727 issues... again...

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dstan

dstan

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I bought a truck this past spring with a 71 440 and 727. I put about 600 miles on it and when shifting into second the tranny started completely locking up. I limped it the mile back to my house and parked it until i got another 727 for it. When i pulled it onto a trailer to get it to the shop it dumped all the atf and 1st went out as well. I found out the previous owner had not installed the kickdown linkage and figured that caused it to overheat and kill itself. I bought and installed a kickdown cable in my newer 727 and thought I was home free. I have put less than 200 miles on it and it dumped all of its atf on the interstate last night. It appears as though the main seal gave out.
I'm wondering if this one might be salvageable since it didn't seem to lock up like the last one did annd what could cause this. As far as I could tell it had been working flawlessly until this point (besides a slow leak from the front of the pan, I kept it topped off though). I'm considering switching to a manual if i have to replace it and was wondering how much it would cost to go from an automatic to a manual as well.
Any advice will be gratefully accepted. Thank you for your time.
 
I would just get one rebuilt instead of playing the guessing game. My buddy has a rebuilder in NC that is pretty reasonable. I could get the info if you want.
 
I wonder if the fluid level wasn't running too high. You know you need to check these; with hot oil,on flat level ground, in neutral, and with the correctly calibrated stick,right?

Too high a fluid level will put the oil into contact with the spinning parts inside, which will aerate it and then it will get flung up into the vent, from where it runs down into the bellhouse and onto the ground. I guess you could call this puking it's fluid out.
If the tranny is working hard,like in a motorhome, the fluid will expand and then it gets into the spinning guts again; so a motorhome should have a good oil-cooler, in an effort to prevent this.Depending on your GVW, you might want to install one too.
An improper dipstick or a damaged one will lie about the fluid level. The top stopper on older sticks can come off it's anchor points.
While driving up the ramp onto the trailer you might have a different problem; all the fluid runs to the back. If the rear seal is bad, the oil would just run out there. If/when the pump sucks air, the forward-drum would lose its pressure, and gone is your forward motion. If the fluid was NOT topped up before the cruise, then the pump could again suck air, aerate the fluid, overheat it, and perhaps throw it out the vent,again,what's left of it;and you are walking again.
The point is, this may just be a comedy of errors,who can say. I would start over with the tranny correctly filled and with the correct fluid.I would also check the chassis over to make sure the brakes and diffs are not dragging, and that the tires are properly inflated.I would also make sure it has a well-positioned oil-cooler on it. Then if it happens again,well,check the fluid. If it stinks or has turned away from it's bright red color, you know it's gotta come down..
Before you drop it tho, I would pay attention to how the TC is performing. If it is slipping excessively, it may be overheating the oil, and you don't want that guy to destroy a third tranny.
 
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This is what I would do were I in your shoes.
1. Check the fluid right now and verify that it is low, not burned and smells right.
2. If it leaks when you start it and it was verified low, then it's either a cracked converter or a seal issue.
3. If it doesn't leak right away add fluid till it's at the full mark.
4. If it still doesn't leak drive it.
5. If it does leak pull it.
 
Did you flush the trans cooler out after it cooked the first trans? If not it may be stopped up which will cause overheating and that will cause it to puke the fluid out.
 
I only know if they flushed it. They reused my 2800 stall converter and it's definitely low now I left a 3 mile trail of atf before it got on my headers and started smoking.
 
Well if it left a 3-mile trail, it's not a vent problem. So if the rear seal is ok, then, well, you know, .......................
I have seen a few crackled TC hubs.It starts in the pump-drive slot and works it's way back,eventually out to the atmospheric side of the seal, and then you get,what you got. If you're lucky tho, it's just the seal.
But I suppose there's always a chance that the dipstick tube o-ring is puking, so check that first;unless it is obviously coming out of the bellhouse area.
 
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