simple 4l80 question
- Thread starter ed hess
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JSM
Active member
Re: simple 4l80 question
I should add.
I have investigated reworking the input shaft on transfer case. If you did you would introduce a weaker area as the shaft would become extremly thin at the front.
Also, the splines are not the weak area in terms of stress, the weak area is somewhere else. Fatigue maybe, actual stress no.
I should add.
I have investigated reworking the input shaft on transfer case. If you did you would introduce a weaker area as the shaft would become extremly thin at the front.
Also, the splines are not the weak area in terms of stress, the weak area is somewhere else. Fatigue maybe, actual stress no.
ed hess
race or get outta the way
Re: simple 4l80 question
well
let me be the bearer of bad news for all of you doing 4l80 conversions.
the ouptput shaft wont handle a high hp application.
having a shaft that is 4l80 (400) on one side and 700/350 on the other is a weak link that can and has been broken.
so now my next question...
which transfer case can bolt to a 400 with a 32 spline (oem) style output shaft and still clear the floor in a syty?
I only bring it up because with my new motor we broke the output shaft this past thursday night standing still against the brakes at 6000 rpm. (peak torq point) with my oem brakes that somebody said needed upgrading. lol
the shaft did have 200 runs on it from the old motor.
and fwiw matt broke his also.
just put another shaft in it and i'll have back tomorrow night to reinstall the 400.
well
let me be the bearer of bad news for all of you doing 4l80 conversions.
the ouptput shaft wont handle a high hp application.
having a shaft that is 4l80 (400) on one side and 700/350 on the other is a weak link that can and has been broken.
so now my next question...
which transfer case can bolt to a 400 with a 32 spline (oem) style output shaft and still clear the floor in a syty?
I only bring it up because with my new motor we broke the output shaft this past thursday night standing still against the brakes at 6000 rpm. (peak torq point) with my oem brakes that somebody said needed upgrading. lol
the shaft did have 200 runs on it from the old motor.
and fwiw matt broke his also.
just put another shaft in it and i'll have back tomorrow night to reinstall the 400.
JSM
Active member
Re: simple 4l80 question
Yep. Exactly where I suspected it will break. In the red area?
http://gallery.jsmanufacturing.com/main.php?g2_view=core.DownloadItem&g2_itemId=262
I will mention also, even a full 32 spline 80e shaft is the same size at that spot. Nothing gets removed from there. as the splines on a 32 are larger than that necked down area.
Guess my engineering degree, and FEA anaylsis was correct.
Got any pictures or mind sending me broken pieces?
Only real option is to go to different material, or complete new shaft design.
Yep. Exactly where I suspected it will break. In the red area?
http://gallery.jsmanufacturing.com/main.php?g2_view=core.DownloadItem&g2_itemId=262
I will mention also, even a full 32 spline 80e shaft is the same size at that spot. Nothing gets removed from there. as the splines on a 32 are larger than that necked down area.
Guess my engineering degree, and FEA anaylsis was correct.
Got any pictures or mind sending me broken pieces?
Only real option is to go to different material, or complete new shaft design.
ed hess
race or get outta the way
Re: simple 4l80 question
jeff ( i think your 1st name is correct, if not let me know)
the red area is exactly the spot. the larger diameter taper area doesnt exist on a 400 shaft as it is the governer gear right there.
i havent seen one but i am assuming the 400 shaft is larger all the way thru.
But are you are saying the 4l80 is large, then necks down and gets large again at the spline?
i just bought the last output shaft tci had on the shelf and i honestly dont know when they will be making more but i didnt ask either.
so what transfer case bolted directly to a 400 that fits under a syty???
(this is needed for next time)
ed
JS Manufacturing said:
jeff ( i think your 1st name is correct, if not let me know)
the red area is exactly the spot. the larger diameter taper area doesnt exist on a 400 shaft as it is the governer gear right there.
i havent seen one but i am assuming the 400 shaft is larger all the way thru.
But are you are saying the 4l80 is large, then necks down and gets large again at the spline?
i just bought the last output shaft tci had on the shelf and i honestly dont know when they will be making more but i didnt ask either.
so what transfer case bolted directly to a 400 that fits under a syty???
(this is needed for next time)
ed
George Blake
DONATING MEMBER
Re: simple 4l80 question
The one's in the conversion kits aren't machined down to a sharp edge. The joint is radiussed. The new ones I'm doing now do away with the radius and it has a dual taper for more strength.
You can't machine it all the way down to a sharp edge. It makes a fracture joint. You have to taper it. It's not as pretty, actually kinda ugly because of the hobbing process, but it is a much stronger joint. If you look at a 2wd shaft from a 4L80 you will see where it gets tapered down instead of just a sharp cutoff. They do that several times down to the base. If you look at the 4L80E shaft itself it's done the same way. I'd like to see a good pic of the broken shaft and the one you replaced it with. If you don't mind I'll take it and compare it to the conversion design so you can see what I'm talking about. If they are taking a stock TH400 and turning it down, let me know and I'll send you how I'm having it done now so they'll do it similarly so the joint is stronger.
There is an aftermarket 700 to 400 convesion shaft that is readily available. If that's the one you are using, it isn't machined. It is a welded joint that gets lathed after welding. They actually take a 700 shaft, cut off the end and take a 400 shaft and cut off the end and weld them together. They are VERY weak and I would NOT recommend using them. I have a strong suspicion that this is what TCI is using. These are massed produced and are used in "switch kits". Tekpack Fitzall I think distributes them.
The reason this is so much weaker is that the weld hardens the shaft at the joint and makes it brittle. The lathing just cleans it up. It is still brittle because of the welding.
Do you want me to see if I can get a TH400 shaft machined for you? It's no trouble at all and will probably be cheaper than the TCI/Fitzall shaft you got.
The one's in the conversion kits aren't machined down to a sharp edge. The joint is radiussed. The new ones I'm doing now do away with the radius and it has a dual taper for more strength.
You can't machine it all the way down to a sharp edge. It makes a fracture joint. You have to taper it. It's not as pretty, actually kinda ugly because of the hobbing process, but it is a much stronger joint. If you look at a 2wd shaft from a 4L80 you will see where it gets tapered down instead of just a sharp cutoff. They do that several times down to the base. If you look at the 4L80E shaft itself it's done the same way. I'd like to see a good pic of the broken shaft and the one you replaced it with. If you don't mind I'll take it and compare it to the conversion design so you can see what I'm talking about. If they are taking a stock TH400 and turning it down, let me know and I'll send you how I'm having it done now so they'll do it similarly so the joint is stronger.
There is an aftermarket 700 to 400 convesion shaft that is readily available. If that's the one you are using, it isn't machined. It is a welded joint that gets lathed after welding. They actually take a 700 shaft, cut off the end and take a 400 shaft and cut off the end and weld them together. They are VERY weak and I would NOT recommend using them. I have a strong suspicion that this is what TCI is using. These are massed produced and are used in "switch kits". Tekpack Fitzall I think distributes them.
The reason this is so much weaker is that the weld hardens the shaft at the joint and makes it brittle. The lathing just cleans it up. It is still brittle because of the welding.
Do you want me to see if I can get a TH400 shaft machined for you? It's no trouble at all and will probably be cheaper than the TCI/Fitzall shaft you got.
ed hess
race or get outta the way
Re: simple 4l80 question
i dont have the broken one on hand yet as i sent it with the unit and the new shaft.
it did not appear to be welded or lathed.
i had heard of a welded unit also but this one wasnt that.
ask me in a couple weeks (pm) and i will try to get pic for you.
but i have to finish my short list as soon as i get it back as the 1st index race in 3-19 which doesnt give us much time to start tuning, dial in for the 10 index, finish license runs and kick matts 6. lol
ed
i dont have the broken one on hand yet as i sent it with the unit and the new shaft.
it did not appear to be welded or lathed.
i had heard of a welded unit also but this one wasnt that.
ask me in a couple weeks (pm) and i will try to get pic for you.
but i have to finish my short list as soon as i get it back as the 1st index race in 3-19 which doesnt give us much time to start tuning, dial in for the 10 index, finish license runs and kick matts 6. lol
ed
George Blake
DONATING MEMBER
Re: simple 4l80 question
TH400 conversion shaft
If this is the one you are using, then it's the cut, welded, and lathed shaft. It'll break just like the other one. This is the tekpack fitzall switch kit.
Here's an example of one of the kit's.
Switch Kit
There are many others, but this is the shaft you got. When it breaks, give me a PM and let me get a shaft machined for you and we'll see how well you do. Is that cool?
TH400 conversion shaft
If this is the one you are using, then it's the cut, welded, and lathed shaft. It'll break just like the other one. This is the tekpack fitzall switch kit.
Here's an example of one of the kit's.
Switch Kit
There are many others, but this is the shaft you got. When it breaks, give me a PM and let me get a shaft machined for you and we'll see how well you do. Is that cool?
ed hess
race or get outta the way
Re: simple 4l80 question
yeah thats it.
fwiw i expect this one to break eventually also.
but it didnt look welded or lathed to me.
however i saw the new one complete and the old one i have only half of it in my hand.
so what other shaft is available?
and does anyone know what t-case was used behind a 400?
ed
George Blake said:
yeah thats it.
fwiw i expect this one to break eventually also.
but it didnt look welded or lathed to me.
however i saw the new one complete and the old one i have only half of it in my hand.
so what other shaft is available?
and does anyone know what t-case was used behind a 400?
ed
George Blake
DONATING MEMBER
Re: simple 4l80 question
The only other ones available right now are for the 4L80E that Jeff has been doing and I've been having done. Jeff is right in that the next step up is going to something like a 300M and machining the shaft from scratch and having it heat treated.
Trust me. The one you ordered is lathed flat off and welded and then machined down smooth. I talked Fitzall about it early on when I first started checking into the 4L80E conversion. I then talked to a metalurgist in Cincinnati(Cincinnati Steel). Explained it to him and he basically told me no. I'm no metalurgist so I trusted him. You also do not want to anneal a shaft, machine it and then reharden it. It will lose 40 to 50% of it's strength doing that. It must be cold machined. Relax and try a different route first before jumping into another adaptor and transfer case. I know your usually in a hurry, but just check first.
The only other ones available right now are for the 4L80E that Jeff has been doing and I've been having done. Jeff is right in that the next step up is going to something like a 300M and machining the shaft from scratch and having it heat treated.
Trust me. The one you ordered is lathed flat off and welded and then machined down smooth. I talked Fitzall about it early on when I first started checking into the 4L80E conversion. I then talked to a metalurgist in Cincinnati(Cincinnati Steel). Explained it to him and he basically told me no. I'm no metalurgist so I trusted him. You also do not want to anneal a shaft, machine it and then reharden it. It will lose 40 to 50% of it's strength doing that. It must be cold machined. Relax and try a different route first before jumping into another adaptor and transfer case. I know your usually in a hurry, but just check first.
JSM
Active member
Re: simple 4l80 question
The only larger transfer case I know of is a 4x4 type. I think Ryan in chicago went that route. You do end up with another shifter.
Yes, stop by a tranny shop and look at a stock 80e shaft for sure (I suspect 400 is the same, aside from the govenor gear) It will neck down, then is larger for the spline section.
For the 80e shafts I turn them down, and respline them ;but the area in red BARELY gets machined at all.
As George mentioned the key is a smooth transistion with as large of radius as possible.
The only larger transfer case I know of is a 4x4 type. I think Ryan in chicago went that route. You do end up with another shifter.
Yes, stop by a tranny shop and look at a stock 80e shaft for sure (I suspect 400 is the same, aside from the govenor gear) It will neck down, then is larger for the spline section.
For the 80e shafts I turn them down, and respline them ;but the area in red BARELY gets machined at all.
As George mentioned the key is a smooth transistion with as large of radius as possible.
JSM
Active member
Re: simple 4l80 question
Rolling in terms of pushing metal into a round corner I doubt is done on a cast crank. I am no crank expert but i suspect the term is misused slightly, and really just means a large radius.
That can and is done on the shafts I have done. At some point the size of radius make little difference in final strength.
I looked into getting complete custom shafts made up to my own custom design. I had to buy a minimum of 25 forgings, couple month lead time, and use all my 401k for deposit.
If you try to buy a solid chunk and go billet, it is just as bad, if not worse.
Now if we can get a GP of say 200 shafts, I can make something happen.
In the end although it is the "weak" length in chain as I see it. It is still much stronger than anything inside a 700. An personally I would rather have a weak link at a point that will not damage other objects if it does break.
Ed's is a welded shaft from what I gather and he got 200 runs out of it in the 9sec range. The ones George and I have are NOT welded and should be even stronger than that.
There will always be a weak link, question is where do you want it and if you fix it, what is the next link to address?
Rolling in terms of pushing metal into a round corner I doubt is done on a cast crank. I am no crank expert but i suspect the term is misused slightly, and really just means a large radius.
That can and is done on the shafts I have done. At some point the size of radius make little difference in final strength.
I looked into getting complete custom shafts made up to my own custom design. I had to buy a minimum of 25 forgings, couple month lead time, and use all my 401k for deposit.
If you try to buy a solid chunk and go billet, it is just as bad, if not worse.
Now if we can get a GP of say 200 shafts, I can make something happen.
In the end although it is the "weak" length in chain as I see it. It is still much stronger than anything inside a 700. An personally I would rather have a weak link at a point that will not damage other objects if it does break.
Ed's is a welded shaft from what I gather and he got 200 runs out of it in the 9sec range. The ones George and I have are NOT welded and should be even stronger than that.
There will always be a weak link, question is where do you want it and if you fix it, what is the next link to address?
ed hess
race or get outta the way
Re: simple 4l80 question
I talked with him about this.
we discussed this as the weak link when he originally built it.
as you read above making a 1 up or limited quantity of custom shafts is cost prohibited.
there just isnt enough demand and never will be.
running awd has a power limit and we are at it.
the only inexpensive answer is to ramp in the power slowly on launch to avoid loading and unloading the (read slip spin slip spin) to have the drivetrain live.
matt told me he broke his output shaft after changing to slicks, so they are up against the same limitation as well.
this is why i stated elsewhere that this is my final build on this thing.
just run it, maintain and repair as needed.
only other alternative would be to changing to 2wd.
thats just not going to happen.
just back and off and have fun in the 10.0 index class, bracket race and have fun.
ed
qbnkiller said:
I talked with him about this.
we discussed this as the weak link when he originally built it.
as you read above making a 1 up or limited quantity of custom shafts is cost prohibited.
there just isnt enough demand and never will be.
running awd has a power limit and we are at it.
the only inexpensive answer is to ramp in the power slowly on launch to avoid loading and unloading the (read slip spin slip spin) to have the drivetrain live.
matt told me he broke his output shaft after changing to slicks, so they are up against the same limitation as well.
this is why i stated elsewhere that this is my final build on this thing.
just run it, maintain and repair as needed.
only other alternative would be to changing to 2wd.
thats just not going to happen.
just back and off and have fun in the 10.0 index class, bracket race and have fun.
ed
JSM
Active member
Re: simple 4l80 question
If someone REALLY wanted a custom, it can be done and I could make some up isn't a big deal aside from several hours of labor.
Just the chunk of metal alone is around $600 before machining it to go billet. I could machine it, as well as just about any local machine shop that knows a little bit about splines,etc.
Figure though 12hrs or so for a one off, at ~$50hr for most shops. Adds up quick.
Again for 99% of syty owners this will never be a problem.
If someone REALLY wanted a custom, it can be done and I could make some up isn't a big deal aside from several hours of labor.
Just the chunk of metal alone is around $600 before machining it to go billet. I could machine it, as well as just about any local machine shop that knows a little bit about splines,etc.
Figure though 12hrs or so for a one off, at ~$50hr for most shops. Adds up quick.
Again for 99% of syty owners this will never be a problem.