230sl crank issues ac??

[Ahealey12]

I’m not finding very many posts about a crank breaking just seeing posts that it is common on a 230sl when added stress with air conditioning. Is this still an issue with the buds Benz kits with updated compressors? I’m daily driving this in San Antonio and am pretty interested in getting ac but also don’t want to destroy my engine just to have ac.

[ja17]

The newer style rotary compressors are much kinder to the crankshaft with less vibration and drag. The problem is often caused by the installer not performing the specified torque on the crankshaft bolt. Eventually the crankshaft pulley assembly and vibration dampener become loose and ruin the end of the crankshaft. You must be certain that the bolt is torqued to specs. In addition the Factory manual describes an upgrade procedure that can be performed using an improved stretch bolt, and three heavy belden washers along with larger dampener pins which greatly strengthen the assembly. The set-ups with the newer compressor may not need the upgrade as long as the crankshaft end is in good shape and the bolt is torqued correctly. Your engine might already have the improved stretch bolt and washers. A different torque procedure is used with the stretch bolt assembly (described in the BBB). Just having the new stretch bolt assembly greatly improves the set-up even if you do not perform the difficult procedure to install larger pins. After the 230SL the pagoda engines did not have this issue. The pulley/dampener/hardware assembly was improved.

[Ahealey12]

Awesome thank you Joe!!

[Lenosa]

I’ve got a 230SL myself and was worried about the crank issue too. From what I’ve gathered, the Bud’s Benz kits with the updated compressors seem to address the problem pretty well. I drive mine daily in hot weather, and the AC has been a game-changer, but I did have my engine checked before installing it.