Blown tranny now. Honestly, what next?

RemCharger

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The company that built the tranny make their own convertors apparently. They chose the stall speed(2800)based on the dyno numbers and car weight, etc. So here is one of the problems. The shop that dyno'd the engine has a reputation for their dyno being a little generous. In my engines case, maybe 50hp and 50-70tq. I'll put the dyno sheet below. The car was chassis dyno'd and the rear wheels put down 345hp. Either something was slipping badly, or somehow 150hp was lost from crank to tires. That seems like a lot to me. When I gave the engine specs to two other engine builders, both said that engine, especially with my cam, would never make the power the engine dyno was reading. If the power was off, would that throw off the 2800 stall speed? I didn't know at the time that they have a not so great reputation for their torque converters.

View attachment 1334723
Back in the day when the rpms came out, edelbrock claimed 535 with a similar build but bigger cam. So your numbers with the 268 doesn't sound egregious
 

Geoff 2

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Dark fluid means the fluid has overheated or the friction surfaces [ clutches, bands ] have been been slipping...or both. Either way, tranny has to come apart.
I don't know why you would use a stall c'ter with that mild cam, not needed. You just add heat & slippage.
 

66Satellite47

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I have built 727's for about 50 years, not a pro, but very experienced. Burned fluid, means damaged internal parts. I'd find a better trans builder & a much better convertor.
 

Mark1972

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If you are driving checking places. Only one in Winnipeg I trust is seven oaks transmission on mcphillips. just finished a 727 for me.
I've dealt with them going back about 12 years, and yes, they have been excellent. I'll call them first thing.
 

65hemi

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Talk to Rick in Oakbank. Works out of his own shop. Your engine builder has Rick’s contact info.
 

66Satellite47

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I built my own 727's for over 30 years for my drag cars. I only burned up one. Rebuild it in the pits that nite. Went to the finals next day.
 

pnora

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Might be a stupid question but did you check your flex plate to converter bolts and make sure they didn’t shear off?
Lotsa aftermarket Chinese made crap out there....
Not possible if the engine cranks over and runs.
 

66Satellite47

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Convertor bolts can loosen up. I know. Back in the day I started using the Green Loketite (replaces welding & brazing). Loose convertor bolts are a bitch.
 

IT'S DYNAMITE

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Btw, here are the engine specs.

440 Block bored .030"
Align bored
Decked
Factory cast-iron crank ground .010" under
New SCAT H-beam rods
Keith Black pistons(10.1-1)
Eddy RPM intake
Eddy E-Street heads (75cc chamber's)
Engine balanced
Doug's headers
CompCams XE268H cam and lifters
CompCams 1621-16 roller rockers
Melling M63 HV oil pump and pick up
Carter M6903 fuel pump
ProBillet distributor
MSD wires
440Source 6 quart oil pan, windage tray.
3.55 Yukon Duragrip 8.25
1970 Satellite (3500lbs)
Hi Mark,
This has nothing to do with what happened to your trans,but when I look at you breakdown of engine build and I see that you used all the good parts I am surprised that you used your cast crank! I am an engine builder ASE Certified Master Machinist owning my own shop and I never did a 440 with a cast crank never mind machining it .010/.010. With all the rest that you spent on good parts a steel crank would have given you a much better deal as far as longevity.
It is too bad you are not closer to Maine as I also have a transmission business and would like to see the unit BEFORE any one gets there hands on it. The trans tells the story as you take it apart for inspection.
Regards
Dom
 

66Satellite47

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Hi Mark,
This has nothing to do with what happened to your trans,but when I look at you breakdown of engine build and I see that you used all the good parts I am surprised that you used your cast crank! I am an engine builder ASE Certified Master Machinist owning my own shop and I never did a 440 with a cast crank never mind machining it .010/.010. With all the rest that you spent on good parts a steel crank would have given you a much better deal as far as longevity.
It is too bad you are not closer to Maine as I also have a transmission business and would like to see the unit BEFORE any one gets there hands on it. The trans tells the story as you take it apart for inspection.
Regards
Dom
I'm not a builder, just a guy that uses good builders. Although I never used a cast crank, but for a mild application I'm sure they are just fine. I used up numerous OEM steel cranks due to my 7000+ rpm abuse. A 6200 RPM will last a very long time.
 

Sparky Anderson

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Why pay someone to rebuild your transmission especially a 727, it's a very easy transmission to rebuild yourself at a fraction of the cost. Plus you know exactly what's in it, don't trust some of these people out there. Tear it apart and inspect it first, a ton of very good YouTube videos plus some really good books on Amazon. Replace the torque converter, don't chance it after what has happened. A good source to get a rebuild kit and parts is A & A transmission. Plus in the end you be walking around with your chest swelled up for doing a good job.
 

12icer

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Possible spray failure if you have nothing sprays are something that a lot of shop’s don’t bother with in a rebuild but if a trans sits up for a while is a definite need
 

12icer

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Possible spray failure if you have nothing sprays are something that a lot of shop’s don’t bother with in a rebuild but if a trans sits up for a while is a definite need
That was SPRAG before predictive text
 

70mopar

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Do bad things happen in 3's? My goodness, what next. A month ago it was another stamped steel rocker with a pushrod through it. Now It appears I've smoked my 727TF tranny. Went for a nice 20 mile drive yesterday. Kind of a shake down run. I'd finished the roller rockers, oil and filter change, fuel filter inspection, plugs checked, and checked the timing to confirm still at 35 degrees total. All good. Come home to pick up the wife and we make it 3 blocks and then poof. The engine just died(has never happened before), so I got it in neutral immediately and pulled over. In park now, started the car, put it in drive, and it revs to about 2500 before moving. I shut it down immediately and towed it home. Oil quite dark, but the level was spot on. The tranny oil was fine just the day before. Could not get the car to move in any gear, including reverse. Park worked. Now, what to do. Tranny was rebuilt 3 years ago. Brand new 2800 stall TC was supplied as well. The had all the engine specs, as well as the dyno paperwork. In 3800 miles of driving I've maybe gone over 4500 rpm twice, and maybe spun the tires a couple times. People bug me because I drive it like an old man. I treat it very well. How could a tranny built to handle 450+hp and 500+tq give up so easily? Also, I've read if all the gears went together, it could be the torque converter. Stupid question, but how do you diagnose a bad TC?
That is a bad day. When the automatics go they go quick. Too bad you are not close to me, I have a rebuilt 727 that I switched out and put in a 4 speed. Good luck.
 

Nxcoupe

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The company that built the tranny make their own convertors apparently. They chose the stall speed(2800)based on the dyno numbers and car weight, etc. So here is one of the problems. The shop that dyno'd the engine has a reputation for their dyno being a little generous. In my engines case, maybe 50hp and 50-70tq. I'll put the dyno sheet below. The car was chassis dyno'd and the rear wheels put down 345hp. Either something was slipping badly, or somehow 150hp was lost from crank to tires. That seems like a lot to me. When I gave the engine specs to two other engine builders, both said that engine, especially with my cam, would never make the power the engine dyno was reading. If the power was off, would that throw off the 2800 stall speed? I didn't know at the time that they have a not so great reputation for their torque converters.

View attachment 1334723
I own a chassis dyno and I think I can help here. A dyno looks at rpm vs acceleration knowing the weight of the drum, so any slip in converter throws off the calculation. I can say that an auto trans with a lock up converter will show about an 18 to 20% driveline loss, vs a stall converter showing an approximate 25% driveline loss.

Just an fyi, hope it helps. And I have a car on the dyno now that had a std trans in it and we swapped in a built auto with a stall spd, so we are strapping it down to test the dyno and are going to bring up his previous manual trans pulls for a comparison.

It sounds to me like your converter came apart since all gears are gone. Usually 3rd gear goes if the kickdown linkage isn't adjusted correctly in my experience.
 

66Satellite47

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A 727 rebuild is fairly simple. If you get a factory service manual or many of the pubs out there. A 727 is a strong trans. They have VERY many stock configurations. You need to get the parts for a HP design. That mainly means the race front band, front servo lever (3.8 or 4.2), good clutches in the front drum and 10 or 12 springs in the front drum. That will be very close.
 
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