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Im rebuilding my first LS motor (2015 L96) and ran into something that I'm hoping to get some confirmation on. While cleaning up my work bench, I found a piece of paper that I missed in the main bearing packaging stating that the thrust bearing in the Mahle MS2199A kit must be installed with the side with 3 grooves on the trust surface pointing towards the back of the motor. I panicked a little for a moment because I missed this paper and did not notice that the thrust bearing had 3 grooves on one surface and 2 on the other. However, after I thought about it more, only one of the thrust bearings halves had an oiling hole AND the block and main cap for the trust bearing only has one tang locator each. Am I correct in thinking that it would have been impossible to install the thrust bearing incorrectly aside from installing the oiling half of the bearing on the cap instead of the block (I didn't do this but as far as i can tell, this would have been the only incorrect installation possible). In my head, I cant imagine a way that the block half or cap half of the thrust bearing could be installed 180 degrees from the way that it is currently installed (other than maybe if the cap itself were installed backward putting both tangs on the same side of the bore instead of 180 degrees separated) . Id probably just pop the main cap off and check but I've already torqued the TTY bolts on the main and don't want to retorque or replace if its impossible to install the trust bearing wrong assuming the halves are on the correct side and the cap isnt installed backwards. Attached a photo of the summit listing for my main bearings for reference
Last edited by bgbbgb246; Dec 9, 2025 at 12:13 PM.
It’s impossible to put it together backwards. The 3 grooves go to the rear as long as you didn’t cut the tang off the shell.
I was able to confirm that the 3 grooves are in fact to the back by looking real close at the edge of the thrust surface with a flashlight through the bottom of the motor and down through cylinder 3 and 4. And yes, for the L96 at least, it would have been impossible for me to put the 3 grooves forward aside from maybe putting the cap on backwards.
Thrust bearing orientation 
