2000RD688 Posted February 2, 2017 Share Posted February 2, 2017 I was wondering what you guys think about valve adjustments. I had a new engine built about a year and a half ago. It was a total build out of frame. When I picked the truck up at the dealer is asked the service manager when he wanted it back to check it over and adjust the valves. His answer was we don't. He says it was dyno broken in so you don't have to. Now that goes against everything I have ever heard and believe in. So I ran it. I have done oil samples from the first oil change to watch everything. All was going well until late the last oil change. It started burning oil, and my copper and iron levels are way up. I took the sample to Mack, and was told to run it. We have since had our other truck in framed with a total different result. We were told at 5000 miles bring it back for valve adjustment. Same company, just a different branch. So I'm just looking to hear some thoughts on this matter. Quote Link to comment Share on other sites More sharing options...
Freightrain Posted February 2, 2017 Share Posted February 2, 2017 Interesting topic. I had the heads off my 237 last spring. I've wondered if it is good to retorque the heads and go through the valves at 5K miles like the motor books mentions. Since mine is just a toy it doesn't see the long term running a working truck sees. But still, for maintenance the old books state to do this. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment Share on other sites More sharing options...
j hancock Posted February 2, 2017 Share Posted February 2, 2017 After break in and using it for some miles, run the valves. Gives a chance to check things out. Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
fjh Posted February 2, 2017 Share Posted February 2, 2017 In my opinion I would lift the lids and check the set due to quality concerns of parts theses days !Before volvo took the raines the quality of reman parts was way better! I do not like remac heads particularly they tend to be sloppy and do not follow wear limits for replacement of guides and valve stems and the quality of the replacement valves and seats them selves are in question! Way back when Mack was mack you could count on getting decent stuff NOT These days! 1 Quote Link to comment Share on other sites More sharing options...
Mackpro Posted February 2, 2017 Share Posted February 2, 2017 I think the factory used to say first valve adjustment at 75,000 miles then every 120,000 after that . However that was on new engines . I think I would give it more than 5000 miles to let the valves and seats to wear in before adjusting the valves. 1 Quote Link to comment Share on other sites More sharing options...
2000RD688 Posted February 2, 2017 Author Share Posted February 2, 2017 Thank you all for the insite. I'm just worried that's all. We're slow now, but I don't want to be having issues once the work is in full swing. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.