Car is an 08 GL550 with 25k miles.

Manual says 39k miles: https://www.mercedesbenzraleigh.com/...amg_diesel.pdf

Dealer says 70k miles...?

But neither state a time frame.

 

From 2007 to 2014 the GL has the 7G-Tronic transmission, however only on 2009 to 2014, MB recommends the transmission fluid and filter should be done every 40K or 4 years.

 

I cant find the information in my damn manual.

In the link above, it says 39kmi for a 2008 so I dunno.

Do you happen to know the recommendation for the 08?

 

For both 2007 and 2008 MB recommends to change transmission fluid and filter one time only at 39K, there is a note that reads "not time dependent, only mileage-interval applies". I asked MB why they recommended only one time change on 2007 and 2008, and starting on 2009 they recommends to change fluid and filter every 40K although is the same transmission, and I got no answer. I prefer to spend some money in oil and filter instead of spending a lot to repair a burnt transmission.

 

I would leave it alone until 37-40k. Then Every 50k miles

 

Something else that you should consider is to replace fluids on the transfer as well the differentials. I change at the same time I do the transmission.

 

I think these are relatively straight forward and can do them myself.

Happen to know fo any DIY threads or videos?

Debating on the tranny because will need to take it to the dealer.

Also because there are instances when changing the tranny fluid has caused problems because the transmission becomes "used to" the old oil. Although I feel like my tranny's fluid should be ok to change due to the low miles.