Man, this thing is really screwing up my xmission.  Any help would be greatly appreciated.

The truck has about 190k miles on it.  One of the sites says to put in a new separator plate? and shift kit.  This seems an odd fix to an engine code.

I would like some real advice as soon as anyone has a chance to check it out.

Thanks in advance!

1870 is a generic "Transmission Component slippage" code. Most people consider it a "Torque Converter Excessive Slip" code, but it's really not.
Here's the scoop. Provided the trans is NOT actually slipping in ANY of the gears, this can be fixed quite easily.
Most all GM transmissions will set this code for one reason or another. The main reason on the 4L60E trans has to do with the PWM(Pulse Width Modulated) system for the lock-up converter. When the PCM(Powertrain Control Module) signals the solenoid to close, stroke a couple of valves, and cause the converter to lock-up, it does it gradually, so it doesn't just come on at once, like they used to(on-off). What is happening is, when the PWM solenoid cycles, it causes the valve in the valve body to oscillate rapidly, eventually wearing the aluminuminum bore in the vb. When this happens, the solenoid can no longer control the apply rate of the converter, the PCM sees this as a malfunction, and assumes the trans/converter is slipping. Once it sets this 1870 code, the trans defaults to full line pressure, and it will normally cancel any further attempts to lock-up the t-converter. Then you get really bangy shifts, and possibly harsh engagements, until you turn the key off. Once you turn the key off, and restart it, everything goes back to normal, until the PCM sees the same problem next time it tries to engage lock-up.

Otay, now that you are totally cornfused, here's the fix!
In order to eliminate this problem, the valve body must be removed. In the valve body there is a "Torque Converter Regulator Valve", and an "Isolator Valve", both in the same bore of the vb, with a spring in between them. To fix this problem, you want to remove the spring that is in there now, and replace it with one the will basically "block" the valves from moving. This will turn the trans from a PWM type lock-up system to the older style, On-Off system. No more 1870!!!
It sounds way more complicated than it is, tho. We do these dang near every day, and I incorporate this mod on EVERY 4L60E I build.
Dennis, I will send you a couple of pics of the vb, and the valves in question. You could do this yourself, I'm sure. It should take about an hour, total...if you take a break in there somewhere!

COOOOOOLLLLLL!!!!!
Joel, you DA MAN!!! again...

The only issue I see is that the crossmember has to come down so supporting the xmission and pulling the wiring bundles off the crossmember may take a little time to ensure we don't bust the clips.

I'll check for the info and get started tomorrow.

Thanks again for the help!

Actually, you don't have to remove the crossmember. Just take the bolts out, lift the trans, and move the xmember back a couple of inches, and then set the trans back down on it, with the stud for the trans mount sitting ON the xmember, instead of going thru the hole in it. This will get you enough room to pull the pan off.

Joel,
I swear if I ever need my tranny overhauled I am going to pay the shipment to Texas. You are an absolute genius.

I am proud to call you my friend.

Scott

jeanyus? ME?!
Naw...I jess reads a lot ov books...well...I looks at da pichurs mostly... and I tinker wid ficksin trannys when I'm not messin 'round here!!

Thanx, Scott!! I be proud to call all of the C3VR members my friends!(well...all except...(censored))

Since Joel is a genius, i'm sending him my tranny so he can fix it where the engine won't foul out #7 plug.  rearn2go722007-03-17 19:46:06

I assure you that when my vette's xmission takes a dump, I'll be sendin' it (the xmission, not the dump) to DA MAN!

Thanx for clarifying that, Dennis!

Just in case anyone else wants to see where/how this mod is done, check out the pics here. Dennis, you may want to look at these...I added one that shows where to put the long, 8mm headed bolts that hold the VB on. If you get them in the wrong place, it can cause some MAJOR damage to the guts...then you will be sendin me the dump!!
This mod is effective on any of the '96-'99 4L60E trans. The later units have a slightly different set-up on the valves, and the mod is a little different.
The '94-'95(early) units do not use the PWM system, so there's no issue with them.

                                                         Click for link


[QUOTE=rearn2go72] Since Joel is a genius, i'm sending him my tranny so he can fix it where the engine won't four out #7 plug.
[/QUOTE]

Jim, I can absolutely guarantee that your engine will NOT be fouling ANY of the plugs for as long as I have the trans here...
Adams' Apple2007-03-17 19:44:27