'67 Barracuda Fastback S 383 4 speed rear end issue?

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67fish383S

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New owner here, and my questions are piling up. My noob status is quickly becoming apparent, so sorry for that. I think I may have an intermittent problem with the 3.23 sure grip rear end, but I'm not sure, so...

According to the previous owner, the car has a new McLeod diaphragm style clutch & throw-out bearing, flywheel was resurfaced, clutch linkage was rebuilt, and shifter was upgraded to a Hurst Competition plus conversion from the original inland shifter mechanism, so I'm assuming it is not a clutch issue. I am not aware of any work done to the rear end, so I'm assuming that is original and 53 years old. Here is the symptom as best I can describe it...

It happened a couple of times on the test drive, and I assumed it was just my inexperience with driving it, but now I am questioning that. When starting from a dead stop in first gear, I get what I can only describe as a severe shuddering of the rear end. It feels like the tires are wanting to spin, but they won't let go and the whole car shakes until i disengage the clutch, give it more throttle, and slowly re-engage the clutch (sometimes a few times) until I get it going smoothly.

After buying the car and getting a better feel for driving it (I have had it a week), I went a while without a problem, but now it seems to be happening again intermittently. I swear the clutch action feels different when it happens, and I don't think it's me. The clutch action feels 'normal' most of the time and I don't have issues up shifting or down shifting gears 2, 3, or 4. Does this sound like a problem with the drive train or the driver? I have as of yet not intentionally tried to do a burn out. I have been in 'baby it' mode for the most part up to this point. Any sage advice to an admitted greenhorn would be most appreciated. Thanks
 
Does this happen when pulling out around a turn or going straight? Around a turn it could be the clutches in the sure grip which is normal. Just let the clutch fly and drift the turn you won't hear any noises.

You mentioned it has a diaphragm clutch. Is the large overcenter spring still on the peddle assembly under the dash? It shouldn't be. A diaphragm plate does not need a over center spring. It will be noticable on the engagement on a RPM shift or pulling out .
 
New owner here, and my questions are piling up. My noob status is quickly becoming apparent, so sorry for that. I think I may have an intermittent problem with the 3.23 sure grip rear end, but I'm not sure, so...

According to the previous owner, the car has a new McLeod diaphragm style clutch & throw-out bearing, flywheel was resurfaced, clutch linkage was rebuilt, and shifter was upgraded to a Hurst Competition plus conversion from the original inland shifter mechanism, so I'm assuming it is not a clutch issue. I am not aware of any work done to the rear end, so I'm assuming that is original and 53 years old. Here is the symptom as best I can describe it...

It happened a couple of times on the test drive, and I assumed it was just my inexperience with driving it, but now I am questioning that. When starting from a dead stop in first gear, I get what I can only describe as a severe shuddering of the rear end. It feels like the tires are wanting to spin, but they won't let go and the whole car shakes until i disengage the clutch, give it more throttle, and slowly re-engage the clutch (sometimes a few times) until I get it going smoothly.

After buying the car and getting a better feel for driving it (I have had it a week), I went a while without a problem, but now it seems to be happening again intermittently. I swear the clutch action feels different when it happens, and I don't think it's me. The clutch action feels 'normal' most of the time and I don't have issues up shifting or down shifting gears 2, 3, or 4. Does this sound like a problem with the drive train or the driver? I have as of yet not intentionally tried to do a burn out. I have been in 'baby it' mode for the most part up to this point. Any sage advice to an admitted greenhorn would be most appreciated. Thanks
Sounds to me as if the clutch is giving you the problem. You could elevate the rear of the car and do some basic investigation.
 
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Does this happen when pulling out around a turn or going straight? Around a turn it could be the clutches in the sure grip which is normal. Just let the clutch fly and drift the turn you won't hear any noises.

You mentioned it has a diaphragm clutch. Is the large overcenter spring still on the peddle assembly under the dash? It shouldn't be. A diaphragm plate does not need a over center spring. It will be noticable on the engagement on a RPM shift or pulling out .
Now that you mention it, it may be happening more on turns, but I would swear it has also happened on a straight away. I will pay more attention going forward and try what you suggested. I looked at the clutch pedal and could not see anything that looks like a spring on the mechanism.
 
Now that you mention it, it may be happening more on turns, but I would swear it has also happened on a straight away. I will pay more attention going forward and try what you suggested. I looked at the clutch pedal and could not see anything that looks like a spring on the mechanism.
Well, I would definitely crawl under there sooner than later or have the previous owner informed of your concerns before some nightmare ruins the car and your day. That can only get worse.
 
Here is a picture showing its location. Its a good size spring. You have to get under the column and look up for it.

upload_2020-3-23_11-32-53-png.png
 
New owner here, and my questions are piling up. My noob status is quickly becoming apparent, so sorry for that. I think I may have an intermittent problem with the 3.23 sure grip rear end, but I'm not sure, so...

According to the previous owner, the car has a new McLeod diaphragm style clutch & throw-out bearing, flywheel was resurfaced, clutch linkage was rebuilt, and shifter was upgraded to a Hurst Competition plus conversion from the original inland shifter mechanism, so I'm assuming it is not a clutch issue. I am not aware of any work done to the rear end, so I'm assuming that is original and 53 years old. Here is the symptom as best I can describe it...

It happened a couple of times on the test drive, and I assumed it was just my inexperience with driving it, but now I am questioning that. When starting from a dead stop in first gear, I get what I can only describe as a severe shuddering of the rear end. It feels like the tires are wanting to spin, but they won't let go and the whole car shakes until i disengage the clutch, give it more throttle, and slowly re-engage the clutch (sometimes a few times) until I get it going smoothly.

After buying the car and getting a better feel for driving it (I have had it a week), I went a while without a problem, but now it seems to be happening again intermittently. I swear the clutch action feels different when it happens, and I don't think it's me. The clutch action feels 'normal' most of the time and I don't have issues up shifting or down shifting gears 2, 3, or 4. Does this sound like a problem with the drive train or the driver? I have as of yet not intentionally tried to do a burn out. I have been in 'baby it' mode for the most part up to this point. Any sage advice to an admitted greenhorn would be most appreciated. Thanks
There's a thread on here somewhere about clutch adjustment that you may want to visit. Type in "clutch adjustment question" in the search box
 
it can blend in pretty well, here's a pic of a B body setup for reference
View attachment 1715553555
Here is a picture showing its location. Its a good size spring. You have to get under the column and look up for it.

View attachment 1715553553
Thanks to you both for the visuals. It definitely does not have the spring installed. I can see the attachment point where the spring would go. I did note however that the spring attachment point is making contact (rubbing against) it's neighbor to the left, the parking brake bracket. It doesn't look like the interaction would ever be enough to block movement of the clutch pedal, but there are definitely metal filings on the outer surface of the clutch spring attachment point.
 
you might be getting oil on the clutch and not slipping when hot just grabbing
 
Verify that the motor mount bolts, motor to bell housing to transmission bolts transmission mount bolts are all preset and tight.
 
Something very simple to try... get a bottle of Fords friction modifier and pour it in the differential. If they've never changed the formula of this stuff, don't spill a drop! Its smell registers right there with a dead skunk. Vapors from the empty bottle would clear the break room.
 
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Something very simple to try... get a bottle of Fords friction modifier and pour it in the differential. If they've never changed the formula of this stuff, don't spill a drop! Its smell registers right there with a dead skunk. Vapors from the empty bottle would clear the break room.
:rofl:
 
Turns out that my issue was 100% caused by the clutch pedal spring attachment point interacting with the parking brake bracket. It took quite a bit of messing around, but once I got the clutch pedal moving completely freely, it drives like a different car. Not a fan of how much side-to-side play there is in the pedal mechanism and I expect I will be messing with it regularly unless/until I replace it or rebuild it. Anyone have experience with that? Are there suitable replacements available and/or can they be successfully rebuilt?
 
drawing shows there are renewable bushings. Finding new could be a challenge. No guessing if they are all the same size. The bushings at brake pedal weren't. Good luck
 
drawing shows there are renewable bushings. Finding new could be a challenge. No guessing if they are all the same size. The bushings at brake pedal weren't. Good luck
There is a FABO member that makes Replacement bronze bushings for the pedal assemblies. I put a set in mine, a year ago, they are nice pieces.
I will try to find his name,,,,
 
New owner here, and my questions are piling up. My noob status is quickly becoming apparent, so sorry for that. I think I may have an intermittent problem with the 3.23 sure grip rear end, but I'm not sure, so...

According to the previous owner, the car has a new McLeod diaphragm style clutch & throw-out bearing, flywheel was resurfaced, clutch linkage was rebuilt, and shifter was upgraded to a Hurst Competition plus conversion from the original inland shifter mechanism, so I'm assuming it is not a clutch issue. I am not aware of any work done to the rear end, so I'm assuming that is original and 53 years old. Here is the symptom as best I can describe it...

It happened a couple of times on the test drive, and I assumed it was just my inexperience with driving it, but now I am questioning that. When starting from a dead stop in first gear, I get what I can only describe as a severe shuddering of the rear end. It feels like the tires are wanting to spin, but they won't let go and the whole car shakes until i disengage the clutch, give it more throttle, and slowly re-engage the clutch (sometimes a few times) until I get it going smoothly.

After buying the car and getting a better feel for driving it (I have had it a week), I went a while without a problem, but now it seems to be happening again intermittently. I swear the clutch action feels different when it happens, and I don't think it's me. The clutch action feels 'normal' most of the time and I don't have issues up shifting or down shifting gears 2, 3, or 4. Does this sound like a problem with the drive train or the driver? I have as of yet not intentionally tried to do a burn out. I have been in 'baby it' mode for the most part up to this point. Any sage advice to an admitted greenhorn would be most appreciated. Thanks

Here ya go
 
Don't know why your clutch pedal would move, is the c-clip missing from the shaft? It's on the right or opposite side of the pedal.
 
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