4L60E/4L65E swap?!

I've just read a little bit about the newer engine/tranny combo's for GM cars and trucks ('99 and up). This was the first I'd heard of a 4L65E. Does any one know if I could swap a 4L65E into my "98 Silverado Z-71? Would I have to change any of the computer or wiring harness? Would it work with all the other existing components of the drive train? We all know how worthless the 4L60E is, and I've read that the 4L65E is leaps and bounds of an improvement. Also, the 4L80E swap would require an entirely new computer and wiring harness, and I can't get a straight answer if it would work with the other existing components in the drive train. I'm on my 3rd 4L60E, and this one might be going. I'd love to change up for a standard, but, again, I'd have to change the other drive train components, and I'm working with a limited budget here. Any and all help would be greatly appreciated.

DMH a.k.a. The White Elc

did it work?  

whitelc396:
<P>I've just read a little bit about the newer engine/tranny combo's for GM cars and trucks ('99 and up). This was the first I'd heard of a 4L65E. Does any one know if I could swap a 4L65E into my "98 Silverado Z-71? Would I have to change any of the computer or wiring harness? Would it work with all the other existing components of the drive train? We all know how worthless the 4L60E is, and I've read that the 4L65E is leaps and bounds of an improvement. Also, the 4L80E swap would require an entirely new computer and wiring harness, and I can't get a straight answer if it would work with the other existing components in the drive train. I'm on my 3rd 4L60E, and this one might be going. I'd love to change up for a standard, but, again, I'd have to change the other drive train components, and I'm working with a limited budget here. Any and all help would be greatly appreciated.</P>
<P>DMH a.k.a. The White Elc</P>

A 4L65 is not going to fix your problem. It is not that much stronger or a miracle cure (and a 4L60 can be rebuilt to a 4L65 to because there is only a few parts that are different and will fit) I know you might think I am being cute and heartless but you should have figured out after second tranny change what the problem is. It is NOT the tranny but you tire size, usage and gear ratio combo that is slow baking tranny. You want a real long term fix here?? Tell you want, get another 4L60 (even from a bone yard but not from a lifted truck that has already been baked some) and put it in truck. Next take tire diameter and divide it by 7.2 and that will give you approx axle ratio you "should be running". Install those gears in axles and maybe add a small aux tranny cooler to and you will not have any more tranny problems. What is happening is that your current setup is force tranny to ride converter stall a lot and that will bake a tranny over time. Until you fix this with proper axle gearing you are going to keep replacing trannies and blaming them rather than real cause here.  

Snowman, just out of curiousity, where does 7.2 come from? Sorry sort of random.  

Based on years of messing with 4x4's it gives and proper over all ratio with a 700R4's and 4L60's tall OD ratio. With a 4L80 you want to use about 7.4 and with a not OD tranny, use 8.0 as a compromise. If you run the numbers you will see that 35 / 7.2 equals 4.86 so use a 4.88 and that sounds deep and scary to some but it would cruise at about 2100 RPM which is still a bit tall but doable. This number as a product of getting in the correct RPM range for top gear cruise in OD and have OD actually work and not fry tranny trying to use it.  

I have to say its not the bigger tires that get it, I found out the hard way that going with less than factory size tires can still ruin a 4L60E.  I had 33X12.50 16s the first time I went through my tranny...drug it out, got it rebuilt, popped her back in and decided to be easy on it, I went back with some little 255/70 16 tires that measure out to like 28s, no wheeling, popped it into 4 every now and then, and mostly highway miles back and forth to college, 4 months later, there it went again, rebuilt it once again, decided to put my 33's back on and made it 8 more months, now I'm back to it being out again.  Was gonna do the 4L80E swap but figured out its gonna take a little more money than I bargained for, so I was looking at the 4L65E...turns out after many many hours spent on google...various mechanic shops, even talking to random guys I met out on the trail in my jeep, the 65 isn't going to hold up to much more than the 60...so from all my research...your still gonna waste money going to the 65