I knew automatic transmissions were complicated, but holy shit there are so many parts in this thing--and the 4L60 is very old design. I've been helping a friend rebuild the tranny on his Blazer after the 3-4 clutch pack went out. There are a gazillion little pieces and seals. This is so much more complicated than engine internals. It kind of makes you wonder how somebody came up with this shit.

3/2/2010 12:49:10 AM

Automagic or autotragic?

3/2/2010 7:40:12 AM

a 5 speed manual is bad enough. I wouldnt break an automatic apart if my life was on the line.

3/2/2010 7:52:39 AM

Quote :

"I wouldnt break an automatic apart if my life was on the line."

3/2/2010 9:23:05 AM

The FSM will be your friend... if you can find one, it will make you not want to rip your eyeballs out for volunteering to help with that...

3/2/2010 9:25:51 AM

if you need some alldate shit let me know

3/2/2010 9:30:02 AM

we've got the GM service manual, he got it from TransStar next to Thoff on West Street. But there are a few parts where the explanation and the diagrams don't fully explain how to do it or seem to contradict each other. For example, yesterday we were installing the 2-4 band and the diagrams don't explain exactly how it should be oriented (and it's not obvious for someone who's never built an automatic).

Probably the worst part of it is the fact that when you buy a rebuild kit they literally throw 5 dozen o rings in a pizza box (seriously, it's a pizza box that says "TransStar" on it) and hand it to you. Many of the o rings look very similar and none are labeled in any way. So when you try to replace an o ring you have 3 different ones that might work. One might be slightly thicker than the old one you had on there, or it fits different. But then you ask yourself, "ok is this fitting differently just because it's new or because it's the wrong part?" To make matters worse, GM changed a few little things over the years so you have to be careful.

But I will say, I've learned a lot about automatics from this project and I've only been lending a hand. A valve body is the most complex car part I have ever seen. The casting has maybe 100 passageways in it, and then there are a bunch of solenoids that all do different things. And a lot of the solenoids work in a slightly different way. The 3-2 kickdown solenoid for example is duty controlled like a fuel injector to control the rate that the 3-4 clutch pack disengages and the 2-4 band engages. But then the two main shift solenoids are turn on or off.

I still don't think I fully understand all the little ways that the fluid flows in the transmission during various types of shifting.

3/2/2010 10:01:44 AM

I understand enough to know not to buy one!

I drove a friends automatic car (first auto ive driven in months) to pick them up at the train station today. It was cold outside and that thing was herky jerky hard shifting the entire way.

3/2/2010 10:56:44 AM

Didn't they rebuild a 4L60E on Extreme 4x4 one time?

3/2/2010 11:24:54 AM

transstar fucking sucks!

3/2/2010 12:52:59 PM

i pulled apart an automatic fwd transaxle out of a camry for klang's class last semester. holy fuck it's complicated.

3/3/2010 11:02:12 AM

Quote :

"It kind of makes you wonder how somebody came up with this shit."

yea it blows my mind the shit that was developed before any real CAD software was available

3/3/2010 11:38:27 AM

RPM 4l60e's ftw!

3/3/2010 6:13:14 PM

and how much nitrous?

[Edited on March 3, 2010 at 7:46 PM. Reason : and what level?]

3/3/2010 7:46:41 PM

as much as you dare put to it. level V personally, i believe they have a VI now though.

3/3/2010 9:14:51 PM

transmission is assembled and in the car but currently reverse doesn't work and neutral makes the car move forward there are about a gazillion things that could be wrong but right now my friend is thinking it's something in the valve body. so he's checking the 3-2 shift valve and the check balls. yesterday we were messing with the servo a little bit

3/7/2010 4:18:30 PM

FML. Reverse housing split. Apparently this isn't uncommon. Project aborted.

3/14/2010 6:41:50 PM

Quote :

"I wouldnt break an automatic apart if my life was on the line."

3/15/2010 12:58:50 AM

Update on this project:

So it turns out that what split was the sun gear shell, and that does happen sometimes on higher mileage 4L60E's. My friend just went and actually welded it back together with an oxyacetylene torch and a coat hanger. I rode in the Turbo Blaze today and it is now shifting in all gears. He is breaking it in for 300 miles.

4/11/2010 12:55:11 AM

He spent dozens of hours removing and tearing apart a transmission, but then couldn't afford a welding rod?

4/11/2010 1:14:44 PM

i'd just swap in another unit

fuck rebuilding a tranny

4/11/2010 7:16:04 PM

Quote :

"He spent dozens of hours removing and tearing apart a transmission, but then couldn't afford a welding rod?"

Yeah... why do you think he rebuilt the tranny himself instead of getting another one? Rebuild kit is like $100

4/12/2010 1:07:36 AM