Transmission cooler split
Thread Starter
Newbie
Joined: Nov 2025
Posts: 5
Likes: 0
Transmission cooler split
Hello again. I did some hot stress testing in the C43 this weekend whilst the temperature was up ~30C. This morning there was a small puddle under the right hand side of the front bumper so I knew it was the transmission cooler as I had been monitoring it as there were a few tiny blobs of coolant seeping out of it. Well I've gone to take it out and whist knocking in my 5mm allen key bit into the bolt holes it has split the casing to for the cooler and water is pouring out. I've already called Mercedes and the part is obsolete so I don't think this is going to be an option. I've tried online with the part number given to me and there aren't any available from what I can see. Has anyone had this issue and did they go down the aftermarket/ modified route of repair? There is a video I have seen where a fellow Brit front mounts the cooler using an aftermarket cooler and lines and seems to have done this a few times with other C43s:
Thanks, Tom. Based in UK
Thanks, Tom. Based in UK
Newbie
Joined: Jun 2026
Posts: 1
Likes: 0
'99 S202 C43 AMG
So i got my C43 a few months back. While the previous owner maintained it incredibly well, the only issue my mechanic identified was a leak from the gearbox oil cooler. When i tell you it has been the biggest pain in the backside trying to source the original OEM part (A2022700095) I'm sure you'll know yourself!
I've got the part on back order with Mercedes, but I'm not holding out any hope given the part is no longer being manufactured. I've called a few specialists across the UK and the issue we have is that this specific gearbox oil cooler was only ever used on this generation C43 AMG. So it wasn't a component on other W202s, or even other R129 SLs or W210 E-Class from that same time period. As a result, it's bloody difficult sourcing that part as so few of them ever existed.
What I'm planning on doing is, given the fact my leak isn't a major one yet, getting my mechanic to remove the part and then taking it to a local specialist who work on repairing car radiators / oil coolers. I can then connect the correct hoses which are still readily available from Mercedes. Otherwise, the only other option is to get an aftermarket one fitted. However, given the placement of the oil cooler you will likely need custom pipes fitted elsewhere underneath the body and braced. I'm trying to get everything as original OEM as possible, but if I can't get it fixed this'll likely be my only option.
Let me know if you have any better luck than me!
I've got the part on back order with Mercedes, but I'm not holding out any hope given the part is no longer being manufactured. I've called a few specialists across the UK and the issue we have is that this specific gearbox oil cooler was only ever used on this generation C43 AMG. So it wasn't a component on other W202s, or even other R129 SLs or W210 E-Class from that same time period. As a result, it's bloody difficult sourcing that part as so few of them ever existed.
What I'm planning on doing is, given the fact my leak isn't a major one yet, getting my mechanic to remove the part and then taking it to a local specialist who work on repairing car radiators / oil coolers. I can then connect the correct hoses which are still readily available from Mercedes. Otherwise, the only other option is to get an aftermarket one fitted. However, given the placement of the oil cooler you will likely need custom pipes fitted elsewhere underneath the body and braced. I'm trying to get everything as original OEM as possible, but if I can't get it fixed this'll likely be my only option.
Let me know if you have any better luck than me!
