1988 W124 260E Automatic Transmission Issues

[Gadgeteer]

I'm a newbie here and recently acquired my first old-school Benz. It's a 1988 W124 260E and i very happy i got it. As with many pre-owned vehicles, there are usually some things that need to be fixed.

For my 260E i believe the issue is the 4-speed Automatic Transmission (model 772.409)

Here are some of my concerns. Perhaps experienced owners can give me good advice on what to do.

1. 1. I noticed a sudden jolt every time i shift from P to R.
2. 2. When driving on D, car sometimes also jolts from 1st to 2nd gear. This happens especially when i slightly release the gas pedal before it shifts. However, if accelerating, it shifts smoothly.
3. 3. Once on 2nd gear, it shifts to 3rd gear right away, only after a few seconds, without going through the usual power band for 3rd gear.
4. 4. It doesnt seem to shift automatically to 4th gear. However, if i accelerate and manually move the shifter from 2-3-D, it goes into 4th.

The transsmission shifter bushings needed replacement and so i had my mechanic do this. At this time i also had him check the modulation pressure. Based on my transmission model, presure should be 3.0. Upon checking, there was nothing wrong.

The rubber disk coupling had also been replaced recently.

With these symptoms, what could the problem be? I'd haete to think that i need to overhaul my tranny. Hopefully i can still fix it without doing so.

Could it be the downshift switch under the gas pedal?

I've heard that the use of the additive "TRANS-X AUTOMATIC TRANSMISSION SLIP-STOP & LEAK FIX" really works and can free up a blocked valve body and prolong the life of the tranny.

I live in Manila, Philippines and the cost of a surplus tranny will cost an arm and a leg, the same with the cost of overhauling my existing tranny.

Hoping for your experts advise!

Cheers!

Leo

 

[optimusprime]

auto

Hi can you check the vacuum ,it as a lot to do with the changing of our type of auto box. A valve that helps the gearbox change smooth. Its on the gearbox itself.

 

[optimusprime]

Hi can you check the vacuum ,it as a lot to do with the changing of our type of auto box. A valve that helps the gearbox change smooth. Its on the gearbox itself.

The part to check is the gearbox modulator.A new type modulator can be purchased from Mercedes . Get it checked out first ,before you strip it out.

 

[rorf]

I would suggest you change the oil and filter too - how many miles/kms on the clock?

 

[Dieselman]

The lack of upshift to 4th sounds a bit ominous. That is usually the first sign the box is in trouble.

The hard shifts do sound like the vacuum either to the modulator, or the modulator itself.

 

[Gadgeteer]

Thanks for the initial inputs, guys. They did check the vacuum to the modulator and the modulator itself. They had this special tool to check pressure. It was the first thing the checked as they had the same observations as you guys. They said all seemed okay. Pressure is 3.0 for my 722.409, and up to specs. So the mechanic said it could be blockages in the valve body and/or issues with the lining.

In terms of mileage, i have no idea. When i got the car, the odometer was busted and meter reading was reset. The previous owner only had the car for a year (He has a few Benzes and usually sells them after awhile). But basing it on the many 260E's I've come across over the years, and on the road network we have here (We don't have many autobahn or LA freeway type of roads, Mileage could be in the area of around 200,000 kms.

Has anyone tried the Trans-X Slip-Stop and Leak Fix additive? They said it does help loosen up stuck valves. Any feedback?

Hoping for your continued advise.

 

[optimusprime]

Gadget do a an oil change, and filter at the same time. Its what I would do first. You don't want to strip it if its a simple fix.

 

[Gadgeteer]

Gadget do a an oil change, and filter at the same time. Its what I would do first. You don't want to strip it if its a simple fix.

Got it, will do. Hopefully it's just that. I'll report up once i've done the change.

 

[maxypriest]

i have a 260E 102K gearbox that shifted perfectly in my garage for sale - bargin at £50. Taken out for a manual conversion.

The transmission fluid was like new (ribena colour, with no burning smell).

0776 4429123

 

[Gadgeteer]

i have a 260E 102K gearbox that shifted perfectly in my garage for sale - bargin at £50. Taken out for a manual conversion.

The transmission fluid was like new (ribena colour, with no burning smell).

0776 4429123

Maxypriest, wow... i'd buy that in a minute if i was anywhere near your location. I'm in Manila, Philippines where a gearbox like yours could run up to anywhere between £800-£1000. I know, unbelievable, really.

Oh, well....

 

[Bert_W164]

On my clk230 I had similar issues, rough changes, box use to **** itself at high rpm shifts, from 1st to 2nd...lose drove between D and P, Judders into first all sorts. Sounded like a box failure. Star said clutch slip and what not.

drained oil...may be 2L came out.

Flushed it using 2-3L. .black oil then the ribena coloured stuff. Cleared codes.

Fortunately this cured all my problems.