Re: 4L60E Complete Rebuild
Posted: Sun Oct 26, 2014 3:45 pm
ok cool thanks!
Sorry for raising an old topic, but maybe someone will be interested.
I rebuilt one for my truck about 4 months ago using a kit from Pro-Built Automatics
I bought a 93 core that was described as having no overdrive. Opening it up I found some of the nastiest smelling oil and a fractured sun shell. Ultimately, in addition to the kit, I also replaced the reverse/input drum, just in case. The kit includes a new OEM sunshell that is hardened and supposed to address the earlier failures. You'll hear conflicting opinions on that one.
Overall it wasn't too bad, but I did have to make a handful of tools. You'll need a spring compressor for the forward clutch pack down in the very bottom of the transmission, but that one is easy to do using a long bolt, a large washer to pull against the transmission case, and a U-shaped piece of steel to contact the spring carrier, but leave the center open so the snap ring can be removed. I ended up taking some scrap 3/4" steel rod, cut a large washer in half, and welded the halves onto either end of the rod so that the cut-ends contacted the spring carrier. The rod had a hole drilled through the center for the bolt to pass through.
Another tool you'll need is a spring compressor for the input drum. I got by using a piece of 3/4" angle iron that I filed to size so that it fit snugly into the snap ring groove. I then drilled and tapped two 1/4-20 holes that lined up with the ring of the spring carrier. I was able to walk the bolts down to compress the springs enough to remove the snap ring. However, the snap ring was a bear to remove and still required some finesse. When I put it back together, I had much stiffer springs to install (part of the shift kit)... let's just say I kept my face clear of that assembly.
The only other tools you'll need are bushing drivers. The bushings can be driven out using a chisel point punch which will destroy them, but you'll need a proper driver to drive them in. Care must be taken as some of these are very soft and easy to damage. I ended up taking some 2.5" round aluminum bar stock and machined it as needed for each set of bushings. Fortunately I've got a small table-top lathe that could do the job. I certainly wouldn't try to do this with some sockets.
Otherwise, as Durallymax said, it's all about patience and keeping your work clean. You should count on having to order different thickness steels to get some of the clutch packs shimmed correctly, fortunately I got lucky. I do have one pack that is .010" looser than what Pro-built advised in their instructions, but it was well within factory spec and I'm not drag racing or making shifts with the torque management disabled.
I also replaced the torque converter with a new unit, I didn't want to risk debris from the old one killing my work. I replaced all of the solenoids, except the pressure control solenoid. The pressure control solenoid was supposed to be pretty reliable (and pricey), but I got unlucky and had to drop the pan to change it for a new one. Lesson learned: Do it right the first time! This is no different than an engine... don't cut corners unless you're ready to do it all over again. I would have rather spent that $100 up front rather than spend time checking transmission pressures and dropping the pan. I also risked burning up the 3-4 clutch because the line pressure was too low. I got lucky!
All said and done, I wrapped up about $1200 in my complete 4l60e rebuild kit like this https://mechanicguides.com/best-4l60e-rebuild-kit/ , bellhousing to tailshaft. Bear in mind that in my application the engine makes about 400 ft-lbs so I felt it was too risky to get away with a stock rebuild, hence the added cost of the Pro-built kit. If I needed a rebuilt transmission for a stock truck, I'd likely let someone else do it for me. In this case, however, I was looking for the challenge and didn't want to pay $2000+ for a comparable unit from a reputable builder.
One intresting video about rebuild https://www.youtube.com/watch?v=7u0c50zWWis
