How to check/replace timing chain - time to get truck running again

Discussion in 'GM 6.5 Diesel Engines' started by gahammerle, May 8, 2010.

  1. gahammerle

    gahammerle Saved by God's grace

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    Been awhile since I've been on here. Had trouble with my truck in April of 2009, and haven't been able to drive it since. See this earlier thread if you want background:

    http://www.thetruckstop.us/forum/showthread.php?t=10347

    Anyway, now that it is warmer and I have more time on my hands, I want to get it running again. It's been suggested my timing chain may have jumped a tooth or two or has stretched. I have never checked/replaced a timing chain nor seen it done. I've searched on here to see if someone has done a writeup, but couldn't find anything. I have the Haynes manual for the truck, but it only shows gassers.

    So if someone could post a step by step on how to check the timing chain and also, if it needs replacement, how to replace, I would be grateful. If you could let me know what parts need to replaced (whether just checking or replacing) such as gaskets, etc. and if bolts can be reused or if I need to use new ones. Also, if there are other parts that would be wise to replace during a timing chain swap, I'd like to know that too.

    Thanks. I miss my truck. Looks pretty sitting in the driveway, but I miss the sound and driving it.
     
  2. ak diesel driver

    ak diesel driver Active Member

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    Pretty hard to check timing chain without physically looking at it. Did you ever get your CPS fixed?
     
  3. buddy

    buddy New Member

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    You can learn from some others that realized they could install the CPS backwards because the mounting tab came off. Replacing it with a new one would be a good idea, as it likely to cause the timing issues you were having.
     
  4. gahammerle

    gahammerle Saved by God's grace

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    I did replace the CPS with a new one. That was prior to the last Scantech readings.
     
  5. Big T

    Big T Active Member

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    Rotatable CPS, I resemble that.:rolleyes5:

    I talked with Bill Heath and he said they leave the timing chains in for 250K miles. Factory specs allow for up to 5/8" deflection. I replaced mine while doing the Heath cooling upgrade and it had 1/2" deflection at 155K miles. As noted, my impossible timing issues were due to the mounting bracket separating from the CPS. If you're in there, replace the CPS. They're like $50 at RockAuto. The plastic on the CPS softens up over time.

    As to the step-by-step, you need to pull the water pump and then the timing cover housing to be able to check the timing chain deflection. I skimmed your prior thread and I really doubt it's a timing chain issue. It's more likely the CPS or the Optical Filter Harness.
     
  6. gahammerle

    gahammerle Saved by God's grace

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    I did take the Optical Filter Harness out of the loop last year with no difference.
     
  7. 1hot57

    1hot57 New Member

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    Ok guys dont laugh to loud, what is a cps? Also I have installed a Heath boost kit and it raddles like hell. My 95 c3500 has 160000 miles and runs a little hot when pulling my horse trailer so I thought I would install one of Heaths cooling kits and fan since my truck only has a 5 blade fan.Any thoughts on this are appreciated. George Reed Valparaiso in. Also am planning a timing chain change at the same time.Whats a good brand chain to use?
     
  8. robzombie4551

    robzombie4551 robzombie4551

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    land of the lost. TAKE YOUR COUNTRY BACK

    [C]hicks [P]umping traight guys.

    Okay, really crank/cam position sensor.
     
  9. tanman_2006

    tanman_2006 Just a farm kid...

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    If he heard mine with ~150K on it I doubt he would keep driving it. Mine rattles like a kids bicycle.
     
  10. Missy Good Wench

    Missy Good Wench Wild Blonde from Cloud Mt

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    I seriously doubt that the chain has jumped.

    The timing sprockets wear very very little, though the chain can stretch a tad the ECM will adjust things as this happens.

    Grab the crank pulley or use a break bar with a socket on it and see iof you can rock the crank gently back and forth.

    The first tiny bit of movement either way will be the slop in the chain.

    The pistons dont take much to turn, but the valve train takes a fair amount to move.

    I ahve seen these engines with 250K on them and the chain was still within reasonable limits.

    Not in the best condition but still runnable.

    Missy
     
  11. handcannon

    handcannon Active Member

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    I have no direct experience, but bk95td has on several occasions reccommended Cloyes brand to others.

    Don
     
  12. ak diesel driver

    ak diesel driver Active Member

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    mostly because of the amount of chain slop in the others
     
  13. Missy Good Wench

    Missy Good Wench Wild Blonde from Cloud Mt

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    I went back and scanned though the first thread on this issue.

    IMHO the IP is shot.

    The swapping of ECM's and such was a good tool to use in diagnostics, but now I think you are up against the wall on this thing.

    The codes and dieing issue seems to follow along.

    If you can get ahold of a KNOWN good IP, swap the sucker out and give it a go.

    My bet is that a fresh 5521 pump will fix the things issues.

    If you can borrow a known good IP and use to test it, this would be great and not have to spring for the new one up front.

    I do not believe the issue is the timing chain, not even.

    The Pulse width error code and the intermitent ballance codes ternd to indicate that the IP has issues.

    Keep us posted
     
  14. Tookie

    Tookie New Member

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    If the timing had jumped, it wouldn't start and run sometimes
     
  15. gahammerle

    gahammerle Saved by God's grace

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    I'm back :)

    I've been swamped at work for the last 18 months - many weeks working 80-90 hours and some days putting in as many as 20 hours. And all on salary :(

    Anyway, this work project is coming to an end so I'm getting some free time plus my oldest turned 16 so I need another vehicle.

    I shot an email to Bill Heath a few days and he had me call him. Just got off the phone with him. He suggested I go back over all the grounds, but he also mentioned it is important to make sure they are all terminated on the intake manifold. I had checked/cleaned grounds previously, but didn't pay attention to where they were attached. I just reattached them to where I found them. They could have been moved from the factory locations by previous owners/shops.

    So that is my next step. I won't be able to get to it until next weekend I think, but I'll report back when I'm done.
     

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