Main Menu

4 Speed tranny questions

Started by GoMangoBoys, October 06, 2019, 09:02:04 PM

Previous topic Next topic

0 Members and 1 Guest are viewing this topic.

GoMangoBoys

I bought a 4 speed at the Fall Carlisle On Friday.   I have several questions.
1.  I think it is an overdrive tranny.  I thought this when I saw the size of what should be the gears for 3rd.  I shifted it into this gear and turned the input shaft.  The output turned about 1.3 turns.  This would be correct for a 0.73 output ratio overdrive.

2.  The numbers stamped on the passenger side do not match any website that I find for decoding them.  There is a picture attached.

3.  The bosses for mounting the shifter near the end of the tail shaft have no holes drilled and tapped in them.  Is this normal?

I was on the fence about whether I wanted to get an overdrive transmission.  Now that I bought one, I think I am off the fence.  I does look like the gears are in good shape. I plan to clean everything, replace all the bearings and put it back together.  Not too bad for a rebuild I think.

Thank you.

Cuda Cody

Pie date wheels are saying it was cast in 1982 or 1983.

Chryco Psycho

1 - correct it is an OD trans , alum case & will have a 5.125 front brg retainer diameter , the Truck & van was .71 od , the A body used .73 with a different set of gears
2 - 82/83 would be correct
3 - The later Od trans had the rear bosses for the shifter but they were not tapped , it is not hard to drill the holes & tap them fro the shifter mount pad , you can get the Pad new from Passon or Brewers , use tapered allen head bolts & locktite to mount the plate .
The shift rods will also be available from the same suppliers , the front 3-4 shift lever is inverted on the shift plate on the trans , you will have to bend the shift rod slightly to clear the crossmember under the car
You can use a belhousing with the large 4.80" brg retainer hole & just have the front retainer milled down to 4.80" to fit
A driveline should be able to get a rebuild kit for it for around $170 this will include new brgs , syncros & gaskets , they can be tricky to assemble as you have to drop the counter shafy into the bottom of the trans then install the mainshaft & tailhousing assy upside down then lift the countershaft or as I do it drop the counter shaft into place with the whole trans upsidedown into place then slide in the countershaft pin & last rotate the tailhousing 180* & bolt it up .


RUNCHARGER

I think you're running a big block. Build it with a nice fat torque curve and a set of 3.91 gears. It'll work quite well.
Sheldon

gzig5

I've got one of those set aside for when the day comes.  I can hardly wait. It came with a 71 vintage bell housing that I think was opened up for the 5.125" bearing retainer.  If I had my druthers, I'd have turned the bearing holder down to fit the bell housing. I also fell into a stock '70 small block bell housing for $50 so I am covered either way if I want to go with a standard A833. I haven't opened it up yet but I was told it's in A OK shape, hopefully will look as good as yours. 
I've got 3.55 gears now and I think I might go with the 3.91s with the OD trans.  On the other hand, if I stroke the 340 to 416 or replace with a 408, I may keep the 3.55s because 450+ lb ft of torque will get the car moving just fine without steep rear gears.  Also need to decide on stock clutch actuation or hydraulic throwout bearing, which is where I am leaning.

Chryco Psycho

I prefer the hyd system but not cheap

gzig5

I've had a bit of luck scrounging the parts and I think I'm only in a bit over $400 for the trans, shifter and rods, bellhousing with fork, TO bearing, flywheel, and usable three-finger clutch.  I need the pistol grip handle, clutch pedal conversion, and either mechanical linkage or hydraulic.  I've got a bit of room to splurge on a hydraulic unit which will be easier to make work with the headers.   If I can borrow a pistol grip to trace a copy of, I have a crazy idea to cut one out of SS bar stock, forge the shape, weld/shape the bolsters and carve the grips from some really nice walnut I have left over from a rifle stock project.  Got to have something to do inside during the winter, right??


edison1970

The only draw back to the od trans was the aluminum case. It was common that the front bearing would get loose and spin causing a loud squeling. You can drill a hole in the front bearing retainer a put a set screw in to ensure that it doesn't do that.

Chryco Psycho

Quote from: gzig5 on October 07, 2019, 05:40:53 PM
I've had a bit of luck scrounging the parts and I think I'm only in a bit over $400 for the trans, shifter and rods, bellhousing with fork, TO bearing, flywheel, and usable three-finger clutch.  I need the pistol grip handle, clutch pedal conversion, and either mechanical linkage or hydraulic.  I've got a bit of room to splurge on a hydraulic unit which will be easier to make work with the headers.   If I can borrow a pistol grip to trace a copy of, I have a crazy idea to cut one out of SS bar stock, forge the shape, weld/shape the bolsters and carve the grips from some really nice walnut I have left over from a rifle stock project.  Got to have something to do inside during the winter, right??

Sounds like a great plan to build your own Pistol Grip !

GoMangoBoys

Since this is the OD tranny, what Hurst shifter do I need?

Chryco Psycho

The normal Hurst E body shifter & rods will work fine , I prefer the 70 T/A shift levers as they have 2 holes & you can move the rods closer to the pivots & shorten the throw


gzig5

Quote from: Chryco Psycho on October 07, 2019, 07:35:15 PM
Quote from: gzig5 on October 07, 2019, 05:40:53 PM
I've had a bit of luck scrounging the parts and I think I'm only in a bit over $400 for the trans, shifter and rods, bellhousing with fork, TO bearing, flywheel, and usable three-finger clutch.  I need the pistol grip handle, clutch pedal conversion, and either mechanical linkage or hydraulic.  I've got a bit of room to splurge on a hydraulic unit which will be easier to make work with the headers.   If I can borrow a pistol grip to trace a copy of, I have a crazy idea to cut one out of SS bar stock, forge the shape, weld/shape the bolsters and carve the grips from some really nice walnut I have left over from a rifle stock project.  Got to have something to do inside during the winter, right??

Sounds like a great plan to build your own Pistol Grip !

I'm a glutton for punishment.

I wasn't aware of the special shifter for the TA.  Happen to have a pic?  Quick search came up empty.  That might be interesting to play with to adjust the feel/throw of the shifter.

RUNCHARGER

The tabs have 2 holes in them for the rods to go into. One hole is in the normal place and the other hole is closer resulting in less throw. It's a great mod.
Sheldon

Chryco Psycho

The shifter is the same , only the shift levers on the side of the trans differ as Sheldon described

dodj

Quote from: Chryco Psycho on October 07, 2019, 09:42:08 PM
The normal Hurst E body shifter & rods will work fine , I prefer the 70 T/A shift levers as they have 2 holes & you can move the rods closer to the pivots & shorten the throw
Quote from: RUNCHARGER on October 08, 2019, 07:08:07 AM
The tabs have 2 holes in them for the rods to go into. One hole is in the normal place and the other hole is closer resulting in less throw. It's a great mod.
Learned something new this morning.  :drinkingbud:
"There is nothing your government can give you that it hasn't already taken from you in the first place" -Winston Churchill