tranny slipping?
timbermutt
07-09-2005, 08:20 AM
My 96, 3.1, 160,000 lumina has a service engine light coming on. It will stay on for a day or two then go off. We had Autozone pull the code which is "P1870- Manfacurer Control. Transmission". 1st mechanic said vale body in trans has internal defect. 2nd said trans component detecting a slippage. It seems to drive fine. Anybody's 2 cents will be greatly apprciated.
shroom
07-19-2005, 11:08 PM
same here, i got a used but good trannie i am putting in right now, man what a pain, they have 3 hidden bolts, good luck with yours, mine wouldnt even shift after reving it to shift for a week, then nothing
Fulkrum
07-21-2005, 12:30 AM
RE: 4T60E trans...
From what I've been able to dig up (and I'm researching intensively to determine whether or not I really have to drop $2500 for a complete trans o-haul), the slipping could be a failing TCC solenoid (the P1870 code has more than a dozen possible causes). If the TCC solenoid is good, however, another common cause is that the Torque Convertor Clutch valve has worn the bore that it is in. This allows fluid to flow around the valve, instead of against it. The correct cure is to replace the valve body with an updated part. Given all of that, it seems that BOTH of the mechanics you spoke with are right; your tranny IS slipping and the valve body is defective (suffering from a problem that stems from a poor design).
My 160K mile '97 LS is giving me the same P1870 code. My mech reset it on Tuesday and I drove it 50 miles this morning and 30 miles this evening without the SES light coming on again so it would seem that I'm at the early stages of the problem. I'd really like to know whether I can just replace the TCC solenoid and the valve body, change out the filter and fluid and be done with it.
Know any SF Bay area equivalent to Art Carr?
From what I've been able to dig up (and I'm researching intensively to determine whether or not I really have to drop $2500 for a complete trans o-haul), the slipping could be a failing TCC solenoid (the P1870 code has more than a dozen possible causes). If the TCC solenoid is good, however, another common cause is that the Torque Convertor Clutch valve has worn the bore that it is in. This allows fluid to flow around the valve, instead of against it. The correct cure is to replace the valve body with an updated part. Given all of that, it seems that BOTH of the mechanics you spoke with are right; your tranny IS slipping and the valve body is defective (suffering from a problem that stems from a poor design).
My 160K mile '97 LS is giving me the same P1870 code. My mech reset it on Tuesday and I drove it 50 miles this morning and 30 miles this evening without the SES light coming on again so it would seem that I'm at the early stages of the problem. I'd really like to know whether I can just replace the TCC solenoid and the valve body, change out the filter and fluid and be done with it.
Know any SF Bay area equivalent to Art Carr?
Fulkrum
07-21-2005, 02:03 AM
Fulkrum
07-21-2005, 09:36 PM
Well, I got some bad news: it's overhaul time.
That slight "surge" that began three or four months ago that felt like a vacuum problem was a TCC lockup problem all along. Turns out that , by the time it gets bad enough to trigger the P1870 code, the damage has already been done. Just like every other idiot light on the planet; it doesn't tell you when you have a little problem, it tells you when you're SOL.
I won't know the death toll until tomorrow afternoon late -- I'll try to post a list of casualties. So far, though, I've got borderline burned trans fluid, clutch material in the pan, blackened metallic cumulus on the magnet; all the tell-tale signs of advanced damage caused by slippage that, while I could feel it, the on-board system didn't report it until it was too late to head off a major repair.
Bottom line: it all adds up to Ka-CHING! $$$$$
GM's going to get an earful and maybe the NHTSA, as well. You can join me in the chorus at:
1-800-222-1020
That slight "surge" that began three or four months ago that felt like a vacuum problem was a TCC lockup problem all along. Turns out that , by the time it gets bad enough to trigger the P1870 code, the damage has already been done. Just like every other idiot light on the planet; it doesn't tell you when you have a little problem, it tells you when you're SOL.
I won't know the death toll until tomorrow afternoon late -- I'll try to post a list of casualties. So far, though, I've got borderline burned trans fluid, clutch material in the pan, blackened metallic cumulus on the magnet; all the tell-tale signs of advanced damage caused by slippage that, while I could feel it, the on-board system didn't report it until it was too late to head off a major repair.
Bottom line: it all adds up to Ka-CHING! $$$$$
GM's going to get an earful and maybe the NHTSA, as well. You can join me in the chorus at:
1-800-222-1020
JunkyardLife
07-22-2005, 08:09 AM
These trannys are pretty crappy.. Good luck getting one over 150,000 miles. Most seem to have some sort of problem under 100,000.
Mines slipping at 98,000. Itll probaly need the whole thign replaced sooner than later. Im scared to get one from the junkyard since so many of these trannys are trashed. Maybe if I found a rebuilt unit. Although changing a FWD tranny severely sucks :(
Mines slipping at 98,000. Itll probaly need the whole thign replaced sooner than later. Im scared to get one from the junkyard since so many of these trannys are trashed. Maybe if I found a rebuilt unit. Although changing a FWD tranny severely sucks :(
Fulkrum
07-26-2005, 02:05 AM
OK. I'm back and here's what I learned -- the HARD way.
When your Lumina does that "surge" thing under modest throttle on a slight grade at about 50mph+? Yeah, THAT surge thing where the RPM bobs up and down over about a 100RPM range?
THAT surge thing is your TCC lockup valve failing to achieve a seal and allowing the TCC to slip in and out of lockup. Very BAD.
IF you feel that, get it to your local tranny man the SAME DAY. If you do, he might be able to just kit the valve body and put you right back on the road. Gotta drop the front subframe to do that so your costs could top out around $1,100. If, however, you wait until the SES light comes on, you're tranny is TOAST. The SES light will not trigger an error condition until the slipping gets really bad and, by then, the internal damage will most likely be extensive enough that you'll need to put it on the bench and completely rebuild it. Then, once its out of the car, you may as well change the rear main seal on the engine, and make sure the lower engine mount is good. If it isn't and you don't change it now, it'll be a very long time before you dig this deep again.
Total damage: over $3,000.
When your Lumina does that "surge" thing under modest throttle on a slight grade at about 50mph+? Yeah, THAT surge thing where the RPM bobs up and down over about a 100RPM range?
THAT surge thing is your TCC lockup valve failing to achieve a seal and allowing the TCC to slip in and out of lockup. Very BAD.
IF you feel that, get it to your local tranny man the SAME DAY. If you do, he might be able to just kit the valve body and put you right back on the road. Gotta drop the front subframe to do that so your costs could top out around $1,100. If, however, you wait until the SES light comes on, you're tranny is TOAST. The SES light will not trigger an error condition until the slipping gets really bad and, by then, the internal damage will most likely be extensive enough that you'll need to put it on the bench and completely rebuild it. Then, once its out of the car, you may as well change the rear main seal on the engine, and make sure the lower engine mount is good. If it isn't and you don't change it now, it'll be a very long time before you dig this deep again.
Total damage: over $3,000.
bk220y
08-24-2005, 07:00 PM
yeah, i got a lumina used with 120,000 miles on it, first thing i did was change the tranny fluid, to late for you now, but any car, CHAnGE the tranny oil 30,000-50,000 miles, change the oil-saveyour car milage now
-----170,000 and still going
-----170,000 and still going
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