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crankshaft thrust bearing wear small block 400

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Flipper, Jun 11, 2001.

  1. Flipper

    Flipper Registered Member

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    West of Mpls. MN
    Having problems with thrust bearing wear with 465 tranny and small block 400, anyone have a similar problem? Is there a heavier thrust bearing out there or a better oiling bearing?
    Been using standard clevites 77
     
  2. Thunder

    Thunder 3/4 ton status

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    Thrust bearing wear can be caused by:
    A very heavy(lead)foot.
    A bent or worn crank.
    Auto tranny/torque converter problems or mis alignment between trans and engine.
    Even bad motor mounts can cause problems espically the rear one.
    Cleavite 77s are very good bearings. they should hold up to most any normal loads and are very forgiving. Federal mogul makes some bearings they call Competition series bearings. They have harder linings and are used with forged cranks. I think they would wear out the thrust face on a regular cast crank if there are overload problems.
    If you are getting a lot of thrust bearing wear,I think you may have problems that new bearings wont fix.
     
  3. Triaged

    Triaged 1/2 ton status

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    Do you have a heavy duty clutch plate in it? When you hit the cluth the fork forces the crank foward. What side (or both) of the bearing is warn? If it is the back than the problem could be the clutch. The fork may be pressing against the clutch at all times if it is way out of adjustment. The only things that I know of to fix the problem are a stock clutch plate, adjusting the clutch linkage (if it is adjusted incorectly), high quality bearings (if the ones in there are junk), and swaping in an automatic.

    '71 Blazer CST with alot of rust
     
  4. blazbrnc

    blazbrnc 1/2 ton status

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    When the motor was rebuilt was the crank end play checked? It's been a while since I've rebuilt a small block, but the last time I did the endplay was over the tolerance. The better parts stores stock oversize (thicker) thrust bearings. If the motor was built with excessive endplay, all of the crank movement could be wearing out the bearing face.
     
  5. WOODYJ

    WOODYJ 1/2 ton status

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    I had a problem with the thrust bearing wearing. Finally found out the Torque Convertor was broken inside and was balooning up putting allot of pressure on the crank. I don't think you would have that problem with a 465 though. Keep looking for something on your clutch or alignment of the tranny with the crank.

    k5woody I Don't Understand The Jeep Thing Either!!!
     

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