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Clunk when downshifting

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Old Aug 31, 2016 | 01:31 PM
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Default Clunk when downshifting

I have a 69 bb 4 speed coupe and when downshifting to slow the car I sometimes get a clunk coming from the underside of the car. Also, when in third gear and decelerating, the car sometimes pops out of gear.

My question is are these issues related? The car is currently in the shop to have these along with a few other minor issues inspected. I was told the drive shaft was out of alignment so they are sending it off to be repaired. The u-joints checked out ok. Do I have a transmission problem? I was also told when they removed the yoke from the transmission after pulling the drive shaft that it had some wear to the end that connects to the transmission. They said it was chewed up.

Should I have the transmission pulled and rebuilt?
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Old Aug 31, 2016 | 02:02 PM
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From: palm springs ca
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When you let off and it pops out of gear it (in most cases) are the syncros. The gear has part of the syncro on it and there is a syncro clutch which is the shift slider. That could be out of adjustment (linkage) but when a gear grinds it is the syncro part of it grinding against the clutch ring in the trans.
The clunk can be your differential rubber snubber. If the yoke is bad along with popping out of gear, a good trans guy can cut thru the chase by checking the linkage, then taking the side cover off the trans.
A few bad shifts under power can dull the dog house parts of the syncro that is on the gear and clutch ring. the brass part of the syncro only slows the gear down to engage it.

Dom
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Old Aug 31, 2016 | 04:21 PM
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Originally Posted by Bhebert449
...The car is currently in the shop...Should I have the transmission pulled and rebuilt?...
What does the shop recommend?

Last edited by Easy Mike; Aug 31, 2016 at 04:21 PM.
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Old Aug 31, 2016 | 06:41 PM
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Originally Posted by Easy Mike
What does the shop recommend?
they don't work on transmissions so they recommend I take to a transmission shop. I think I'll just live with it for a while. It' does not affect the drivability of the car much.
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