Kellerfarm2 Posted February 10, 2022 Share Posted February 10, 2022 (edited) I had to replace ejector. Now I'm trying to adjust exhaust valve gap. After replacing the cam and Jake brake assembly. With the spring loaded push rods collapsed each exhaust rocker to top of yoke is .365 yes. .365 gap... before I do anything help... I'm 5 hours from a mack dealership... Edited February 10, 2022 by Kellerfarm2 Added picture Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/ Share on other sites More sharing options...
Joey Mack Posted February 10, 2022 Share Posted February 10, 2022 first.... are you starting on #1? Do you know how to tell if you are on #1?. I see you are trying to check #4.. A valve adjustment on that engine requires checking the bridge clearence first, then the valves then the engine brake in that order.. one cylinder at a time in the firing order. If that engine has ceramic lifters, you have no room for error. please read up on how to do it properly.. I see you did a cam replacement, I assume you have a book.. jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489033 Share on other sites More sharing options...
Kellerfarm2 Posted February 10, 2022 Author Share Posted February 10, 2022 I don't know about ceramic lifters. Other than it was rebuild about years ago. Yes picture is of number piston. I have not done anything with the exhaust valves yet. I was measuring each exhaust rocker clearances. All are very close to the .35 gap... I haven't done anything with bridges yet... I'm just trying to get started... without a f up. Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489041 Share on other sites More sharing options...
Popular Post Joey Mack Posted February 10, 2022 Popular Post Share Posted February 10, 2022 ok. when ou said you put a cam in it, I assumed you did the repair, therefore you would have been reading the book for the procedure. OK thats out of the way.. there is a smal inspection cover on the bottom of the flywheel housing. it may be rectangular with 6 little bolts, or round with 2 bolts. remove it... you will see a pointer cast into the housing. you will see the edge of the flywheel, where the timing marks are stamped in pairs... 1&6.... 2&5.... 3&4.. I will stop here, because I need to know how much you know before I write this book.. It is also good to have the 'Barring tool' to rotate the engine,, jojo 3 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489049 Share on other sites More sharing options...
Onyx610 Posted February 10, 2022 Share Posted February 10, 2022 This should be good, I’ve never done this/needed too yet. I look forward to the information provided. Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489057 Share on other sites More sharing options...
fjh Posted February 10, 2022 Share Posted February 10, 2022 8 hours ago, Kellerfarm2 said: I don't know about ceramic lifters. Other than it was rebuild about years ago. Yes picture is of number piston. I have not done anything with the exhaust valves yet. I was measuring each exhaust rocker clearances. All are very close to the .35 gap... I haven't done anything with bridges yet... I'm just trying to get started... without a f up. Pay ATTENTION TO JOES NEXT POST! 35 on the set! the set is a way off either your not measuring right or it was a real bad set to start with Or you have another possible cam issue! ! these are (rarely )that far out most of the time 2 or three thou one way or the other after 2-3 years! You should be seeing 16 thou +/- 1 or 2 on intake 24 + / - 1 or 2 ! I'll let Joey write the novel ! 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489059 Share on other sites More sharing options...
JoeH Posted February 10, 2022 Share Posted February 10, 2022 I think this is where you post a link to the Mack eMedia book for this engine and say "follow the procedure in here to the T!" Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489070 Share on other sites More sharing options...
Onyx610 Posted February 10, 2022 Share Posted February 10, 2022 Page 21… https://ww2-secure.justanswer.com/uploads/HE/HeavyEquipmentTech/2015-02-26_224055_mack_e7_valve_an_jakes_overhead.pdf Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489075 Share on other sites More sharing options...
Mark T Posted February 10, 2022 Share Posted February 10, 2022 21 minutes ago, Onyx610 said: Page 21… https://ww2-secure.justanswer.com/uploads/HE/HeavyEquipmentTech/2015-02-26_224055_mack_e7_valve_an_jakes_overhead.pdf That engine in the picture the guy posted has a Jake. not a Power Leash Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489077 Share on other sites More sharing options...
Mark T Posted February 10, 2022 Share Posted February 10, 2022 If he's measuring between where the master piston is hit , then there's no telling what he's measuring. The part he has the picture of isn't the valve adjustment. That's where the master piston of the Jake comes out when the Jake itself is activated and gets hit to push the slave piston to bump the valve off the seat. Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489078 Share on other sites More sharing options...
Mark T Posted February 10, 2022 Share Posted February 10, 2022 That balled seat with the hex on it is where you adjust the exhaust valve lash. Then the Jake lash is set under the slave piston. That big gap between the Jake and the domed cap is closed up when the engine is running with the Jake activated. Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489079 Share on other sites More sharing options...
Mark T Posted February 10, 2022 Share Posted February 10, 2022 (V) is the valve lash adjustment and the (J) is where you set the lash for the Jake. !!! just the adjusting part . The Feeler gauge goes between the rocker arm and valve bridge to set the exhaust valve. On the Jake the feeler goes between where the slave piston contacts the part of the valve train it hits. That space the picture is focused on (in my opinion) doesn't really mean much , unless updates were ignored or something there is worn excessively. That will seem like a huge gap, but without the engine running and the Jake activated.... it will be. !!!!! this could be a problem area though if not matched to the new cam or the master piston is peened over from use over the years. I can remember updates on these parts back when these were new. Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489083 Share on other sites More sharing options...
Kellerfarm2 Posted February 10, 2022 Author Share Posted February 10, 2022 9 hours ago, Joey Mack said: ok. when ou said you put a cam in it, I assumed you did the repair, therefore you would have been reading the book for the procedure. OK thats out of the way.. there is a smal inspection cover on the bottom of the flywheel housing. it may be rectangular with 6 little bolts, or round with 2 bolts. remove it... you will see a pointer cast into the housing. you will see the edge of the flywheel, where the timing marks are stamped in pairs... 1&6.... 2&5.... 3&4.. I will stop here, because I need to know how much you know before I write this book.. It is also good to have the 'Barring tool' to rotate the engine,, jojo Sorry I miss stated I didn't replace cam. But removed rocker arms and the shaft that pivot on... the rocker arm assembly.... Jake brake assembly. I didn't go that far into the engine... Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489089 Share on other sites More sharing options...
Popular Post Vmac3 Posted February 11, 2022 Popular Post Share Posted February 11, 2022 Hello everyone, Here is a copy and paste from the Mack ASET AI/AMI engine manual. If this procedure is deviated then severe engine damage will occur. I highly recommend that you have someone that is qualified to perform this task. This engine that you have is equipped with ceramic lifters. If those Jake heads are removed and not installed correctly or if those pushrods are not seated in the rockers then you may break a lifter. V Valve Lash Adjustment Procedure for Jacobs Equipped Engines Mack ASET AI.pdf 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489136 Share on other sites More sharing options...
Joey Mack Posted February 11, 2022 Share Posted February 11, 2022 "V" is absolutely right!!!!! Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489176 Share on other sites More sharing options...
Mark T Posted February 11, 2022 Share Posted February 11, 2022 13 minutes ago, Joey Mack said: "V" is absolutely right!!!!! Jojo Exactly. If this dude is measuring that space above the push rod.... he's clueless. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489180 Share on other sites More sharing options...
Joey Mack Posted February 12, 2022 Share Posted February 12, 2022 I am reluctant to speak harshly, however.. yes.. as you know, one wrong move and the valvetrain rattles.. It's over... The truth for me is this... 20+ years ago when I was new and ambitious, I did a cam job on an ASET... Keep in mind, I had already done a bunch of valve adjustments and E-Tech cam's prior..... I rolled the engine up on #1... ran the rack.... cranked it up.. ran like crap and miss fired.. My heart fell into my stomach... I ran the rack starting on #6, not #1.. I went to my boss and told the truth about my F-up... he said "fix it' and dont do it again... 10 hr's later, I put new lifters in it and it purred like a Dog... A hard lesson, but..... It helped make me who I am today... My 2 cent's... jojo 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489182 Share on other sites More sharing options...
Onyx610 Posted February 12, 2022 Share Posted February 12, 2022 Well he wasn’t so clueless that he decided to come here and ask for help…I’m sure he knows quite a bit of things that would make alot of us look clueless. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69188-2003-ai-460-exhaust-valve-gap/#findComment-489183 Share on other sites More sharing options...
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