Slipping Trans

Discussion in 'Automatic Transmission' started by 87silveradok20, Nov 13, 2017.

  1. 87silveradok20

    87silveradok20 Full Access Member

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    So I’m looking at a suburban with a 6.2/700r4. The guys says the trans slips after you drive it for more than 4 or 5 miles. Is the trans toast or is it still save able?


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  2. 1987 GMC Jimmy

    1987 GMC Jimmy Full Access Member

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    I would assume it needs a rebuild, and even though you maybe could do a few little housekeeping measures to improve/temporarily fix the situation, it's better to bite the bullet now and get it over with instead of hurting the transmission worse. I'd be looking at things like TV cable condition/adjustment (fraying), trans temp when warmed up, fluid condition, and types of particulates in the filter, fluid, and magnet to get a better idea of what's going on. That's just my opinion, though.
     
  3. Honky Kong jr

    Honky Kong jr Super Sarcastic Man

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    I would think so. Excuse my ignorance, but did GM really put the 700R4 behind a diesel?
     
  4. 87silveradok20

    87silveradok20 Full Access Member

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    Ok I’ll look at all that when I check it out


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  5. 87silveradok20

    87silveradok20 Full Access Member

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    That’s what the guy says


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  6. Honky Kong jr

    Honky Kong jr Super Sarcastic Man

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    They can barely handle the torque of a 4.3 let alone an oil hammer seem kinda self defeating to me.
     
  7. yevgenievich

    yevgenievich Full Access Member

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    Early diesels gm used barely made enough torque to match regular 350 gas motor. But they were almost twice as efficient in mpg
     
  8. CSFJ

    CSFJ Magnificent Bastard Supporting Member

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    Lol, I had the exact same thought.
     
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  9. HotRodPC

    HotRodPC Administrator Staff Member

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    Well hell yes, you of all people I'd have expected would know that. OEM All day long !!!
     
  10. HotRodPC

    HotRodPC Administrator Staff Member

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    You, you're excused, I wouldn't have expected you to know. Only difference was the converter. You don't want to put a gas converter in a diesel and vice versa. Had to do with different torque specs at low/higher rpms.
     
  11. HotRodPC

    HotRodPC Administrator Staff Member

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    Trans DOES likley need a rebuild. This is the typical sign of dried up hardened clutch drum seals and they're not sealing once the fluid gets warmed up and thinner so it leaks past the seals and does not compress clutch drums. If it has not been allowed to slip alot and it hasn't tore up the clutch packs just yet, there MIGHT BE a slight chance of a patch up or short term revival.

    I hate hate hate additives in any damn thing. Fluids are formulated. When you go mixing weights, brands, synthetics, conventionals and such it just fux up all the formulation. Kinda like backing a cake. You don't follow the recipe it doesn't turn out as intended. At any rate, I just don't blend fluids and don't care for additives and witch potions to fix shit. HOWEVER, one of the few I'm for since you've got nothing to lose, is a good trans additive. Get a good trans conditioner and it's possible it might slowly soften those rubber seals and bring it back to life for a short while. I do know a guy who did this and it cured his problem. It got better and better the more he drove it. He did give it 2 doses of treatment. I wouldn't waste my money on any more than 2 bottles. If 2 don't get it, none will. He got another year out of his. This only works if it's a vehicle that has sat for a very long time and the seals got hard. If it's been driven recently and hasn't sat for many months then don't even waste your time with the additives. Just pull it and rebuild it.
     
  12. Honky Kong jr

    Honky Kong jr Super Sarcastic Man

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    I like my TH400s and Glides 700s get gone lol.
    Just seams dumb but the converter thing makes it make more sense. Probably like the difference in a B.B. or SB converter the whole anti ballooning thing.
     
  13. HotRodPC

    HotRodPC Administrator Staff Member

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    My preference has always been a Th350. All a Th400 offers is pure strength, but I like the characteristics of a Th350 much better. My street stip truck had a Th350 in it and I'd break it about once a year and have to replace the front input shaft or the intermedate sprag but guess how many fux I gave? NONE. Back then a refresher rebuild kit was about $60 and I always had spare hard parts. Sometimes I think me running a Th350 gave me just enough advantage to win some of the races I won against guys running power robbing heavy Th400's.
     
  14. bucket

    bucket Super Moderator Staff Member

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    It's pretty much a safe bet that if a 700r4 slips at any time, it's toast and needs rebuilt.
     
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  15. HotRodPC

    HotRodPC Administrator Staff Member

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    I'd totally agree if it wasn't for the guy I was talking about who saved his and got another year out of it, but it was in a 92 Chev 1500 with a 700r4. I too was a bit shocked. He didn't let it slip though. He called me immediately and I told him it's a gonner that only chance in hell it'll come back to life is to try the additives since the truck had sit over 2 years. He bought it cheap and put a fuel pump in it to get it running and then told me the trans slips.
     

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