Simple question about throw-out bearing

Discussion in 'transmission and Drive train' started by mathd, Jan 25, 2012.

  1. mathd

    mathd solid fixture here in the forum

    I need some help there.. its a simple question but ohh well i spend the past 5 day trying to figure this out, as stupid as it can be i cant decide myself :/
    I need a longer throw-out bearing for my clutch fork.

    Summit list 3 input shaft diameter for the gen 1 350 sbc for a 80 camaro
    one is for a 1.125 input shaft and the other is for a 1.375" and 1.378" input shaft diameter(measured the smooth outer colar to 1.375" on my trans).

    Now what is the correct one? for a 4 speed borg warner?
    Also what lenght should i use? they range from 1.288 to 1.3/4, i have about 1" 1/8 now, didnt measure accuratly.

    Right now am looking at this one:
    But am totally unsure about the input shaft diameter and lenght.
    Also, when i check on jegs for the same parts number they list a different input shaft diameter.. this leave me speechless.
  2. grumpyvette

    grumpyvette Administrator Staff Member

    input shaft is the SPLINE shaft the clutch disk rides on not the smooth outer collar the throw-out bearing rides on, that 1.375 throw out bearing is most likely correct, the SPLINE shafts come in different tooth counts if you count those and order the matched disc its most likely going to fit
    discs come in 10 spline and 26 spline count types and 10.4" and 11" diam. for most chevy clutches, naturally the spline count must match the input shaft and the diam. must match the pressure plate

  3. mathd

    mathd solid fixture here in the forum

    I already have my clutch, am using a hays 168 tooth flywheel and a 10.5 centerforce clutch with 26 spline(matching my trans input shaft)
    Its the throw out bearings size that got me confused.

    If the smooth outer collar the throw-out bearing rides on measure about 1.375 +/- a few thou then the grooved input shaft is smaller, so i assume it that i have a 1.125" input shaft?

    Or just simply, have any part number i can order? That could make life alot easier :).
    Right now am looking at those:
  4. grumpyvette

    grumpyvette Administrator Staff Member
    I have found two different types of "short" clutch release bearings for Chevrolet. National P/N CC1705C is listed as "angular contact". P/N 614018 is listed as "sealed, self-aligning." Use the 614018, it is the newer style bearing.
    remember the arm mounts like this
    keep in mind theres three common throw out bearing heights and youll need the correct height for your particular application to get proper clutch function
    BUY this its correct for your application (ACCORDING to centerforce tech center)

    Tech Department
    - (928) 771-8422
    26 spline
    I'd point out that,
    many times clutch chatter is the result of an un-even flywheel surface, any decent machine shop can surface grind the existing friction surface a few thousands to correct that issue.
    clutch chatter is the result of un-evenly applied clamping surfaces, usually a high spot(S) on the clutch pressure plate its housing or the flywheel surface, , but heat warping or a broken spring or mis-aligned spring will also cause this symptom.
    the flywheel should be torqued to the crank flange, an impact gun should never be used as its possible to warp the mount surfaces is tightened un-evenly
    if the clutch vibration does not go away once the clutch locks up,
    you've more than likely,
    got a drive line component alignment or rotation assembly or drive line balance issue.
    you'll want to verify the flywheels mounted so its not wobbling, it may be warped, or the crank flange its mounted too has been bent or theres debris between the flywheel and crank flange, you,ll want too use a dial indicator mounted on the block and rotate the flywheel to find out, if the flywheel friction surface or outer diameter ,changes its distance from the block as it rotates

    read ALL the links


    Last edited by a moderator: Sep 17, 2017
  5. mathd

    mathd solid fixture here in the forum

    Ok that make sense to me now. Thanks for the answer :)

    On the clutch alignment tool, when we assembled my clutch we did not have the tool, so we used the transminssion's input shaft while tightening the pressure plate, while it was more hassle to hold the trans and have someone else tightening the pressure plate i assume that got the clutch alignment correct since the trans get in and out easily? or should i buy the tool and re-do the clutch alignment?
  6. grumpyvette

    grumpyvette Administrator Staff Member

    the tool makes it easier to do, the alignment, but if the trans is able to fully seat, theres not much point in buying the tool now,for that job,as its already aligned, but ID sure suggest owning one for future clutch jobs
  7. mathd

    mathd solid fixture here in the forum

    ok thanks,
    at 7$ i did add it to my summit cart for futur use :)

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