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-   -   Thud from the rear after quick acceleration, now I have issues... (http://forums.pelicanparts.com/porsche-911-technical-forum/1064336-thud-rear-after-quick-acceleration-now-i-have-issues.html)

JohnTucker 06-16-2020 04:35 PM

Quote:

Originally Posted by icarp (Post 10908397)
Maybe the center of the clutch has broken , just an idea
ian

Right?

Question to the OP...if you have someone push in the clutch while the car is in 1st, does that clunking sound stop? (While you're turning the tire back and forth as in the video)

Sdgg91 06-16-2020 05:55 PM

Quote:

Originally Posted by JohnTucker (Post 10908602)
Right?

Question to the OP...if you have someone push in the clutch while the car is in 1st, does that clunking sound stop? (While you're turning the tire back and forth as in the video)


There is no clunking when pushing in the clutch. It feels like it’s in just neutral. I’m going to take it to the pcar mechanic this week and have them give me an opinion on it.


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Sboxin 06-16-2020 08:59 PM

My guess - - ring/pinion gear tooth broke . . . let us know what you find . . . thanks,

Regards,
Roy T

Sdgg91 06-17-2020 10:39 AM

Quote:

Originally Posted by Sboxin (Post 10908837)
My guess - - ring/pinion gear tooth broke . . . let us know what you find . . . thanks,

Regards,
Roy T


I will let you know for sure. What do you think that runs me?

Who wants to play price is right?


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76FJ55 06-17-2020 12:18 PM

With an open diff, and the car up on stands (both rear wheels off the ground) and the transmission in gear, one wheel should freely spin forward while the other spins backward. if this doesn't happen then you either have a limited slip diff, or something inside the diff has failed.

Discseven 06-17-2020 12:45 PM

SD... had rear wheel bearing go and it sounded like muffler hit the ground and was dragging for a brief moment. Then went away.
.

Sdgg91 06-17-2020 03:25 PM

Thud from the rear after quick acceleration, now I have issues...
 
Quote:

Originally Posted by Sboxin (Post 10908837)
My guess - - ring/pinion gear tooth broke . . . let us know what you find . . . thanks,

Regards,
Roy T


I just drove it around the block again. With my limited knowledge I am pretty sure you are right.

If it was a CV issue there would always be noise when the car was moving regardless if it is in gear or not.

THE car steers and drives 100% normal in neutral or in gear with the clutch pushed in.

Right now I only get the clunk noise when the car is in gear and while moving and usually when i give the gas a relatively quick change in velocity. There is no grinding but a very distinctive click and “slack” in the drivetrain when I give the car gas along with a distinctive transfer (light jolt) of power to the wheels. You can really feel the motor transferring power to the wheels and the delay is very distinct(and pretty abrupt). Fortunately the car is surprisingly drive-able as long as I exchange my lead foot for a hair trigger.

SO I think a broken gear tooth or something there about would be my bet.

Stay tuned, I take her in tomorrow to the PCar mechanic.

I thought these cars were supposed to be tough!.. the last thing I thought I would have to deal with is a potential tranny issue.

Sdgg91 06-17-2020 03:28 PM

Quote:

Originally Posted by Discseven (Post 10909753)
SD... had rear wheel bearing go and it sounded like muffler hit the ground and was dragging for a brief moment. Then went away.
.


I’m pretty sure it is not a bearing, that would be best case scenario. I find out tomorrow for sure.

Bamberg96 06-17-2020 07:46 PM

Did you check your rear sway bar mounts? They can tear from the tub and new ones have to be welded back on. Original or aftermarket can be used - I chose factory

Sdgg91 06-18-2020 05:04 AM

Quote:

Originally Posted by Bamberg96 (Post 10910403)
Did you check your rear sway bar mounts? They can tear from the tub and new ones have to be welded back on. Original or aftermarket can be used - I chose factory


Yep, they are solid in place.


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76FJ55 06-18-2020 07:06 AM

When you have the car in gear and on stands the ring ans pinion are not rotating. you said before that when you were rotating one wheel forward through the clunk the wheel on the opposite side was rotation in the opposite direction. this confirms that the ring and pinion are stationary. To me this indicates that the noise is originating after the ring and pinion since it wouldn't be moving in this scenario.

Sdgg91 06-18-2020 07:23 AM

Quote:

Originally Posted by 76FJ55 (Post 10910745)
When you have the car in gear and on stands the ring ans pinion are not rotating. you said before that when you were rotating one wheel forward through the clunk the wheel on the opposite side was rotation in the opposite direction. this confirms that the ring and pinion are stationary. To me this indicates that the noise is originating after the ring and pinion since it wouldn't be moving in this scenario.


So would that make you think it is some type of broken tooth in the differential causing the noise?


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uwanna 06-18-2020 08:08 AM

When you reassembled your CVs are you sure you used the correct orientation of the
inner vs outer ring on the joint cage. Incorrectly done can cause a lockup problem and perhaps your problem. Check out this thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/850548-cv-joint-cage-orientation.html

76FJ55 06-18-2020 08:19 AM

Quote:

Originally Posted by Sdgg91 (Post 10910776)
So would that make you think it is some type of broken tooth in the differential causing the noise?


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IT could be in the differential, but it could also be something in the CV, causing it to bind. If it were me, I'd put the car back up on stands (if it isn't still) and then unbolt one of the CVs at drive flange at the diff. Then with the car in gear i'd rotate the diff from the remaining CV. If the problem persists than unbolt the remaining CV at the trans end. with both CVs disconnected you should be able to turn the flange at the transmission and the opposite flange should spin the the reverse direction. this should take relatively little effort (assuming you have an open diff). if you can turn the flanges with no clunk, then it points to a CV issue. if the clunk still exists with both CVs disconnected the problem is most likely inside the differential.

gomezoneill 06-18-2020 09:35 AM

Most likely the CV joint! In 50 years of working on cars I've never heard of a pinion tooth breaking off.

Mahler9th 06-18-2020 10:07 AM

I have seen plenty of ring and pinion failures... but all have been 915 set ups.

If you haven't yet checked for proper assembly of CV's that might be worthwhile. I have helped quite a few people with CVs in the past few years and have seen plenty of instances where they did not get assembly right... but all realized things were not right before refitting to the car.

Sboxin 06-18-2020 10:37 AM

Quote:

Originally Posted by gomezoneill (Post 10910998)
Most likely the CV joint! In 50 years of working on cars I've never heard of a pinion tooth breaking off.

Sh . . . it happens . . . and tooth slid from diff housing into 5th gear nose and locked up shifter . . .
But, I am more in agreement with others that CV might be the problem or clutch . . . hopefully not the trans . . . in any case I would not drive the car . . .

Regards,
Roy T

http://forums.pelicanparts.com/uploa...1592505084.jpg

gomezoneill 06-18-2020 10:46 AM

Quote:

Originally Posted by Mahler9th (Post 10911046)
I have seen plenty of ring and pinion failures... but all have been 915 set ups.

If you haven't yet checked for proper assembly of CV's that might be worthwhile. I have helped quite a few people with CVs in the past few years and have seen plenty of instances where they did not get assembly right... but all realized things were not right before refitting to the car.

Wow never saw that, No insult intended. I've done hundreds of CV joints and found many put together incorrectly. The op said he had his apart so my first instinct would be to check them.
If it's the r&p I feel for the guy. Mostly 915 this guy's got a G50.

Sdgg91 06-18-2020 11:06 AM

Quote:

Originally Posted by gomezoneill (Post 10911109)
Wow never saw that, No insult intended. I've done hundreds of CV joints and found many put together incorrectly. The op said he had his apart so my first instinct would be to check them.
If it's the r&p I feel for the guy. Mostly 915 this guy's got a G50.


I will get in there this weekend and check the CVs. But everything moved and flexed normally before I put the axle back in on both sides and in my opinion it would be pretty easy to tell if you didn’t reassemble the CV joints correctly after doing the job.

Also wouldn’t the car behave poorly no matter what gear or neutral position the transmission is in? In neutral and moving at any speed the car feels 100% normal - no noises or clunks.

Last scenario: if I am in second going 25 or so coming to a stop I press in the clutch shift to neutral and release the clutch the car makes a pop(or high pitch clunk) type of noise. (It does this in all gears not just second)


Did I say this is my first 911, and I bought it about 3 months ago....


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gomezoneill 06-18-2020 11:20 AM

Quote:

Originally Posted by Sdgg91 (Post 10911149)
I will get in there this weekend and check the CVs. But everything moved and flexed normally before I put the axle back in on both sides and in my opinion it would be pretty easy to tell if you didn’t reassemble the CV joints correctly after doing the job.

Also wouldn’t the car behave poorly no matter what gear or neutral position the transmission is in? In neutral and moving at any speed the car feels 100% normal - no noises or clunks.

Last scenario: if I am in second going 25 or so coming to a stop I press in the clutch shift to neutral and release the clutch the car makes a pop(or high pitch clunk) type of noise. (It does this in all gears not just second)


Did I say this is my first 911, and I bought it about 3 months ago....


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I have no doubt that it's related. The circlip may have popped off that holds the cv to the shaft. I would be pretty confident that it will be simpler than you think.


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