Gearbox or Clutch issues..... |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Gearbox or Clutch issues..... |
falcor75 |
Jun 6 2017, 12:08 AM
Post
#1
|
Senior Member Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia |
I finally got my car driving after four years of restoration and it seems to work ok.
I have noticed a faint whining noise from the transmission, it goes away when coasting so its somehow related to the power transfer from engine to gearbox First I figured it might be my clutch adjustment but now I'm not so sure. I've read alot of threads the last week on clutch and clutch adjustment and mine doesnt follow the commonly agreed recomendations... According to Dr Evils info the clutch should engage in the upper third of the throw, mine engages in the bottom third. (At speed with the clutch depressed the rpms jump up to the road speed in the second inch off the bottom.) My pedal has no rearwards play in it as it seems it should have, If I loosen the double 11 mm nuts to get a bit of play I cant engage first gear without awful grinding noises... My pedal set is overhauled with new bushings. Clutch tube is firmly welded to the firewall Flywheel and clutch and pressure plate are new. Throwout bearing and the other wear parts on the clutch arm are new. Got a new clutch cable on order. (I dont think its likely to be the culprit but I'll change it anyway) I'm kind of out of ideas.... the car drives ok but its not as it should be accoring to all the threads I've read and this annoys me a bit.... I'll have to live with the whining noise this summer. I'll have the gearbox overhauled the coming winter.... |
wndsrfr |
Jun 6 2017, 04:43 AM
Post
#2
|
Senior Member Group: Members Posts: 1,436 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
I finally got my car driving after four years of restoration and it seems to work ok. I have noticed a faint whining noise from the transmission, it goes away when coasting so its somehow related to the power transfer from engine to gearbox First I figured it might be my clutch adjustment but now I'm not so sure. I've read alot of threads the last week on clutch and clutch adjustment and mine doesnt follow the commonly agreed recomendations... According to Dr Evils info the clutch should engage in the upper third of the throw, mine engages in the bottom third. (At speed with the clutch depressed the rpms jump up to the road speed in the second inch off the bottom.) My pedal has no rearwards play in it as it seems it should have, If I loosen the double 11 mm nuts to get a bit of play I cant engage first gear without awful grinding noises... My pedal set is overhauled with new bushings. Clutch tube is firmly welded to the firewall Flywheel and clutch and pressure plate are new. Throwout bearing and the other wear parts on the clutch arm are new. Got a new clutch cable on order. (I dont think its likely to be the culprit but I'll change it anyway) I'm kind of out of ideas.... the car drives ok but its not as it should be accoring to all the threads I've read and this annoys me a bit.... I'll have to live with the whining noise this summer. I'll have the gearbox overhauled the coming winter.... The clutch should begin to engage at the lower third of the throw to allow it to have free play at the top. The whine is common to the pinion gear, no concern unless it drowns out the engine! |
rgalla9146 |
Jun 6 2017, 05:14 AM
Post
#3
|
Advanced Member Group: Members Posts: 4,624 Joined: 23-November 05 From: Paramus NJ Member No.: 5,176 Region Association: None |
Differential
|
ChrisFoley |
Jun 6 2017, 06:41 AM
Post
#4
|
I am Tangerine Racing Group: Members Posts: 7,958 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
My pedal has no rearwards play in it as it seems it should have, If I loosen the double 11 mm nuts to get a bit of play I cant engage first gear without awful grinding noises... There should be no free play in the cable. The free play comes from a coil spring on the cluster which pushes down (not up) on the pedal. If you can't pull up on the pedal to measure the free play you probably have the spring reversed. That said, your whine probably comes from inside the gearbox and isn't directly related to clutch adjustment. |
falcor75 |
Jun 6 2017, 07:14 AM
Post
#5
|
Senior Member Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia |
If I disconnect the clutch cable the spring pulls the pedal to the floor. But when the cable is tensioned so I can shift ok then I cannot pull the pedal back even a quarter of an inch.
|
ChrisFoley |
Jun 6 2017, 07:23 AM
Post
#6
|
I am Tangerine Racing Group: Members Posts: 7,958 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
|
Keith914 |
Jun 6 2017, 07:53 AM
Post
#7
|
Member Group: Members Posts: 248 Joined: 29-April 16 From: Laguna Beach, California 92651 Member No.: 19,948 Region Association: Southern California |
Just experienced this same issue. Solution was to take a dime, grind the edges down a little to fit in and behind the small white plastic plug that forms the fulcrum for the throw out bearing. Or get a new plug. Your's is probably worn down so that the fork is contacting the case before it can release the clutch. Easy solution but requires removing the tranny to get at it (IMG:style_emoticons/default/mad.gif)
|
ChrisFoley |
Jun 6 2017, 08:56 AM
Post
#8
|
I am Tangerine Racing Group: Members Posts: 7,958 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
Either that or put a washer behind the ball on the trans.
This is usually required when the flywheel has been machined beyond a certain point. |
falcor75 |
Jun 6 2017, 10:11 AM
Post
#9
|
Senior Member Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia |
The front of the clutch tube is nice and fixated to the tunnel. Just doublechecked it.
Flywheel is new and so is the little plastic cup in the clutch lever. It just struck me tho that maybe the the new plastic cup doesnt allow the ball to seat properly into it? Not sure what kind of tolerance there is between those parts? |
Keith914 |
Jun 6 2017, 03:27 PM
Post
#10
|
Member Group: Members Posts: 248 Joined: 29-April 16 From: Laguna Beach, California 92651 Member No.: 19,948 Region Association: Southern California |
Given the fulcrum pressure it is unlikely that the ball has not seated.
|
Keith914 |
Jun 6 2017, 03:30 PM
Post
#11
|
Member Group: Members Posts: 248 Joined: 29-April 16 From: Laguna Beach, California 92651 Member No.: 19,948 Region Association: Southern California |
Given the fulcrum pressure it is unlikely that the ball has not seated. Last suggestion - look aat the action of the fork as someone presses the clutch to and from the pedal stop - see if the edge of the case is nstopping it's full travel. Perhaps a long shot!
|
porschetub |
Jun 6 2017, 11:59 PM
Post
#12
|
Advanced Member Group: Members Posts: 4,725 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
The front of the clutch tube is nice and fixated to the tunnel. Just doublechecked it. Flywheel is new and so is the little plastic cup in the clutch lever. It just struck me tho that maybe the the new plastic cup doesnt allow the ball to seat properly into it? Not sure what kind of tolerance there is between those parts? Interesting,my bits ( (IMG:style_emoticons/default/biggrin.gif) ) are all new like yours,posted lately cause the front of my tube is moving and the replys are that it needs to be solid,have you done several adjustments since fitting? |
Keith914 |
Jun 7 2017, 09:08 AM
Post
#13
|
Member Group: Members Posts: 248 Joined: 29-April 16 From: Laguna Beach, California 92651 Member No.: 19,948 Region Association: Southern California |
Yes on Forrest's car - solved problem.
|
forrestkhaag |
Jun 7 2017, 03:10 PM
Post
#14
|
Senior Member Group: Members Posts: 935 Joined: 21-April 14 From: Scottsdale, Arizona Member No.: 17,273 Region Association: Southwest Region |
Kieth is correct on the solution in my case (no pun intended).... (IMG:style_emoticons/default/sunglasses.gif)
My tranny throw out fork ball was sporting a washer against the tranny case but the plastic ball cup bushing was worn to expose the crown of the little fork ball. As Kieth said, we filed down the edges of a dime (thanks to Lemon's intimate knowledge of the cause of grinding and lack of throw-out). Once the dime was inserted in the recess in the fork, we reinstalled the plastic bushing over it to eliminate lateral play, and the KEP Stage II clutch achieved a nice pedal feel and good engagement and disengagement. Sidebar: In addition to removing and installing the tranny three times in three days (IMG:style_emoticons/default/hissyfit.gif) , we took the time to also put a 1/4" aluminum plate in the firewall where the clutch cable enters the tunnel. As Clouseau said, "case soulve-ed" (IMG:style_emoticons/default/beerchug.gif) |
falcor75 |
Jun 7 2017, 10:39 PM
Post
#15
|
Senior Member Group: Members Posts: 1,579 Joined: 22-November 12 From: Sweden Member No.: 15,176 Region Association: Scandinavia |
Hmmm, my 2276 Engine thats in the car now was supplied with a Kennedy Stage 2 clutch/pressureplate so thats a common denominator. My plastic cup was split into two parts so I replaced it with with a new one.
|
Lo-Fi Version | Time is now: 27th September 2024 - 03:23 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |