How easy would it be to swap a 4L60e for a 4L80e

[Peter D. Hipson]

As best as I can tell... <g> 

At 11:05 AM 3/13/99 -0700, you wrote:
>There are many differences between the 4L60E and the 4L80E.
>
>The main electrical connector that interconnects the engine wiring harness
>to the transmission is not the same and there are different numbers of wires
>used (I don't know what they are all used for).

I'd believe that! <g> If someone can tell me what's in the 4L60E, I can
compare with the 4L80E.

>
>There are two different PCM's that control the 4L80E. One comes on the
>diesel engines and the other for the gas engines. 

Yes, and there is a third PCM for turbo diesels, too! Each is (totally)
different and not interchangable. As well, there are two (at least) 4L80E
transmissions, the early and the late models. The TCM/PCM is different for
each, so that makes about five different TCM/PCM combinations! 

>I'm not sure whether there
>are differences internally within the transmission for these two
>applications that might also need to be considered when looking for a
>transmission.
>
>The 4L80E uses a different flywheel and torque converter. I'm not sure
>whether the crankshaft end would need to be reworked to mate to the 4L80E.

I believe the flex-plate is compatible, but if nto that is a minor expense
considering the cost of the tranny--for diesels, I can get them for about
$25 (used). 
>
>The transmissions are different lengths which would necessitate a change of
>your drive shaft.

And probably rear mounting bracket, too.

>
>I have read of people that have done the swap successfully, so with enough
>knowledge, time, and money, you can have a 4L80E which is a much stronger
>transmission. And I would guess that it would ultimately be cheaper for you
>to swap out to a 4L80E transmission rather than to keep paying for a
>transmission rebuild every so often.

I'm sure a swap is a good idea. I'd contact JET and see what they have for
kits--they sell a complete kit, TCM, 4L80E, harness, etc. Might be just the
trick to get you going.

>Good luck,
>Brent Wiscombe
>bwiscombe at msn.com
>Mesa, AZ
>
>
>
>_______________________
>
>-----Original Message-----
>From: Doug Bazarnic <doug at ddelectronics.com>
>Date: Saturday, March 13, 1999 1:36 AM
>Subject: How easy would it be to swap a 4L60e for a 4L80e
>
>
>>I just broke the input hub / shaft assembly for the second time on my '95
>>Chevy 1/2 ton truck.  It keeps blowing out the aluminum lugs that retain
>>the snap ring for 3rd gear.   I do have extra ponies under the hood, but I
>>don't see how the extra power would be causing this problem.  (It's 355
>>cubic inches, B&M blower, Air Flow Research Heads, large roller cam, Cola
>>Crank, Ross Racing Pistons, Eagle Rods, etc etc)  The truck only runs in
>>the low 14's, but this tranny breakage is nuts.
>>
>>The truck has a total of 42,000 miles on it and I've broken an Art Carr 10"
>>Torque Converter, and the aluminum input hub/shaft twice now.  The aluminum
>>hub is a cast piece of sh*t, and it's teeth that hold the snap ring in
>>place leave.  This last hub (which was brand new from GM and about 6 months
>>old) lasted less than 8,000 miles.   Either I'm putting too much thru this
>>tranny,  or it's a real piece of crap.
>>
>>Ohh, and by the way, I drive it like it was a Corvette on a road course!
>>It weighs in at 3944 lbs.
>>
>>So the $100 question is: How easy would it be to swap the 4l60e vs the
>>4l80e.  Can the stock computer talk to a 4l80e without any probs?   I've
>>got the mastertune software that lets me change what ever I want, so shift
>>points / line pressure wouldn't be a problem, if the stock computer can do
>>it.   Also, are the wiring harness connectors the same?
>>
>>Thanks,
>>
>>Doug Bazarnic
>>
>>P.s.  If anyone is interested in my calibrations / chip sw, lemme know, as
>>I'd be happy to share.
>>
>>
>>
>>
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Thanks, 
        Peter Hipson (founder, NEHOG)
        1995 White NA Hummer Wagon