This is for a 2015 MB GLA45. 6 liters of 001989850309 (236.21 spec) fluid was purchased back in late 2020 when I thought I was going to do my own DCT fluid change. After researching and finding the instructions on how to do it, I decided to take it to the dealer in 2023 and have it done. The dealer installed 001989850313 (236.21 spec), which is a different part number than what I purchased (13 vs 09). Both seem to meet the specification and the 13 seems to be a more modern part number as the 09 is no longer on the bevo spec site but is listed as an OEM part number on several sites, such as FCP Euro: Mercedes Dual Clutch Transmission Fluid (1 Qt) - Genuine Mercedes 236.21 | FCP Euro
The 2015-year model doesn't require the transmission additive. I still have the 09 fluid and want to use it and not waste it (was expensive). I am at 21k miles on the current fluid and it is recommended to be replaced at 31k or 3 years. I was wondering if I can remove (extract) one or two liters of the 13 fluid currently in the transmission and replace it with one or two liters of the 09 fluid, maybe every 1k miles until I use up all of the 09 fluid? Should I just extract as much as of the 13 fluid as I can and replace with the 09 in one shot? I would consider extending past the 31k mark if I do proceed with installing the 09 fluid, maybe 5k or more but certainly not doubling it due to the filters not being changed. I have a dipstick for the transmission and have a few of the locking tabs.
Some of my concerns are of slightly different chemistry between the two, if they are compatible (should be?), and if there is a different thermal expansion between the two fluids which would necessitate getting the level correct at the specified temperature (maybe difficult to do without xentry).
Anyone have experience with these two fluids?
The 2015-year model doesn't require the transmission additive. I still have the 09 fluid and want to use it and not waste it (was expensive). I am at 21k miles on the current fluid and it is recommended to be replaced at 31k or 3 years. I was wondering if I can remove (extract) one or two liters of the 13 fluid currently in the transmission and replace it with one or two liters of the 09 fluid, maybe every 1k miles until I use up all of the 09 fluid? Should I just extract as much as of the 13 fluid as I can and replace with the 09 in one shot? I would consider extending past the 31k mark if I do proceed with installing the 09 fluid, maybe 5k or more but certainly not doubling it due to the filters not being changed. I have a dipstick for the transmission and have a few of the locking tabs.
Some of my concerns are of slightly different chemistry between the two, if they are compatible (should be?), and if there is a different thermal expansion between the two fluids which would necessitate getting the level correct at the specified temperature (maybe difficult to do without xentry).
Anyone have experience with these two fluids?
