Bent Liberty Input Shaft Video....

rdsnake

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If you haven't been following my threads here is the start.

http://www.modularfords.com/forums/f17/bent-liberys-input-shaft-might-try-86710.html

I ended up pulling the trans out today. Right away I spun the shaft and I was correct, the input shaft was bent.

I was going to send it out to Liberty to have it straighten but I think im just going to order a new one.

Also I noticed the shim is melted on the oppsite end of the input shaft due to the heat of the bent input shaft. Hopefully end play will be in spec or I will have to fix it.

Got some great video of it. The first video is the top view of the shaft. The sec. video is a side view, if you look between the throw out bearing tube and the input shaft, you can see the wobble. Also in the sec vid. you notice CobraChris08 say "go" very quietly! Thanks Chris you rock!





Kevin
 

sschassis

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I did reply to this thread on modular ford & here is it again Liberty input its different than D&D ........ D&D uses viper input because the spline are further down on shaft it will fit better on twin disc plus much stronger shaft than Liberty GM input shaft also.......

with Liberty shaft you will have to do some grinding on clutch disc to make liberty shaft fit ... if you are using McLeod twin disc

..... with D&D you don't have to do any grinding

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tinosc281

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liberty input shaft

i have one brand new available and the shim kit. was going to use on my trans.also i have a brand new centerforce lm 26 spline clutch disc.
 
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rdsnake

rdsnake

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I did reply to this thread on modular ford & here is it again Liberty input its different than D&D ........ D&D uses viper input because the spline are further down on shaft it will fit better on twin disc plus much stronger shaft than Liberty GM input shaft also.......

with Liberty shaft you will have to do some grinding on clutch disc to make liberty shaft fit ... if you are using McLeod twin disc

..... with D&D you don't have to do any grinding

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Ok I remember you posting on mfords. just thought id share the video
 

cobravenom39

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How many Liberty input shafts have ended up getting bent. I know you're high horspower, but that's ridiculous.
 
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rdsnake

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Jesus that thing is really bent out of wack
Shit, your telling me..You should have felt it at 100 MPH....Felt like my wheels were about to fall off...


How many Liberty input shafts have ended up getting bent. I know you're high horspower, but that's ridiculous.
4 that I know of. Most of them being local guys. Larry, Carl, and I, another guy ive been pming back and forth on Mfords. FYI, Carl has just a pulley and bent his....High horse power has nothing to do it, or at least I think.
 

Dana

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Before you condem the input shaft, you should pull it out of the trans and see if the shaft is actually is bent. There are a couple of scenerios that could occur that could produce the result you are seeing besides a bent shaft.

Support the shaft by it's centers at both ends and then rotate it to check for runout.

Dan
 
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rdsnake

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Before you condem the input shaft, you should pull it out of the trans and see if the shaft is actually is bent. There are a couple of scenerios that could occur that could produce the result you are seeing besides a bent shaft.

Support the shaft by it's centers at both ends and then rotate it to check for runout.

Dan

Will do, I already have the input shaft out.
 

Wiked03

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How many Liberty input shafts have ended up getting bent. I know you're high horspower, but that's ridiculous.
I bent one too, and so did Larry.



Thats what mine looked like only mine might have been a little worse. I couldn't even drive the car over 70 mph in 5th or 6th gear... but for some reason my vibe was almost unnoticeable in 4th gear. :dunno:

Before you condem the input shaft, you should pull it out of the trans and see if the shaft is actually is bent. There are a couple of scenerios that could occur that could produce the result you are seeing besides a bent shaft.

Support the shaft by it's centers at both ends and then rotate it to check for runout.

Dan
Maybe I should send LDC my bent shaft and you guys can do some testing on it. I don't have the tools or knowledge to diagnose what happened. I just know it was fugged up and replacing it made the vibe go away. I would love to be able to prevent it from coming back. :clap:
 

Dana

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I bent one too, and so did Larry.


but for some reason my vibe was almost unnoticeable in 4th gear. :dunno:
In 4th gear, the input shaft is locked to the main shaft. This would limit any movement on that end that could occur in other gears. The pilot bearing stabilizes the front of the shaft.


Maybe I should send LDC my bent shaft and you guys can do some testing on it. I don't have the tools or knowledge to diagnose what happened. I just know it was fugged up and replacing it made the vibe go away. I would love to be able to prevent it from coming back. :clap:
I don't know about diagnoising why it happened, but I'd be happy to take a look at it and let you know what I find.
Dan
 
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rdsnake

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In 4th gear, the input shaft is locked to the main shaft. This would limit any movement on that end that could occur in other gears. The pilot bearing stabilizes the front of the shaft.



I noticed mine more in the lower gears 1,2, and 3...almost never in 4,5, and 6. Seems totally oppsite then Carl's.

Dan, Also FYI I mounted it up and spun it. It is 100% bent. Main shaft and counter shaft should be ok.

Kevin
 

Mr. Unknown

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Dude I remember what you were saying at your house about the wheel hop and blowing the half shaft. But I still have no idea how that caused that. Are you sure maybe heat didn't fug it up? the way the clutch sits on it? I'm fuckin lost at how that thing got jacked.
 
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rdsnake

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Dude I remember what you were saying at your house about the wheel hop and blowing the half shaft. But I still have no idea how that caused that. Are you sure maybe heat didn't fug it up? the way the clutch sits on it? I'm fuckin lost at how that thing got jacked.
You and me both...Their is a million different reason why it could have bent..
 

Dana

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Dan, Also FYI I mounted it up and spun it. It is 100% bent.
Main shaft and counter shaft should be ok.

Kevin
That's good.

Now you should try to figure out why it bent.

I honestly can't figure out how it bent while in use (assuming that the shaft was ok at the time it was installed), although the point that it bent at may give a clue. I have seen them bend during the reinstallation into the car, along with clutch disks, but never after everything was together and working properly.
I suppose if the shaft wasn't heat treated properly and evenly, it is possible it could bend near the bearing as your appears to have done.

Any ideas yet?
 
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rdsnake

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That's good.

Now you should try to figure out why it bent.

I honestly can't figure out how it bent while in use (assuming that the shaft was ok at the time it was installed), although the point that it bent at may give a clue. I have seen them bend during the reinstallation into the car, along with clutch disks, but never after everything was together and working properly.
I suppose if the shaft wasn't heat treated properly and evenly, it is possible it could bend near the bearing as your appears to have done.

Any ideas yet?
Yeah, I agree it did bend where the bearing rides. Like I said before it bent when I snapped a half shaft. I did a hard shift 1st to 2nd gear, right when I hit sec. gear the half shaft snapped and I bent the input shaft. Tell you the truth I have no idea why it bent. I'm going to have one of my dad's buddy's take a look at it.

Hopefully I won't bent another one under normal use (no broken half shafts).

I'll reply back in a couple days. I'm leaving for Vegas today so I won't check up on the treads.

Kevin
 

CREJoe

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The input shaft isn't 'twisted'. It is BENT!
My mistake. Since the shaft is supported on both ends and should only see torional loading, I suspect the input shaft isn't located to the crank centerline correctly (concentricity). If you are running an aftermarket can (bellhousing) it's probably off. As a rule of thumb, I always check the relation of the locating hole on the can to the crank with a dial indicator. It's not at all uncommon to need to do this. If it is off, it will still go together but will eventually bend the input shaft. Let me know if I can help out.

Joe
 

sschassis

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Hers a question does this make sense …….. Would you take 390HP shaft replace it with 325HP shaft ..not.. so the shaft from liberty are from LS1 camaro or trans am those have 26 long spline shaft & they machine it to fit the cobra application …… now would you take 390 hp shaft & replace it with 500 hp shaft I would … D&D uses viper input shaft plus D&D sell built t56 viper trans .. viper use (1) piece counter shaft the cobra uses (2) piece counter shaft.. They advertise to handle over 1000hp & that shaft it is in those transmissions that way beyond 500hp of strength they have tested the shaft way over 1000 hp like the guys at super viper also in west Chicago

I was told liberty was going to change the shaft not sure
 

dougwg

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It figures...Liberty SUCKS!
we shall see

JB's input appears to be bent also... we dropped his trans off Monday.

Craig said he would pull it apart and see whats up and we could have the trans back Thursday.

I just called and talked to Paul, he said he won't even be able to look at it till late next week:(
 

Since 1964

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we shall see

JB's input appears to be bent also... we dropped his trans off Monday.

Craig said he would pull it apart and see whats up and we could have the trans back Thursday.

I just called and talked to Paul, he said he won't even be able to look at it till late next week:(
Why bother going there if they won't warranty the work? They flat out tell you that "if you race there's NO WARRANTY", and that 26 spline input shaft has NO BUSINESS in a Modified Cobra, we should be buying D & D's unit for the Viper, besides, it fit's better with a twin disc which "I" happen to have.

I will give them props for being up front, but like I said, it doesn't matter what they do rebuilding yer trans, so "I" won't go back, that's for sure.
Jerry at Sutton can rebuild a T56 in his sleep and I doubt if Sutton is going to deny me at least a free tear down to see what's wrong.
 

Dana

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Doug, is it possible the machining is damaging the heat treatment?
From the few pics I have seen, I haven't seen a bent shaft in person yet, and from what I am told, it is bending near the bearing at the big end of the shaft. What do you think? Do they work in this area?
I can think of no way that any force sufficient to bend one of the shafts that is treated properly can be exerted on it.
Dan
 

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