Auto transmission problems ?

[Mr Chippy]

Hi all,
I took my newly acquired 1995 E250 W124 for a shakedown run over the weekend, and I would like to ask for some advice on the auto transmission.

If I am accelerating quite hard, the change from 1st to second seems to slip a bit, then if I back off the throttle to let it change better, almost as soon as its in second, it bangs into 3rd. There also seems to be a reluctance to change down through the gears, unless I nail the throttle to engage the kickdown.
Is this usual, or does it need looking into?

The ATF seems to be more brown than red, but its also quite runny.

 

[sunking101]

Hi, the fluid shouldn't be brown so I'd get that changed immediately. A lot of problems can be cured with a proper flush and new auto fluid, hopefully you'll be lucky.

 

[jules335500]

Yes get the oil and filter changes once every 18months....shld be red in colour but if brown its scorched.auto gearboxes hate the heat so if u tow in the summer most good gearbox placed recommend oil coolers and regular oil changes.

 

[Mr Chippy]

Thank you both for your speedy replies.

I had planned to get the fluid changed, but wasn't sure if Mercedes used the usual dexron II. This is because there is not much colour to the ATF at all. Its very wishy washy but with a hint of pink and brown. Its difficult to tell to be honest and it does look a bit runny, hence planning to change it. The only concern I have is that I have always thought auto gear changes should engage with a slight jolt rather than be silky smooth. You have convinced me to change the fluid though, so I will get it booked in to a local specialist next week. Thanks.

 

[sunking101]

The best auto gearboxes do silky smooth changes but some have a jolt which is perfectly normal and within their design parameters. Make sure whoever does change your gearbox fluid does it properly - this takes several 'goes' as when you drain the system it only drains part of the old fluid. You need to refill and drive 'round a bit afterwards, then do it again. Any specialist transmission place will know this or if you're taking it to MB I presume they will too!

 

[Mr Chippy]

Thanks skunking.

There is a specialist near me called Southern Automatic Gearboxes, and they are very good and Ive used them many times before. They have one of these oil changing machines that works whilst the engine runs, then the transmission pump, pumps all the fluid out to the machine from one pipe, and the machine pumps new fluid back in through the other. The end result is that all the oil gets changed in one go. Then all thats needed is a new filter and a check of the sump magnets and the job is done and dusted.

I have heard of people, mostly Americans, who use one bucket with new fluid in, and another empty bucket. Start he car and move through all the gears and the transmission does all the work, but its a bit too scary for my likeing. Some things are best left to the experts, and this is one of those things.

 

[turnipsock]

Yeah, but how do they change the filter?

It's an idea though.

I haven't seen it for a while, but you used to get flushing oil for engines. You would drain the oil and then stick in the flushing oil. Then drain that. Then change the filter and put in the new oil.

 

[MW]

The W124 box is easy to drain, with a good tight 7mm Allen key plug. The beauty is that the sump is easy to remove as is the filter. Unusually, the torque converter is easy to drain as well. Haynes makes it clear, but all you need to do is to take off the radiator fan casing, (a few clips) remove the fan(easy, as one bolt). Then turn the engine while looking underneath at the bottom of the torque convertor for the 7 mm drain plug as it moves past the gearbox spacing, which looks like a cage. When visible, mark the front pulley with tippex at 6 o/clock for next time. Undo the plug and drain about 2 litres from the torque convertor. Europarts do a filter and new rubber sump gasket for about £10. Dextron 11 is fine. I do the filter and oil at 3 years (36k) and the oil at 15k.
If you have a good gearbox place get them to do it, but it only takes about 1 hour and costs £20, to go yourself. Try to watch the company to make sure the filter really is changed.

 

[Mr Chippy]

Thank you MW, that's some very good advice.
I think I'm going to stick with the specialist, although £20 all in sounds very attractive, but they will also test the box and should be able to advise on its general condition. I'm also hoping that they can tell me why its reluctant to change down, but is quick to change up. Maybe the kick down cable or something needs some adjustment. I have no idea so I'll let them on it first.