![]() |
|
|
|
Registered User
|
CV Joint Question???
Hi Pelicans...
Wondering if anyone can shed some light on this for me? (RHD '78 911SC) I have a 'wurring' noise coming from the rear that changes volume (quiet to loud and inconsistant). After reading a few threads, it seems my CV joints may have 'given up' ? I've checked the condition of the boots etc and all seems ok except the right hand inner boot seems to be different to the other 3? (see pics, and this is a right hand drive car if that makes any difference?). I doubt this could be the cause of the noise, but should I change it? Also, am I on the wrong track with thinking the CV's are the problem noise? I checked through the service history of the car and apparently the wheel bearings were changed and the CV joints re-packed in Jan '10. Any assistance is very much appreciated! LEFT ![]() RIGHT - DIFFERENT TO OTHER THREE and seems to cover the joint??? ![]()
__________________
'65 Porsche 912 (painted dash) #451232 '65 Porsche 912 (painted dash) #451425 - 13 days younger '78 Porsche 911SC - Resto garage queen |
||
![]() |
|
Registered
Join Date: Nov 2003
Location: Seattle
Posts: 1,785
|
The left flange/boot is the old style, the kind that wraps over is the newer style with replaceable boot.
FYI, when you change to the newer style, you may or may not need slightly shorter bolts to make up the difference. Noise could be any number of things, but at least that answers the boot question. ![]()
__________________
Rob 1980 SC - 2011 Tiguan - 2018 Tesla M3P |
||
![]() |
|
Registered
Join Date: Feb 2009
Location: San Antonio Texas
Posts: 521
|
'wurring' noise could also be rear wheel bearings. Pretty common wear part, and if your CV joints look fine, then that could be it.
__________________
Chuck ------- 70 & 75 911S 96 993 C4S '10 F-150 |
||
![]() |
|
Registered
|
...especially if the noise changes when making left or right turns...
__________________
Mike 1976 Euro 911 3.2 w/10.3 compression & SSIs 22/29 torsions, 22/22 adjustable sways, Carrera brakes |
||
![]() |
|
Registered
Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
Posts: 9,032
|
FIG,
First, re-torque the CV joint bolts. Be sure to use a calibrated torque wrench. Grab each axle shaft in the middle and move it axially. Is there a difference left-to-right? With the rear wheels off the ground (neutral, parking brake off) grab the tires and wiggle (up-down, left-right) to see if there is movement. Inspect the engine-to-transmission nuts for tight. Inspect the transmission and engine mount hardware for tight. Here is ‘almost everything you need to know about CV joint bolts’. Reconstructing Constant Velocity (CV) Joints It is very long but VERY worthwhile reading. Note: you have too long CV joint bolts here (red arrows). Spec is 1-2 threads protruding with 1½ thread ideal. Always use new Schnorr washers. Re-torque after ~100 miles. ![]() I agree about a ‘turning test’. A freeway cloverleaf interchange is a good test track for one direction. Best, Grady
__________________
ANSWER PRICE LIST (as seen in someone's shop) Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50 |
||
![]() |
|
Registered
Join Date: Oct 2006
Location: MYR S.C.
Posts: 17,321
|
fastenal sells the bolts in 5mm lengths and the washers too. you have to buy a bag of 50, but they are not that much.
i would rather have too long than too short.
__________________
86 930 94kmiles [_ ![]() 88 BMW 325is 200K+ SOLD 03 BMW 330CI 220K:: [_ ![]() 01 suburban 330K:: [_ ![]() RACE CAR:: sold |
||
![]() |
|
![]() |
Registered
|
Thats what she said.
__________________
78’ SC 911 Targa - 3.2SS, PMO 46, M&K 2/2 1 5/8” HEADERS, 123 DIST, PORTERFIELD R4-S PADS, KR75 CAMS, REBEL RACING BUSHINGS, KONI CLASSICS |
||
![]() |
|
Registered
|
Does the noise occur when you put a load on the car, and does it goes away when you let off; is it gear dependent? Were the rear wheel bearings changed (kind of a hassle) or just the front and are you sure the noise is coming from the rear?
__________________
72 911 Although it is done at the moment, it will never be finished. |
||
![]() |
|
Registered User
|
MysticLlama, thanks for the info!
cbush, the bearings were replaced last year so I hope not, but will check. IROC & tobluforu, the noise is inconsistant (happens with steering straight, turning, on and off load... gets louder and softer, in and out?) T77911S, cheers for that! Grady Clay, I re-torqued (to 33lbs), no difference left to right axially, no movement with the wheel test. I havn't checked the tranny to engine yet... will do! Will get some washers. Thanks so much for your effort in replying! I will try the 'freeway turning' test and see if the noise is more evident? My intention is to do an engine drop (I have a hoist in my warehouse) when I'm back from vacation and repair some oil leaks from top/rear of the motor. Of course, I need to remove the axels from the transmission to do so, so I was going to replace the CV's (as they haven't been according to vehicle history?) Hopefully it's the CV's and replacing them will rid me of that noise? If not, at least my CV's will be new... LOL. Thanks everyone for their advice, as usual, can always count on the Pelicans!!!!
__________________
'65 Porsche 912 (painted dash) #451232 '65 Porsche 912 (painted dash) #451425 - 13 days younger '78 Porsche 911SC - Resto garage queen |
||
![]() |
|
Registered User
|
Here is a pic of the RHS inner CV, are those wear marks the cause of my noise do you think?
I've since re-packed and installed the same CV and replaced the bolts (shorter bolts and added shnoor washers). Noise is still there. Unfortunately Pelican dont have CV's in stock ATM (thats why I re-installed), but are trying to source for me. I'll replace all four. ![]()
__________________
'65 Porsche 912 (painted dash) #451232 '65 Porsche 912 (painted dash) #451425 - 13 days younger '78 Porsche 911SC - Resto garage queen Last edited by FIG; 03-21-2011 at 10:57 PM.. |
||
![]() |
|
Registered User
|
CV's replaced = Noise stopped!!!!
FTMFW!
__________________
'65 Porsche 912 (painted dash) #451232 '65 Porsche 912 (painted dash) #451425 - 13 days younger '78 Porsche 911SC - Resto garage queen |
||
![]() |
|
Almost Banned Once
|
Quote:
__________________
- Peter |
||
![]() |
|
![]() |
Registered User
|
CV's were relatively easy... the wheel bearing on the other hand... NOT SO EASY (but completed!)
![]()
__________________
'65 Porsche 912 (painted dash) #451232 '65 Porsche 912 (painted dash) #451425 - 13 days younger '78 Porsche 911SC - Resto garage queen |
||
![]() |
|
Registered
|
subscribe
__________________
Its easier asking dumb questions than fixing dumb mistakes 1974 Porsche 911 Coupe, RSR Project 1976 Porsche 911 Targa, Black 1986 Porsche 911 Carrera, Black 2006 Porsche Cayenne S, Black |
||
![]() |
|