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why do people think I have a 4l60?

7.5K views 22 replies 16 participants last post by  jrSS  
#1 ·
I've talked to a couple local guys about rebuilding my transmission and as soon as I say 4l70 they go...no its a 4l60...

What's the difference?
 
#2 ·
http://www.google.com/url?sa=t&rct=...wgEVIE1NHg3oam3_RcOCw&sig2=kBvimkjQ141jZJ0k5LKenw&bvm=bv.44770516,d.cGE&cad=rja

The Hydra-Matic 4L60 / 4L65 are differentiated primarily because of gearset design. Each of the two planetary gearsets in these four-speed automatic transmissions have four pinion gears in the 4L60, and five pinion gears in the 4L65 and 4L70. The 4L65 was introduced in the 2001 model year as a heavy duty (HD) variant with more robust parts that provide increased strength. Beginning in 2002, many of the technologies from the 4L65 applications that add durability have been incorporated into the 4L60, such as more robust bushings and bearings. The 4L70 is a variation of the five-pinion 4L65, with additional strengthening in the output shaft and reaction internal gear to handle increased engine torque.
External fit form and function are identical between the three variants of 4L60E, 4L65E, and 4L70E transmission assemblies. Most commonly any of these transmissions are referred to as “4L60 family” units.
 
#3 ·
They're in the same family/share some of the same parts (majority). The 4l60 would shatter with (what I think) the dirt WOT down shift or hard launch. 4l70 has 5gear planetaries, hardened output shaft, input speed sensor amongst other things. 4l60 has 4gear planetary. Next time they open their mouth, show them the RPO code.
 
#5 ·
Well damn. Literally 3 different people stop me and say no its a 60... One of which was a transmission guy... I didn't know the difference so I just say ok bud.. Ha

Thanks a lot!
 
#6 ·
Many shops will refer to them all as a 60. I am sure they know the difference. I wouldn't go in telling them they are wrong, as its just semantics. Also anytime a 60/65/70 transmission is "built" they are built to 70 specs plus upgrades even if it a 60. So that's another reason everyone just calls them a 60. Cause once they get built they are all the same.
 
#12 · (Edited)
(about your friend:) Yea...ok bud. If that makes you feel warm n fuzzy about your truck.


60E->65E was where the bigger upgrades were (5 pinion planetary, etc), 65E->70E was mainly the ISS and a few minor things.

Remember (most) all of the parts interchange, at heart these things are still a 700R4 from the early 80s. Throw in electronic control, a few beefier parts and minor design changes/tweaks, boom = 70E.
 
#17 ·
This.

So then it's great grandfather would be th TH350. As the 80 came from the TH400.
And this.

The 60/70E was NEVER designed to see this much power. They still blow up in F bodies and older Vettes yes, but not nearly as often as with our trucks. Why, you ask? Simple, it a combination of a few things:
1) Our trucks are much heavier than a Vette/F body/Blazer,
2) the LS2 is making more power/TQ than any other engine these transmissions were paired with (other 4L65/70E+LS2 combos exist, GTO for example), AND
3) It's the weakest link between the engine and tires.
AWD:
4) AWD guys are even worse off, 2WD guys can break the tires loose and light the tires up, which moves some stress off the trans. AWD continually has grip (usually) so this stress cant be relieved nearly as much.

Not scientific by any means, but this is what Ive observed over the years. A weak design, too much TQ, and AWD (if applicable) are a recipe for disaster.
 
#21 ·
Also most "trans shop" guys know that a lot of the 1/2 ton gm trucks/suburbans etc came with a 4l60 and therefore, in their mind there is no way that a TB came with a bigger trans then those vehicles. The 4L70E takes a lot of heat on here, and rightfully so, but you have to remember that a lot of tbss are out there running around on their factory trans without issue, you just don't hear from those people bc they are not on forums and most of those people are not enthusiast types, rather daily driver-grocery getter-soccer mom types. On this website all of us are not just "owners" per say but are enthusiants and therefore, modify and drive our rigs harder then the average joe. The bottom line is you are asking a lot of the trans. Think about this: a transmission gets a load from both sides (input and output) The input side sees a lot of HP/TQ, and the output sees a much larger load with the weight and AWD then say a lighter car that came with this eng/trans combo (like the gto.) The 4L70E will stand up to a stock ls2 all day, and will easily stand up to the weight of our trucks, but when you combine the two you are pushing the limits of the trans, add in the mod and spirited driving our crowd brings and it's no surprise these things don't last in stock form. My .02