Clutch change and higher quality replacement parts
 

Hi All,
my TA has the ST-10 trans and have never been a big fan of 4 speeds. This combo is terrible with 3.42 rear. Above 45 mph, I wish it had an OD. Oh well, have decided to live with it for now but, I hate the motor buzzing at hiway and freeway speeds.
More stick shift troubles- Activating the clutch had started to change as the engagement area on the pedal motion was changing. My instincts tell me something was cracking/breaking, etc. I removed all the linkage to inspected all of them- all seemed 'ok'. that told me it was either the clutch fork or pressure plate related. Oh Fun! I have to pull the trans- yuck
So be it as I did not want to get stuck on the side of the road, etc.
Ended up buying the parts at NAPA as neither Auto Zone or Oreily's carried them. this really surprised me
The problem ended up being a broken clutch fork- in 2 places. Gladly, I bought the clutch fork as well while at the NAPA store before I tore my car down. With the bell off, I pulled the plate and disc to inspect that. All looked 'OK' but, I replaced them both as well since I was already this deep into it.
You stick shift guys may or may not be aware of this- and I want to share for us all to benefit from-
The replacement clutch fork from NAPA is much better quality than EOM. This surprised me.
It is noticably heavier and thicker metal too and made is USA.
Hoping this help you down the road when it is time to service your clutch, etc

Looking back, I wish I would have photo'd the 2 together but, did not think of it at the time. Here is a pic of part of the box showing part number, etc

Steve,how many rings on the ST-10?I have a 3.42 first gear ST-10 in my 62 421 GP.I found a set of 2.68s to put in the back,drives like a OD trans now.No feathering the clutch to get it moving and like 1900-2000 on the highway.Tom

Thanks for the info Steve. My road race project is going to have a Super T-10. I'll have to look into that fork. I want things to be as bulletproof, low-maintenance as possible.

Eric

Eric,they made a lot of ST-10 first gear ratios.The strongest as I was told was the iron case 2.64 first gear hi nickle gear version used for awhile in NASCAR.The weakest is the one I run the 3.42 first.I believe there is a chart,maybe Richmond showing the TQ ratings by first gear ratios.Tom

ST-10
https://www.richmondgear.com/wp-cont...hmond/RG25.pdf

Road race ST-10
https://www.richmondgear.com/wp-cont...hmond/RG26.pdf

I do not know Tom as trans is in the car. Whatever was original and non had an OD anyway. The car really needs it
Sounds like your combo is much happier than mine is

Eric, hoping you are well BTW. when you can, maybe compare a stock EOM fork to a NAPA. I think you will be as impressed as I was. Glad I bought it

Tom, going by memory, for what that is worth, I am thinking these cars were equipped with 2.43 first gears. Does that sound right?

I would think so if original.Tom

Correct

I had a 3-something first gear ST-10 aluminum case in the 79 Camaro with a stout 383 I autocross for a long time before it got the IA swap. Never had any issues with fork and I was even using an old 3 finger Zoom I had left over from my high school Impala! Also the Lakewood scattershield.

Just for conversation, both of the ST-10's I had in my '79 t/a, both split the cases under the torque of a healthy 455.
I had Paul Cangelosi build a custom fine spline M22 4 speed consisting of new Autogear supercase, steel midplate and new gearsets (optional ratios), along with other high quality hardware he uses. Trans is rated for 600ft.lbs. torque and price was $2400.
No more grenaded ST-10's.

https://www.5speeds.com/

the NASCAR ST-10 had a steel midplate and castiron case to help it live.Tom

yes, but you won't find those from a retail outlet..........

I had one,Bill Blair offered me one.I have seen the cases and mid plates for sale also.Tom

I had always thought that the ST-10 was a stronger, better trans than the Muncies were but, could be wrong.
I remember 35-40 years back. I had just finished up a '69 4 speed GTO Judge to sell and was playing with it, etc. I powershifted into 2nd gear and lost the trans. Al the worked was 4th gear. I limped it home and replaced the trans before I sold the car. ouch

Have seen and heard of countless Muncies blown up but, not so many ST-10s.
Still happier with my automatics, esp 700s.
I do have a new, pricey 6 speed dual OD trans I bought but, have not used it yet. Saving it for my 69 GTO build. That stick shift trans I may like, we will see

save your money and get a TREMEC no matter what anyone says the ST 10 is a crude trans as well as Muncies The Tremec is so smooth

The BW ST-10 may be "crude" by modern standards, but if you are running modern lubricants, and have the shifter adjusted and tight, they are a good shifting, relatively quiet and durable trans. With my 3.23 diff ratio and original Goodyear GR70-15 tires, the cruising RPM is not horrid.

I had a '77 T/A with the original unmodified Super T-10, 2.43 first gear.
The car had a '72 455-HO and a 3.73 rear gear (12-bolt out of a '70).
I absolutely abused that thing. Drag racing with 9" slicks, lots of street racing with hard shifts. I messed up a synchronizer ring once due to driver error. All of the other parts (gears, shafts, case) were zero failure. That's why I'm confident that road racing will be a piece of cake for the one I have now (out of a '78 T/A; so it's the same model).

All the experts claim that the best mod is switching to the older cast iron mid-plate to reduce shaft deflection. Those seem to be impossible to find so I bought what I think is the next best thing...a billet aluminum midplate from Richmond. "Billet" isn't an advantage in and of itself; but it doesn't have all the thin hollowed-out places that the OEM cast plate has.

FWIW,
Eric