73 spool trans mount/ Drive shaft Blues..

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swingingdart

swingingdart

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Hey, can someone tell me if I'm putting this thing in the correct direction?
I have the crossmember mounted with the open side to the back, but now the bolt holes to the transmission is too far forward (it seems the trans it too far back?)
let me know your guys thoughts!
 
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Also,,,,
Is 1-1/2" of yoke shaft sticking out of transmission too much? This is measured from the back of the U joint yoke to the rubber transmission tip.
 
Oldmanmopar said:
Your drive shaft should measure 48 1/2 inches Center of U-joint to Center of U-joint with a 111 inch wheel base Dart. 108 inch Wheel base Duster/Demon are 45 1/2
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I have had a strange vibration that is somewhat pulsating and increases with speed. In your opinion, could this be the culprit?
 
Okay, measured drive shaft, it is 47.375"- 47.25" CL of U joints. (UGH)
Looks like its time for a new driveshaft. I did some calling and I was asked about my engine size, I know this was being used to know the wall thickness of tube to use.
So now I have another random question, how much HP is safe to put to a stock 318 drive shaft? I know my 318 won't hurt a stock one, but kind of curious incase someday I want a little more power and drop a 360 in that might have 500hp max (Maybe)
Thoughts?
 
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swingingdart said:
Okay, measured drive shaft, it is 47.375"- 47.25" CL of U joints. (UGH)
Looks like its time for a new driveshaft. I did some calling and I was asked about my engine size, I know this was being used to know the wall thickness of tube to use.
So now I have another random question, how much HP is safe top put to a stock style 318 drive shaft? I know my 318 won't hurt a stock one, but kind of curious incase someday I want a little more power and drop a 360 in that might have 500hp max (Maybe)
Thoughts?
Click to expand...

Diameter is more important than wall thickness. If you have to buy a new tube, use at least a 3 inch tube.

And since you are stepping up in tube diameter you might as well step up to 1350 U joints while you‘re at it.

You can buy forged flanges and slip yokes very reasonable today.

Drive shafts are like pushrods. You can’t get them too big.
 
swingingdart said:
View attachment 1716092365
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I like to push the yoke into the transmission and bottom it out. Then pull it back 3/4 inch - 1 inch. Measure center of the yoke eye to the center of the differential yoke eye, that is the length of drive shaft you need. Tell the drive shaft maker how you measured. "Eye center to eye center is XX.XX length."
 
Okay guys, I looks like I'm at 47-5/8 CL U joints. (I measured from back of joints, see pics)
I stabbed it back into the transmission and it felt like a mile went in, I tried to mark a reference point but couldnt seem to get a consistent measurement (user error)
Also, I noticed my slip yoke had a groove in it, just enough to catch the finger nail.
Is this a telling sign of a bigger issue? (I'm pointing to groove)

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I
318willrun said:
I like to push the yoke into the transmission and bottom it out. Then pull it back 3/4 inch - 1 inch. Measure center of the yoke eye to the center of the differential yoke eye, that is the length of drive shaft you need. Tell the drive shaft maker how you measured. "Eye center to eye center is XX.XX length."
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I stabbed it in, backed out 1", its 48.5" just like @Oldmanmopar said. Jeez, there's some smart guys on here!
I guess it's timeto cough up the cash for a new shaft.
I sure appreciate all the help guys! :)
 
Rat Bastid said:
Diameter is more important than wall thickness. If you have to buy a new tube, use at least a 3 inch tube.

And since you are stepping up in tube diameter you might as well step up to 1350 U joints while you‘re at it.

You can buy forged flanges and slip yokes very reasonable today.

Drive shafts are like pushrods. You can’t get them too big.
Click to expand...
The slip yoke I have is about 6" long or so, is this a normal length for an A body?
Since this one has a groove in it, I think it needs replaced. The slip yoke is actually out of a small motorhome, along with the engine block and transmission.
 
What ever u-joint you have on the rear end stay with the same size at the trans. Easier for future replacement, If your going to up grade both ends and change the yoke on the rear go to the GM style u-bolt clamps on the rear . Far better design. 833 4 speed is the same as a 727 slip yoke shaft on the trans. Buy a new slip yoke and save yourself the headache and problems you may acquire with a used one that you don't have knowledge with its history running it in a car yourself.

Call Dan at Brewers transmission. He will hook you up with the correct info and slip yoke.

Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
 
swingingdart said:
The slip yoke I have is about 6" long or so, is this a normal length for an A body?
Since this one has a groove in it, I think it needs replaced. The slip yoke is actually out of a small motorhome, along with the engine block and transmission.
Click to expand...


That’s standard length. Like I said, since you have to buy a new tube (and the yokes) I would upgrade to at least a 3 inch tube and 1350 ujoints. You are already buying a new slip yoke, so why not buy a 1350 sized one? The only extra cost is for the 1350 flange on the pinion.

I am from the school that you can’t get the driveline and ujoints too big.
 
Rat Bastid said:
That’s standard length. Like I said, since you have to buy a new tube (and the yokes) I would upgrade to at least a 3 inch tube and 1350 ujoints. You are already buying a new slip yoke, so why not buy a 1350 sized one? The only extra cost is for the 1350 flange on the pinion.

I am from the school that you can’t get the driveline and ujoints too big.
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I agree, bigger and stronger is always better.
Can I change the Pinion yoke with the 3rd member still in the car? (I've never done that before)
 
If its a small yoke leave it be unless there is a problem with the rear. Why open up another can of worms. The Joints small or big take the same caps. I ran many 4 speed cars with the smaller joints with slicks on and didn't have issues. Unless the pinion angle is incorrect they hols up well. My Duster had the small joints with 29x14.5 slicks 800+ at the crank 5500 converter and never a problem. When we moved the rear forward and I had a shaft made I put GM joints in the rear. You just have to control spring wrap and don't but cheap u-joints in.
 
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