I think is ok?

No, not OK, too low, if it's a good reading. It's not always easy to get a good reading. Get the dipstick clean, push it in all the way, hold it there for a few seconds, pull it out and inspect both sides in a good light. You should be close to the top mark.

[donbryce]

Originally Posted by deanyel

The prescribed method for turning the torque converter is to turn the engine with the crankshaft bolt, probably a 27 mm. The fluid level would be higher when warm so you are not getting good readings. The fluid level is to be checked on a level surface, car at operating temperature, in park, engine running, using a clean cloth.

I thought that transmission fluid drained back into the pan from the cooling lines and torque converter after the engine stops and everything cools down, which would make the level in the pan, measured on the dipstick with the engine at rest, higher. So if you start the engine and measure as described, that would immediately lower the reading mark as fluid is pumped out of the pan and into the converter and lines. Does the fluid level then get higher as the transmission warms up, and if so, why? (I'm not disputing what you say, I just don't fully understand).
And I've always been frustrated trying to read a transmission dipstick while the engine is running, fluid splashing all over in there from, presumably,engine vibration and fluid movement from the transmission pump. Why don't 'they' provide a marker that clearly identifies the correct level when the engine/transmission are cold and 'at rest'?

[Gurunutkins]

Hi Donbryce

you are right that the level does increase slowly as the transmission oil drains back into the pan from the components of the transmission and cooler when the engine is off. when you start the engine the levels drops to the lowest point it will be on the dipstick and some cars have a cold transmission oil level mark on one side and hot on the other. the hot is higher as the oil expands slightly as it gets hot so the level goes up again by about an inch from the cold side.

you should really only take a fluid measurement after about 20 miles of driving with the car in either park or neutral

cheers
Barri

[cth350]

If the torque converter drain plug hasn't been touched in a while, it's not the source of your problem, unless of course, it's been there a while and he is only noticing it now.

When correcting fluid level, resist the tempation to put in any more than half a pint of fluid at a time. Let the new stuff warm up a little before retesting the level.

Like the panda said, run through the gears once or twice before checking the level at idle.

Like the other fellow said, make sure you've got a clean rag. A little bit of lint goes a long way to a problem.

-CTH

[meltedpanda]

I always use a remote starter and bump it until you see it

[body_infinity]

Ok still no luck I am sure I am looking at the right location under the TC grate, just to confirm (see pic below) I am looking for it at location B on the pic is this the window where it should appear?? or is it at point A?

[Gurunutkins]

you should see it about 1cm above the inside leg of the A in your picture. its not at the very bottom of the TC but about 3 - 4cm up the curve
good luck and you should see it with no problem its highly visible

[Gurunutkins]

just read some of the other replies and whilst you can get to it by bumping the starter motor you only have a small window to see it so its best to use a ratchet on the front pulley nut

[meltedpanda]

you do realize that it is only 5mm at the most, it is not big

[Chas H]

I turn the TC with a big screw driver levered against a supported part of that underneath window. Make sure you turn the engine in the correct direction.