GM to Mopar trans swap?!

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BrandunLee

BrandunLee

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About a year ago I snapped the output shaft in my 3 speed Manual 74 duster.(showing off of course) Just recently I've decided that I need to get the beast up and running again for summer cruise nights. My grandpa has an abandoned 84 5 speed manual Skyhawk that he said I can have the trans out of if I can get it to fit. Only condition is its my responsibility to dispose of the car afterward. From what I can find on the internet I can see that GM in the 80s did have a 4 bolt bell housing pattern but is it compatible with my 318? If not can I find a bell housing? I don't want to let a free 5 speed Slip through my hands any help is appreciated!
 
Uh EDIT........You sure this isn't a FRONT WHEEL DRIVE?


There is no doubt the bell pattern will be different. Worse, the input shaft is shorter. I don't know if you could get by with a converter register type pilot (late model Jeep) or not. either modifying the bell or building an adapter plate for the bolt pattern is fairly easy. You'll have to deal with some method to center it, and possibly a different diameter center hole in the bell. "There are" lathes large enough---once I had the center hole in a 340 bell turned out to fit an 18 spline A833

Other problems......if the input is too short, it might be that the clutch splines "land" in an unworkable spot.

"What you really need" is a junk block and crank so you can "jig" it all up and see what you need.

So far as strength? No idea
 
Was that a fully synchronized A-230? That 230 has a generous mainshaft. Where did it let go?
If you can break one of those, the only cure is an a-833.
That 84Buick is a FWD. The last year of the 5 speed was 1980.And it was designed for 110, countem 110 ponypower.
The FWD 5spds were designed for 80 to 90 miserable ponies.

What in the world are you thinking?
 
AJ/FormS said:
Was that a fully synchronized A-230? That 230 has a generous mainshaft. Where did it let go?
If you can break one of those, the only cure is an a-833.
That 84Buick is a FWD. The last year of the 5 speed was 1980.And it was designed for 110, countem 110 ponypower.
The FWD 5spds were designed for 80 to 90 miserable ponies.

What in the world are you thinking?
Click to expand...

Not very knowledgeable about things like that, I know a lot about things I own or like but as far as those old 4cyclinder fwd cars I have no clue. My duster has been in my family for 40 years. Bought by my grandpa and driven by my dad and aunts and uncles in high school. I'm just taking in any option I possibly can because I'm on a tight budget and I really want to get it running again.
 

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I dont see a broken mainshaft there.Or do I? Maybe I do.Is that a broken piece stuck in the yoke? I'd call PassonPerformance and see if he can get you a used shaft, and a new rear bushing, and a yoke. They are a cakewalk to swap out.
Does that tranny have a side cover? That would be the A-230.(the good 3-spd)
Or a top cover?That would be the A745

That looks like shock-loading, as in vicious wheel-hop?
 
Sorry I'm on my phone and it's not loading up the entire reply so I've been getting confused with what your trying to tell me, yes there is a piece in the yoke. It also took a good chunk of of the yoke on the other side I may need another one of those as well
 
AJ/FormS said:
I dont see a broken mainshaft there.Or do I? Maybe I do.Is that a broken piece stuck in the yoke? I'd call PassonPerformance and see if he can get you a used shaft, and a new rear bushing, and a yoke. They are a cakewalk to swap out.
Does that tranny have a side cover? That would be the A-230.(the good 3-spd)
Or a top cover?That would be the A745

That looks like shock-loading, as in vicious wheel-hop?
Click to expand...

Side cover I'm pretty sure haven't seen it in about a year. It doesn't wheel hop I have the traction bars to prevent that
 
You got it.
I learned to call that part a mainshaft, in the tranny shop I once spent years in.
You learned to call the same part a tailshaft.
Same part.
Now, How in the world did you do that?! And with a teener no less. I needs me summathose traction bars. Heck, I need that engine. Bring me that whole entire car, dogonit! Right now!.......................lol
Usually the rear end lets go first .
 
AJ/FormS said:
You got it.
I learned to call that part a mainshaft, in the tranny shop I once spent years in.
You learned to call the same part a tailshaft.
Same part.
Now, How in the world did you do that?! And with a teener no less. I needs me summathose traction bars.
Usually the rear end lets go first .
Click to expand...

Rear end was actually swapped out with a beefier wider rear end out of a police cruiser many years ago, which is why that hasn't give out yet. My first idea was to find a 5 speed out of a 90s 318 Dakota but I can't afford a $1000 transmission right now. Guess I start saving my pennies

And how I did it? I spun the tires one to many times in a row lol
 
I don't follow used parts much, but it "seems to me" as many people that have "gone to" 4 speeds, that some of these 3 speeds should be laying around. You might want to put an ad in our "want ad" section either for parts or complete 3 speed

Also, what year / model we working n?

This a full syncro 3 speed or non syncro into 1st gear? Different gearboxes
 
It's a 1974 and if I had to put it into reverse before 1st to stop it from grinding is that non synchro into first?
 
Re post 15
Maybe yes and maybe no. Could just as easily be a worn out brass ring, or insufficient clutch plate departure, or a warped/faulty clutch disc, or super thin oil.

A side cover is an A230, which is a fully synchronized 3speed.The A230s usually came with a floor-shift.
The cheapo First-Gear-Grinders were usually column shifted.

Im afraid the only sure way to know is for somebody to slide under there and look.
 
Sounds like after the rear end swap your driveshaft is too long that is why it broke the back of the yoke out and the shaft snapped from too much pressure against it.
 
chryslerfat
Did you see the pic of the yoke and the bushing witness marks?

Waitaminute. What happened to the yoke pic? Put it back. You'remaking me look bad. Sorry "fat", that pic is AWOL.

Point is there was lots of room between the end of the bushing and the end of the tube. In fact the seal-boot had left witness marks as well, and I had a moment where I thought the d/s was actually too short.
 
AJ/FormS said:
chryslerfat
Did you see the pic of the yoke and the bushing witness marks?

Waitaminute. What happened to the yoke pic? Put it back. You'remaking me look bad. Sorry "fat", that pic is AWOL.

Point is there was lots of room between the end of the bushing and the end of the tube. In fact the seal-boot had left witness marks as well, and I had a moment where I thought the d/s was actually too short.
Click to expand...

Here it is
 

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AJ/FormS said:
Re post 15
Maybe yes and maybe no. Could just as easily be a worn out brass ring, or insufficient clutch plate departure, or a warped/faulty clutch disc, or super thin oil.

A side cover is an A230, which is a fully synchronized 3speed.The A230s usually came with a floor-shift.
The cheapo First-Gear-Grinders were usually column shifted.

Im afraid the only sure way to know is for somebody to slide under there and look.
Click to expand...

I actually have the whole trans out already
 
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