BT - the dog teeth may not be meant to be removed, but they are indeed not part of the gear. You can sharpen the teeth, but the issues you experienced are not because of these teeth.

 

Yes, the teeth are fine. These teeth engage with the sliding hub when the gear is engaged. This is what makes the "grinding" noise when the syncro is bad or when the driver "beats" the syncro.....or one doesn't wait long enough for the new syncro to break-in....or uses the wrong gear oil. They are very tough. They have nothing to do with the actual "syncro" operation. The "cone" that the inside of the syncro sits on is the important part...that's what you need to show us, along with the inside of the respective syncro.

Brendan is correct, these teeth can be removed....but you can't buy new ones, so you would need to find a good set of teeth on a used gear to remove. The old teeth are fairly easy to remove....as long as you have a fairly new carbide end mill and a mill. Some "butchers" use a cut off wheel to cut the engaging teeth in half, but this always cuts into the gear itself....which is what makes them "butchers". Used teeth are tougher to get off of old gears. You need to cut the gear away until the entire cone assembly comes loose...and the gears are fairly hard (understatement) in the area of the splines where the teeth are located. You need a lathe and a really tough cutter/cutters to machine the old gear away.

Mark Anderson saves broken used gears that have good engaging hubs, just for the ability to get replacement parts. We machine them off on a regular basis and swap them. It is time consuming and is very hard on high grade carbide end mills and cutters. A brand new carbide end mill can cut through one or two sets of engaging teeth, but by then, it is fairly dull. They Rockwell at well over 60.

gb

 

WSM presumes many things like that nuts and bolts are replaced when needed.

As mentioned before in this thread I think, '87-95 gearbox uses three different style syncro rings. 1-3 should all be same. If 1 is different than 2 and 3 while R is same its fairly safe to presume 1 and R have been mixed up.

This refers to old style syncro design used in '78-84 boxes. '85-95 is totally different and above info do not apply at all in your case.

Most likely selector mechanism is holding it in and not that ball.

I would not even think about changing those teeth on gears. Way too complicated. You can clean up their ends like others have done.

 

Thanks for the input gents ....

Here i am going to go over my synchro debacle.

According to the "training manual", synchros for:

1,2,3 are dark steel # 928 304 211 12

4,5 are made of brass # 928 304 211 05

Next the manuals says "5th gear is also made of brass but has "different tip angle on the shift teeth and can be identified with the brown paint"

If I assume that Porsche meant to say "reverse gear" instead of "5th" gear then this makes more sense and the part numbers match up !

my restatement:
Reverse is also made of brass but has different tip angle on the shift teeth and can be identified with the brown paint. # 928 304 211 02

+++++++++++++++++++++++++++++++++++++++++++++++++++

Ok here is what I actually found on the transaxle upon disassembly.

4,5,R have the dark synchros

2,3 had the brass synchros

1st had the unusual dark green synchro with same profile as brass

++++++++++++++++++++++++++++++++++++++++++++++++++++++

Safe to say the shop totally mixed these up @?!

BToski

 

Yes, it should be R.

Very safe.

 

With the transaxle out of the car I performed the following test.

Neighbor cranked up car.
I confirmed driveshaft is spinning.
He pushed in clutch.
I noted that driveshaft never stopped spinning, even after several seconds.
I grabbed the driveshaft (carefully) to see if I could stop it. I could but it has alot of inertia. It started spinning up again as soon as I let go.

Of course, if the driveshaft never stops spinning shifting is never going to be proper. This is probably 1/2 of the shifting problems right here.

Update:
Spent all day trying to remove the Torque Tube and the clutch. Of course the bolts holding the front of the torque tube are hidden inside the bell housing , so one must remove the clutch assy to get enough room inside the bell housing to remove the TT. I tried following the WSM but it was making me loopy so I read a few clutch threads and then got under the car and had at it. Right now the clutch assy is loose but feels like it is hung up on the ball stud. Can't seem to release it from below. Tomorrow I will have to remove the air cleaner and see if I can access the ball stud from up above and hopefully I won't have to retighten the PP to break the SOB loose.

Nothing ever easy on this car.

BToski

 

Since I have their email ..... I just sent this to them.

++++++++++++++++++++++++++++++++++++++++++++++++++++++
I have removed the transaxle from the 928.
I have uncovered numerous shortcomings in the repair for which I paid you $2710.00.

To wit:
1) Oil seals not replaced, oil was leaking onto the torque tube.
2) Synchros not installed in correct locations.
3) Shift rod roll pins installed in wrong location.
4) Main nut on input shaft not torqued properly, driven on with a chisel to an insufficient torque. Nut was not replaced but reused.

etc.

You were given an opportunity to remedy the shortcomings of your repair.
You chose not to do so.

If I do not receive the full amount back, in cash, by Friday at 12 noon, I will have no alternative but to:

1) Picket your business:
2) Call Help me Howard
3) Call the Better Business Bureau
4) File a claim in small claims court

Time is of the essence.

Bruce Toski

+++++++++++++++++++++++++++

This should be interestin'

 

Its should.

 

Not much help really for my situation but thought I would attach to this thread.
Thanks again to Jim Morehouse !

Bruce Toski

 

Addendum to post #145:

Took a full day of grueling under the car work but they are out.
Clutch has to come out before one can reach the 17mm 6 point internal bolts at the front of the torque tube.

Lessons I learned: (reference page 30-6b in the WSM)

1) Disconnect battery.

2) Remove lower engine guard. I need a pic. This was not present on the car I am working on, many shields are missing.

3) I did unbolt the clutch slave cylinder, remove the actuator rod and push the assy out of the way a little. I did not remove the bolts holding a bracket to the bottom of the oil pan. Nothing wrong with doing this however.

4) Remove the two 8mm allen head starter bolts to get starter out of the way for when clutch drops straight down. Of course they had been buggered by some previous neanderthal but fortunately they came out without any big problems.

5) Catalytic converter assembly had to be removed. Unscrew the air injector line first (22mm I think). Of course previous neanderthal had been in here and if was obvious that he did not change the 3hole mount gaskets that mount each side to the exhaust manifolds. Also found a stress bracket that had come undone and will need to be re-welded.

6) Remove the lower bell housing (clutch housing) cover but I never loosened any of the main engine to bell housing bolts (mentioned in some other clutch posts). Found this not necessary.

7) Loosen allen head bolts short splined drive shaft. I think this was 8mm. I had driven the driveshaft in the torque tube too far forward ( see previous post) and had to use a large screwdriver to push it back to make room for the splined shaft inside the clutch to move rearward. The driveshaft moved rearward without too much effort. At this point let me mention that I used a flywheel turning tool which saved alot of effort. Only $20 from www.jegs.com for example. (see pic)

8) Remove 10mm ? bolts (two of them) holding throwout bearing guide tube, push unit forward toward the flywheel.

9) "Disengage clutch release lever from ball joint by pressing lever down toward flywheel" I was not able to do this from underneath but possibly this is because I tried to do this step after I had the pressure plate loose. I had to knock the lever off the ball stud from up above, in the engine compartment, after removing the air cleaner assy.

10) Fabricate sheet metal angles. I left this step out.

11) I did drive the three clutch locator pins forward slightly but did not drive them too far toward the front of the engine. (caveats from other posts)

12) I had some slight interference problems dropping my assy down after removing all the PP bolts. (maybe because I skipped step 10)

* Try not to damage the two long TDC pins

* I did not remove any sensors located at the top of the bell housing. No reason to unless one finds himself banging the PP assy back "upwards" for some reason.

IMHO ... if Porsche would have left a few extra mm here and there, steps 10 and 11 would not be necessary at all and everything would drop out without any problem at all.

This concludes the clutch removal, now you can reach the two 17mm 6pt bolts hiding inside the top rear of the clutch housing. Not sure if really necessary but I supported the rear of the engine with a small scissors jack and a 2x4 while doing all this work.

* Shifter was left in place, just removed the leather boot and shift ****. All other items around here were already removed previously while troubleshooting the poor shifting. (checking for clearance, play, etc.)

* I left the support bracket under the rear of the TT but removed the one in front. In the end I had to remove the rear support (safety) bracket because Porsche did not leave a few extra mm to move the entire torque tube forward and then down. No big deal, just four 14mm ? 6point bolts here. More on the torque tube and shift linkage in a later post....

I found heat spots on the PP surface. The disc has some wear left on it but it will be changed as well. Spigot bearing feels good. I did not find any ball socket bushing at the end of the release lever. I have a feeling that it was left out during the last clutch job ... whenever that was. Hopefully "this" is one of the reasons the driveshaft keeps spinning when the clutch is pushed in.

Time will tell.

Bruce Toski

 

Are you sure about this? I haven't yet removed a 5-speed TT, just AT. No problem with AT. Getting ready to do a 5-speed TT and would like to know whether the clutch really has to come down.

 

With correct tools they can be taken out IIRR.

 

I thought so. I have looked at the area when I probed the TT for bearing location and my recollection is there is room for a socket and ratchet to get to the TT bolts.

 

The photo shows some wear on the PP spring fingers under the release bearing check the bearing but the face of the PP is very abused. Also note that because of supercessions sometimes the wrong clutch arm is used with the updated release bearing and guide tube.

 

Well now you are causing me to second guess myself, but I took a look while clutch was still in and decided in a few seconds time that there was no way I was going to get to the top two 17mm bolts.

Here are pics of the now empty clutch bell housing.

Areas circled in green are where the top two bolts are.
Don't forget ! The heads of the bolts .... are INSIDE the bell housing.

Imagine all the shafts and couplings, throwout bearing and pressure plate in the way and ..... well .... if someone gets the top two out without a clutch removal I would say he is a pretty good magician.

But honestly ... I did not sweat that equation too long as I needed to inspect my clutch for drag anyway.

Bruce Toski