4L60E valve body upgrade kit, AKA P1870 "code buster"

Sparky

Moderator
Skip to the bottom if you don't want the back story.

Technical Stuff and Background:

I've had a bit of a history with the GM 4L60E transmission and dealing with some of the shortfalls of it. Over all, it is a good transmission, but it has a few weak points. A semi-common issue with the 4L60E is the TCC (Torque Converter Clutch) valve bore gets worn because the TCC valve is PWM (Pulse Width Modulated). This allows for a nice, soft engagement of the TCC lock, but it can result in the valve vibrating in the bore and wearing it. Enough of this wear and the TCC valve doesn't seal right - particularly when the fluid is warm - and the converter fails to lock, or locks, then unlocks, and repeats. The TCC not locking results in higher engine RPM, which burns more fuel, but also results in elevated transmission fluid temperatures, which can lead to even more issues such as bands burning up etc. This SHOULD throw a code P1870 "Transmission component slipping" but it doesn't always. One side effect is the computer realizes something isn't right, and then it starts to slam the 1-2 shift extremely hard via jacking the line pressures way up in an attempt to compensate for the issue.

I battled this problem years ago in my old 1998 Camaro that had the 4L60E, until it got to the point of neck-snapping 1-2 shifts and still not being able to figure it out. I ran across the Transgo SK-4L60E shift kit that while I still didn't have that code I was having a lot of the other symptoms. As a last ditch effort hoping that I wouldn't have to replace/rebuild the transmission, I bought that kit. Well, then I found I needed other parts because seals don't come apart cleanly, etc, but after getting it all back together, IT WORKED. No more slammed shifts, no more burnt fluid, TCC locked perfectly every time. The TCC lock instead of a mushy "slip" into lock feels like it shifts into a 5th gear now. That transmission is still running by the way in my current 1999 Camaro, which is cammed, that I drive somewhat aggressively at times, and it hasn't missed a beat. Perfect shifts every time. That transmission has over 170k on it, by the way.

I installed the kit (with a couple other goodies, details below) in my 02 Trailblazer when it had 120k miles on it. At the time I bought it, the fluid had never been changed, and it was very, very dark. Not burned, but past due. At the time of demise of the Trailblazer, it had 215k on it, shifted perfect all day every day, and the fluid was still a nice red color. Nope, aside from the fluid flush I did at 120k using the May03LT method, I hadn't touched the fluid (I know, shame on me, but it was a bit of an experiment too). I'd say that's a good proof! I put the same kit in my current 2007 Silverado 1500 when I bought it a couple years ago.

TL;DR - The Kit
OK so you don't care about the whys or whats, you just want to make your 4L60E a little more durable and prevent issues down the road. Here's the goods.

An ebay seller ctpowertrain has a combo kit that includes basically everything you need, plus some, aside from a new filter and fluid. Very handy. Pay attention to the years as there were minor changes GM made to the 4L60E transmission. They have kits for the pre-96 years too, but because our trucks only go back to 2002 I didn't bother linking those.

1996-2006
http://www.ebay.com/itm/4L60E-4L65E-1996-2006-1870-P1870-Code-Buster-Combo-Kit-Corvette-Servo-ATSG-Book-/270874884435?hash=item3f1166b953:g:WDkAAOSwpDdVeOGx&vxp=mtr

2007-2008
http://www.ebay.com/itm/4L60E-4L65E-2007-2008-1870-P1870-Code-Buster-Combo-Kit-Corvette-Servo-ATSG-Book-/291489137071?hash=item43de1b41af:g:JakAAOSwrklVeOJG&vxp=mtr

As a side note, I have always used the Valvoline Max Life red jug Dex/Merc "high mileage" fluid.
 

ttcfan4476

Active Member
I'm gonna have to look into this, I have 3 4l60's running. None have caused issues yet but if I can stop it before its a problem that is worth it.
 

Reprise

Lifetime VIP Supporter
PWM was introduced during the 1990s. What are the vehicles / MY / miles on your three?
 

Reprise

Lifetime VIP Supporter
Ok. Of the three, since they all shift fine, no issues - I'd leave the K1500 alone - it has the best possibility of all of its accumulators (1-2, 3-4, forward) made of metal. It will also use a different separator plate / gasket kit than the other two.

The other two - kind of a coin flip.
Guessing the Silverado might be your daily driver, since it has the most miles.
It probably has at least 1 plastic accumulator, and the TB likely has two (my '03 Voy had a metal 1-2; the 3-4 and forward accumulators were plastic.

Plastic breaks, and wears faster against the pin / plunger, eventually letting fluid leak past the gap, and weakening the plastic surface to the point that the piston will crack (and eventually break.)

Most of the cttransmission kits that Sparky mentions have the Sonnax pinless aluminum accumulators - good stuff, although you have to plug the forward and 1-2 accumulator pin sleeve (Sonnax provides the check balls; you stake the sleeve when you put them in. The 3-4 has a blind hole, so you don't have to worry about that one)

If there is one of those two that is really due for a fluid / filter change, that would probably be the one I'd start with. Barring that, the one that means the most to you if it were to be down.

Figure it will take you the most time to do the first one, following instructions & double-checking things. If you do a second vehicle, you'll probably do it in half the time of the first one.

Check the pan to see if you have the 'deep' or regular size pan. When you get the filter kit, make sure you get the right kit - if you put a 'short' filter snout into a 'deep' pan, the fluid pressure will pop it out of it's mounting location. If you have a regular pan, but get a 'deep' kit, then the pan won't fit when you try to reattach it.

When you're removing the pan bolts - if one or more of them seems 'stuck' and won't turn (or is getting progressively harder to turn) - stop, as you'll snap them off easily, and then you're looking at using a tap to get the stem out of the case. If you're lucky. I broke one of mine, so I'm speaking from experience. Spray your lube of choice (liquid wrench, etc) along the exposed threads...then reseat the bolt. leave it there for a bit - then attempt to remove it again, and see if you don't get a bit more of the bolt out. You may need to repeat this a couple of times before you're successful Barring that, you can use another trick to get the bolt out (e.g.; heat, etc. )

Good luck. What I've written here should be useful - but your choice of whether to do it - is yours alone. Plenty of good write ups of installing this kit on the site. Many here have done it successfully - and I don't remember anyone actually 'failing' to put in into the vehicle, to the point that they ruined the trans. Well... I did - but that was due to a lack of fluid (put 5qt in, and it wasn't enough). That's one reason I know what I do about the 4L60e in our vehicles.
 

ttcfan4476

Active Member
The ss is my dd, the tb is the wife's. The ss has had a trans change before I got it.
The tb is one that I did a engine trans swap on. It had a bad trans and a miss when I bought it and I bought a lower mile wreck and swapped motor trans and tc out. i dont know any of the history of the wrecks life so I am more ap to change it first.
 
Skip to the bottom if you don't want the back story.

Technical Stuff and Background:
I've had a bit of a history with the GM 4L60E transmission and dealing with some of the shortfalls of it. Over all, it is a good transmission, but it has a few weak points. A semi-common issue with the 4L60E is the TCC (Torque Converter Clutch) valve bore gets worn because the TCC valve is PWM (Pulse Width Modulated). This allows for a nice, soft engagement of the TCC lock, but it can result in the valve vibrating in the bore and wearing it. Enough of this wear and the TCC valve doesn't seal right - particularly when the fluid is warm - and the converter fails to lock, or locks, then unlocks, and repeats. The TCC not locking results in higher engine RPM, which burns more fuel, but also results in elevated transmission fluid temperatures, which can lead to even more issues such as bands burning up etc. This SHOULD throw a code P1870 "Transmission component slipping" but it doesn't always. One side effect is the computer realizes something isn't right, and then it starts to slam the 1-2 shift extremely hard via jacking the line pressures way up in an attempt to compensate for the issue.

I battled this problem years ago in my old 1998 Camaro that had the 4L60E, until it got to the point of neck-snapping 1-2 shifts and still not being able to figure it out. I ran across the Transgo SK-4L60E shift kit that while I still didn't have that code I was having a lot of the other symptoms. As a last ditch effort hoping that I wouldn't have to replace/rebuild the transmission, I bought that kit. Well, then I found I needed other parts because seals don't come apart cleanly, etc, but after getting it all back together, IT WORKED. No more slammed shifts, no more burnt fluid, TCC locked perfectly every time. The TCC lock instead of a mushy "slip" into lock feels like it shifts into a 5th gear now. That transmission is still running by the way in my current 1999 Camaro, which is cammed, that I drive somewhat aggressively at times, and it hasn't missed a beat. Perfect shifts every time. That transmission has over 170k on it, by the way.

I installed the kit (with a couple other goodies, details below) in my 02 Trailblazer when it had 120k miles on it. At the time I bought it, the fluid had never been changed, and it was very, very dark. Not burned, but past due. At the time of demise of the Trailblazer, it had 215k on it, shifted perfect all day every day, and the fluid was still a nice red color. Nope, aside from the fluid flush I did at 120k using the May03LT method, I hadn't touched the fluid (I know, shame on me, but it was a bit of an experiment too). I'd say that's a good proof! I put the same kit in my current 2007 Silverado 1500 when I bought it a couple years ago.

TL;DR - The Kit
OK so you don't care about the whys or whats, you just want to make your 4L60E a little more durable and prevent issues down the road. Here's the goods.

An ebay seller ctpowertrain has a combo kit that includes basically everything you need, plus some, aside from a new filter and fluid. Very handy. Pay attention to the years as there were minor changes GM made to the 4L60E transmission. They have kits for the pre-96 years too, but because our trucks only go back to 2002 I didn't bother linking those.

1996-2006
http://www.ebay.com/itm/4L60E-4L65E-1996-2006-1870-P1870-Code-Buster-Combo-Kit-Corvette-Servo-ATSG-Book-/270874884435?hash=item3f1166b953:g:WDkAAOSwpDdVeOGx&vxp=mtr

2007-2008
http://www.ebay.com/itm/4L60E-4L65E-2007-2008-1870-P1870-Code-Buster-Combo-Kit-Corvette-Servo-ATSG-Book-/291489137071?hash=item43de1b41af:g:JakAAOSwrklVeOJG&vxp=mtr

As a side note, I have always used the Valvoline Max Life red jug Dex/Merc "high mileage" fluid.
I know this is a old post of yours but I'm gathering the items to do this to my 04 Envoy and you said you needed a few extra seals and items to complete.Do you happen to remember what extra you needed thats not included in the main kit,excluding filter and fluid,thank you.
 

MRRSM

Lifetime VIP Supporter
Well Done... @Sparky... You just cannot do a better Write-Up than THIS. By themselves... the Repair Parts just don't mean anything... without a decent, well written Story behind them to explain things.
 
I know this is a old post of yours but I'm gathering the items to do this to my 04 Envoy and you said you needed a few extra seals and items to complete.Do you happen to remember what extra you needed thats not included in the main kit,excluding filter and fluid,thank you.
Help please,talking to Trans Go they ask if my 04 Envoy had the SK 4L60E or 4L60E-HD2,how can you go about identifying which one my Envoy has?
 

TequilaWarrior

Well-Known Member
Help please,talking to Trans Go they ask if my 04 Envoy had the SK 4L60E or 4L60E-HD2,how can you go about identifying which one my Envoy has?
Someone please correct me if I'm wrong, BUT I'm pretty sure on this:

SK4L60E and 4L60E-HD2 are kit part numbers FROM Trans-Go (or cross listing numbers). They are not variants of the transmission itself. The tranny is almost certainly a 4L60E, period. Their question is, what KIT are you wanting to compliment with extra parts. As in the two kits (SK4L60E vs 4L60E-HD2) contain a different set of seals(and springs, accumulators, separator plates, etc...) because they are designed to do different things. They may contain some of the same seals(and other stuff), but exclude different ones. The 4L60E-HD2 is likely NOT the kit you want as it can be used to make your transmission hold any gear at any speed (for race or very heavy duty applications) as well as make your shifts VERY firm. If you're trying to cure some sluggish shift, or shift-bump, or spongy TCC lockup issues the SK4L60E is probably what you're looking for - although admittedly, I'm not sure what else should be purchased to compliment this kit so you don't have to walk to the parts store.
I'm looking at the combo kit posted earlier in this thread (K771870-96COMBO) which includes the corvette servo and have the same basic question as you - what else is needed to ensure a successful install without a walk to the parts store.

EDIT: If you look at the first ebay listing posted by Sparky in the first post of this thread, you can see the customer service number of the shop selling the kit. THEY may be the best people to ask as they create these kits from a collection of Trans-Go parts as well as including proper manuals and other supplier's parts. 1-888-8CT-POWR is the number listed on one of the ebay listing's photos.
 
OP
OP
Sparky

Sparky

Moderator
I know this is a old post of yours but I'm gathering the items to do this to my 04 Envoy and you said you needed a few extra seals and items to complete.Do you happen to remember what extra you needed thats not included in the main kit,excluding filter and fluid,thank you.
If you get the combo kit from CT powertrain it comes with what you need. That was more in reference to my first time when I got just the Transgo part of it and needed the separator plate seals and such (which the combo kit from CT powertrain includes).
 

Online statistics

Members online
1
Guests online
91
Total visitors
92

Members online

Forum statistics

Threads
19,404
Messages
579,598
Answered questions
1
Members
12,136
Latest member
Jschreck87
Top Bottom