4L80 E install question

[Fast Cars]

I hav a question to all of you who did the install.


My transmission output shaft (4WD) only goes 4cm (1,6") into the
transfer case´s input shaft (the hardened 300M aftermarket one).

That may be enough, but I don´t know.

I´ve seen other having the (shorter?) 4WD transmission output shaft
on their tranny too.
So what did you do?

Did you live with the shaft going only 4cm (1,6") into the transfercase`s inputshaft?

On a "normal" hp setup I would not have a problem with that, but on then planned 1500+ hp, I better think twice and ask others....

Every help is highly appreciated.

 

[Houseofperformance]

Re: 4L80 E install question

had the same problem - had to disassemble the transmission and change the output shaft for a longer one

 

[T-Bone]

Re: 4L80 E install question

With a planned 1500 HP, you had better latch on to every CM of the output shaft that is possible.

 

[Fast Cars]

Re: 4L80 E install question

With a planned 1500 HP, you had better latch on to every CM of the output shaft that is possible.

Yes, that´s what I thought.

I just don´t know how to handle that now, as it´s a special heavy duty build from USA
and sending it back and forth would be 1000$ allone, let allone the swap.

I have no problem to invest money into my project, but that´s frustrating big time.
That it will delay my build a month (right at beginning of the season) is frustrating, too

 

[JSM]

Re: 4L80 E install question

I have not seen an output shaft on the 4l80e that short. Normally they are too long and require cutting.

For example look at this 4x4 output shaft

http://cgi.ebay.com/ebaymotors/GM-4...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

GM made a ton of different style output shafts, some even had a parking brake on the output shaft, bolt on yokes, slip yokes, etc etc.

The input shaft isn't the issue, it is actually longer than the stock was if you look and extends out past the transfer case more than stock.

 

[Houseofperformance]

Re: 4L80 E install question

Yes, that´s what I thought.

I just don´t know how to handle that now, as it´s a special heavy duty build from USA
and sending it back and forth would be 1000$ allone, let allone the swap.

I have no problem to invest money into my project, but that´s frustration big time.
That it will delay my build a month (right at beginning of the season) is frustrating, too

you could bring the trany to heinz schenk (coolchevy-raceparts.com) and let him do the swap - there are also some trany specialists in germany - hetzel, automatic berger .....
no need to ship it to the states for this job - i did the swap by myself, and suprisingly the trany still works;-)

 

[jwaller]

Re: 4L80 E install question

looks like you need to find a longer output shaft and install it. pretty easy job. 2 hours tops. no need to delay anything by a month.

 

[THEMADTYPH00N]

Re: 4L80 E install question

How long is the splined area on that shaft you currently have in there? Might be helpful to others so they know what NOT to use.

 

[Fast Cars]

Re: 4L80 E install question

you could bring the trany to heinz schenk (coolchevy-raceparts.com) and let him do the swap - there are also some trany specialists in germany - hetzel, automatic berger .....
no need to ship it to the states for this job - i did the swap by myself, and suprisingly the trany still works;-)

Thanks for the info.

I do know Heinz and we both have the same tranny builder we trust

I never would send my heavy duty built tranny to Hetzel and the others.

 

[Fast Cars]

Re: 4L80 E install question

How long is the splined area on that shaft you currently have in there? Might be helpful to others so they know what NOT to use.

The shaft is 7cm.

For my taste it´s not a good idea to just use a longer transmission shaft.
It would then go farther into the input shaft,
but there would be about 2" not used area of the shaft then between tranny and input shaft.
Not ideal.

I now think about deleting the stock part between the tranny adapter and the transfer case, that would bring them closer together and the shafts would go full in without using a longer one (longer is not alwas better )

I just need to see what porp shaft options I have (that one needs to be very strong for my setup) and if it is too close to the tranny. The stock one is VERY close then.

 

[Fast Cars]

Re: 4L80 E install question

looks like you need to find a longer output shaft and install it. pretty easy job. 2 hours tops. no need to delay anything by a month.

I know a lot about cars and parts, but I´m no porfessional tranny builder.
This transmission is as special heavy duty build with transbrake and all and
I don´t want to mess with it.

I´ll see what the tranny builder recommends.

And maybe I even keep the shaft and mod the setup elswhere (see post above that one).

 

[jwaller]

Re: 4L80 E install question

I know a lot about cars and parts, but I´m no porfessional tranny builder. This transmission is as special heavy duty build with transbrake and all and
I don´t want to mess with it. I´ll see what the tranny builder recommends. And maybe I even keep the shaft and mod the setup elswhere (see post above that one).

yes there are many many ways to solve the same problem. pros and cons to each. if you don't already have prop shaft and drive shaft then you can move things around more because you will be correcting for the change in xcase movement after the fact.

You could thin down the adapter between the trans and xcase and gain a slight amount of length there, but probably not enough.

You could also machine down the front of the xcase so it moves further into the adapter but again this probably isn't the cheapest, quickest or best option.

But if it were me I'd get the longer output in the trans and then cut it to length once you have it back on the bench and measured. I'd put as much of it into the xcase as I could but leave 0.100 or so for thermal expansion.

 

[Fast Cars]

Re: 4L80 E install question

yes there are many many ways to solve the same problem. pros and cons to each. if you don't already have prop shaft and drive shaft then you can move things around more because you will be correcting for the change in xcase movement after the fact.

You could thin down the adapter between the trans and xcase and gain a slight amount of length there, but probably not enough.

You could also machine down the front of the xcase so it moves further into the adapter but again this probably isn't the cheapest, quickest or best option.

But if it were me I'd get the longer output in the trans and then cut it to length once you have it back on the bench and measured. I'd put as much of it into the xcase as I could but leave 0.100 or so for thermal expansion.

I don´t want to touch the tranny.
Chuck Johnson@FLT built it with a lot of special specs and
I don´t want to mess with his perfect build.
I have had no single failure on all trannies I got from him for different cars,
and I want to keep it that way.

Also, I like the fact that the shaft is not too long.
That way it would be less stress to it.

I will deinstall Mikes adapter plate and will not use the stock middle part.

I will have a friends machine shop build me a thick adapter plate where I can mount tranny and transfer case.

That way I will move the transfer case about 1,5" inch nearer to the tranny.
The shafts then fit perfect together.

That´s the best performance solution.

I need a prop shaft and a driveshaft anyway, so it´s not a problem at all.

It´s just good to have friends with a machine shop or it would be very expencive to get
such a special part built.

 

[Norm]

Re: 4L80 E install question

I was at work tonight talking to a few of the machinists/mechanics and showed them this post about this.Most of them thought that amount of contact area would be fine. They didn't really know about 1500 hp breaking that or not. A few of them thought rear axel breakage would happend before the tranny shaft breaks.

 

[Fast Cars]

Re: 4L80 E install question

I was at work tonight talking to a few of the machinists/mechanics and showed them this post about this.Most of them thought that amount of contact area would be fine. They didn't really know about 1500 hp breaking that or not. A few of them thought rear axel breakage would happend before the tranny shaft breaks.

Thanks for the info.
I don´t fear the shafts braking, though, but shredding the splines!

Maybe the contact area is enough.
But I know I could have more, so I´ll do more.
Better save than sorry.
The build is a lot of work and so much money,
so I want to build everything the best and strongest I can.

Believe me MY rear axle will NOT brake (far away from stock)

 

[Fast Cars]

Re: 4L80 E install question

Ok, I did a lot of thinking about that and finally decides
to machine down the stock aluminum adapter that sits between
the 4L80E adapter and the transfer case.
It will not be easy and will need to be dane carefully and precise,
but fortunately I have a friend who can do it.
I´ll post pix when all is done.

Next thing will be to find a custom length heavy duty prop shaft (needs to hold
600hp+) and a driveshaft (holding 900hp+).
Maybe carbon.
Whatever is strong enough (better overrated than underrated).
I´ll see what I can find.

 

[Fast Cars]

Re: 4L80 E install question

Fixed

Everything is like I wanted it, now.
Tanny output shaft shaft now reaches fully into the TC´s input shaft.

Next: finding a good source for the custom heavy duty prop- and driveshaft.....

 

[Quickstop [UK]]

Re: 4L80 E install question

Nice work. Where are you?

 

[1BADV6]

Re: 4L80 E install question

Looks good, how much did you have to take off the front of the factory adapter ?

 

[Fast Cars]

Re: 4L80 E install question

Nice work. Where are you?

Austria