Steve920

I had mounts put on my custom chassis for a 4l60e. I have found some 4l80s around me that i could get for a decent price. There are a few threads discussing the size differences between the two but want to ask for my application. My question is can I use the mount I have on my chassis for a 4l80?? If so how much farther back would I have to move it??

Thanks

01ssreda4

iTrader: (96)

Needs to be moved back several inches, maybe 4ish.

JoeNova

What vehicle???

Steve920

46 chevy pickup.

JoeNova

Overall length differences between the 2 is roughly 1/2".
The mount on the 4L80e sits roughly 1 7/8" behind the mount on the 4L60e

01ssreda4

iTrader: (96)

Maybe that's dependent on what tailshaft you run on each. I just made a custom crossmember and it was at least (minimum of 4 FOUR) inches further back then the original 4l60e mounting point.

01ssreda4

iTrader: (96)

OP, here is a picture of mine, and my beginning mock up of a new crossmember. This is a 4l80e with a 60e stock mount on it. Notice the 3 holes on the left, 3 holes on the right (only one is visible on the passenger side), the stock crossmember went directly between those two sets of holes. That is clearly more then two inches to the rear.

JoeNova

Yes, it will depend on early style vs new style. A truck style 60e has the mount on the tailshaft housing near the front of the trans, and is closer to 8" from what I remember. I don't have a diagram, sorry.

Old style:

Steve920

If the distance difference depending on year of 4l80e is 1 7/8", do you know what years I would be looking for? If you look closely to mine, I can unbolt my mount and flip it around to achieve that without having to cut and weld in new spot. Jegs says the difference is 7".

01ssreda4

iTrader: (96)

We either aren't communicating or you're confused. I ran a truck tailshaft for years, up until 2 months ago when i swapped from ls1/60e to 5.3/80e and the stock mount AND crossmember worked in the stock location with the 60e truck tail. No modification needed. I also referenced the above picture and believed i could slightly modify the stock crossmember and make it work with the 80e which was clearly not the case. It wouldnt even bolt to the car due to hitting the pan by several inches. The only difference in 60s is from 4wd to 2wd, and location there is the same but height needs to be taller for the 2wd, Ive done that swap as well.

01ssreda4

iTrader: (96)

I did not measure but from car and truck tail 60e with fbody mount to my 80e pictured above with the same fbody mount i believe the difference to be 4.5" guessing from memory.

Also, that pic above is a 4 bolt tail LT1 style 4l60e/700r4, thats why its not entirely correct for LS swaps. The 6 bolt LS tail has the mount further forward.

01ssreda4

iTrader: (96)

Here is an LS style truck tail. Notice the difference between its mounting point and the one in the pic above????

http://www.ebay.com/itm/4L60E-TRANSM...RZjI3S&vxp=mtr

JoeNova

Images don't load on my computer at work. I couldn't see anything you posted basically.

rpturbo

iTrader: (47)

I am not sure why yours is so much different. I just had my 2002 LS truck 4l60e out, and my 2006 4l80e is not 4+" different. It is very similar to the comparison pic. Are the F-Body 60's different? As far as I know, the 60e cases are all the same, but as you said, the tailshaft housing is different. I wish I had taken pics, but didn't because I just wanted to eyeball to see what I would be working with.

01ssreda4

iTrader: (96)

Basically what i know is, there are about 3 or 4 output shafts of the th400/4l80e, and several different tail sections and slip yokes. On the LS 60e tails (truck and car) the mount is in the front towards the pan (as pictured in the ebay link), and on the LT/SBC style 60e/700r4 (4 bolt tail) the mount is midway, as pictured above in this thread. So the difference between 4 bolt tails and 4l80e may be 2 inches, but the difference between 6 bolt LS tails is 4 to 5, bc the mount is closer to the pan.

On an LT1/4l60e transplant that got an LS1/LS 4l60e I used his original crossmember and just added a plate to the top that moved the hole back about 2 or 3 inches. Just the difference between an older 60e and newer.

JoeNova

There are 3 different length output shafts for the 80e. 4x4, standard, and heavy duty. If its not a 4x4, its a 99% chance you have a standard length. The longer heavy duty one was used a lot in industrial applications. They weren't ever used behind an LS based engine from what I remember. Mostly diesel applications, maybe a few big blocks.

The way the output shaft is splined is the biggest variance, but the actual tailshaft housing and mount were all the same for them.

Steve920

Am I understanding wrong if I take that as I should be fine with a standard length 4l80e and just rotating my mount?