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4l80e in a Hummer h1

ron993

New Member
Messages
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20
Location
Tomball, Texas
I have 2002 Hummer H1 that has a the 4l80E in it with 68000 miles on it. I changed out my timing chain to Leroy's timing gears and messed up the injection pump timing. I took the truck to a mechanic friend that new how to fix the timing and while he had his computer hooked up he told me the temp sensor in the transmission was going out and was reporting erratic temperature readings. The previous owner told me the fluid was changed around 40000 miles. I figured if I was having to drop the pan I might as well swap all the solenoids out while i was in there.

Here is what I bought https://globaltransmissionparts.com/4l80e-solenoid-replacement-kit-1991-2003-5-piece-set/ along with a new AC Delco internal wiring harness
Some of the parts from global were AC Delco and some didn't have a name on them.

Now the truck is reporting a P1870 code that I know means something is slipping. I am thinking that one of the parts that I swapped might be bad? Does anybody have any ideas?
 
From the little bit of searching I did it seems that the torque converter is the most common failure but I'd try to get a scanner on it while driving to see what's going on.
 
If the problem started with the change, I would suspect a problem with either a solenoid or the installation of the parts. One thing I do know is I hate these universal kits as 91-93 and 94+ use a different pcs, but the cheap kits sell the 94+ pcs for the 91-93 models. I would get a pressure guage and a scanner on it and see if the pressure is following the amperage chart. All it takes is to nick 1 o-ring in the psm or the pcs to ruin a trans. All you needed to do was swap the internal harness as the temp sensor is built into the harness. I'm not a fan of parts swapping as many times you create more problems than you fix doing it.
 
If the problem started with the change, I would suspect a problem with either a solenoid or the installation of the parts. One thing I do know is I hate these universal kits as 91-93 and 94+ use a different pcs, but the cheap kits sell the 94+ pcs for the 91-93 models. I would get a pressure guage and a scanner on it and see if the pressure is following the amperage chart. All it takes is to nick 1 o-ring in the psm or the pcs to ruin a trans. All you needed to do was swap the internal harness as the temp sensor is built into the harness. I'm not a fan of parts swapping as many times you create more problems than you fix doing it.


I know what you mean, I wish now I would have just changed the harness and filter and been done. But I figured with all the skid plates that have to come off and dropping the cross member to drop the pan it couldn't hurt to swap out the other components also. Guess I was wrong... Gonna take it to a transmission shop I have used in the past and let them look at it.
 
Yeah, the under carriage protection is wonderful until
It has to come off.
When it comes to diagnostic issues- as hard as it is, I have learned to just fix the problem then go back afterwards and do upgrades or pm work seperate. Back before everything was electronic it wasn’t that big a deal.

Please let us know how it turns out.
 
I finally had a chance to talk to the transmission guy yesterday. He told me that my problem is most likely with the components that came from Global transmission. He said that they sell aftermarket parts that barely meet the specs and will cause more problems in the long run. I am taking it to him on Monday and he is going to hook his scanner up to it and see what it is saying.
 
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