97 4L60E ~ 213K Miles: Sudden P1870, Harsh shift from 1-2

[mistaake]

Truck has been driving perfectly, no issues, the other night I drove 2+ hrs just fine. Today, about 30 miles into a journey I get stuck in traffic, and it starts shifting hard. P1870: "Transmission Component Slipping" soon followed. Got to my destination, checked tranny fluid level (OK), went home, the whole time, it bangs hard from 1-2 but otherwise drives fine.

Went into the O'Reilly computer system (aka Mitchell ProDemand I believe), suggestion solutions are:
1. replace transmission
2. replace transmission filter
3. other stuff

Now, a few weeks back I did change 3 quarts of ATF since it's not very clean and I don't know when it was done last. I used a fluid extractor through the dipstick tube, measured the quantity I took out, and put in 3 quarts of fresh Valvoline Dexron VI.

I have plenty more Dex VI floating around, should I do this a few more times to see if it's a fluid problem, or is that a waste of time?

I did some research and found this valve body, is that the logical next step?

https://www.ebay.com/itm/4L60E-4L65...ash=item1c9fa70eab:g:2UcAAOSweLBabVC-&vxp=mtr

 

[Supercharged111]

Trans is probably worn, that slam bang shift is the trans maxxing out line pressure in an effort to prevent slippage. It is driven by your code and I'm very surprised the other gears aren't also as harsh. I'm not sure if a slipping TCC would cause this or not, but exchanging 3 quarts at a time in a 13ish quart system is a complete and total waste of time.

 

[someotherguy]

You can change the valve body or you can repair the valve body with a sleeve/valve kit. Very common problem once these transmissions get some miles on them.

https://www.sonnax.com/parts/2458-tcc-regulator-isolator-valve-kit

Richard

 

[Oldblue98]

You can change the valve body or you can repair the valve body with a sleeve/valve kit. Very common problem once these transmissions get some miles on them.

https://www.sonnax.com/parts/2458-tcc-regulator-isolator-valve-kit

Richard

Richard have you done one of these ? And am I correct in assuming this is the type that has to be reamed before install ?
I have chased my tail to the point this is where I think I will need to go next, either valve body or valve kit !
How difficult is the valve body to do? I have not visited a valve body since the power glide and 350/400 transmissions days.
As you have heard me talk about before, trans has been rebuilt to have the same problem I started with, TCC locks in and out until pressure mode goes into the firm 1-2 shifts after it is at operating temps. I have replaced the VSS and brake light switch as well.

 

[Supercharged111]

Oh, you never mentioned the TCC acting up. There are multiple ways to disable the PWM, pinning I believe is the cheapest. Can also command 100% max and min TCC lock in the tune.

 

[Oldblue98]

Oh, you never mentioned the TCC acting up. There are multiple ways to disable the PWM, pinning I believe is the cheapest. Can also command 100% max and min TCC lock in the tune.

Ok, considering this truck is used for quick trips to town and never used on long trips I like that option, TCC was replaced at time of rebuild. Actually had to be done twice, first TCC they installed shuddered and had to be re-done.
Where can I go to read up or watch a video ??? Thanks in advance I did not mean to steal the posting, but it is the problem I have as well.

 

[97K1500Silverado]

Same thing happened so my 1997 k1500. I installed this fix.

No reaming or dropping valve body.

xc_hide_links_from_guests_guests_error_hide_media

It’s been 3 years and 25k miles with no problems.

I also did a complete drain and flush with full synthetic valveoline max life atf.

http://www.walmart.com/ip/Valvoline...utomatic-Transmission-Fluid-1-Gallon/15125768

Also installed trans temp gauge to monitor temps especially when towing.

Black & Green MaxTow Transmission Temperature Gauge https://www.amazon.com/dp/B0095ZKA06/ref=cm_sw_r_cp_api_dEvWAbKE9BA2W

 

[someotherguy]

Richard have you done one of these ? And am I correct in assuming this is the type that has to be reamed before install ?
I have chased my tail to the point this is where I think I will need to go next, either valve body or valve kit !
How difficult is the valve body to do? I have not visited a valve body since the power glide and 350/400 transmissions days.
As you have heard me talk about before, trans has been rebuilt to have the same problem I started with, TCC locks in and out until pressure mode goes into the firm 1-2 shifts after it is at operating temps. I have replaced the VSS and brake light switch as well.

Yeah, the Sonnax kit and probably any similar ones like it are going to require reaming that bore in the valve body, because you're installing a sleeve to cover the worn area. Haven't personally done one; the reamer tools would probably put it out of DIY category for most people. This is a job for a trusted transmission shop.

Outright replacing the valve body no big deal, should be plenty of youtube videos, just skip the ones that talk about shift kits. About the only real catch is to be sure you get check balls back in the correct places. Check the separator plate for wear around the check ball holes and replace plate if needed. With all that in mind though you still may want to take it to a shop since they're used to doing this kind of stuff all day long. Filter and gasket replacement at same time...

You must be registered for see images attach

Richard

 

[Supercharged111]

Any mechanical repair will require dropping the valve body. Don't be scared though, it's still a very simple repair.

 

[Oldblue98]

Same thing happened so my 1997 k1500. I installed this fix.

No reaming or dropping valve body.

xc_hide_links_from_guests_guests_error_hide_media

It’s been 3 years and 25k miles with no problems.

I also did a complete drain and flush with full synthetic valveoline max life atf.

http://www.walmart.com/ip/Valvoline...utomatic-Transmission-Fluid-1-Gallon/15125768

Also installed trans temp gauge to monitor temps especially when towing.

Black & Green MaxTow Transmission Temperature Gauge https://www.amazon.com/dp/B0095ZKA06/ref=cm_sw_r_cp_api_dEvWAbKE9BA2W

Just ordered this, it is simple enough to try what the hell I have chased my tail this far lol. I will post a update when it comes and I get it in. Thanks very much