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Muncie front bearing retainer mods

Discussion in 'The Hokey Ass Message Board' started by Bluedot, Nov 20, 2012.

  1. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    I seem to have made myself a lot of trouble by choosing to put a 455 Olds (starter is on the left) in a Model A coupe, with a 4 spd, and under-floor pedal masters. All that equals absolutely no flippin' way to have enough space for a clutch throwout fork, whether manual or hydraulic slave actuated. So, against my original intentions, I must use a hydraulic TO bearing. The clutch BTW is OEM diaphragm.
    I've searched and read many threads on HTOBs here, but did not see any that addressed my problem. It's a Speedway HTOB, and the instructions say what I imagine they all say. Measure the distance from the back bell surface to the diaphram clutch fingers - call it A. With the HTOB on the trans input shaft and shoved all the way back (as if released), measure from the trans case face to the TOB face, and call it B. Then shim behind the HTOB to make B .05" - .10" less than A. Makes sense - when all assembled, that means the bearing face will be just .05 to .1 from the fingers.
    The problem: My dimension B is already .14" more than A, ie if I assembeld with no shims at all, the TOB is already .14 into the fingers - not good. So I call Speedway, and they say yup, sometimes that happens, and you have to machine the front bearing retainer a bit so the TOB can sit further back. I didn't like that much, as I don't have the ability to do that myself. But worse, it would have to be machined .14" (over 1/8") just to get the TOB face just touching the fingers - no room for adjustment as the clutch wears. To allow for adjustment, prolly would have to take .2 to .25 off. Yikes! I don't think there's enough meat in the retainer to do that.
    And that's my question: How much can be safely removed from from the bearing retainer in the shoulder transition where the TOB will sit, and on part of the face?
    BTW, for reference I compared the face to face dimensions of the HTOB with a fork type TOB. HTOB = 2.375". Short TOB = 2.12" Long TOB = 2.70". Obviously the OEM set-up was for the short TOB, and the HTOB is 1/4" too long. That's the problem.
    HELP! Project has come to a screeching halt. Any ideas welcome (except to go automatic). The 455 and Muncie are going to stay, one way or another.
     
  2. 1ton
    Joined: Dec 3, 2010
    Posts: 688

    1ton
    Member

    Can you make a shim to move the trans back? Might work if there is enough penetration into the pilot bushing.
     
  3. brigrat
    Joined: Nov 9, 2007
    Posts: 5,615

    brigrat
    Member
    from Wa.St.

    I just checked my Muncie retainers and that gets pretty thin in that area, maybe a thinner HTOB manufacturer?
     
  4. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    Thanks for the replies. We thought of the shim idea, or likewise shimming back the bell, which would accomplish the same thing. Pilot bushing is a concern tho, because the Olds pilot is quite a bit shallower (.363") than a Chevy. Engagement would be minimal.
    Shorter HTOB would be best I s'pose, if there is one, but I hate to trash the brand new one I already have.
     

  5. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,957

    gas pumper
    Member

    Can the TO bearing be reduced in thickness by the .200?
    Or the area where the bearing sits on the bearing sleeve, turn the shoulder back to gain you that .200.

    I put an oring kit and new bearing in one last year and kinda remember it being a pretty substantial hunk.

    Frank

    P.S. The front retainer on the trans has a cast in pocket where you want to lenghten it. I don't know if you got that much room there before hitting air.
     
  6. ROADSTER1927
    Joined: Feb 14, 2009
    Posts: 3,127

    ROADSTER1927
    Member

    Custom made shim between the trans and the bellhousing. Gary
     
  7. 1ton
    Joined: Dec 3, 2010
    Posts: 688

    1ton
    Member

    I would think that a special pilot bushing made a 1/4" deeper would not harm anything. If the bushing has a good wall thickness, it would probably work fine sticking past the crank bore by 1/4"
     
  8. chubbie
    Joined: Jan 14, 2009
    Posts: 2,336

    chubbie
    Member

    bluedot, great project! real rods are a "stick" sounds like you have a 4 speed crank, or had it drilled for the pilot. Olds venders sell a pilot bearing that fits in the torque converter "hole" in the crank.I'm useing one and it works. however you have to cut the end off the input shaft 1/8"-3/16. or drill a clearence hole in the crankshaft (where the pilot should be). could you use this adapter bearing ($35) and space back the transmission? the only problem i see is if the centering ring on the bearing retainer will still make enofe contact for safe use
     
  9. Jokester
    Joined: Jan 29, 2005
    Posts: 688

    Jokester
    Member

    Is your pressure plate a raised-finger diaphragm? Perhaps you could use a flat finger one instead. That would gain you plenty of room.

    my 2¢

    .bjb
     
  10. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    Good one Jokester - that will be my Plan C if B doesn't work out. Since I started this thread, I may have found a plan B. Spoke with Speedway, and they have a TOB for T-5 apps that is 1.52 collapsed (current one intended for Muncie's is 1.71). That gives me the shorter length I need. The only conceivable problem I see is that the id of the Muncie one is 1.375, and the id of the T-5 one is 1.379. Only 4 thousandths bigger diam, which is only 2 thousandths radius. Since it just sits on the collar (not a moving part), I'm betting it will work OK. We'll see - shud get it tomorrow.
    If it does not work, I will look at the different clutch idea - hadn't thought of that.
     
  11. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,603

    Johnny Gee
    Member
    from Downey, Ca

    Along the lines of these two posts, Keep in mind that as the clutch begins to wear (disc. becomes thinner) your clearance will disappear. So I would shoot for .100 instead of .050. As far as T-5 being .004 over bore, lightly grease the collar.
     
    Last edited: Nov 20, 2012
  12. On my track roadster I moved the pivot ball to the passenger side and cut a new throwout arm opening in the bell housing, then used a hyd. slave cylinder. I happened to have a Chevy bell housing that had a blank pivot ball indentation on the pass. side that only needed to be drilled and tapped but shouldn't be too difficult to do it on any bell housing.

    Just a thought...your results may vary.

    Charlie
     
  13. thechopperguy
    Joined: Oct 27, 2007
    Posts: 149

    thechopperguy
    Member

    I'm planning to run a Buick 455 and Muncie in my '33 Chevy, so I'll likely run into similar issues. Good to know up front...thanks!
     
  14. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    Chopper guy, I strongly suggest going to swing pedals instead of floor. If I wasn't so far along in design/construction of my A and had it to do over again, that's what I'd have done. Then there's room for the TO fork, and you have choices of rod linkage, cable, or slave hydraulic. And much easier servicability. I'm just too far along to turn back with pedals, brackets, firewall/floor mods, etc etc. Kinda painted myself in a corner and struggling to get out.
     
  15. gtowagon
    Joined: Mar 23, 2011
    Posts: 406

    gtowagon
    Member

    Call mcclod they make the right hydraulic throw out bearing theirs are also are great quality. You don't want a leaky bearing
     
  16. thechopperguy
    Joined: Oct 27, 2007
    Posts: 149

    thechopperguy
    Member

    Bluedot, thank you for the input from your experience. I had been planning on using floor pedals, but I'm nowhere near that phase of my build. I'll figure on using swing pedals. Thanks again, and I hope you get yours sorted out.
     
  17. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    Received the T-5 bearing yesterday, and by all measurements comparing the two bearings, it appears it will solve my problem. I will post again after I try installation later today or tomorrow.
    BTW, the T-5 bearing that Speedway sells is made by Howe - totally different box and instructions, and $50 more than the one intended for Muncie's. It still bugs me that the Muncie version could not possibly work in my precisely correct application it is supposed to be for, but at this point, I'm just happy to find another solution.
     
  18. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    EUREKA!! The T-5 application bearing is in, and appears to be a spot on fit. That problem solved, and on to many others. There's a reason I've named this car Nemesis.
    Today's tip: If buying a hydraulic throwout bearing to use with a Muncie, be sure to do your own homework RE measuring and online research. Don't trust the product application information to be right. Maybe it is, maybe not. I'm hoping Speedway will take back the one that didn't work, purchased many months ago.
    Thanks for all the input, fellas. This place is a wealth of information.
     
  19. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,603

    Johnny Gee
    Member
    from Downey, Ca

    Glad to hear the T-5 set up worked. As far as the tip, and little late now, I should have asked earlier in the thread. You wouldn't happen to be using a scatter shield style bell housing and left out the block protector plate out? That would account for an approximation of .125" in spacing lost.
     
  20. Bluedot
    Joined: Oct 26, 2011
    Posts: 331

    Bluedot
    Member

    JG, good question, but no. Stock bell, stock flywheel, stock diaphragm pressure plate, stock 11" disc. That's what bugged me - it was precisely the application the website and instructions said it was for. Since I'm working with an Olds, I even asked about that in the Q&A section for that part, and was told it would work.
    I sent it back yesterday with a full explanation. Hoping they'll refund me, tho it was bought back in Feb.
     
  21. d-rod!
    Joined: Oct 5, 2010
    Posts: 63

    d-rod!
    Member

    i had the same problem with my big block chevy in my model A, i machined the bearing retainer back just far enough to square it off and made a shim plate between my motor and trans. you could also make a shim for between the trans and bellhousing. when i had this problem i called howe and explained my situation and i was told very angrily that these throw out bearings are not made for street use and the fact that they say street on them is for street class racing and they hold no responsibilty for how they get used and he didnt undestand how these things ended up in the hands of mere hot rodders, i explained to him that a little info in advertising would go a long way
     
  22. d-rod!
    Joined: Oct 5, 2010
    Posts: 63

    d-rod!
    Member

    in the end i made it work and its been fine since so good luck
     

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