Diagnosis fro my 4sp w/OD

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86_c10

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I have an '86 c10 standard cab long bed with a 5.7 sbc and a 4sp muncie w/OD. I recently drove it home from its previous owner and it drove great except for some smoke under the hood at one stop. After about 45m I was on the freeway and had no problems banging through the gears then all of a sudden it wasn't accelerating. Soon none of the gears were working in the sense that the truck wasn't accelerating although the engine was revving up just fine. The smoke under the hood was from a small antifreeze leak that went onto my headers so that isn't the smoking gun. I am puzzled at what might be wrong at this point. The clutch works putting it in gear and I inspected the linkage and it is fine too. I am thinking slave cylinder? There is a fair bit of fluid surrounding it and on the trans so it might be the culprit but not sure. The gears never grinded and it went smoothly up until all of a sudden so I don't think it is the clutch but it could be. Anyone help me out?
 

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Is this a 4 Speed Muncie from an older vehicle, or is it an A833 four speed with overdrive? The latter could be ordered in '85, but the former was out of production a decade prior, I believe.
 

86_c10

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Is this a 4 Speed Muncie from an older vehicle, or is it an A833 four speed with overdrive? The latter could be ordered in '85, but the former was out of production a decade prior, I believe.

It's the original transmission it was not a swap
 

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It's the A833 if it's an OD. And being stock it's not a Muncie. A833 is a New Process transmission.
 

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It does sound like the clutch probably went from your description. If it was the slave, you'd just have problems getting the clutch to disengage, but since it seems to disengage, but just won't go, it would appear to me the clutch is slipping. Did it by chance leak all the hydro clutch fluid all over the clutch to where it could have saturated the clutch disk?
 

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It's a Muncie and it's what came with the truck but no I don't think the fluid went on the clutch the only way to know is to take it all out and look I was just hoping for a simple fix - the option of a t56 swap seems to be the route I may go if it is the clutch
 

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It's not a Muncie. If you're really considering a T56, I'll assure you @bucket would be interested in your 4 speed overdrive and you can call it Muncie, New Process, New Venture, Tremec, Spicer, Eaton or whatever you want. But do let him know if go the T56 route.
 

86_c10

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It's not a Muncie. If you're really considering a T56, I'll assure you @bucket would be interested in your 4 speed overdrive and you can call it Muncie, New Process, New Venture, Tremec, Spicer, Eaton or whatever you want. But do let him know if go the T56 route.

I want to but cannot find one cheap enough if I do find one I will post the old trans for sale
 

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@bucket has a few GM cars and some parts. Who knows? He might even have a T56 laying around somewhere. :shrug: I've mentioned him in your thread, so I'm sure he'll respond in the next day or 2.
 

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@bucket has a few GM cars and some parts. Who knows? He might even have a T56 laying around somewhere. :shrug: I've mentioned him in your thread, so I'm sure he'll respond in the next day or 2.

You know if the tr6060 would fit the same?
 

bucket

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My ears were burning, lol.

Sounds to me like a clutch problem too. But if you want to go the T56 route, it should be a fairly easy swap. I've never put one in a truck, but I've planned it out in my head. If sticking with an SBC or a BBC, you will want the '93-'97 LT1 version. If your '86 has the stock motor, it will have a 1-piece rear seal and you can use the F-body flywheel and clutch kit. You will need the smaller LT1 starter, or a starter for an '84-'92 F-body with the T-5 trans. You "should" be able to combine the stock LT1 slave with your stock truck master cylinder. A driveshaft from a 700r4 equipped truck should pop right in place too. The reverse lock-out solenoid can simply be wired to the brake light switch. I've kinda been checking prices on them recently, you can expect to pay around $1200 for a semi-complete setup, which is down a few hundred bucks from previous years.

And yes, if you pull out your OD trans, count me as highly interested.
 

bucket

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You know if the tr6060 would fit the same?

I believe it's the same basic unit, with a different name and some upgraded internals. But being LS-based, there will be flywheel/clutch compatibility issues.
 

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