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FIXITMAN, Master Technician
Category: GM
Satisfied Customers: 17285
Experience:  ASE Master Certified
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GM 3500: 2004 chevy 3500 w Allison 1000 transmission 5spd,

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2004 chevy 3500 w Allison 1000 transmission 5spd, oil leaking into connector need to change. how do I do this I assume drop pan, any pointers would be nice.


Hello, and thank you for allowing me the opportunity to help you. If I am not online when you are, please allow me time to return. This is very easy to do. Once you drop the pan you will see where the wiring harness enters the transmission. There are just two locking clips on it. You need to unhook all of the internal connectors on the solenoids first. Then release the two locking tabs and slowly pull the wiring harness from the transmission. It is just about as simple as that. I can see if I have any diagrams for you if you need them. Also, be sure you are ordering the wiring by using the transmission model label on the side of the transmission. If you do not then you may not end up with the right harness.


ok I am assuming this is the problem, it is shifting all sourts of crazy if at all fluid is clean and unburned. was parked over winter, had no problems, customer went to bring in my shop for inspection and said that its shifting eraticly, I looked at it and it is in limp mode, inspected harness and it loaded with trany oil so im hoping this will fix, as soon as I clear codes it comes right back


If there is fluid in the connector then that is the first place to start. It is also common for the ignition switch to fail internally and not send the right amount of voltage to the transmission.


ok thank you

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Customer: replied 3 years ago.

helo on this vehicle I changed the wiring harness then started it but still the same. doesn't have transmission codes. but its behaving real funky. likes its in limp mode. ran great coming into my shop for brake issues, after we were done with breaks it would not run that's wen I discovered oil in harness, any ideas?

How long did you have the vehicle for? How are the batteries?
Customer: replied 3 years ago.

had vehicle for about 2 months, has one 12 volt battery wich we just put in with a new altinator (was complaining of the battery light commin on and going off checked and found under charging) . other battery are 6 volts for coach. (this is a motorhome but question is specific to the truck not the coach, its a gm workhourse w-22 if u stay with me I will leave u great tip. just answer is difficult sometimes. it did run fine coming in to my shop earlier post had it shifting badly coming here. after doing a rear brake job it wouldn't even go on its test drive. only code I have is a p2810 any ideas? imdying here. just keeps going into limp mode

How long does it take to go into limp mode once you start driving the vehicle?