W108 250 SE automatic gearbox - does it start off in 2nd??

[Steve Longden]

Hi
I have the above vehicle and have just spent the last 5 years getting the gearbox rebuilt.
The original problem was that is only appeared to have 3 forward gears and it desperately needed a 4th. It is revving out at about 55 mph in the 3rd gear.
It took so long due to a long series of problems/ delays/bad luck/parts delays etc etc. Anyway its back in now and still only has 3 gears. I've gone back to the transmission company of course and they're now saying that all old auto mercs start off in 2nd and the gearbox is as it should be.
What????
My immediate reaction was that this was nonsense, that they're trying to fob me off etc. however I have found in a couple of believable legitimate places online this being confirmed (that 1st is only selected if you manually put it into 'L' gear)
SO....what is going on? If this really is true then what is this car all about? It's almost un-drivable topping out at 55mph. I mean its an S Class luxury cruising saloon.

Does anyone have any experience of this? I have heard of people changing the diff ratios on these to make them more drivable but I just cant believe that this vehicle was commissioned like this.

Can anyone help please

Thanks

Steve

 

[DREAMER NO2]

Steve What is you vin number or auto box type no ?

 

[DREAMER NO2]

Your car was built with a 4 speed auto box,, i recon 3 forward ,,and 1 reverse . Like so many they start in second gear unless selected . Now ,,just may be your engine is lacking a little hunph .in the 3 gear it will keep going faster .You might need a good tune up in both fuel and the ht side . Going back to the box in the specs it reads 4 speed ,i wont say 3 forward and reverse just 4 speed . So keep looking in for further information.

 

[Steve Longden]

Steve What is you vin number or auto box type no ?

Hi
I'm waiting to go to the transmission company that rebuilt it (who currently have the vehicle) to do a test drive so I'll get these details from them

 

[Steve Longden]

Your car was built with a 4 speed auto box,, i recon 3 forward ,,and 1 reverse . Like so many they start in second gear unless selected . Now ,,just may be your engine is lacking a little hunph .in the 3 gear it will keep going faster .You might need a good tune up in both fuel and the ht side . Going back to the box in the specs it reads 4 speed ,i wont say 3 forward and reverse just 4 speed . So keep looking in for further information.

Thanks again
Regarding the core question of 'should it have 4 forward gears or not' I was convinced by Bristol Transmissions , (who rebuilt it) that it indeed should and does. This was based of their engineer stripping the unit an looking at it rather than from manuals etc. I will be asking this questions again of course.
Their current point is that yes it does have 4 forward gears and all are working as they should. i.e. 1st engages when you select L and 2,3& 4 operate when you select D
This argument is backed up by various google searches about does a classic merc auto start off in 2nd
Regarding the engine maybe just needing a little more umph, I'm positive this is not the case, there's quite a difference between an engine that has run out of power and one that needs another gear and power does not seem to be the problem, it's just screaming rev-wise and totally feels like it needs another gear.

It's left us baffled
I don't want this lovely old car to be restricted to just B roads because it cant go over 55

I'll keep looking.....

 

[steveq]

I have a 1965 Merc with an auto box -- possibly the 'box same as yours?

It does have four forward gears and does start off in second gear. On mine it will only start in first gear if the gearlever is put into "2" (and it won't go beyond second gear).

I wonder was the back axle (differential) ever changed on your car?
Maybe the incorrect differential was fitted?
That would impact the final drive ratio and therefore the top speed.

Are the correct wheels fitted?
If the wheels were a smaller diameter than the standard fitment it would impact top speed (although probably not dramatically).

 

[steveq]

I just looked up the Owner's Handbook for mine and it says that the top speed is 122Mph !!?!

I presume that has the engine revving close to the red zone -- I have never gone anywhere near that.

Do you have any documents for your car -- handbook, Haynes manual, etc.?
They should give you good information regarding top speeds in each gear and max speed.

 

[S500 Pete]

Thanks again
Regarding the core question of 'should it have 4 forward gears or not' I was convinced by Bristol Transmissions , (who rebuilt it) that it indeed should and does. This was based of their engineer stripping the unit an looking at it rather than from manuals etc. I will be asking this questions again of course.
Their current point is that yes it does have 4 forward gears and all are working as they should. i.e. 1st engages when you select L and 2,3& 4 operate when you select D
This argument is backed up by various google searches about does a classic merc auto start off in 2nd
Regarding the engine maybe just needing a little more umph, I'm positive this is not the case, there's quite a difference between an engine that has run out of power and one that needs another gear and power does not seem to be the problem, it's just screaming rev-wise and totally feels like it needs another gear.

It's left us baffled
I don't want this lovely old car to be restricted to just B roads because it cant go over 55

I'll keep looking.....

Could it be the torque converter slipping? The older autos didn't lock the converter once rolling. I remember the revs on my old Rover climbing when going up hill although the speed stayed the same.

 

[Steve Longden]

I have a 1965 Merc with an auto box -- possibly the 'box same as yours?

It does have four forward gears and does start off in second gear. On mine it will only start in first gear if the gearlever is put into "2" (and it won't go beyond second gear).

I wonder was the back axle (differential) ever changed on your car?
Maybe the incorrect differential was fitted?
That would impact the final drive ratio and therefore the top speed.

Are the correct wheels fitted?
If the wheels were a smaller diameter than the standard fitment it would impact top speed (although probably not dramatically).

Hi Steve
Thanks, that's useful information, it certainly backs up what Bristol Transmissions are saying about the box but leaves me with a car incorrectly geared.
I quite agree about the possible back axle issue, I've no idea of it's history or what ratio it has although I guess I could jack it up and calculate it and compare with the manual.
I think the wheels and tyres are correct but will check these too.
I only have a Haynes manual for the vehicle which is pretty limited when it comes the real detail of the transmission.
I am aware of an online manual you can download from mbmanuals .com so I might buy one of these.

Does any one have any experience of these manuals?

Thanks again Steve

Steve

 

[Steve Longden]

Could it be the torque converter slipping? The older autos didn't lock the converter once rolling. I remember the revs on my old Rover climbing when going up hill although the speed stayed the same.

Hi
According to mbmanuals it has a fluid coupling rather than a torque converter but I don't know what that means. It doesn't appear to be slipping though

 

[RhodieBill]

Personally, I would get a second opinion at a reputable Mercedes Independent Garage before doing anything else.

I really do not think you can change the Diff to make that much of a difference!

By the way it will also start from first quite aggressively if floored from standstill - and I mean floored!

Also I believe the Speedos in those cars have markings (I -30 II -50 III -90 being max speeds in the gears). Floor it and see if you get to the corresponding speeds at the markings. (1st is very short - hence why they generally pull off normally in 2nd).

Good luck!
.

 

[DREAMER NO2]

Problem is i was working with half a plan .I dont know the type of auto gearbox you have .You have owned this car and if people have worked on it, then you know and should have said what type of gear box it was .Do you know? then post it up to help us help you .I try to help posters and, i read so many posts with half the information on the problem . We know its this model of car ,,but in its production years ist probably had 5 gearboxes fitted .Information i found was that the car was fitted with 4 speed auto box. So please tell us the gearbox number ---- that will tell us if it is a 4 speed -5 speed etc

 

[Steve Longden]

Problem is i was working with half a plan .I dont know the type of auto gearbox you have .You have owned this car and if people have worked on it, then you know and should have said what type of gear box it was .Do you know? then post it up to help us help you .I try to help posters and, i read so many posts with half the information on the problem . We know its this model of car ,,but in its production years ist probably had 5 gearboxes fitted .Information i found was that the car was fitted with 4 speed auto box. So please tell us the gearbox number ---- that will tell us if it is a 4 speed -5 speed etc

Yes, will do.
I have requested this information and am going to test drive and get the vehicle tomorrow so should know more then.

 

[Steve Longden]

Personally, I would get a second opinion at a reputable Mercedes Independent Garage before doing anything else.

I really do not think you can change the Diff to make that much of a difference!

By the way it will also start from first quite aggressively if floored from standstill - and I mean floored!

Also I believe the Speedos in those cars have markings (I -30 II -50 III -90 being max speeds in the gears). Floor it and see if you get to the corresponding speeds at the markings. (1st is very short - hence why they generally pull off normally in 2nd).

Good luck!
.

Can anyone recommend any such garages in the south West (UK)?

 

[RhodieBill]

Can anyone recommend any such garages in the south West (UK)?

Sorry, can't help you there as I'm near Southampton.

 

[Steve Longden]

Yes, will do.
I have requested this information and am going to test drive and get the vehicle tomorrow so should know more then.

The number I have been given for the box is GA230SL Presumably this is the type not the serial number but is it enough? If not i'll get under it and search for more.
I have driven the car today for about 10 miles. Exactly as it always has been - 3 gears in drive, revving out at about 55-60.
If you start in L it initially starts in what feels like a lower gear (presumably 1st) and very quickly changes into what feels like the same gear as it starts off in D (presumably 2nd) so this does confirm what Bristol Transmissions are saying.

 

[Bay Leaf]

Gearboxes are determined by the forward gears eg 4 speed 5 speed 6 etc they don't count reverse as they all have one. But I'm with steveq on this as in has the diff been changed at some time for towing a boat or caravan etc.

 

[steveq]

Is there a rev counter on the car?
If there is one you can see the revs the engine is at when you are doing 55mph.

If there isn't one on your car as standard, I understand that it is possible and relatively straightforward to retro fit a rev counter.
You might not want to to mount it on the dashboard permanently but it might be worthwhile to fit it temporarily while you

 

[steveq]

The number I have been given for the box is GA230SL.

That is the same gearbox as in mine. 4 forward gears and it starts in 2nd by default.

On a quick look your car should have a top speed of 118mph.

Is the speedometer reading correctly?
Maybe check it using another car driving at 50mph.

 

[00slk]

Are we sure the transmission is changing up into 4 or is it staying in second or third gear, this would account for the high revs. Don't think a lower diff ratio would alter the revs that much.