willlib

Hi, I have a ml320 2008 and the oil have been change at 60k like the book says. but not a t 320,000km I was looking at the level of trans oïl and notice that the oil is very dark. I phone to a few dealer and no one tell me the same thing some says do it and other say don't touch it. So I'm wondering if I should do a tans oil change a that time with the mileage that I have. I think that I'm starting to have trouble with the torque converter ( vibration upon acceleration after 40km/h)

CLK Group

I have had the transmission service (fluid, filter) and differential done every 40,000 miles. Currently have 105,000 with no issues.

willlib

but me I never change the oil between the 60k km and the 320000km that I have. so, changing the oil now do you think it It will not affect the transmission?

CLK Group

I don't believe your current fluid is providing any protection and is probably contributing to problems.

You will not damage your transmission and differential by having the service done.

PSDCampervan

I agree but not enough to just drain, change filter, clean pan & refill as many shops will try to do.... must drain torque converter as well & flush trans oil cooler w/ filtered compressed air so maximum old fluid is flushed out prior to refill w/ new. A flush like this will use 16 quarts of ATF ($$) but produce excellent results.

willlib

tanks for the advice, I did think about the trans cooler but I's a good Idea, I will look for the procedure in this forum.

Automotive_buff

@willlib Hope these help. If you need any other sub-document let me know.

paulg

Just did the oil change this weekend.

Very messy (unnecessarily so) and takes a few hours, but well worth it. I can't see how this could ever make transmission problems any worse.

I was lucky and found the torque converter drain plug, so I would guess that 90% of the oil has been changed, I couldn't be bothered to flush the oil cooler, I got bored with how long it was taking! 90% oil change is still much better than leaving the old stuff in there...

No special tools required, but some form of pump will be needed as the oil has to be pumped upwards through the drain hole.

If you don't have a diagnostic plug-in that will read transmission temperature, you will need something like an infra-red no-contact temperature gauge (about a tenner from ebay) as the oil level is set at 45C.

The oil is outrageously expensive, but lasts around 40,000 miles, so cheap on a per-mile basis.

My changes are now much smoother and I can relax for another few years...

dfghhgfd

A word of caution on changing the transmission fluid with that many miles/kilometers on it.

After that amount of time there will undoubtedly be some sludge build up in the transmission. Flushing out all the fluid can have some devastating affects on the transmission. Fresh transmission fluid will clean out the transmission. Good. But, with high miles and the potential sludge build up can actually end up being a bad thing! What can happen? As the new fluid circulates throw the 'dirty' transmission housing it will inevitably break loose some of that sludge as it cleans. Sounds good, but automatic transmissions work with many small ports and tubes that can be clogged by any debris floating around in the transmission fluid. Yes, there is a filter that you most likely replaced, but that only filters what is sucked out of the pan not what breaks loose in the transmission before it gets to the pan.

It is tempting to drain the pan, torque converter and cooler and think you are good to go, but it might be a very bad decision. Try doing just the pan and filter. After a year or so, do it again. In that way you are getting new fluid in the transmission little by little without blasting all that new fluid in at once. That way the sludge might dissolve before it breaks off and clogs up the transmission.

Just a thought. Good luck.