T-5 experts-- Chewed up Output shaft

[Mustang5L5]

Well i just tore down the T-5 i have for my AOD-T5 Conversion.

EVerything checked out fine with no wear at all....except

The end of the output shaft where it contacts the 15 or so needle bearings on the imput shaft was chewed to hell. I did notice before i tore the trans down that there was a bit of side to side endplay of the input shaft. WOuld this be a cause, or a result?? The trans was upgraded with a steel input bearing retainer and i checked back and forth endplay at both ends of the trans when it was together and got 0.001"

EVerything else in the trans looks excellent. It did not have many miles on it since a previous rebuild since all the blocker rings and synchros showed very little wear. Like i said everything looked new inside, except for the output shaft.

SO the big question....what would chew this up like that? Just the end of the shaft was chewed...the bearings themselves looked fine.

and secondly...what's the going rate for a new output shaft? Where can i get one. IS it worth replacing??

Or perhaps does anyone have a good used one sitting around?? I don't really want to buy a $200 part for a trans i got for free. I'd rather just get a used one.

 

[Rick 91GT]

Whats the imput shaft gear look like, most times it is a imput shaft faliure that takes out the bottom cluster shaft....

 

[Mustang5L5]

I have the input shaft in my hand right now. It looks brand new. Not a chip on the teeth or any excess wear at all on the outside and the inside. All the teeth on the blocker ring-like portion are still pointed and barely worn.

Only wear on it is where the splines are. The area where it would contact the steel bearing retainer shows a little ring around like it's been spun against it a little bit. But i'm reaching here. There is very little wear in general

Rest of trans checks out too. Shift forks fine, sliders fine, 2nd gear fine, 3-4 slider fine, all gears fine, all blocker rings look new....

It's just the damn output shaft.

The person who gave me the trans said it was noisy. I'm going to ask them what gears. If it is the output shaft i would think it's noisiest in 1st (prob reverse too) and quietest in 3rd and make no noise at all in 4th since the input and output shaft are 1:1. Is my thinking correct?

 

[Rick 91GT]

Yep your right 4th would the quiestest since it is a 1:1. The front bearings is known to starve for fluid just bad design...usually if the front bearing is going, along with the imput shaft it whines fairly loud in the low gears.

Was there any grit or pieces stuck to the bottom magnet, it is weird that the bottom shaft is trash but the imput is fine....they mesh together.

I've bought a few of those shafts, damn powershifting..lol D&D usually has them in stock, thought I paid $225 for my last one.

 

[speed1972]

is it the input shaft or the output shaft that you are having problems with? You're talking about both ends of the tranny here....

 

[Rick 91GT]

is it the input shaft or the output shaft that you are having problems with? You're talking about both ends of the tranny here....

I believe he ment the Cluster Gear...

 

[Mustang5L5]

No not cluster gear. The cluster gear is perfect. No signs of wear at all.

Perhaps Output shaft is the wrong term. I beleive the T-5 manual calls it the "Mainshaft"? It's the long shaft that the speedo gear mounts on. The area i am talking about is the little nub right in front of the 3-4 synchro. The 15 needle bearings inside the input shaft would ride on this little nub. The nub is what is chewed up.

EDIT: i just checked the T-5 manual. It's called the "Output shaft assembly".

 

[speed1972]

If I had to venture a guess on this, almost sounds like you either have too much endplay or possibly the "nub" is out of spec. Measure the diameter of that nub and copmare it. You might find a spec on it in the manual or someone on here should have one to compare it to. If that isn't it, put it back together and check clearances. Do you have any pics to provide a visual?

Larry

 

[retro50]

This is usually caused by not enough tranny fluid in the case. Or the driveshaft could be bent. If there is any vibration in the driveline it can travel up the mainshaft to the pocket bearing Right where the mainshaft and the input meet. Also having the pinion angle not correct will cause the same thing. One more clue to look at is the rear bushing in the tailshaft and also look at the driveshaft yoke. If these are severly worn you probably found the culprit. As far as the shaft is concerned alot of tranny shops will have good used ones kicking around pretty cheap. I had one last summer do the same thing it was the driveshaft that caused it. It also made some loud noises in the first 3 gears. The whining it was making was caused by the mainshaft centerline being spread apart from the cluster centerline. Therefore seperating the gears from each other. I put it back together with a used mainshaft and everything quieted down. Mine was like yours everything looked fine except the mainshaft. I even reused the old input and all of the old gears. I just put in a rebuild kit with bearings and syncro's and it now has 35,000 miles on it and it is quiet as a mouse.

 

[NKau]

Don't know what would cause problems with the output shaft exclusively except for a mangled driveshaft?

 

[Ranchero5.0]

Ditto that about not enough fluid. Excessive time in nuetral will do it too. 4 pot main shafts are the same as V8

Jamie

 

[Mustang5L5]

No pics right now. I'll try to get a good one tomorrow but my digicam is pretty much on it's way out.

Anyone have the diameter that the "nub" of a good mainshaft should be? I have a set of calipers and micrometers and all that.

Would an improper pilot bearing cause this? Isn't the 4-pot pilot bearing bigger in center diameter? SO if a 5.0 input shaft went into it, there would be room to wiggle? I only bring this up because like i said it looks like the input shaft did wiggle while the trans was in. Of course this could be a result of the mainshaft wearing out. I tested the input shaft on the pilot bearing I have and it fights tightly. I cannot tell you what the conditions of the tranny were previously to my getting it. Maybe the dirveshaft was out of balance and maybe it was run low on fluid. Maybe the wrong pilot bearing. I can't really say. It's gonna be going back in my car with a new FMS aluminum driveshaft anyway so i'll fix that prob.

Anyway i've already begun looking for a new mainshaft. Can you guys clue me in on a good price for a good used one?? Also, what's the going rate on new ones and where could i buy one from? Also, anyone have the part number for the roller needle bearings that ride on the "nub".

EDIT: I found it. Mainshaft from Hanlon Motorsports is about $240 I'm just gonna look for a good used one.

 

[Mustang5L5]

PS. Anyone know anything about this?

http://stangcrazy.com/tech/techarticles/t5tsb.htm

I'm not gonna do this, but i'm just curious...is this a common problem?

 

[xmtrxmt]

Hey man, I had the exact same thing happen to mine just a couple of months ago. I whent to rebuild it becouse it was making crazy noise like it was scubing and whinning like hell. I took it apart and the mainshaft was mangled were it meets the input shaft but the needle barens were perfect. I couldnt inderstand, so I feel you pain. I used a differnt mainshaft and now I have a damn vibe like the driveshaft is out 180 degree. fliped it, same thing, and my damn cluch fork is shakeing. When I press the cluch all the vib goes away so Im thinking that maybe the damn pilot bareen has gone bad and is the cause of the tore up mainshaft as well as the vibe that I have been getting. I parked it for now until I can find the problem before I destroy another mainshaft. If you figure it out let me know. Thanks

 

[Mustang5L5]

Yeah i'm starting to think this tranny has issues with the pilot bearing as the input shaft looks like it wiggled around in the bearing as if it had a lot of play. I tested it on a 5.0 bearing and it is tight.

Of course i don't know i can only speculate