Clutch adjustment

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Dino soar, Oct 13, 2019.

  1. Dino soar

    Dino soar Road Train Member

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    I forgot to mention that my flywheel was resurfaced.

    I read somewhere that a two piece clutch brake is thinner than the one piece that you get from Eaton. I put a two piece in mine.

    For whatever reason after I adjusted the release bearing I had to turn and turn and turn and turn and turn the clutch rod and I'm still not at 1/8 of an inch. The clutch Rod was so tight I had to readjust the clutch because it was hanging up on the forks. I measured almost 2 in of play at the pedal but it just seems like a lot. And the clutch brake itself at that point measures about an inch off the floor but dang it feels like I'm all the way down. If I finish adjusting the linkage to where I really have an eighth of an inch I don't know if the clutch brake will engage or if I'm going to have too much play on the pedal.

    I think they tell you if the clutch brake is at least a half an inch off the floor you are okay, but I'm wondering if any of this has to do with the flywheel being resurfaced and having the thinner clutch brake?
     
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  3. Working2party

    Working2party Medium Load Member

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    Normally you want to add material to the clutch brake to compensate for flywheel surfacing. Which isn’t a big deal since you’ve already installed a 2 piece brake. Many places will have an oversized brake in stock and a $20 bill should cover it. A few thousandth around your clutch/fork/brake will make a big difference at the pedal.

    When your done you want measurements around 1/8” and 3/8” around the fork and 1 1/2” free play and 1/2” off the floor for the brake at the pedal.
     
  4. BoxCarKidd

    BoxCarKidd Road Train Member

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    Lots of good replies and I just have to say thanks to everyone.
    The reason I mentioned the smaller gap is for driver preference. I am not short but have struggled with some trucks. Had to pull myself up with the steering wheel to reach the clutch brake. That was no problem for me. Driving a REO on the farm at 15 taught me some things.
    Saw one fleet truck thathad 2X4's bolted on top of all the pedals.
    It is possible to adjust some things off spec a little bit for personal preference. The area between clutch brake function and clutch enguagement can become pretty close.
    If you let some jug head drive your truck in the parking lot it can be a problem. The clutch brake functions high and it is easy to be using it to stop the truck. Wipes out the clutch brake real quick.

    After your last post I will just make some comments.
    1: The front bearing cover can wear at the clutch brake surface. There is a way to measure from the front of the input shaft to it. A go or no go deal.
    2: Surfacing the flywheel increases the overall space. How many times has it been surfaced?
    3: What is the condition of the clutch shafts and bushings?
    4: What is the condition of the tips on the clutch fork.

    While all of these things may be minor when combined it can become a problem. If you had to do all that cranking on the pressure plate adjuster some things are probably not correct.
     
  5. Dino soar

    Dino soar Road Train Member

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    Everything is new. The input shaft bearing cover the bearing the clutch Forks cross shafts everything is new.

    The flywheel I had resurfaced, but I have no idea if it was resurfaced before that. I assume they didn't go beyond what the limit is, but like I said I have no idea if it was resurfaced before.

    I have been eading about resurfaced flywheels and how it moves the clutch farther away from the transmission.

    I've read that a lot of times they will put a 1/8 in fiber spacer behind the clutch brake.

    I don't know if the two piece is any thinner but I've been reading that the average clutch brake is .375. If I get the fiber spacer that is .125 or 1/8 of an inch.

    I think that would help greatly.

    What do you think?
     
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  6. Dino soar

    Dino soar Road Train Member

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    Yes I am looking at the 1/8 in fiber spacer.

    .375 for the regular clutch brake and .125 for the spacer should give me .500.

    I have seen oversized clutch brakes at .440 and .560. The spacer would put me right between them.

    Is there any reason that either the spacer or a new clutch brake would be a better choice?

    I like the design of the haldex 2 piece clutch brake that I have on there.
     
    Last edited: Oct 14, 2019
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  7. Working2party

    Working2party Medium Load Member

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    Ideally you want to put a brake in that keeps your from adjusting your new clutch adjuster. (Manufactures Suggestion)

    The only problem I can see with the fiber disc is because they should be installed before installing the tranny. I don’t know if it will stay with a slit cut in it?? If it would this would be the way to go.
     
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  8. Rideandrepair

    Rideandrepair Road Train Member

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    He’s running into the same thing I had on myTruck, my linkage had to be adjusted ( lengthened) quite a bit,at least 3-4” once all was new and set up correctly. I had played around with all of it, adjusting it well beyond its normal limits, to keep it going. I’m just curious wether or not he’ll have to adjust the pedal stop in Cab, once everything’s set up right. Having changed the driveline from original, maybe. Thanks, you do a great job of explaining not just the how’s but also the why’s. Lots of info on doing ABC. Not much on the actual reasons for each step. You’ve taught Me more about the operation of a clutch than all the manuals and videos put together. None of the surprises I ran into doing mine were addressed anywhere. Thanks again for helping Me out of so many jams I ran into.
     
  9. Dino soar

    Dino soar Road Train Member

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    There is a website that sells the fiber spacers that they show you how to cut them.

    For a 2 in shaft you cut it from 2 inch to inch and a half in a v cut. That's what they say to put it on with the transmission in.

    I assume the fiber material gives a little bit so that would allow you to get it over the shaft.
     
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  10. BoxCarKidd

    BoxCarKidd Road Train Member

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    I have seen some trucks running that set up. Others with the disc on top of the dust cover but it can work.
    On some old trucks I add the washer during installation. It is easy to take out if if I don't like it later. You should be able to adjust that out just fine with all the new parts.
    Sorry but I do not recall about pedal stops on FLDs.
     
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  11. Working2party

    Working2party Medium Load Member

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    Wear on your motor, cab mounts, and in some cases your cab air bag height can change the clutch linkage adjustment. I know you’ve already done a lot to this truck and if replacement of those Items are still in your plan. Get them replaced before you get call your clutch adjustment done. You might need to readjust your linkage if you replace them down the road.

    Just a heads up before you spend to much time getting it “right on”
     
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