CK5
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1982 C/K 6.0L Caitlyn Mall Crawler (Interior time)
- Thread starter Babaganoosh
- Start date
I would have thought it would toss a check engine light
Pretty sure the ecm is supposed to be able to read line pressure, I'd check w/ 208 on that. If it infact can, it should have set off a check light if it were low. If that is so, then you'd know that it would be problems controlling the clutches and would be able to follow up on that.
It's does have a pressure switch, I don't get it.
There's 2 big ways that the tranny could have burned up. Low line pressure and bad clutch engagements. So if the ecm was reading ok pressure. Then the problem should have been in the control of the clutches. Which would narrow down the dubious wires to look at.
Sounds like a great plan, and I agree with the clutches not engaging properly.
The trans ECM probably doesnt get a pressure reading back to it, it will just PWM the current to correlate to the appropriate pressure and assumes it is working, most trans don't have a pressure sensor(although that could be changing in very modern stuff, I'm not sure). Some of the new stuff can measure shift speed and adjust, I think thats why they added the input speed sensor to the 4L65E, which previously the 4L80E had it and the 4L60E didn't, but it still doesn't have pressure feedback that I am aware of.
When you get this one hooked back up, hook up a trans pressure gauge to the test port. I've ran the hose up through the shifter hole before, just remove the boot. Should be a 300 - 400 psi gauge, as the pressures can range from 100 to up over 300 psi depending on gear, throttle position, engine load, speed, etc. And check your pressures during shifts and stuff, and if it feels soft even if the pressures are good, fix it right away so you don't burn another one up. You should have it shifting nice and firm, not harsh, but it should be firm to last a while with any significant power levels.
I guess my point is, with all your troubles I would definitely hook up a pressure gauge so you know what is going on, and don't drive it until the pressures are correct and the shifts feel correct. For ~$30 you can pick up an ATSG manual for your trans and it will give you all the correct pressures and test procedures and also have a troubleshooting section that can tell you what to check.
When you get this one hooked back up, hook up a trans pressure gauge to the test port. I've ran the hose up through the shifter hole before, just remove the boot. Should be a 300 - 400 psi gauge, as the pressures can range from 100 to up over 300 psi depending on gear, throttle position, engine load, speed, etc. And check your pressures during shifts and stuff, and if it feels soft even if the pressures are good, fix it right away so you don't burn another one up. You should have it shifting nice and firm, not harsh, but it should be firm to last a while with any significant power levels.
I guess my point is, with all your troubles I would definitely hook up a pressure gauge so you know what is going on, and don't drive it until the pressures are correct and the shifts feel correct. For ~$30 you can pick up an ATSG manual for your trans and it will give you all the correct pressures and test procedures and also have a troubleshooting section that can tell you what to check.
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I slept on it and believe the problem is the harness inside.
Funny thing you suggest checking pressures I had a gauge on the seat and was waiting to go home to test it.
Funny thing you suggest checking pressures I had a gauge on the seat and was waiting to go home to test it.
Only reason I drove it was to have it at my dad's wake, it was getting better and had just a slight issue then all he'll broke loose and esploded.
Sounds like you at least have some direction on fixing the problem. That's honestly better news than we've heard in a while.
I'm going to use a multimeter and ohm the harness from the ecm to the trans and see if that's good but I suspect it's inside the trans.
If so, isn't that the job of the trans builder to get the inside wired correctly?
Would think so but meh
If all of your transmissions are burning up, what would lead you to believe it is not because of the truck???
Martin
Martin
I'm not sold either way.
I remember him messing with the pigtail in the trans, maybe before blazer bash? Either way I would keep a very open mind about the cause of the issue and definitely ohm out the harness as you mentioned.
I remember him messing with the pigtail in the trans, maybe before blazer bash? Either way I would keep a very open mind about the cause of the issue and definitely ohm out the harness as you mentioned.
Well the first one was the converter, I get that 2nd one was junk from the start, the 3rd one is now the suspect to really diag it.
It's was after blazer bash in the middle of trans swaps, you are correct I did and I think I might have crossed a qire wrong but I double and tripped checked it. This is why I think it's internal to the trans but I want to ohm it all out again.
I tend to agree you need to look at every aspect. Line pressure probably being very important.
This many failures is uncommon without some sort of problem.
This many failures is uncommon without some sort of problem.
Really I have only been through 2 now, the 3rd one was just junk i got for free and already broke. I'm going to start fresh and make sure my T's are crossed.
Builder called, said he recommended a new case to much monkey business in mine he wasn't sure played correct with each other.
Has one ready to go that a customer backed out, he wants to upgrade it to the specs I had as far as the performance and stronger parts.
800 out the door with warranty and assurance it's correct.
Has one ready to go that a customer backed out, he wants to upgrade it to the specs I had as far as the performance and stronger parts.
800 out the door with warranty and assurance it's correct.
