P1870 converter issues

[Shagadoodle]

Hi, Today my truck threw the infamous 1870 slipping detected! Just as a background of the truck it's a 98 Tahoe 1500 with 182k miles and has a transgo hd2 valve body kit installed along with a corvette servo. This was installed when i recieved the p1870 code for the first time. Also has an additional tranny cooler. All this was installed 6 months ago and was working great. No issues towing no leaks. Yesterday towing a light load of a motorcycle and a bed the torque converter began slipping. When it's cold it tends to perform better and lock up easier but when warm it takes a while to lock up and I have to back off the throttle to get it to go in sometimes. I don't notice any slippage at speeds over 70 which and correct me if im wrong but i believe the lockup plays no role in at Rpms that high (2100 ish). when it is in lockup, it doesn't seem to hold it very well and under a light loadds won't go completely unlocked but will instead go up about 2-300 rpm (slipping i believe). Furthermore I checked the fluid and the level is good but it's fairly dark and kinda smells burnt. Definitely doesn't look the same as the fluid I put in it 6 months ago.

What I'm wondering is if it's just my converter clutch worn too far or am I looking at a full rebuild ? If it's just a converter which one should I get? I've read about the trailblazer ones but would like some input. If i am due for a full rebuild what kit would be most reccomended and what other components should i replace at the same time?

Thanks for the help its much appreciated.

 

[SunlitComet]

do you have a harsh 1-2 shift at all? are your sure it is just the converter letting go or does it flare in any gear? the ideal speed to duplicate is with a hot tranny between 55-62 mph. The fact tho that you indicate the condition of the fluid as burnt and dark means you should get a pan drop change. the kit you put in should have also addressed the p1870 but it is possible the problem is just to far along. the tech 2 scanner and i am sure some other can run a test to see if the converter does have an issue or not but you will have to consult a dealer or tranny shop to get the test performed. there are tsb's on the issue.

 

[Shagadoodle]

do you have a harsh 1-2 shift at all? are your sure it is just the converter letting go or does it flare in any gear? the ideal speed to duplicate is with a hot tranny between 55-62 mph. The fact tho that you indicate the condition of the fluid as burnt and dark means you should get a pan drop change. the kit you put in should have also addressed the p1870 but it is possible the problem is just to far along. the tech 2 scanner and i am sure some other can run a test to see if the converter does have an issue or not but you will have to consult a dealer or tranny shop to get the test performed. there are tsb's on the issue.

Yes my 1-2 shift is harsh but i was under the assumption that was caused by the error code and the computer telling it to apply excess pressure in order to correct the slippage. i'd like to think that the kit i installed did solve the valve body issue as it drove just fine for the past 6 months with an occasional 300 mile tow. luckily i added a pan with a drain plug when i did the kit so changing to some clean fluid won't be hard at all. Ill have to take it to a shop one weekend to let them scan it.

 

[SunlitComet]

correct about the line pressure. just making sure the system is reacting as expected.

You know i had to get my original one done and receive it back after a rebuild with that harsh shift. the tranny shop never did the job right and failed in less then 4 years and 50k with random p1870 all along the way. the way it failed is what bothers me. I don't know if i will ever get my hands on the tranny to tear it down but final failure point was in a hotel parking lot idling to get a fluid change and it just clunked and spun down. no oil pressure at that point. $2500 was spent on rebuilding it back then and it was a failure from the start.the replacement was a used one which failed upon install. the second unit after that is in great shape. i guess that is four tranny build in less then 4years. not cool.