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Anybodys balancer hit there crossmember

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by DERBINATOR, May 30, 2001.

  1. DERBINATOR

    DERBINATOR 1/2 ton status

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    I have a 1976 3/4 ton frame with a sb 400 motor 350tran. and 203 transfer case. I just installed new trans. mounts and know my balancer hits the frame crossmember when I'm on the throttle hard or have it flexed hard. I looked at a mid 80's blazer with a 400 motor and there was about an inch of clearance there. GM must have changed something in this area? or I've got something wrong? I put spacers between the transmission crossmember and the frame to lift the front of my motor and it helped but I still only have about an 1/8" gap. Anybody have any ideas?
     
  2. thatK30guy

    thatK30guy 1 ton status Premium Member

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    I have heard and seen this happen before when people swapped in a motor out of a car or 2wd truck into the 4wd. The crossmembers are different between the 2 and 4wd's, so in order to make a car or 2wd motor work properly in a 4wd truck, the motor mount that bolts to the block needs to be off or for a 4wd version motor. In short, the 2wd mounts are shorter than the 4wd mounts and therefore causes the rub against the crossmember.

    When In Doubt, Whip It Out!
     
  3. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    How's the motor mounts? Mine were bad and the new ones lifted the engine at least 1/2 inch.
    Also not uncommon for some of the rivits from the plates that the motormount bolts too to break and let the motor drop some. Had that happen and lost about 3/8 of an inch. After fixing those problems I have a nice 1.25 under the ballancer.

    Diging it in the dirt with my K5's
    Grim-Reaper
    <A target="_blank" HREF=http://grimsk5s.coloradok5.com/>http://grimsk5s.coloradok5.com/</A>
     
  4. Wheels

    Wheels 1/2 ton status

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    What size/diameter balancer are you using? There are about three different sizes for balancers. For external balanced engines, like the 400, most are the 8" diameter variety. Streetdampr (streetable version of the Fluidampr) makes a 6 3/4" diameter balancer that should give you a tad more room. The run about $200.
     
  5. bandit

    bandit 1/2 ton status

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    My buddys blazer had this problem with 350 in it it was due to bad motor mounts we replaced thoso and ht tranny mounts and everything is ok know

    AJ
    Soon to wheelin spot near you
    Project Harvey[​IMG]
     
  6. fad2blk99

    fad2blk99 1/2 ton status

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    First of all, make sure you have the right balancer. I wouldn't want to screw around with that.

    When I put my new motor in, my balancer was pretty close to hitting the crossmember, but I lowered the T-case crossmember about 3/4", which tilted the motor back and gave me plenty of clearance. -Tommy

    <P ID="edit"><FONT SIZE=-1>Edited by fad2blk99 on 05/30/01 09:32 PM (server time).</FONT></P>
     
  7. Pugsley

    Pugsley 1/2 ton status

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    I used to have an 82 C30 with a 454 that had the balancer rub. New motor mounts and a new trans mount took care of it.

    I'm not creative enough to comeup with a new signature [​IMG]
     
  8. DERBINATOR

    DERBINATOR 1/2 ton status

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    Thanks for the input. I put new motor mounts in about 2 years ago and trans mounts about a month ago but I better be taking a closer look at them and where they mount to the frame.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Listen to Grim, my dads '74 K20 was also cracked where the motor mount "stubs" bolt to the frame, and was rubbing the large balancer on the front crossmember. I put the same motor/balancer in my truck, with uncracked "stubs" and I have no clearance issues whatsover. GM made improvements in this area later on, although I don't believe all of the stub pieces are interchangeable between all the years. The later ones if I remember right have plates riveted in to spread the load better.

    Dorian
    My tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
    No anti-theft measures on your truck? No pity when its stolen
     
  10. DERBINATOR

    DERBINATOR 1/2 ton status

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    Finally got a chance to take a closer look last night and I found the passenger side motor mount to be in pretty bad shape. Put on a new one and now I have plenty of room.
    thanks!!
     

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