rbahr

I am having a problem shifting into 3 & 4th on the track (IE very high engine RPM's) Feels like the clutch is not fully disengaging. Other symptom I noticed is that very recently trying to start the car, and the starter just spins without engaging the starter ring.

Pretty sure I will be pulling the tranny this weekend, just wondering if folks may have some insight.

Thanks

Ray

AudiOn19s

Weird indeed. It's probably going to have to come apart to know for certain.

I've heard of the ears/ feet (whatever you want to call them) coming breaking off of the throw out bearing as well as I remember seeing a failure of the fork itself that actuates the throw out bearing. I can't see either of those being on 3-4 only though.

But you'd think syncros wouldn't be an issue at high RPM

Wish you the best and hope it's something simple.

rbahr

Thanks Andy,

BTW, the axel worked well, will be replacing both sides with some blues with the tranny work.

More info:

LWFW, fairly new, ~3k miles - pretty much all track, I did have one of the calipers off recently, so the brake fluid container was empty, and I (sadly) did not bleed the Clutch MC, a huge PITA, also the 'normal' trick of shifting into reverse does not produce a lot of grinding - will double check that later...

Ray

Macster

Can't be any less a PITA to drop the tranny vs. bleeding the clutch hydraulic system. For the shifting problem my recommendation would be to bleed the brakes again. Then finish with a proper bleed of the clutch hydraulic system.

If the shifting misbehavior remains and you find no other possible explanations then you can always drop the transmission.

As for the starter problem it reads like when the starter begins to turn the pinion gear is not engaged with the ring gear.

First a bit of background.

There are two types of starters. A one way or over-running clutch driver type. The other type is an inertia or Bendix drive.

The one way/over-running clutch driver type has a starter solenoid that works a lever than slides the pinion gear out on a splined shaft until it engages the ring gear and concurrently closes a switch that then energizes the starter motor. This ensures the starter motor doesn't turn until the pinion is enaged with the ring gear. When the key is released to the run position the solenoid is powered down and a strong spring retracts the pinion gear from its engagement with the ring gear. There is an over-running clutch with the pinion gear that as the engine begins to run on its own this clutch then causes prevents the flywheel from over driving the starter motor as the solenoid level withdraws the pinion gear from its engagement with the flywheel ring gear.

The inertia or Bendix drive type starter has the starter motor begin to turn which causes a threaded sleeve between the shaft and the pinion gear to turn the pinion gear and slide it outward to engage the flywheel ring gear. Once all the way out the threaded sleeve against a stop then locks the pinion gear ot the starter motor shaft and the flywheel is turned and the engine starts. As the engine begins to run under its own power this causes the threaded sleeve to retract the pinion gear and a spring ensures the pinion gear then retracts fully from the flywheel.

Based on the behavior you report I suspect the type of starter is 2nd type, an inertia drive or Bendix starter and the threaded sleeve is not able to move the pinion gear into engagement with the flywheel. The starter motor spins but the engine does not.

Assuming the starter motor shaft is ok not sure if the threaded sleeve and pinion gear are available separately if these are worn or damaged.

If they appear ok one might be able to resurrect the starter by taking the sleeve and pinion gear off the shaft thoroughly cleaning these and assembling with a proper application of the right kind of heavy/high temperature grease if grease is still used in this application.

AudiOn19s

Bleed the slave first for sure given recent events.

I got a super long bleed hose for my bottle. Then lay under the car with feet out the back and head towards the fromt and act like you are going to hug the transmission, I believe I did it through the subframe and then you can get to the bleed valve more easily than you would think. Of course the whole process is blind and done by feel but it's not horrible.

996FLT6

^what he says. I also would check the clutch spring as well. Mike

996FLT6

Does your clutch pedal have any movement rt/left? My clutch spring went south under high loads and on track could not even get into 3rd to 4th or back down my clutch pedal would get stuck halfway in engagement. I would have to literally had to use my foot to push the clutch pedal up and it would release down fully but same vicious cycle again if I had to change gears 3-4. Mike

rbahr

Thanks All,

I have been off on a business trip, so not had time to look at things. I had started to pull stuff apart, the starter is definitely acting like it is not happy which is annoying..., BUT probably should bleed the clutch 1st...

Has anyone ever made an 'extension' that would extend the bleed valve on this part?

Thanks

Ray

rbahr

I bled the slave cylinder and it turns out that it was air or humidity in the slave cylinder line, seems fine now. I also took the starter apart cleaned and lubed everything and that seems fine now also.

Ray

rbahr

An update: Replaced the clutch slave cylinder and the problem went away!

Ray