Torque convertor drain back valve ?

Gdogg

Gdogg

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Oct 2, 2009
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Does anyone know if a 92 with a Cummins has a drain back valve for the torque convertor? The problem is if you let it sit more than a couple of days the convertor drains down and has to fill up for the truck to move. I don't know if it has one on it (thats bad) or if it can be added. Thanks:thankyou2:
 
I don't recall when Chrysler started installing the check valves, but if the trans has ever been worked on it is a crap shoot whether the valve is in there anymore. A lot of shops remove them.

There are a few options to help...

1. Put the truck in neutral for a little bit before taking off. This will circulate the oil. Leaving a stock trans in park and running it will not.

2. Modify the valve body. You can either put an aftermarket manual valve in it or drill a hole in the casting. This will allow oil to circulate in park.
 
My 91 does the same thing, so does my friends 89&92...about 10 seconds in neutral usually fills it back up
 
Thanks mondtster, The trans was at one time rebuilt, and I think thats when the problem started. Do you know where the drain back valve is? I know torque-flites do not pump in park, I told the guy that owns the truck to put it in neutral when he starts it and thats what he has done for a few years now. Do you know any more about after market manual valve? or drilling the casting? I thought I remember that these trucks had a problem with the valvebodys and the fix was a new valvebody. Could the problem on this truck be in the valvebody? Its a nice truck and worth the time to fix it, I just have to figure it out.:thankyou2:
 
xtreme8504 said:
My 91 does the same thing, so does my friends 89&92...about 10 seconds in neutral usually fills it back up
Click to expand...

Same here, was told this was front pump clerance. When i rebult my trans the clearance was within spec, still does it. lol
TOMMY
 
I did talk to a couple of trans guys, one said there is a drain back valve, and the other said it was the flywheel needed to be centered by dial indicating it in, he said the convertor is not centered in the pump and that was causing the convertor to leak down (the trans doesn't have a external leak ). He said he has fixed them by doing this. Funny thing, I did put a new flywheel in this because the center broke out of it. Maybe it could be the clearance in the pump? I was hoping there is a external valve kit like early Ford E4od's had, that would be easier to do.
 
Gdogg said:
Thanks mondtster, The trans was at one time rebuilt, and I think thats when the problem started. Do you know where the drain back valve is? I know torque-flites do not pump in park, I told the guy that owns the truck to put it in neutral when he starts it and thats what he has done for a few years now. Do you know any more about after market manual valve? or drilling the casting?
Click to expand...

The drain back valve is simply a check valve that goes in the cooler line. Its location has varied over the years so I would just follow the lines and see if you can find it. If it isn't there, I wouldn't worry too much about it. Chrysler didn't use any check valve in there for decades. You just have to be aware of the "problem" and know how to deal with it (put the trans in neutral).

Here's the manual valve I'm referring to:
Sonnax Transmission, Torque Converter, Performance, Driveline Parts :: Transmission :: 22771-09 :: Part Summary

Personally, I wouldn't drill the casting. Modifications like this are a royal pain to reverse down the road if you decide to go a different route. I have a spare manual valve if you really want to fix it. PM me if you're interested.

TOMTOM said:
Same here, was told this was front pump clerance. When i rebult my trans the clearance was within spec, still does it. lol
TOMMY
Click to expand...

I think someone was mistaken.

Gdogg said:
I did talk to a couple of trans guys, one said there is a drain back valve, and the other said it was the flywheel needed to be centered by dial indicating it in, he said the convertor is not centered in the pump and that was causing the convertor to leak down (the trans doesn't have a external leak ). He said he has fixed them by doing this. Funny thing, I did put a new flywheel in this because the center broke out of it. Maybe it could be the clearance in the pump? I was hoping there is a external valve kit like early Ford E4od's had, that would be easier to do.
Click to expand...

The pump bushing might be beat up from breaking the flexplate, but I really doubt this is the cause of the issue. Converter drainback is a known characteristic of torqueflites and has been for years. Besides, even if the flexplate is off center slightly shouldn't matter, considering that converters pilot off of the crank.
 
mondtster, does the sonnax valves let this trans pump in park? or what does it do? I see in their instructions this note -, Note: To prevent converter slippage, restricted cooler flow and possible hydraulic noise, remove the
cooler line drain-back valve. I'm wondering where is it? I guess it must be in one of the cooling lines. I'm going to talk to the guy that rebuilt this trans but it was done about 2003 or 04, maybe he can remember something
It will be a few weeks before I can work on this truck, but I will let you know what happens
 
Gdogg said:
I see in their instructions this note -, Note: To prevent converter slippage, restricted cooler flow and possible hydraulic noise, remove the
cooler line drain-back valve. I'm wondering where is it? I guess it must be in one of the cooling lines.
Click to expand...
The 1st gen trucks running the A518 don't have a check-valve in the fluid cooler/heater lines. ;)
 
Well, I picked up the sonnax valves, actually a kit call "The Sure Cure"
it has the manual valve along with a bunch of other valves and parts
to fix the most common problems with this trans. It cost $100, I will
put it in in the next couple weeks and let you guys know how it works.
:Cheer:
 
Gdogg said:
Well, I picked up the sonnax valves, actually a kit call "The Sure Cure"
it has the manual valve along with a bunch of other valves and parts
to fix the most common problems with this trans. It cost $100, I will
put it in in the next couple weeks and let you guys know how it works.
:Cheer:
Click to expand...

Just an FYI, but the valve is available separately too. Costs ~$20.

Good deal though, should help your "problem".
 
Mine did not do it untill last rebuild. I checked in to it and found that they took out the drain back valve out of the cooler circut because it gets pluged with trash and will take out the transmission. I have raced Mopars for 34 years and all my 727's did that. Just put it in neutral as mentoned and it pumps right up.$.02
 
Well it took some time but I finally got back to this this truck, I put the sonnax kit in the trans and I'm happy with the results, the shifts feel better and it will go right in gear after you start the engine. It did say in the directions to remove the drain back valve, but didn't say where it is at. It is still a mystery if it ever had one and where it would have been. Thanks Guys
 
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