Re: [Amc-list] clutch questions

[Frank Swygert <farna@xxxxxxx>]

HA! I don't know about the synchro, mine only lasted about a week, maybe 150 miles. Could have been because I had it behind a 4.0L right from the start though.... ;> 
I figured if I had it rebuilt it would last a while, and it did. Except the synchro. I was even taking it easy! The synchro is the weak link -- it simply won't take much abuse or torque. The first Rambler I had was a L-head 61 American wagon with the trans jammed in second when I got it. Of course it had 170K+ on it. The synchro had two of the three "dogs" gone, the third was jamming the trans. Took it out and to a friend of my dad's who'd run a shop for years. He took one look in the cover, yanked the remaining dog out, and told me I'd "learn to shift it without grinding". He also explained double clutching for down shifting. Took me a couple weeks, but I learned what speed to shift at by engine sound. I was the only one who could drive the car without grinding the gears, and even I did on occasion. 

You can leave the Classic tailshaft housing on. The seal in the housing is the same as the American, and in the same location. You just have that flange hanging out under the car is all. All splines on the small BW trannys are the same IIRC -- even the M-35 yoke will fit a T-96... I think. I'm not sure about the M-40, but I'm pretty sure they do. The M-8 and M-1x use the same yoke as a T-89 and T-10 standard shift trans -- that I know for a fact! 

One thing to note when changing trannys from pre 63 (64 American) and post is that the speedo turns the opposite direction. The speedo runs off the TOP of the driven ger on the tailshaft in early cars, bottom in late ones. The reason is that early cars are taller and have a shallower trans tunnel. I found this out the hard way when the trans went in my 63 American. A 65-66 M-35 was rebuilt to replace it. IIRC the driven gear has to be changed as well. The tailshaft housings interchange, of course. 

Four point mount cars have the rear mounts on the bell housing. Three point mounts have the rear mount on the tailshaft housing. Change tailshaft housing for four to three, you can just remove the mounts from the bell (or change bells) to convert from three to four. 

The old T-96 isn't designed to downshift for engine braking. It just wasn't done in the 30s-50s. That's the main reason the synchro doesn't last today -- people shift it like a modern trans. You should only downshift with your foot on the brake and speed falls to the point you need second to start back, not "early" and let clutch out for engine braking. You have to think 40s-50s, and maybe grandma/pa driving. 

I bet the clutch was just glazed or had some of the surface "expanded" from moisture. Could have been some of the arm/spring mounts stuck too. Or as you surmise -- trash (mouse nests) in the housing. If you ever do change it go with the bigger disc though. Certainly won't hurt! Will reduce slipping on take-off, which would make it harder for someone learning a stick to drive is all, might even "jerk" if you let the clutch out to soon! 

I wouldn't worry about the clutch. They either work or don't, and I've never had one suddenly go out. The throwout will make noise before going south, and the disc will start slipping bad. Since you don't count on the car for daily driving you can wait a week for a clutch to come in. That car doesn't stress the clutch a lot. 

While I've writing, does all the Twin-Stick controls work correctly? That's important to keep the OD in good health, especially the kick-down circuit! You also need to use 2nd+OD with that trans. That's why the big gap between 2nd and 3rd when not using OD. With a standard gear T-96 2+OD is about the same as 3rd. 


----------------------------------------------
Date: Sun, 14 Oct 2007 18:23:28 -0700
From: Tom Jennings <tomj@xxxxxxx>

-- Frank Swygert <farna@xxxxxxx> wrote:

> > I've got a "J" sitting here at the house. It has a larger input bearing
> > and slightly larger main shaft inside, but it uses the same clutch disc.
> > AMC was the only manufacturer to use it as far as I can tell, and it was
> > only made the last couple years the T-96 was used (~70-72 range). It's
> > one tough cookie to find parts for!!
>   

Wow, I can imagine! Does the synchro last any longer though?

You said you stuck a classic T-96 in an American? Did you just swap the 
tailshaft housing? is the output shaft exactly the same (splines and final 
seal)?

Mine's old style, four-point mounts, I forget if the rears are on the trans 
or the bellhousing and I'm too lazy (and clean) to crawl under the car 
tonight to look.


I'm fine now with this dimwitted old T-96. I'm doing heel'n'toe to blip the 
throttle to do 3-2 downshift. If I wanted a new car I'd buy one  :-) 

Surprise! Clutch stopped slipping! It's not that weird -- besides rust or 
glaze, it probably literally had a mouse nest in it. Spun that out with 
driving I guess. I didn't and won't push my luck though, I just got it near 
its power band in 3rd and floored it up a hill, no slippage. There were 
mouse nests all over, including one in a frame rail (I have to shop vac 
that one out.) Not that I trust it to last, but I at least got a reprieve. 
It always operates perfectly, Throwout bearing is silent, pedal fine, if 
high, smooth no chatter. Eh, I'm driving it. Will buy a clutch next payday 
or the one after, and watch ePay in the mean time for bargains.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)

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