Worth a transmission fluid change?
Discussion
I've got a now 10 year old SLK I've had from 3 years and 30,000 miles. It's always been full MB serviced, including the transmission fluid at 40,000 miles. Oddly there doesn't seem to be a further change specified but with the car now at 90,000 miles and every intention of keeping it as long as I can, I'm wondering whether another change would be worthwhile or am I just wasting my money?
Are they 7-speed? The early 7-speeds were one-off atf change at 3 years or 37,500 miles, IIRC, whereas later 7g+ boxes, from c.2011/12 were every 5-years/77,500, whichever comes first. At some stage Jaguars, amongst others were 'sealed for life', although most now agree a regular change is necessary, after all, once it's out of warranty, manufacturers aren't really interested and they often seem to work to a 'life' of c.7years.
If it was mine and I was keeping it, I'd change it.
If it was mine and I was keeping it, I'd change it.
It's a 2009 7 speed so yes, seems to be a change at 37,500 (you're right, not the 40,000 I was thinking) and then that's it which seems strange to me.
They're quoting £421, which is more than the entire service of the rest of the car, hence giving me pause, but equally it feels like a prudent thing to do.
They're quoting £421, which is more than the entire service of the rest of the car, hence giving me pause, but equally it feels like a prudent thing to do.
I'm pretty sure MB say they're all one-off changes, unless that's altered in very recent cars.
Mine's a 5 speed and was one of the last that was sealed for life - literally a couple of thousand VINs later they introduced the 3yr/37,500 mile change, so with mine being on a Mercedes service plan they wouldn't do it.
I paid for it around 60K miles and even then the dealer was very reluctant to do it. If anything, the previously imperceptible gear changes became slightly noticeable, especially downshifts when slowing.
If it's not giving any concern I'd be minded to leave it alone. You can understand why Mercedes would want to push the initial change outside the 3yr PCP/Lease ownership window, but there's no reason why they wouldn't call for futher changes if they felt them necessary.
I've also seen it suggested the gearbox should be reset and re-adapted, which is quite an involved process - but ask on forums and the general view seems to be that that's nonsense.
Mine's a 5 speed and was one of the last that was sealed for life - literally a couple of thousand VINs later they introduced the 3yr/37,500 mile change, so with mine being on a Mercedes service plan they wouldn't do it.
I paid for it around 60K miles and even then the dealer was very reluctant to do it. If anything, the previously imperceptible gear changes became slightly noticeable, especially downshifts when slowing.
If it's not giving any concern I'd be minded to leave it alone. You can understand why Mercedes would want to push the initial change outside the 3yr PCP/Lease ownership window, but there's no reason why they wouldn't call for futher changes if they felt them necessary.
I've also seen it suggested the gearbox should be reset and re-adapted, which is quite an involved process - but ask on forums and the general view seems to be that that's nonsense.
£421 sounds a like a main stealer price?
My Indie (MBS Mercedes, Southampton) carried out an auto gearbox filter and fluid change on my 2003 SLK 320 and although I had a service plus some other work carried out at the same time I seem to recall the gearbox element was in the £150-200 bracket.
My Indie (MBS Mercedes, Southampton) carried out an auto gearbox filter and fluid change on my 2003 SLK 320 and although I had a service plus some other work carried out at the same time I seem to recall the gearbox element was in the £150-200 bracket.
Ari said:
It's a 2009 7 speed so yes, seems to be a change at 37,500 (you're right, not the 40,000 I was thinking) and then that's it which seems strange to me.
They're quoting £421, which is more than the entire service of the rest of the car, hence giving me pause, but equally it feels like a prudent thing to do.
I am having the same train of thought with my E class. If you pay £421, how do you know they actually changed the fluid?They're quoting £421, which is more than the entire service of the rest of the car, hence giving me pause, but equally it feels like a prudent thing to do.
Sheepshanks said:
I'm pretty sure MB say they're all one-off changes, unless that's altered in very recent cars.
It was changed with the 7g+ gearboxes, which I think coincided with the introduction of stop/start but, if not, it was around the same time.They also use different fluids, so you just need to ensure that whoever is changing it is aware of that.
Its well worth doing, cheaper than a new gearbox... I found Mercedes dealers were the cheapest on fluid as well... I did our SLK a few years ago, bit on my blog about it...
https://jtccc.wordpress.com/our-cars/mercedes-slk/
I also did our Jeep, with an oil and filter change, and after 12 months sucked some more fluid out with an electric pump and replaced it with new. As stated above, some remains in the torque converter.
https://jtccc.wordpress.com/our-cars/jeep-grand-ch...
https://jtccc.wordpress.com/our-cars/mercedes-slk/
I also did our Jeep, with an oil and filter change, and after 12 months sucked some more fluid out with an electric pump and replaced it with new. As stated above, some remains in the torque converter.
https://jtccc.wordpress.com/our-cars/jeep-grand-ch...
The Mad Monk said:
I am having the same train of thought with my E class. If you pay £421, how do you know they actually changed the fluid?
Well I guess you have to have some faith. Otherwise where do you stop? How do you know that they changed the engine oil? The spark plugs (if scheduled) and so on?For what it's worth, the MB dealer might be expensive, but I've never had cause to doubt the work that has been done.
buzzer said:
Its well worth doing, cheaper than a new gearbox... I found Mercedes dealers were the cheapest on fluid as well... I did our SLK a few years ago, bit on my blog about it...
https://jtccc.wordpress.com/our-cars/mercedes-slk/
I also did our Jeep, with an oil and filter change, and after 12 months sucked some more fluid out with an electric pump and replaced it with new. As stated above, some remains in the torque converter.
https://jtccc.wordpress.com/our-cars/jeep-grand-ch...
That's really interesting, thank you. https://jtccc.wordpress.com/our-cars/mercedes-slk/
I also did our Jeep, with an oil and filter change, and after 12 months sucked some more fluid out with an electric pump and replaced it with new. As stated above, some remains in the torque converter.
https://jtccc.wordpress.com/our-cars/jeep-grand-ch...
I have a much better understanding of why it costs so much now. I assumed it was like engine oil, undo the sump, drain it out, screw back in and refill from top.
Ari said:
That's really interesting, thank you.
I have a much better understanding of why it costs so much now. I assumed it was like engine oil, undo the sump, drain it out, screw back in and refill from top.
No problem, its a good investment I believe. you will hear people say that it causes problems... thats because they wait for a problem to start before changing the oil! at 90k its a good time for an oil AND filter change, it will probably extend the life of the gearbox by quite a bit.I have a much better understanding of why it costs so much now. I assumed it was like engine oil, undo the sump, drain it out, screw back in and refill from top.
buzzer said:
No problem, its a good investment I believe. you will hear people say that it causes problems... thats because they wait for a problem to start before changing the oil! at 90k its a good time for an oil AND filter change, it will probably extend the life of the gearbox by quite a bit.
That's helpful, thank you. 
I'd hate to think what MB would charge to replace one!Gassing Station | Mercedes | Top of Page | What's New | My Stuff