Auto box slipping - PeachParts Mercedes-Benz Forum

MrTibbs · #1 10-23-2011, 02:42 PM

Hi guys,

I'm new to this forum (though was a regular poster on the pelican parts Porsche site until recently).

I've got a couple of W123s - a 230E saloon/sedan and a 280CE. I just bought the CE in an auction and driving it home it was clear the auto box isn't quite 100%. Basically it's slipping - particularly noticeable when pulling away from standstill; it seems to have no power. When accelerating in gear (I think when it's in top gear and the trans has a solid coupling) it's fine, but the box is definitely slipping.

I've had a look and the fluid looks like it's at the right level and is clean (I suspect the previous owner tried a fluid and filter change and realised it hadn't solved it). I've not tried adjusting the vacuum module yet, but I suspect it'd be a lost cause.

So my question is whether you reckon I should just bite the bullet and look for a known good box to swap in - how difficult is it to change the box? I have a garage with a pit and some decent jacks etc.

One final thing - where's the oil filter on the 2.8 M110 engine? Can't seem to see it anywhere obvious.

Thanks for you help,

Mike

mbdoc · #2 10-24-2011, 08:38 AM

What year car? USA or euro version?
Makes a difference on trans type.

Oil filter on drivers side, access from under the car.

MrTibbs · #3 10-24-2011, 02:02 PM

Hi,
It's a 1983 Euro (I live in the UK).

I've just started it, let it idle for a couple of minutes and checked the level of the trans fluid - it was well above both lines marked on the dipstick. It was about halfway between the lines scribed on the dipstick and the first bend in the dipstick (it has two sets of bends or kinks in it). I think this means the trans has too much fluid in it, is that right? Car is parked facing slightly downhill (not much, car will roll at a bit slower than walking pace in neutral). Should I suck some of the fluid out of the car do you think? would too much fluid cause slip?

The car was also making a whooshing noise when I drove it home. I thought that was trans related, but looks like my thermofan is seized. When I shut the car down the fan stopped spinning almost immediately (and when the car was running the fan looked to be going at engine speed).

If I do still have a trans issue, I have a line on a used trans the guy reckons is OK (and it's very cheap). Might try draining and refilling with a filter change first though.

Car has been sat for a few years I think - am I being totally optimistic thinking it might be due to that? Fluid looks very clean and doesn't smell burned.

Mike

mbdoc · #4 10-24-2011, 02:44 PM

On a 1983 280CE the trans issue is most likely a B2 band or piston mis-adjustment!

MrTibbs · #5 10-24-2011, 03:38 PM

I just started the car again and moved it through the gears before checking and the level still looks high to me.

Then I turned it round and checked it - level was lower but still above the highest mark on the dipstick (and it's fairly cold today - around 10 degrees C). So averaging it out I'd say it was overfilled.

I'll try to suck some fluid out (I'll check the level again tomorrow), and see if that makes a difference.

Mike

MrTibbs · #6 10-27-2011, 02:28 PM

Well I sucked about a litre of fluid from the trans with an oil extractor (cleaner thoroughly) and now it's at a more sensible level. Didn't get a chance to road test it though ao not sure if it's cured or not yet.

I did notice the fan has seized on - the fan rotates at pretty much engine speed. I can rotate the fan with the engine off, but it's very stiff and certainly doesn't spin at all (when I turn the engine off the fan stops immediately). This would explain the noise it was making when accelerating, and might explain some of the low power feeling. The plugs are also quite carboned up so I'll replace those when I get a chance and do a compression test to check all's well with the engine.

So hopefully I'm getting there slowly

Mike

MrTibbs · #7 11-02-2011, 11:40 AM

OK so I've had a chance to investigate the issue a bit more. It seems that in 2nd the trans has a definite whine. in other gears it's less noisy (though still a lot of roar from the fan). I'm guessing this means 2nd gear is worn.

I've found a very cheap autobox from a 280TE that I'm going to pick up and swap in in the hope that makes the car more driveable. It might seem over the top but it was cheap and close to where I live and I can at least clean it up and check it out while it's off the car (can't test it of course, but the seller reassures me it's in good condition).

Mike