Metal Debris in Manual Transmission
04-09-2012, 06:04 PM
#1
Burning Brakes
Thread Starter
Manual Transmission
A bit of recent history.
Since last november after a track day there was a loud sound coming from the torque tube while exiting the track. This lead to me replacing the TT bearings with Constantines Super Bearings along with the forward shift cup bushing and a new rear shift coupler.
After doing this it was very hard to shift into first gear. This lead to inspecting the clutch and intermediate plate and finding that it was time for a clutch replacement which included resurfacing the flywheel, refurbing the intermediate plate and replacing both clutch discs, pressure plate, throwout bearing, plastic bushing for the shift arm and slave cylinder. I also properly adjusted the intermediate plate.
Still hard shifting into first and not as smooth into other gears.
I then had a vibration at 4000 rpm and upon further inspection noticed that the motor mounts were shot and I replaced them.
I drained the oil in the differential in preparation for installing a LSD and found what looks like the reverse lock out spring.
Any and all advise is welcome.
Since last november after a track day there was a loud sound coming from the torque tube while exiting the track. This lead to me replacing the TT bearings with Constantines Super Bearings along with the forward shift cup bushing and a new rear shift coupler.
After doing this it was very hard to shift into first gear. This lead to inspecting the clutch and intermediate plate and finding that it was time for a clutch replacement which included resurfacing the flywheel, refurbing the intermediate plate and replacing both clutch discs, pressure plate, throwout bearing, plastic bushing for the shift arm and slave cylinder. I also properly adjusted the intermediate plate.
Still hard shifting into first and not as smooth into other gears.
I then had a vibration at 4000 rpm and upon further inspection noticed that the motor mounts were shot and I replaced them.
I drained the oil in the differential in preparation for installing a LSD and found what looks like the reverse lock out spring.
Any and all advise is welcome.
Last edited by Mako 928; 09-21-2012 at 10:48 PM.
04-09-2012, 06:26 PM
#2
Sharkaholic
Lifetime Rennlist
Member
Lifetime Rennlist
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Greg it looks almost exactly like what came out of one of my 5sps. Best guess is the bigger pieces are from the reverse lockout spring, and the rest is the usual hairy plug.
04-09-2012, 07:04 PM
#3
Former Sponsor
Not trying to confuse you, but there are actually two portions of each gear, in the transmission. There is the actual "teeth" that turn to create the ratio and there is an "engaging" portion of each gear, that the syncros are associated with.
The two large pieces are from an actual gear, not the "engaging portion" of a gear. I'd need to see them closer and from different angles to tell you what gear they are off of.
The lower right piece looks like an engaging tooth. Again, need to see it closer and from multiple angles to tell you more.
The "rest" looks like chips off of these pieces.
There are no "spring" pieces in there, right now.
Almost all "hard shifting" problems are related to the clutch....especially if it involves more than one gear. The "multiple disc" clutches can be very hard to install and adjust correctly....and even when everything should be right, they still sometimes will not completely release. Even with as many as I've done, over the years, I still have 20% not release properly and I have to redo them. This is not my "favorite" Porsche clutch design!
Even though you just replaced everything, did you confirm that it actually stops spinning? With the car running, in nuetral, you need to actually look at the torque tube, from the rear "clamp bolt" hole and have an assistant push down the clutch. The torque tube shaft should quit spinning in less than two seconds.
The two large pieces are from an actual gear, not the "engaging portion" of a gear. I'd need to see them closer and from different angles to tell you what gear they are off of.
The lower right piece looks like an engaging tooth. Again, need to see it closer and from multiple angles to tell you more.
The "rest" looks like chips off of these pieces.
There are no "spring" pieces in there, right now.
Almost all "hard shifting" problems are related to the clutch....especially if it involves more than one gear. The "multiple disc" clutches can be very hard to install and adjust correctly....and even when everything should be right, they still sometimes will not completely release. Even with as many as I've done, over the years, I still have 20% not release properly and I have to redo them. This is not my "favorite" Porsche clutch design!
Even though you just replaced everything, did you confirm that it actually stops spinning? With the car running, in nuetral, you need to actually look at the torque tube, from the rear "clamp bolt" hole and have an assistant push down the clutch. The torque tube shaft should quit spinning in less than two seconds.
04-09-2012, 08:24 PM
#5
Former Sponsor
04-09-2012, 09:06 PM
#6
Burning Brakes
Thread Starter
Shane:
What the camera did not show on the plug is that they are smaller bits of metal and ( unfortunately) not the usual "graphite" type of oily stuff.
Greg:
Thank you for your reply. Great advise ( as always) on looking at the rear of the torque tube to determine if the clutch is releasing. I wish I knew about this before I drained the oil. But as it is now the transmission is coming apart.
Brutus:
Not quite what I need to hear right now
What the camera did not show on the plug is that they are smaller bits of metal and ( unfortunately) not the usual "graphite" type of oily stuff.
Greg:
Thank you for your reply. Great advise ( as always) on looking at the rear of the torque tube to determine if the clutch is releasing. I wish I knew about this before I drained the oil. But as it is now the transmission is coming apart.
Brutus:
Not quite what I need to hear right now
What ever they are it is NOT a good thing ! Might as well be bits of gold.
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04-10-2012, 12:43 AM
#10
Burning Brakes
Thread Starter
Shane:
Believe me I was hoping for the same.
brutus:
No worries, facts are facts and that is where I am at now. I just need to figure out how to get some more gold to get this done.
Believe me I was hoping for the same.
brutus:
No worries, facts are facts and that is where I am at now. I just need to figure out how to get some more gold to get this done.
04-10-2012, 01:58 AM
#11
Race Director
Do you have the dual disc clutch or the later single disc?
My new racer has a good trans...but I think the clutch might be slightly out of adjustment which makes it very difficult to shift gears.....or it could be I suck at 5 speeds....
No matter what.....figure it out.....parting out your pristine car is NOT an option...not even close...
My new racer has a good trans...but I think the clutch might be slightly out of adjustment which makes it very difficult to shift gears.....or it could be I suck at 5 speeds....
No matter what.....figure it out.....parting out your pristine car is NOT an option...not even close...
04-10-2012, 03:13 PM
#12
Burning Brakes
Thread Starter
Brian:
I have the dual disc set up in my car. I finally understand after all these years of ownership how to properly adjust the damn thing. And the funny thing is that I never had any issues with it when I replaced the clutch seven years ago. Go figure.
I am really feeling defeated at this point not just from having done all of the recent work ( and only having been able to do " shake down" runs since November) but it looks like I will have to be moving soon and not sure where my next location will be so stress is adding up.
That is why I am at the point of "calling it quits" not because I don't still love 928's its just because of current circumstances.
And... when I first replaced the TT bearings thinking that was all that need to be done I was getting ready to do more track days and hopefully mix in a DE with something you would be doing similar to what you guys just did at Thunderhill.
Just one more reason that I am feeling really low at this point.
I have the dual disc set up in my car. I finally understand after all these years of ownership how to properly adjust the damn thing. And the funny thing is that I never had any issues with it when I replaced the clutch seven years ago. Go figure.
I am really feeling defeated at this point not just from having done all of the recent work ( and only having been able to do " shake down" runs since November) but it looks like I will have to be moving soon and not sure where my next location will be so stress is adding up.
That is why I am at the point of "calling it quits" not because I don't still love 928's its just because of current circumstances.
And... when I first replaced the TT bearings thinking that was all that need to be done I was getting ready to do more track days and hopefully mix in a DE with something you would be doing similar to what you guys just did at Thunderhill.
Just one more reason that I am feeling really low at this point.
Last edited by Mako 928; 04-10-2012 at 03:31 PM.
04-10-2012, 03:52 PM
#13
Race Director
Brian:
I have the dual disc set up in my car. I finally understand after all these years of ownership how to properly adjust the damn thing. And the funny thing is that I never had any issues with it when I replaced the clutch seven years ago. Go figure.
I am really feeling defeated at this point not just from having done all of the recent work ( and only having been able to do " shake down" runs since November) but it looks like I will have to be moving soon and not sure where my next location will be so stress is adding up.
That is why I am at the point of "calling it quits" not because I don't still love 928's its just because of current circumstances.
And... when I first replaced the TT bearings thinking that was all that need to be done I was getting ready to do more track days and hopefully mix in a DE with something you would be doing similar to what you guys just did at Thunderhill.
Just one more reason that I am feeling really low at this point.
I have the dual disc set up in my car. I finally understand after all these years of ownership how to properly adjust the damn thing. And the funny thing is that I never had any issues with it when I replaced the clutch seven years ago. Go figure.
I am really feeling defeated at this point not just from having done all of the recent work ( and only having been able to do " shake down" runs since November) but it looks like I will have to be moving soon and not sure where my next location will be so stress is adding up.
That is why I am at the point of "calling it quits" not because I don't still love 928's its just because of current circumstances.
And... when I first replaced the TT bearings thinking that was all that need to be done I was getting ready to do more track days and hopefully mix in a DE with something you would be doing similar to what you guys just did at Thunderhill.
Just one more reason that I am feeling really low at this point.
On the clutch adjustment front....I think I need to adjust the clutch in my new racer.....thinking about going up to Thunderhill this Saturday to check out the NASA race weekend and adjusting the clutch plus the suspension? Interested in going?
04-10-2012, 04:11 PM
#14
Burning Brakes
Thread Starter
After a few pm's with Bill I am feeling that I need to pull the trans regardless of what I decide to do so that is currently on the agenda.
I really appreciate the support and I hope that I will be able to rebuild the trans that I have if not then a local trans. will be in my future. Thanks again.
Let me see where i am at in the next couple of days with this project, I would very much like to meet up with you at Thunderhill and if I can help with the adjustments I would be more than happy to do so.
I really appreciate the support and I hope that I will be able to rebuild the trans that I have if not then a local trans. will be in my future. Thanks again.
Let me see where i am at in the next couple of days with this project, I would very much like to meet up with you at Thunderhill and if I can help with the adjustments I would be more than happy to do so.
04-10-2012, 11:35 PM
#15
Three Wheelin'
Chin up!
I just went through this, a bunch of gear teeth broken. It even looked like more teeth came out than were on the gear in the first place, as though they multiplied and got bigger too.
As bad as trans problems are there's always some 928 friends to help out and get you going.
It's also an opportunity. I'm now in the middle of a huge special trans project but just putting in a freshened stock box could make for an enjoyable car.
The problem is that trans problems happen suddenly, it's not like a worn engine where you get to dream of doing things while it's on the way out.
I just went through this, a bunch of gear teeth broken. It even looked like more teeth came out than were on the gear in the first place, as though they multiplied and got bigger too.
As bad as trans problems are there's always some 928 friends to help out and get you going.
It's also an opportunity. I'm now in the middle of a huge special trans project but just putting in a freshened stock box could make for an enjoyable car.
The problem is that trans problems happen suddenly, it's not like a worn engine where you get to dream of doing things while it's on the way out.