Tailshaft bushing removal/install

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jbc426 said:
While chasing a high speed driveline vibration(dead smooth below 98 mph with dramatically increasing resonance above that), I bought the tool to change the bushing in the car without disassembling the transmission. It works like a charm.

However, even with a brand new installed bushing and yoke, the clearance between the two parts is excessive on my stuff. A buddy of mine is making oversized bushings to reduce that clearance, but having the yolk plated and ground to a larger outside diameter is another option.

I've yet to do either so far, as I can't figure out how to measure the inside diameter of the installed bushing with the output shaft in the way.
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jbc426- I replaced my tailshaft bushing recently. the new one I bought felt like it had the same amount of slight play as the used one I had in the car. I am not a mechanic but perhaps the slight play is necessary to avoid seizing as the slip yoke heats and expands...? Maybe a tighter clearance can be run with reduced service life and the factory specs are designed for reliability at standard highway speeds and below...? Curious if anyone out there has customized these parts for tighter clearances- what their using the car for, how they achieved the tighter tolerances and what their longevity experience has been.

66fs- What are you using for a tailshaft bushing and slip yoke in a car that runs 100 mph all day? Is it the stock spec sizes?
 
Stock, never apart for 400,000 miles 1967 Barracuda 273 Commando original 904, it needs going through now though.
 
66fs- I am assuming if your slip yoke and tailshaft bushing were original then they are the same tolerance as the standard spec clearances. (Unless maybe the 904 has different set of clearance specs than the 727)
Again I am not a mechanic but I assume either transmissions have many things that can become tweaked/worn a bit and contribute to a vibration at 100 mph. Heck at that speed it could be something not related to the transmission at all.
 
Fishing68 said:
66fs- I am assuming if your slip yoke and tailshaft bushing were original then they are the same tolerance as the standard spec clearances. (Unless maybe the 904 has different set of clearance specs than the 727)
Again I am not a mechanic but I assume either transmissions have many things that can become tweaked/worn a bit and contribute to a vibration at 100 mph. Heck at that speed it could be something not related to the transmission at all.
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I've had more than a few A bodies, manual 4 speed and automatic 904 and 727, and all were driven at least to 100 mph out west, even a 170 cu in /6. The 273's up to 140 mph, just because. All with untouched trans yokes and bushings. I don't believe wear is as much a factor since we have had cars with a lot of serious miles on them. I doubt that the slip yoke and tailshaft bushing is a problem unless they are aftermarket and not to specifications, Chinese? I always had high speed rated tires balanced very well. The most probable suspect in my mind would be the drive shaft balance, if you can rule out tire balance. But I balance everything, including engine, flywheel, pressure plate, drive shaft, brake rotors and drums.
 
Fishing68 said:
jbc426- I replaced my tailshaft bushing recently. the new one I bought felt like it had the same amount of slight play as the used one I had in the car. I am not a mechanic but perhaps the slight play is necessary to avoid seizing as the slip yoke heats and expands...? Maybe a tighter clearance can be run with reduced service life and the factory specs are designed for reliability at standard highway speeds and below...? Curious if anyone out there has customized these parts for tighter clearances- what their using the car for, how they achieved the tighter tolerances and what their longevity experience has been.

66fs- What are you using for a tailshaft bushing and slip yoke in a car that runs 100 mph all day? Is it the stock spec sizes?
Click to expand...
You’re correct about the heat and tolerances. I learned, these bushings will last forever without wear. As long as some other driveline component hasn’t been damaged, neglected u joints for a long period, etc. Or the transmission output shaft never had severe play. These bushings only need replaced under severe wear neglect. But, there’s always a person that drives too far or too long with wear items needing replaced. But, if you’re going through the hassle of addressing tranny. It’s a good time to replace it regardless. Cheap, piece of mind, etc.
 
Resurrecting an old topic. No resolution from the OP, and I've had the same problem twice.

67 Charger in the Silver State Classic, walked 2 tailshaft bushings out of the housing. One walked in and was rattling free on the shaft, the other walked out the back and pushed out the rear seal, carving it up on the way out. Tail shaft, output shaft, drive shaft (length and diameter), yokes, slip yokes, u-joints, rear end (from 8.75 to 9"), gear ratio, pinion angle were ALL CHANGED between incidents. Only thing in common was sustained speed above 125 mph.

Starting to suspect the sustained pinion climb is putting me out of alignment, even though static is perfect. Also suspecting that the rear bushing is not getting enough lube and may need to run an external restricted line off the pressure port to the rear bushing through the side and into a groove.
 
I don't think NASCAR cars had the problem you are experiencing. I do know they preferred the 64-65 rear trunion set up with a ball bearing instead of the bushing. Did you use the same main housing and tail housing both times?
 
changed the tail housing, but not the main. I'm wondering what the sustained pinion climb is in degrees while pushing that brick at 160. Calvert racing monoleaves.
 
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