dbugsr

Thanks for the input......original bolt....stretched/hourglassed!

I am familiar with the number you posted via the Mack dealer here who said the (409GC157) is the one we need and that the (409GC167) is for the turbo version. The Mack dealer also states that at least to the best of his ability and knowledge that the bolt we need specifically is no longer available through Mack or aftermarket sources available to him so far. Really know very little about the motor any more than it is supposed to be a 250hp, V8 Mack naturally aspirated.....finding parts has been very difficult, one machine shop locally found main bearings in Mexico because we couldn't find those any place else. If you have any other sources or places to obtain parts for these motors, we would be glad to hear from you. They are a great running motor when they are running, but they are problematic. This motor is in an off road haul truck, thus it is getting severe duty application. Thanks for the input thus far!

According to Mack the part is discontinued/not available even from aftermarket suppliers. Looking for old equipment/antique junk yards......anywhere. The whole problem is the pitch of the thread, it is 7" long - 3/4" diameter - main bearing cap bolt, that according to our bolt supplier has a 6 - 12 pitch. That means mudd to me, it is not metric, not standard, not SAE. Machine shops are scepticle at cutting threads on to a grade 8 bolt, because they are not sure of the alloy composition of the main bearing cap bolt and also, they say the original threads for that bolt are cold rolled into the original bolt. Again, this is all mudd to me. We have called all over trying to locate this part with no luck so far. So, that being said, anyone with any ideas throw them at us please. @ Glenn......we will try to get some pictures, it is still in frame, only naturally aspirated, not turbo. In an old rust bucket Mack Haul Truck.

Does anyone have or can anyone tell me where I can find a main bearing cap bolt for this motor: Mack # 409GC157. Please post back.