|
|
|
|
| Author |
|
|
Large Registered Member
|
Scary Transmission noise....
Yikes!!
A new noise I've never heard before, that is giving me a very sick feeling... Let me preface this by saying this '85 Carrera OEM 915 tranny has never been worked on, and has 136k miles. Clutch, while it has 70k miles since replacement, does not slip. Yes of course it has normal wear of a tranny this old. I don't speed shift, and never slip it in to first without being completely stopped. The noise it makes is not the typical "grind" you would hear when attempting to shift too quickly, or if dumb enough to attempt to shft into first while rolling at 10 mph... When shifting from 1st to 2nd, at ~3k rpm, with clutch still engaged attempting to go to 2nd, I heard a sound that was like a Skill Saw cutting through 3/4" plywood. Very high pitched and high rpm... It did go into gear with only slightly more effort required... I tried again, and the same thing happened... I then avoided 2nd gear for the rest of my commute... As I neared the end of my drive, it started to do the same thing going into 4th gear... After I parked the car, I left the engine running, clutch engaged, and was able to go through all the gears with NO noise or trouble... I still have no problem getting into 1st, and reverse... For now... I know I'm probably running on borrowed time for the clutch, but is my tranny done too?? WTF??? Any thoughts would be appreciated!
__________________
'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
||
11-03-2005, 10:10 AM
|
|
|
Registered
Join Date: Dec 2004
Posts: 225
|
I think the advice you are going to get is to first drain the tranny fluid and look for chicklets on the drain plug. Then proceed from there........
Good luck with this..... NF |
||
|
11-03-2005, 12:11 PM
|
|
|
Large Registered Member
|
test drive update...
whirring noise only occurs when car is moving, and any attempt is made to put into 2nd or 4th gear. Clutch pedal in and car moving, as soon as I move towards 2nd, the whirring starts.. If I hold that position, and slowly stop the car, the whirring slows down and stops when the car stops moving forward. I can put the car in 2nd gear when the car is stopped, and move forward with no clutch slippage... As soon as I attempt to move out of 2nd, the whirring noise starts again, and ceases as soon as the shifter is in nuetral position, moving into 3rd with no noise or problem. Moving into 4th, is a repeat of the problem shifting into 2nd...
__________________
'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
||
|
11-03-2005, 02:41 PM
|
|
|
Registered
Join Date: Dec 2004
Location: Novato, CA
Posts: 3,064
|
How's your clutch adjustment? Could it be that the clutch is just not disengaging fully when you attempt to shift?
ianc
__________________
BMW 135i. Nice. Fast. But no 911... "I will tell you there is a big difference between driving money and driving blood, sweat and tears." - PorscheGuy79 |
||
|
11-03-2005, 03:27 PM
|
|
|
Large Registered Member
|
Not sure.. Will check it...
Question though... The fact that the whirring noises happen only when attempting to go into 2nd or 4th gear while moving? Wouldn't I be experiencing the same condition for shifting into 3rd and 5th?
__________________
'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
||
|
11-03-2005, 03:30 PM
|
|
|
Registered
Join Date: Oct 2005
Location: Redlands, CA
Posts: 225
|
hi!
2nd & 4th (and R) are at the bottom of the shift pattern. I haven't taken apart my shift linkage (yet), but is it possible that the coupler had moved, causing poor engagement? Brad
__________________
'78 911 SC '61 Mercedes 220b '74 Westy 2.0 |
||
|
11-03-2005, 03:38 PM
|
|
|
|
Large Registered Member
|
"
__________________
'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
||
|
11-03-2005, 10:49 PM
|
|
|
Large Registered Member
|
'
__________________
'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
||
|
11-04-2005, 12:19 PM
|
|
|
Registered
Join Date: Sep 2006
Location: Leesburg, VA
Posts: 102
|
Patrick,
Did you ever resolve this? Mine just started the same noise.
__________________
Kirk J. 78 SC euro |
||
|
04-08-2007, 09:02 AM
|
|
|
Registered
Join Date: May 2000
Location: Los Alamos, NM, USA
Posts: 6,044
|
"if dumb enough to attempt to shft into first while rolling at 10 mph...'
If the 1st gear synchro system and clutch are in in good order this is not an issue at all. This myth comes from people's experiences only being with worn out and/or misadjusted 915 transmissions, clutches and shifters. If the transmission is having the problems stated, stop driving the car and address the problems - most likely a worn 2nd gear synchro ring. However, given the described sounds I will predict the 2nd gear synchro hub (dogteeth) and 1st/2nd operating sleeve have been damaged (teeth blunted and rounded off) and will also require replacement. Continuing to drive with the synchro system "clashing" can quickly turn a $400 overhaul parts bill into a $800 to $1000 bill. Good luck. |
||
|
04-08-2007, 09:29 AM
|
|
|
Registered
Join Date: Apr 2006
Location: Newcastle, WA
Posts: 966
|
shifter bushings
__________________
James 1969 911E Slate Grey 1981 911SC Wine Red 1997 911C4S Ocean Blue |
||
|
04-08-2007, 09:33 AM
|
|
|
Registered
Join Date: Nov 2004
Location: Greater Metropolitan Nimrod, Oregun
Posts: 10,040
|
it is unlikely to be the shifter bushings, which would elict a grunch from every gear - altho it is certainly a good idea to replace them and to tune up the entire shifter & coupler
BUT, the high pitched whine sure sounds synchros to me AND, it is generally wise to do whatever Jim says...
__________________
"A man with his priorities so far out of whack doesn't deserve such a fine automobile." - Ferris Bueller's Day Off |
||
|
04-08-2007, 02:01 PM
|
|
|
|
Registered
Join Date: Sep 2006
Location: Leesburg, VA
Posts: 102
|
Yes, I know it needs to come apart in my situation, but figured I would ask if he found the cause since it sounded similar. In my case, whining sound (like it's crying) comes shifting into and out of 3rd and 4th. No grind, just whine - as if a bearing has failed.
__________________
Kirk J. 78 SC euro |
||
|
04-08-2007, 03:28 PM
|
|
|
Registered
Join Date: Apr 2006
Location: Newcastle, WA
Posts: 966
|
There are lots of needle roller bearings in there that are really small. I re-did my 915 last month. There is also a large race for each shaft under the bearing retainer plate. The one for the pinion shaft (1/2) fails often too. John Walker is our local expert and he reassembled both shafts for me. He is on the board and might be able to advise you.
__________________
James 1969 911E Slate Grey 1981 911SC Wine Red 1997 911C4S Ocean Blue |
||
|
04-09-2007, 06:28 AM
|
|
|
Registered
Join Date: Sep 2006
Location: Leesburg, VA
Posts: 102
|
Came across this thread in a search and thought I'd update in case anyone runs across this problem in the future.
In my situation, the whining sound I heard was caused by a loose shift selector fork (the one that mounts to the access panel). Because it was loose it would pivot and make contact with the spinning gear on the pinion shaft. Tightening the 3 nuts that hold the fork solved the problem.
__________________
Kirk J. 78 SC euro |
||
|
07-24-2007, 08:36 PM
|
|
