Hello everyone!

I have now encountered the harsh 1-2 shift three times (over about 3 months) and then it just goes away, but I never received the SES light until this past weekend when it happened again. Now, of course, I have the P1870 code (comes up twice actually for some reason). I also have the common surging in overdrive when you have the slight load on the engine and driving at about 45-55 MPH (been that way since I have had the truck at 59k, current mileage 90k). This is on a 99' Silverado 4x4.

I have read many threads and info on the Internet about the many 4L60E issues and fixes and have decided to go with installing a TransGo Shift Kit. I believe from everything I have read that this is the best solution instead of just installing the Sonnex TCC with boring out the valve body. The TransGo HD2 kit seems to be the most complete kit out there, fixes the issues with the 1-2 shift and surging, and allows for 3 different stages when installing.

So, now here are my questions:

1) I have never worked on transmissions and I am not sure I should attempt to do this myself, but every trans shop I have contacted in the Denver area says they do not recommend a shift kit and actually want to rebuild my trans from around $1600-$2400 and that is only standard parts! I have been told numerous times that the only way to fix the P1870 code is to remove the trans and rebuild it. I know that is crap, but does anyone know of a trans shop in the Denver area that will just install the shift kit? I would even consider someone wanting to earn side money that knows how to do this.
2) Is there anything else I should consider instead of a shift kit? Better or easier solution?
3) What stage should I go with for my stock trans? After all I read, I figured Stage 2 programming would be best for me.

Please, I really would like some help on this, any experience or ideas are most welcome.
Thanks in advance!

 

the problem is that you have modulated lock up and what happens is that the vlave that controls the lockup is called the isolator valve, this valve pulses and wears the valvebody out. this causes leakage and the converter slips. the cheap repair, not fix, is to by a remanufactured gm vavle body the isolator valve body is oversize and has a seal to prevent that.

 

If you need someone to install the Shift Kit, try 626 4437456. Tell them where you at, and they should give you a shop that specializes in Trans-go Shift kit installations.

 

I have used the Superior Products 4l60l kit and have had success with getting arid of the 1870 code a few times. Its a cheap try.

 

i got that code last week. after goign to the track. car seems to shift harder than before. i wonder if i dont pull the tranny that its gonna get worse and eat itself up?

 

That 1870 code is coming from the TCC regulator valve. It has worn out its bore in the valve body. This is a very common problem as the TCC regulator valve is a very busy valve. Thats why they tend to wear so much. I would either do a replacement GM valve body, or install a Sonnax kit in it. I know of rebuilders who will install a heavy duty spring in the TCC regulator valve train which would cure the 1870 code.


transman

 

If you install the Performance Shift kit from Trans-Go, it will have you replace the existing valve with an udated Isolator & Converter valve that will work even with a worn bore. This also let you use any style lockup plate in the torque converter.