?W124 Auto box experiences?

[smeeeee]

Hi All,

Very happy to have Big Bertha back in my grubby mitts now, I'd just like your opinions and experiences on the quality of the gear change on the 4 speed Auto box in this car please.

Mine's a 300D and, although the gear change is smooth under load and higher up the rev range, I notice that if I drive it slowly to try and get the gear box to change lower in the rev range, it does change but it's VERY jerky, it kind of lurches forward as the revs drop.

Is this normal (car is 12 years old and has done around 117K). The engine and drive train is very smooth indeed and I'm just wondering if there is anything I should be looking out for with this model, or whether I shouldn't worry about it as they all do that!!

Thanks in advance peeps

 

[grober]

I always find the autobox is less "jerky" if its used in the E mode rather than S mode. Thats assuming you have the S/E mode switch?

 

[smeeeee]

I always find the autobox is less "jerky" if its used in the E mode rather than S mode. Thats assuming you have the S/E mode switch?

nope, I'm afraid I must have the pauper's version as it's only 4 speed and no switches

It's generally only jerky in the lower gears, so from 1st to 2nd and a bit less noticeable from 2nd to 3rd (that only leaves one more )

It's awful when it's cold since it holds onto gears longer, when warmer it's less so.

Don't get me wrong though, it's 100% better since having the fluid and filter changed, I thought I'd need a new gear box as it was very jerky in every gear!

Thanks

 

[fnkhan68]

just to add a correction , the gearbox on your car will not have a e/s switch as it is a diesel. diesel 124's did not come with this feature on the autobox. the reason the car holds onto lower gears for longer when cold is so that the car reaches working temperature quicker and then changes gears quicker once its warmed up. it is a mechanical feature of the car but still the gear changes shouldnt be that jerky. when i had the fluid and filter changed on my 124 the gear changes were so smooth that you couldnt feel them, the car just glided but then i am comparing a petrol car against a diesel. have you tried checking all the vaccum pipes to see if there are any splits or cracks or come off as this could also affect gear changes.

 

[jpskiller]

mines same jercky from n to 2 holds gears till about 3500 revs, 3 and 4 smooth, and reverse is a jolt, had atf done, 2 week ago, a bit better, but still there who knowes might get better, but prob just worse.

 

[smeeeee]

just to add a correction , the gearbox on your car will not have a e/s switch as it is a diesel. diesel 124's did not come with this feature on the autobox. the reason the car holds onto lower gears for longer when cold is so that the car reaches working temperature quicker and then changes gears quicker once its warmed up. it is a mechanical feature of the car but still the gear changes shouldnt be that jerky. when i had the fluid and filter changed on my 124 the gear changes were so smooth that you couldnt feel them, the car just glided but then i am comparing a petrol car against a diesel. have you tried checking all the vaccum pipes to see if there are any splits or cracks or come off as this could also affect gear changes.

thanks,

yes, I realised why it was worse when cold, just thought I'd mention it as it's annoying. Mr 124 had a good old poke around on the car and everything is functioning, I just wondered what other people's experience was in the diesel and whether I should expect to have to replace the gearbox shortly.

cheers,

 

[hitt]

just to add a correction , the gearbox on your car will not have a e/s switch as it is a diesel. diesel 124's did not come with this feature on the autobox. the reason the car holds onto lower gears for longer when cold is so that the car reaches working temperature quicker and then changes gears quicker once its warmed up. it is a mechanical feature of the car but still the gear changes shouldnt be that jerky. when i had the fluid and filter changed on my 124 the gear changes were so smooth that you couldnt feel them, the car just glided but then i am comparing a petrol car against a diesel. have you tried checking all the vaccum pipes to see if there are any splits or cracks or come off as this could also affect gear changes.

If I wanted to check the vacuum hoses . . where would I look?
My gear changes can be a little on the jerky side at times too.

 

[94mattda]

220 TE Transmission change

Hi i bought a 220 te 1993 in january and two days later the car died. The car has had a total engine rebuild at a cost or £1511 but i have noticed that the gear changes on the auto box are slightly jerky and clumpy since i had the engine done but only when it changes down... any ideas.... dont really want to have to pay for a new gear box.

 

[PJH]

It's generally only jerky in the lower gears, so from 1st to 2nd and a bit less noticeable from 2nd to 3rd (that only leaves one more )

Mathmatically, the change from 1st to 2nd is the biggest change and will mean the greatest change of engine RPM.

Mine is worst 1st to 2nd as well.

 

[bolide]

Early diesel W124s should shift very smoothly. If they don't it will be a vacuum system problem, a worn gearbox or a combination of the two. Adjusting the vacuum system is possible but I've never done it or found anyone who can

The Multivalves can be a little harder shifting. My theory is that the torque curve isn't as flat as the earlier engines and that some shifts (1-2 particularly) drop the engine back onto a part of the torque curve where the engine is very soft and the resultant shift is fairly harsh. Multivalves flare shifts under load, unlike the older cars, and it's all vacuum controlled. Again it's adjustable

The vacuum systems get clogged with carbon deposits so it's worth checking all the vacuum pipes for leaks & clogging. Bad doughnuts, worn diff mounts, worn diff input bearings, worn rear suspension arm bushes, worn rear subframe bushes and worn engine mounts all contribute to jerky R-N-D shifts but the fundamental causes are probably gearbox wear and/or low pressures. If you get the car in the air and shift R-N-D with the footbrake on and observe movement in the diff & rear wheels the results can be surprising

Nick Froome
www.w124.co.uk

 

[MangoMan]

I see here a lot of people are saying that the change from 1s to 2nd is jerky using low revs, surely you mean 2nd to 3rd. As I understand it, and all mine have done it, is that these gearboxes always pull away in 2nd unless you floor it from standstill, more or less.

This is of course if you have it in 'D'.

By the way, mine is quite smooth unless you try to make it go into 4th doing less than 30mph, it just doesn't like it. But 35mph+ no probs.....

 

[smeeeee]

I see here a lot of people are saying that the change from 1s to 2nd is jerky using low revs, surely you mean 2nd to 3rd. As I understand it, and all mine have done it, is that these gearboxes always pull away in 2nd unless you floor it from standstill, more or less.

This is of course if you have it in 'D'.

By the way, mine is quite smooth unless you try to make it go into 4th doing less than 30mph, it just doesn't like it. But 35mph+ no probs.....

I think, by your sig, that you have a 24 valve petrol engine, these have a switch on the auto box that sets either comfort or sporty mode, in comfort mode it starts in 2nd, in sporty mode it starts off in 1st I believe.

 

[fnkhan68]

no the 4spd box pulls off in 2nd in standard mode unless you floor it from a standstill or if you are stationary you can put the car in N and then 2 and then D and the car will take off off in 1st gear. my car is only jerky from 1st to 2nd but the rest of the gears are so smooth that you can hardly feel the changes especially when they change down. these auto boxes really are good and strong and is one of mercedes strong points in comparison to other brands.

 

[smeeeee]

no the 4spd box pulls off in 2nd in standard mode unless you floor it from a standstill or if you are stationary you can put the car in N and then 2 and then D and the car will take off off in 1st gear. my car is only jerky from 1st to 2nd but the rest of the gears are so smooth that you can hardly feel the changes especially when they change down. these auto boxes really are good and strong and is one of mercedes strong points in comparison to other brands.

bit confused now, to tell the truth.

There's nothing about this procedure in my user manual and my car (a 300D) starts off in first whatever I do


Are you sure?

 

[bolide]

Pre-facelift diesels start in 2nd unless you floor the throttle. Multivalves start in 1st

Most older Mercs start in 2nd unless you have the selector in 1 or you give it full throttle

Nick Froome
www.w124.co.uk

 

[MangoMan]

I could be wrong here Smeeeee, but you might think it's 1st, because it would feel like 1st, but believe me I very much doubt that it is. Pull away with the lever all the way back (2)? and you should notice the difference......

 

[smeeeee]

Pre-facelift diesels start in 2nd unless you floor the throttle. Multivalves start in 1st

Most older Mercs start in 2nd unless you have the selector in 1 or you give it full throttle

Nick Froome
www.w124.co.uk

Is there anything you don't know about W124s Nick?

 

[Ian B Walker]

Paul, your car is a multivalve facelift model in case you are confused.

 

[smeeeee]

Paul, your car is a multivalve facelift model in case you are confused.

I'm always confused Ian multivalve facelift what? Oh yes, I remember now, must remember my pills today...

 

[Dieselman]

The later cars do indeed start off in first gear not second.

I suspect the hard shifts are as a result of either low vacuum to the vacuum modulator on the side of the box or the modulator requires adjustment.

I've not done this but there is a linkage that adjusts the modulator pressure so shifts can be adjusted from slurred to HARD.

A quick check of a slipping box is to disconnect the vacuum pipe to the modulator, this should give a really hard shift with no slip or flaring.