So I’m rebuilding a 4l60 out of a 2013 Silverado. Yep, 2013. V6. Didn’t even know they made a 4l60 that late. Notice, I say 4l60 and not 4l65 like I was expecting. The question that I’m asking myself mainly, is why…..why does this trans still have 4 pinion planets if in the later years GM’s switch to 5 pinion was made partly to cost reasons? If the 4 pinion is stronger, then why put a stronger planet in a v6 truck? A bare bones work truck would surely get the cheaper and weaker of the planets. I’m being facetious of course….but why not just one one same part for all the transmissions? I mean GM went through the trouble of putting the better sprag in this trans and some STUPID square drive bolts on the bell housing. But no 5 pinion planets? Weird

 

Since 2013 was the last year ever for the 4LXX transmissions, they probably had some old parts in the warehouse that they needed to get rid of.

GM was/ is really bad/ good about this.

I had a '92 Camaro (last year-model for the third-gen F-body) that was SUPPOSED to have 28-spline axles. It had 26-splines. I went to the trouble of taking apart three other '92 Camaro axles in junk yards over the years, and all of them had 26-spline axles.

Everyone on thirdgen.org said that there was no way, that the axles must have been swapped at some point, but they didn't look swapped to me. I think GM had some early '80s axles that they needed to get rid of, and they threw them on the assembly line in 1992. Who's going to know, right?

You will see a lot of weird parts combinations at the beginning and end of a production run of a vehicle.

 

I work for an OEM supplier, and I have long suspected this is why our orders tend to get randomly changed when vehicles are being discontinued. It would not surprise me in the least if they scrounge the warehouse to save money on the last run of a model.

 

Almost certainly using remaining inventory

I've seen LS engines around the 05 changeover year that had one bank of "gen 3" rods and the other bank was "gen 4" rods
100% this is how it came from GM...most of the time with 100k or more miles on the clock

Many others have reported the same

There's no logical explanation for that...it's just GM using up what they have on hand.

 

My Father has told me many times that this is exactly the situation here.

Very common indeed to run-out any old inventory (New Old Stock).

He has taught me fairly well I think.


-Marcello III

 

I have recently gotten into a 4l65e according to numbers but though oema inside friction's and all had 4 pin planets it too was a late late model

 

The 4L60E is a family of transmissions, it was used through the 2014 model year. All 4L60E's had 4 pinion planets. A lot a people equate the bolt on bell-housing to mean it's a 4L65E but that is NOT the case.
The 4L65E was built for the 6.0L engine starting 2001 and up. The 4L65E was updated to include 7 frictions in the 3-4 clutch, five pinion planets & etc.
The 4L70E New product announcement covers the changes of both the 4L65E & 4L70E. Some people also believe that when they introduced the ISS that it is a 4L70E and some say the 2009 & up is a 4L70E because of the internal mode switch. None of that is true!!! From 1997 with the addition of the LS engine & the bolt on bell-housing you CANNOT tell a 4L60E from a 4L65E from a 4L70E just by looking at it. You must know the ID codes to tell them apart or tear them apart.
I cut my teeth with GM and the 700R4 that I watched during my career as a transmission re-builder evolve into the most loved/hated transmission of all time.
Google 4L60E vs 4L65E vs 4L70E and you can read up on the basic changes.
Just keep in mind that my knowledge of the 4L60E family doesn't compare to @vorteciroc because he helped design the dang thing and most changes were internal.

 

I've seen some 4L65E coded units that the 5-pinion planets were taken from them by previous builders at the dealer level... I never did that but I did see 2 guys do that for their personal projects. If 2 did it were I worked, there has to be 100's more that did it too. I have also seen shops that work for the SRTA program just install what ever they had to ship the unit code they required.

 

I've seen some 4L65E coded units that the 5-pinion planets were taken from them by previous builders at the dealer level... I never did that but I did see 2 guys do that for their personal projects. If 2 did it were I worked, there has to be 100's more that did it too. I have also seen shops that work for the SRTA program just install what ever they had to ship the unit code they required.

 

Thanks @Tranzman . But My Father says You and many of the other Regulars here are extremely knowledgeable!

Dad says that He did get to do some 4L60E/ 65E/ 70E Engineering on the "Repair side of things" while he worked as an Engineer for GM SPO
(Service Parts Operations).
However, He only was assigned to the 4L80E while working as an Engineer for GM Power-Train/ Hydra-Matic.
He says the 4L80E was done out of the Hydra-Matic Plant, but the 4L60E/ 65E/ 70E was done at a separate Facility.

He also says; what he recalls is that the 4L65E came with Upgraded Input-Shaft and high-count 3-4 Clutch Pack.
He then said only some 4L65Es came with 5-Pinion Planets (a Down-Grade) and only some came with an Upgraded Output-Shaft (2-Wheel Drive).