47RE trans guru help wanted

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KTA-Cummins

Diesel Doctor
Joined
Jul 23, 2006
Messages
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I have an issue with a 47RE I am hoping somebody might be able to give me some ideas on as to where to track the problem down at. The issue is the torque converter locking up without it being commanded. The valve body is a full manual as made several years ago by a transgo kit. In reverse the converter and transmission is fine. When you put it in a forward gear it is also fine until you apply some throttle and the throttle valve is increased just a touch then it drags the motor down and kills it. This started after installing a sonnax 4 spool switch valve, so I took it back out and put the stock valve back in, but left the seperator plate modified as per the instructions and still have the same issue. Anybody got any ideas? Could excessive line pressure cause the converter to lockup? Ideas wanted before I start fighting this thing again.
 
KTA-Cummins said:
I have an issue with a 47RE I am hoping somebody might be able to give me some ideas on as to where to track the problem down at. The issue is the torque converter locking up without it being commanded. The valve body is a full manual as made several years ago by a transgo kit. In reverse the converter and transmission is fine. When you put it in a forward gear it is also fine until you apply some throttle and the throttle valve is increased just a touch then it drags the motor down and kills it. This started after installing a sonnax 4 spool switch valve, so I took it back out and put the stock valve back in, but left the seperator plate modified as per the instructions and still have the same issue. Anybody got any ideas? Could excessive line pressure cause the converter to lockup? Ideas wanted before I start fighting this thing again.
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You could pull the power trans relay to determine the possibility that it is an electrical noise/PCM issue.
 
It does the same thing with the multi wire connector unplugged. The problem is definitely hydraulic and not electrical.
 
Nobody has any ideas? Guess I am shooting in the dark on my own with this one then!
 
You could separate tv position from throttle position to help determine if it is TV related or pump RPM related.
 
Sounds like you might have a cross leak in the v/body. Also check your switch valve and spring on the front d/s of the v/body.
 
I did do that. if I twist the tv linkage on the trans end the converter locks in any forward gear. It does not lock in reverse regardless of TV position. Therfore I am assuming it is not a cross leak issue or it would lock either way I am guessing. Does anyone know of a good online source that shows the hydraulic circuits? I don't have a TM for this 47RE since it was installed in place of an RH in a 95 truck along itme ago.
 
How does the switch valve normaly work for lockup? Does it allow oil to dump normaly and then upon lockup it keeps it from dumping and thus applys lockup, or does it apply oil pressure to the converter to command lockup? This problem all started when installing a new converter and a sonnax switch valve kit, that is why when I put the stock valve back in I thought it might fix the problem, it is better, but still not fixed. The seperator plate is still modified per the sonnax instructions, perhaps I will have to replace it as well.
 
So I am attempting some diagnosis and have found a problem. I checked line pressure and it is nothing crazy with 60psi at idle in drive. I then pulled off one of the cooler lines at the transmission and I have no flow out of either port. Would no cooler flow cause the torque to lockup? None of the lines are hooked up so what are some of the possible reasons for no cooler flow?
 
Well thought I was onto something but I was wrong. Cooler flow is OK I just didn't realize that my 10gpm meter was to big to measure the amount of flow. I took the line loose and have a nice garden hose type of stream coming out at idle. So I pulled the valve body off, took it apart and inspected it and could find nothing wrong. Is it possible for the lockup solenoid to be bad and to be stuck engaged?
 
man you have one pain in the ass, you are all ready in above my head, but i keep watching to see wth is wrong with it. i dont want to stay dumb. good luck
 
Have you dropped the pan and made sure the valvebody itself is tight?
 
Biggest problem is both ATS and Suncoast have worked on this VB at diffrent points in time so what is in it doesn't always match the book, that and it has been converted to a full manual as well so that alters some circuits too. I think I will probably just hjave to get a stock VB and build it from scratch. I have had the VB off 3 times now changing stuff around and I still have the same results. 4th time is the charm though right????lol
 
Thanks Josh. I may have to run down there and get it just to try to be sure I can isolate the problem to the valve body. I think since it is fine in reverse it has to be in the VB and not in the Torque converter or it would lock up in reverse as well as the forward gears.
Do any transmission shops have such a thing as a valve body tester? Something that could be used to isolate where in this thing the problem might lie?
 
Do you have a Mag Hytec double deep pan by chance? If so, make sure you filter adapter is on correctly.
 
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