Ongoing limp mode issue

[chefmike]

I can't find my original thread, so I started a new thread.

I had an ABS light and occasional limp mode. Output sensor fixed the ABS, but I am still going into limp. It was fine for a while, then started back. It throws codes for slipping and pressure solenoid. Silly me, i figured it was telling the truth: I dropped the pan, changed the filter, swapped out all the 4 solenoids and the pressure board, as well as did a new harness. The plug had atf in it. I cleaned it out with contact cleaner. Put it all back together. Drove great, shifts fantastic.

And went into limp when it got to temperature. It is always after 10-15 minutes, then lIMP.

So I tried to order a adld cable to run scan tech, but the site was down. In the mean time... Other thoughts? Tomorrow I will check cables on top. Other thoughts include brake switch (not sure where it is, but it powers tcc lock up, which could over heat trans and limp it?) VSS buffer? i have on non-stock tires... 235-85? I will double check. Its what some folks were running for better mileage. This problem has been intermittent since the tires got put on now that i am thinking about. Growing in frequency. could that be the source?

Throw me some bones here! Oh, I checked the grounds by the trans dip tube and cleaned them.

 

[THEFERMANATOR]

Do you happen to remember the code numbers?

 

[chefmike]

68, 72, 85, 86 one time

Then it switched to 68, 72, and eighty something (didnt right it down:85,86, or 87)

I will go pull it now as well... Brb.

 

[chefmike]

Actually the next time was 68, 73, 85, 86: i found the note with my handy paper clip!

But tonight was just 68... Which in combination with the metal sludge in my pan probably means actual mechanical issue possibly?

Thoughts? I got the cable ordered to be able to put a scanner on it.

 

[THEFERMANATOR]

68, 85, and 86 are all slippage codes, but 73 is a pressure code. Sounds like you may have some issues going on with the valve body. The actuator feed limit valve is a known wear area in the 4L80E VB, and can cause this.

 

[chefmike]

Ugh. Decision time... I seem to be riding the edge of a lot of issues and either need to commit or jump ship. I am considering selling my project and getting a 2002-2006 suburban gasser.

Shop fees would suck to get this fixed and I need to get this truck back on the road.

I guess I would need this http://www.ebay.com/itm/4L80E-Valve-Body-91-92-93-94-95-96-with-harness-and-solenoids-/271634675500. Or this http://www.ebay.com/itm/4L80E-91-96...D-TRANSMISSION-CONTROL-WARRANTY-/261469243781

Can the valve body be done without dropping the transmission? I know it is just bolted on there... But how tricky is the swap?

 

[Will L.]

The very best transmission option in the new gasser burb would be the same one you have now. My 2001 6.0 burb has a 4l80e the tranny is coming up very soon in it. 197,500 miles on it. Problem with a new to you suburban is unless you get maintenance records with receipts- you don't really know what you get anyways.

 

[chefmike]

True. I know it has the same tranny. They kept it the same until 2009 IIRC, but updated the control of it.

It would also have ten years less wear on all the wiring, plastics and components. It is also much quieter inside, which I value. It is also a $500-800 difference in annual fuel consumption. It is also a trade off of what the time spent on this one is worth, paying to return to routine maintenance rather than life support. Transmission now, engine likely within a few years, radiators leaking, turbo is leaking, valve covers are leaking, tires are worn, dashboard is cracked beyond repair, vent door actuator is non functional, radio is failing again, speakers need replaced, grounds have to be cleaned continually to chase away the craziest electronic ghosts that creep in...

I have a career, two small children and a start up business on the side, as well as a marriage to maintain and a life to live. Time can be worth something.

Sometimes it can be better to set the bird in the hand free...

I havent given up yet... I will run the gmtd scan and see what I can learn.

 

[chefmike]

Whats the best way to diagnose the root of the problem? I got the cable in to run gmtdscan (basic). How much "repair" does the sure cure kit apply? http://www.amazon.com/dp/B00CB3NE48/?tag=jhuntlink-20

I would be willing to get in there and try to fix. Likely be easier to sell in spring regardless.

 

[WarWagon]

Shop around for a trans rebuild shop and just do what needs to be done - a complete overhaul. There is one here that will do it for ~$1100 + hard parts like gears. For example hard parts like OD planataries do wear out on these. The possible valve body issues have worn the bands and clutches and unless fixed properly will continue to do so on new parts. On the other hand it has 200K on it, and these transmissions need a debris to fluid change every 25K to live w/o valve body wear esp the TCC solenoid body.

Oil leaks are cheap as is make up oil. Some people spend over $5k on a good sound system so the radio is an annoyance and cheap to fix to stock standards. Engine is not "likely" - it's on it's way out now via blowby or will live a long life till cracks suddenly doom it. It's 20 years old with 2x design lifetime and IMO it's always something on these even when new. So don't sweat the small stuff - it's the major issues you need to decide your time on. A second ride makes sense so you can get to repairs at your leisure.