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> Rookie transmission question, broken first repair
Charles Freeborn
post Apr 27 2022, 12:52 PM
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My transmission is reported to have a broken 1st gear. Not uncommon.
I've taken one pass through the EvilWerks videos (I bought the series) and as best as my memory can provide - the 1st and reverse gears are under the outer cover and not nested inside with the rest of the gear clusters. So, here's the question: If the damage is limited to just those components can one do a diagnosis and repair without cracking open the whole gearbox? Obviously if upon inspection things like synchros, etc are worn I'm all in, but this trans is reported to be sound other than the broken 1st, but yeah, race car...
Any transmission repair advice welcomed.
Thx.
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Charles Freeborn
post May 20 2022, 06:05 PM
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Aaaaand the carnage:
Attached Image
Attached Image
Attached Image
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1st/Rev stack destroyed
So is the 1st /Rev carrier
couple of other sliders,
all the synchros and the ring gear is iffy... not to mention the main case is getting sloppy (main shaft bearing race not secure)

Yeah, gonna cost...


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wndsrfr
post May 21 2022, 10:32 AM
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QUOTE(Charles Freeborn @ May 20 2022, 04:05 PM) *

Aaaaand the carnage:
Attached Image
Attached Image
Attached Image
Attached Image

1st/Rev stack destroyed
So is the 1st /Rev carrier
couple of other sliders,
all the synchros and the ring gear is iffy... not to mention the main case is getting sloppy (main shaft bearing race not secure)

Yeah, gonna cost...

Yep...I've come to the realization that the transmission on a track car with over 200hp has become another consumable....
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Charles Freeborn
post May 22 2022, 04:48 PM
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QUOTE(wndsrfr @ May 21 2022, 09:32 AM) *

QUOTE(Charles Freeborn @ May 20 2022, 04:05 PM) *

Aaaaand the carnage:
Attached Image
Attached Image
Attached Image
Attached Image

1st/Rev stack destroyed
So is the 1st /Rev carrier
couple of other sliders,
all the synchros and the ring gear is iffy... not to mention the main case is getting sloppy (main shaft bearing race not secure)

Yeah, gonna cost...

Yep...I've come to the realization that the transmission on a track car with over 200hp has become another consumable....


Certainly a number of components within..

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Charles Freeborn
post Jun 15 2022, 09:34 AM
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Trans going back together.
The only parts salvageable from the old one are the main shaft, intermediate plate and 3 of the forward gears. The old case, all consumables were done. Even the ring and pinion were trashed. If anyone ever tells you a welded diff is a good idea, turn around and walk away...

We changed the gearing a bit to better suit our road courses 'round here. Going with A, HA,N, S. X. We'll see how that all feels.

Attached Image

Master tech Gordon giving the parts a good talking to:

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The huge advantage of getting help from a pro is he's got pretty much every conceivable shim and spacer on hand. No stopping and waiting to order fiddly little parts.

Attached Image

Shafts are assembled, Pinion depth set, pr-load and RP lash all set. Final assembly tomorrow. Wavetrac is on order and will go in later this summer or over the winter. There's a worldwide shortage of diffs at the moment.

I went from knowing very little about transmissions (I've understood the basic principles, but never torn one down before) to having at least a rudimentary understanding of how a Porsche synchro box works. After I've done it a dozen more times I'll feel comfortable taking one on myself. When you see it done right you begin to understand how precise they actually are. The notion that you can tear it down, measure a couple gaskets and re-assemble isn't true. Maybe if it was less than 10 or even 20 years old, but a 40 plus collection of parts has worn, stretched and distorted to the point that you have to start over with baselining all of the tolerances.

QUOTE(Charles Freeborn @ May 22 2022, 03:48 PM) *

QUOTE(wndsrfr @ May 21 2022, 09:32 AM) *

QUOTE(Charles Freeborn @ May 20 2022, 04:05 PM) *

Aaaaand the carnage:
Attached Image
Attached Image
Attached Image
Attached Image

1st/Rev stack destroyed
So is the 1st /Rev carrier
couple of other sliders,
all the synchros and the ring gear is iffy... not to mention the main case is getting sloppy (main shaft bearing race not secure)

Yeah, gonna cost...

Yep...I've come to the realization that the transmission on a track car with over 200hp has become another consumable....


Certainly a number of components within..

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Posts in this topic
Charles Freeborn   Rookie transmission question   Apr 27 2022, 12:52 PM
914werke   Broken..? First start with issue/symptoms what it ...   Apr 27 2022, 01:57 PM
Tdskip   Popping out of gear I assume?   Apr 27 2022, 02:19 PM
Charles Freeborn   Not sure. Engine and trans were both out when I g...   Apr 27 2022, 04:39 PM
mepstein   It’s false economy to just look at part of the t...   Apr 27 2022, 04:56 PM
brant   It’s false economy to just look at part of the ...   Apr 27 2022, 05:37 PM
stownsen914   It's easy to pop the rear cover off the trans ...   Apr 27 2022, 09:07 PM
Charles Freeborn   It's easy to pop the rear cover off the trans...   Apr 28 2022, 10:41 AM
Charles Freeborn   Well... I tore it apart today with the help of a l...   May 18 2022, 05:40 PM
mepstein   Cool find on the 904 main shaft.   May 18 2022, 05:55 PM
Charles Freeborn   Aaaaand the carnage: 1st/Rev stack destroy...   May 20 2022, 06:05 PM
wndsrfr   Aaaaand the carnage: 1st/Rev stack destro...   May 21 2022, 10:32 AM
Charles Freeborn   Aaaaand the carnage: 1st/Rev stack destr...   May 22 2022, 04:48 PM
Charles Freeborn   Trans going back together. The only parts salvagea...   Jun 15 2022, 09:34 AM
brant   Just advice I wish I had followed the advice myse...   Jun 15 2022, 02:33 PM
Charles Freeborn   Good advice - especially if enduros are in the mix...   Jun 15 2022, 04:03 PM
brant   We didn’t go with a kit We found a good cooler a...   Jun 15 2022, 04:43 PM
Charles Freeborn   Great ideas. Thanks. I imagine a significant benef...   Jun 15 2022, 06:58 PM
stownsen914   You can even use the oil fill and oil drain plugs ...   Jun 17 2022, 04:56 PM
914werke   Wow! Carnage~   Jun 17 2022, 06:08 PM
Charles Freeborn   Wow! Carnage~ Yeah, it was chewed. Sorted ...   Jun 18 2022, 09:56 AM


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