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Do I have a dying tranny or torque converter?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Bowtied, Aug 14, 2002.

  1. Bowtied

    Bowtied Registered Member

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    Hello all,
    I have two individual symptoms with my drive line so I'll give both and let you decide if they are related or not. (talking about an 87 blazer with a 350 ci and 350 turbo)
    First: If I jump in my truck after it has not been run for several hours and start it and immediately throw it into drive or reverse it acts like it isnt engaging. It will rev up without moving then after a few seconds it will engage and act like nothing was ever wrong. Now if I start it and let it just idle for a few seconds it will engage positively every time. So it only "slips" just afer start-up. Once engaged it will function fine and still shifts nice and tight.
    Second: I noticed this second symptom while pulling a lightly loaded trailer (about 1,000 lbs). I had driven several miles on back roads and came to a stop. When I went to leave the stop the truck reved up to about 1300 rpms without the tranny engaging. I tried a secon time and it did the same thing. When it did engage it really jerked and made a bang. The third time I tried, she pulled out fine. That was 2 weeks ago and it has only done this slip-bang thing 2 other times and I drive it at least 20 miles a day on the hwy and in town.

    What is failing in my driveline? I can't figure it out. The day after it did its little slip-bang thing I did a little "display" with some awesome tire spinning on asphault (okay, okay, it was wet asphault) and it didnt complain at all and its been about two weeks since so ifeel like it isnt broke yet but it will be soon.

    Thanks for any info you can share.

    Bowtied
     
  2. FRIZZLEFRY

    FRIZZLEFRY 1/2 ton status

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    Is it full?Mine used to do that when it was low on fluid.
     
  3. BigBurban350

    BigBurban350 1/2 ton status

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    The start-up slipping is most likely due to cold tranny fluid. The fluid is to thick and does not flow through the valve body quickly, so clutch/band engage ment is retarded. The slip bang would not be the torgue converter because it is not mechainically connected(TCC is used in 3rd if you have it). Its seems like something in the valve body is sticking, like when you come to a stop it would shift down from 2nd to 1st, but it doesnt fully enage into 1st. Gets some transmission flush(like tranny honey) to clean up some of the gunk and do a transmission flush after that(drop trans pan and replace filter). /forums/images/icons/wink.gif
     
  4. ftn96

    ftn96 1/2 ton status

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    When was the fluid last changed? /forums/images/icons/shocked.gif

    If un-known or 10,000 miles ago, I'd drop the pan, replace the filter and gasket. Refill with aprox. 5 quarts. Then see what it does. /forums/images/icons/wink.gif
     
  5. alec78

    alec78 1/2 ton status

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    If you haven't already, check your fluid level. If it is low top it off and try again. If it is at the correct level do a rag check. (put a drop out of your tranny and a drop of fresh fluid on a paper towel/shop rag, give it an a little while and see if the out of tranny spot has spread more than the fresh. If it is, your fluid has seen better days. Don't trust color as it really doesn't mean squat)

    If you decide to do a fluid/filter change, try not to distrube the pan too much. When you get it down, look for debris in it. Clutch material or metal flakes accumulate under where they came from.

    The filter/pickup could have a crack in it causing it to pull air.

    If you can do a pressure test. The front pump could be bad.

    I know its a lot but I hope this helps.
     

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