Questions on 4L60E to 4L80E swap.

[ResourceReaper]

So I have read the great writeup here on the 60/80 swap. Since I'll be dropping in a 408 in place of my 5.3 that's in there now, logic tells me do the trans first. It would suck to drop the motor in first and blow the trans due to the added power, and not be able to drive the truck at all.

So in my 2005 Silverado 4x4 with the 5.3L and 60E trans, I want to swap in the 80E transmission. I see the basics I have to do, but there are a few things in that write up I have questions on.

Can I use my original transfer case without changing the gearing on it?

Can I reuse the driveshaft and yoke?

I took a look at the parts list in the original 60/80 swap thread, what is the bare minimum of parts that I need to get this done? Thank you in advance!

Edit:

I think a new harness for the transmission, transmission itself, the flexplate and spacer, torque converter, PCM re-flash, and the cross member modification? Is there anything else?

- Rr

[Mickeymotormount]

1) The yoke will have to be changed to the heavier duty yoke that fits the 4L80E(not sure of the # of splines). The driveshaft will have to be shortened since the 80E trans is longer than the 60/65E trans. The front drive shaft will have to be lengthened since the transfer case was pushed back by the longer trans.

2)I don't think the transfer case can be used. I would have to think you will need the heavier duty transfer case to mate up to the 4L80E's finer splined shaft.

[farmtruc]

Someone used to make an input gear for the tcase but last time I spoke with him he was making them in group orders only.
We have used them several times. Just disassemble the tcase and install the new gear.
The tcase will now accept the larger output shaft of the 80e.
You may need the case housing or tailshaft if its called for the trans as well. Can't Rememebr. Thinking the number of bolt holes are different. The piece that sits between the trans and tcase

The 80e write needs updating. Fewer parts are needed and there are various methods to accomplish the conversion.

[ResourceReaper]

Someone used to make an input gear for the tcase but last time I spoke with him he was making them in group orders only.
We have used them several times. Just disassemble the tcase and install the new gear.
The tcase will now accept the larger output shaft of the 80e.
You may need the case housing or tailshaft if its called for the trans as well. Can't Rememebr. Thinking the number of bolt holes are different. The piece that sits between the trans and tcase

The 80e write needs updating. Fewer parts are needed and there are various methods to accomplish the conversion.

1) The yoke will have to be changed to the heavier duty yoke that fits the 4L80E(not sure of the # of splines). The driveshaft will have to be shortened since the 80E trans is longer than the 60/65E trans. The front drive shaft will have to be lengthened since the transfer case was pushed back by the longer trans.

2)I don't think the transfer case can be used. I would have to think you will need the heavier duty transfer case to mate up to the 4L80E's finer splined shaft.

Hmm... I saw in the write up that they used a 3/4 ton driveshaft. Doesn't the length of it depend on your cab size?

as far as the transfer case goes, could I just go and pick up a transfer case from a 1500 HD and put in? They had the 6.0L and I'm assuming the 80E transmission.

Forgive the stupid questions. This is the first time I am dealing with doing any modifications on a RWD vehicle. This is the first truck I've ever owned that I want to modify, so there are a bunch of things I still need to learn.

farmtruc, I also saw that I need a custom harness for the transmission? Does Nelson Performance make / sell them?

Also as an after thought can the PCM be programmed off the truck? It might be worthwhile for me to purchase one if it can be done so that I can have everything flashed on it, ready to go.

[ResourceReaper]

also if I pull a transfer case from a truck with an 4L80E, how do I know which spline count I need? Is there a simple way to tell?

[Mickeymotormount]

4L60/65E has 27 teeth on the spline. 4L80E has 32 teeth on the spline.

[ResourceReaper]

4L60/65E has 27 teeth on the spline. 4L80E has 32 teeth on the spline.

AH THIS is the information that I was looking for. So basically you are saying that I'll need a transfer case from a 4L80E, or the input gear.

[Mickeymotormount]

This info is what I Googled. Not speaking on familiarity.

[ResourceReaper]

So in reality, I'm looking at 80E trans, transfer case, harness, yoke, and drive shaft modification? Correct me if I am wrong, but if I have a 05 Silverado Ext Cab, I should be able to use a drive shaft from:

AVALANCHE 1500 02-06 4x4
ESCALADE ESV 03-06
ESCALADE EXT 03-06
SUBURBAN 1500 00-06 4x4
YUKON XL 1500 00 4x4
YUKON XL 1500 01-02 4x4; exc. Denali
YUKON XL 1500 03-06 4x4

[kewljay223]

if they are all 1500's wouldnt they have the 60e? which would give you the same shaft you have now right??? or do you mean the 2500/3500 versions of what you listed?? if thats the case and you go that route, Mickey warned me about the possibility of the rear end being different (HD truck) which means that u-joint might not fit....

to be honest, you might save some money going that route but you might have to change the joint and who knows if the shaft is bent/ or whatever. im at the end of my 80e swap right now. i went with just modding mine. i didnt want the headace of searching around for a shaft and getting it checked out anyway. the shop called me today as a matter of fact saying that its done. ill be picking it up tomorrow and putting it in. everything else is done. theoretically i should be able to drive it by end of day.....

unfortunately it will cost me about 500 bucks because they are replacing all joints, carrier bearing, new yoke, shortening it and balancing . i didnt have to do all that but the shaft/parts are 18yrs old.... haha time for sevice. if you just get it shortened its about 120 bucks + cost of yoke. since yours is an 05 thats all you should have to do.

for the flex plate, kinda depends what converter your gonna use. is a stock one coming with your trans? if not you obviously gotta buy one. if you get a stock one yes, you will need FLAT flex plate and spacer. if you get aftermarket with stall (what i did from site sponsor circle D) they have an 80e verter with a 60e bolt pattern which is what i got. this allows you to use your stock dished plate WITHOUT spacer. you just need to oblong the 3 holes a bit. thats pretty much your only 2 options AFAIK.

if you dont mind doing the wiring, you dont need to spend 100 bucks on the harness adapter. just take apart the round conector and move two pins around. the only other wiring is adding the two wires for the fron VSS and pinning them into the PCM connectors. 4 wires TOTAL to deal with. DONE. read a few pages into this thread and it shows you exactly how. pretty easy to do. http://www.performancetrucks.net/for...-4l80e-424904/

and i think you said you have the rest covered such as oil cooler lines and crossmember mod. good luck!

oh and there are 3-4 different output shafts on the 80e's you will have to look at yours to get the correct yoke. i was able to look in through the seal with a flashlight and see that i had the kind with the splines that went the full 5" some only go about 3 and have an oring. some are slip yokes only. some are bolt on. just make sure you get the right one. you might have to take the rear housing off to know for sure... bu i cant help you much more than that though.