mcratchet1 Posted May 24 Share Posted May 24 I have 03 Mack mr688s 350hp i had to replace #1 injector the push rods on exhaust side has springs on top of them. I have never seen this before. So I adjusted intake and exhaust as normal. But I have a rattle now so they must be to loose. Is there a certain way to adjust them with those springs? Any help would be appreciated Quote Link to comment Share on other sites More sharing options...
fjh Posted May 24 Share Posted May 24 24 minutes ago, mcratchet1 said: I have 03 Mack mr688s 350hp i had to replace #1 injector the push rods on exhaust side has springs on top of them. I have never seen this before. So I adjusted intake and exhaust as normal. But I have a rattle now so they must be to loose. Is there a certain way to adjust them with those springs? Any help would be appreciated there is a little cover on the the bottom of the fly wheel housing remove it turn the engine till you see valve set 1/6 centered in the hole if the number one valve is tight its likley on the wrong stoke make one more rev of the crank both valves should be loose proceed set to 16 intake 24 exhaust! 1 Quote Link to comment Share on other sites More sharing options...
mcratchet1 Posted May 24 Author Share Posted May 24 Yes I did that I guess my question is on exhaust push rod that has spring do I need to compress spring then check exhaust or leave spring alone Quote Link to comment Share on other sites More sharing options...
mcratchet1 Posted May 24 Author Share Posted May 24 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 24 Share Posted May 24 Compress the spring. Are you sure you were up on #1 and not #6?? Quote Link to comment Share on other sites More sharing options...
mcratchet1 Posted May 24 Author Share Posted May 24 Ok so push down on the springs and set the exhaust . Just push springs down by hand? I made sure I was on right one stared on 1&6 6 was tight 1 both were loose and push tubes were close to being even Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted May 24 Share Posted May 24 ok , now someone help the ole man ;;;; Im guessing that picture is of a Jacobs not dynatard ; and what's the purpose of the spring on push tube??? I say it keeps tension on tube to rocker ???. how's the push rod made ::: screw together with replaceable parts ?? at least it's a positive to see mechanical changes NOT electronic. Quote Link to comment Share on other sites More sharing options...
Solution JoeH Posted May 24 Solution Share Posted May 24 https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6147 Go to that link and click "View File" in the item description. It'll download the book for that engine. Page 401 starts the Valve Adjustment Procedure. Follow it to a T. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 24 Share Posted May 24 Ok Mech, the spring loaded pushrod is for the EGR bump on the back cut of the exhaust lobe. It is supposed to suppress valve slap. Now,,,, mcratchet.... A for sure way to know you are up on #1 is when you set the flywheel to 1&6, the #2 exh. Rocker is 'rocked'... Very important on Mack engines, especially after 2001!!! 1 Quote Link to comment Share on other sites More sharing options...
mcratchet1 Posted May 24 Author Share Posted May 24 Yes exhaust valve up on #2. I got it, I just did not snug down enough on exhaust valve to put enough pressure down on spring. Once I did that she’s running great. Thanks for all the quick help! I really appreciate it!! 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Joey Mack Posted May 24 Popular Post Share Posted May 24 Thats what we do here.. keep on keepin on... Take time to give credit to the guy that solved it.. it looks good to new comers.. 2 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted May 25 Share Posted May 25 2 hours ago, JoeH said: https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6147 Go to that link and click "View File" in the item description. It'll download the book for that engine. Page 401 starts the Valve Adjustment Procedure. Follow it to a T. I always enjoy interesting reading material. will print/ and have something to read in am with coffee, much better then having to talk to w---! you know 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted May 25 Share Posted May 25 is that set up consider a jacobs ?? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 25 Share Posted May 25 Mech, it 'IS' a Jacobs, series 690.. It is a new breed after the E-7 680 series.. I cant compare it to Macks Dynatards.. just not that smart... Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 25 Share Posted May 25 Mech,,, you dont know how bad I wish we were neighbors. I would love to Learn from You and l would Love to teach you what I know.. With Great Respect... Jojo 1 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted May 25 Share Posted May 25 13 hours ago, JoeH said: https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6147 Go to that link and click "View File" in the item description. It'll download the book for that engine. Page 401 starts the Valve Adjustment Procedure. Follow it to a T. A pictures worth a thousand words! 😁 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted May 26 Share Posted May 26 On 5/24/2024 at 8:33 PM, Joey Mack said: Mech, it 'IS' a Jacobs, series 690.. It is a new breed after the E-7 680 series.. I cant compare it to Macks Dynatards.. just not that smart... only thing comparable to the dynatard is a pack of fireworks bought at local dollar store. both make a little pop pop po noise and not much more. LOL 1 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted May 26 Share Posted May 26 On 5/24/2024 at 8:35 PM, Joey Mack said: Mech,,, you dont know how bad I wish we were neighbors. I would love to Learn from You and l would Love to teach you what I know.. With Great Respect... Jojo mutual thoughts on this end. might not be to far off in future. can't take much more of CT. would also be first time in 60 + yrs I would look forward in going to school. 1 Quote Link to comment Share on other sites More sharing options...
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