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07 AC 355/380 Cam bolts fell out


rubar
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I have an 07 CXN613. I have what I understand is a AC 355/380 engine. It seems a little underpowered, but other than that it is fine. It appears that the cam retaining bolts backed out. This allowed the cam to walk forward and let the lobes rub against the journals. I'm preparing to replace the cam and lifters, crank gear and idler gear. Doesn't seem to be too bad of a job. I would like to know if I need to change any other parts while I am in there. I would like to make a little more power. I have read on here that there are different cam keys and other different parts. While it's apart I'd like to go ahead and change whatever I need to so I can increase power. Any advice and part numbers would be greatly appreciated.

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There are different cam keys. If your cam was changed before it could have been put in incorrectly. Also you can get a Mack dealer to request a horsepower upgrade and find out if the injectors and or the turbo will need to be changed along with programming. Sometimes you can just get away with programming. Also you can have the dealer check if the programming is at step 12B. If it is not have them program it to step 12B as I have seen the programming help with low power.

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All AC/AI ASET engine take the straight key way regardless of HP level. Only the older ETECH 98-02 ( pre-CCRS engines) used the offset key ways. The 355/380 puts out the same torque as a 427HP. To bump any higher you gotta change the turbo and injectors and do the download. If your gonna do that might as well go all the way to 460P. All parts and labor will get close to if not over $5000

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Thanks for the info. I just wanted to make sure that I didn't need to change anything else while the engine was apart. I may not go any higher on the HP, but I didn't want to have to go back in for something simple since I am already there. I didn't realize that these engines were internally the same.

Would all pieces of the puzzle have to be done at the same time? Could I go ahead and put the injectors in now while I have it apart and then later change the turbo and do the download? Got any part numbers for the turbo and injectors?

One other question, while tearing the engine down I noticed a couple of bent pushrods. I'm sure this is from the engine and cam being out of sync before the engine quit. I don't see anything wrong with the valvetrain. Should I go ahead and pull the heads and check for bent valves, or do you think it would be OK to go ahead and reassemble everything?

Thanks again for any help.

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Look at the heads and valves carefully. Check the H-rings after you remove the rollers. If you have a bad H-ring or rings you have to remove the heads to replace them. There are special tools to check and replace them. This engine should have ceramic rollers and the cam kit only comes with 2 new ones. I always recommend replacing all the rollers along with the eup rollers. Also check the eup roller guide pins as they wear and break also. If you pull the valves replace the valve seals and rotators if there is no head damage. The rotators fail quite often I have found. The new rotators are an updated design that go under the valve springs instead of on top. Also change the valve keepers if you remove them.

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Got everything apart and it's looking good. Cam was a pain to get out. Several of the lifters had the rollers broken and had turned in such a way that it was difficult to get them back up in their bores. I'm going to go ahead and put rings and bearings in it while its apart. What's the best way to get the injectors out. I've read there is a tool for pulling them, but I haven't been able to find it. If there is not a tool, then what size bolt do I need to screw into the top of the injector?

Thanks for the help so far.

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They usually do. Just make sure all the combustion washers came out with the injectors. If not you will need to get them out. You can use a long pick to get them out. You do not want to double stack the washers. Does this engine have Power Leash if so are you familiar with the valve adjustment procedure?

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It is way different. You need a .045 feeler gauge for the power leash and .024 for the exhaust valve and a 6 inch pound t-handle to set the power leash and exhaust valve. You loosen both lock nuts on the exhaust rocker arm and loosen both adjusting bolts some. Then loosen the adjusting bolt on the end of the rocker arm and push down and insert the .045 feeler gauge under the power leash piston and tighten the adjustment bolt with the 6 inch t-handle and tighten the lock nut. Leave the .045 feeler gauge in and insert the .024 feeler gauge under the rocker arm and tighten the other adjusting bolt with the 6 inch pound t-handle and tighten the lock nut. Then remove the feeler gauges. I find it easier to remove the .045 feeler gauge first. It is a different adjusting procedure than the jake brake set up as you can see.

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  • 1 month later...

Sorry for not posting sooner. Truck went back together very well. Valve adjustment procedure was a little confusing at first, but I got it done and it ran great. I am very disappointed in my Mack dealer though. The truck came from a large fleet and had a 65 mph speed limit. I was also second guessing myself about the valve adjustment so I decided to take it in and get them to increase the road speed and adjust the overhead. I also asked the service adviser if the HP could be verified and increased and he said there was nothing they could do. I have taken a few of my other trucks to them in the past and have had no trouble.

This time they kept my truck almost 3 weeks to run the overhead and to increase the road speed. They said they were about a week behind, but they should be able to work me in since it was a simple job. After a week I started calling them every day and I got the same response. They kept telling me they were almost done and to call back that afternoon and in the afternoon they would tell me to call back the next morning. I finally told them to put back together whatever they had apart and I would come get it. When I got to the shop to pick it up, they said it was done. They charged me $100 to check the fan clutch (didn't do anything, just verified that it worked), $650 to run the overhead, and another $650 to increase the road speed. I was upset to put it mildly. It was late on Friday afternoon when I picked it up. All the important people were gone from the dealership. I called and left messages with the service manager as well as the branch manager, but haven't heard back yet.

Not only do i think the prices are a little high, but they screwed up my engine hours, the ABS and traction control no longer work, and the speedometer is way off.

The work was done by Tri State truck center in Jackson, MS. Does anyone know if there is a main customer service number I can call and get some help? Can the hours be set back correct?

Sorry for the long post. I appreciate any help.

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Wow!!!! It sounds like they reflashed the modules and did not save the customer data. That is not necessary to change the road speed. I will try to get the coporate number for Mack on Monday. They probably left the ABS fuse out or disconnected the ABS module. The ABS fuse is in the fuse panel under the hood. I know we charge 1 hour to perform customer data programming such as road speed. The bill sounds like they possibly reflashed and reprogrammed the EECU and VECU to step 12b which does help with power complaints. They are supposed to get customer authorization before reflashing the modules. If I rember correctly the engine hours can not be programmed to the original hours. I could be wrong on that though. The valve adjustment is 4.9 hours on that engine. I would be very upset as you are. All it takes is pride in your work and good customer communication. I am glad I work for a mom and pop MACK dealership. Sorry to hear about the treatment you have gotten as it makes all Mack dealers look bad. I am glad that you got the engine back together and running good.

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Wheeler-If my regular mechanic decides to hang up his tools, I might have to cross the state for decent service.

see that parts is open on Saturday. that's better than over here

Success is only a stones throw away.................................................................for a Palestinian

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Thanks Wheeler. I hate that about the engine hours. I was hoping they would be able to put it back.

I can see 4.9 hours for the valve adjustment. $650 seems a little high for that. That's more than $130 an hour. Hopefully they'll call me back Monday and I can get it back in and fixed pretty quick.

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