SimonK

My gearbox was rebuild incorrectly (went in only for the repair of the main shaft bearing). All I did is 10K miles and I developed similar noise as before. Rebuild-er didn't know his stuff which created some more damage.

This is the state of affairs now...

1. Reverse gear wheel (which changes direction) needs new bearing.
2. Small ball from the reverse gear lever fell from damaged spring into the diff housing. Need new spring.

Fine, will fix this.

I have some questions on how to proceed...

My tech says the main noise I have is the small 4 point bearing.

Fine, changing this too!

Then he discovered other things and here things get tricky and expensive..

1. Lever bearing is completely worn out: what are my options here? Can I change just the bearing? Tech says the real problem is bearing in the housing which needs to be changed. What does this mean? Why the real problem? He also says my detent from gbox is helping here...

2. AND THE REAL DILEMMA... What do I do here?

1st and 2nd gears are worn in the synchronization teeth he says. So the shaft needs changing as they are part of it.

My considerations...

My 1st and 2nd gears engage fine when car is warmed up. Perhaps they are a bit notchy when stone cold but when warm, perfect. I was told until cars warm up our gears are always a bit notchy especially with short shifters fitted - myth or fact? When I drive I never grind from 1st to 2nd or 3rd to 2nd.

So the real question is; DO I NEED TO REPLACE THIS SHAFT OR NOT? I presume unless I grind the gears the situation will remain in a status quo and with other things replaced my gearbox should run fine? Also, in another 100K I will probably need to replace main shaft bearings again. Wait until then and hunt for second hand shaft in the meantime? Or do I bite the bullet and get it sorted out 100% now...

Thanks.

SimonK

Here are the photos. Detailed analysis and comments are most welcomed...

SimonK

New info: My current tech says I need to replace the shaft, in order to fix 1st 2nd gear damage. Another tech says it is fixable with a press and can get just the gears for 89$ each? ??? Who is right, who is wrong?

Kevin

All the pictures that you have shown have wear and damaged parts..

The question is do you want to install aftermarket non Porsche gearsets?? No Way is any Porsche gearset $89.00

BTW, the popular upgrade when you have a damaged mainshaft and 1st and 2nd gear is purchase the 997TT shaft and gearset!

The question that you need to ask yourself is>> do you want to have another short term fix with other problems surfacing in 10K miles??

Did you question or force your first rebuilder like you are questioning the results of the 2nd rebuilder?? Many times there is a fine line between saving the customer monies and parts wear that MUST be replaced..

jbossolo

I went through a full tranny rebuild recently and each of my gears was around $1K. Total cost of my rebuild, with a core exchange case, was close to $10K. You get what you pay for. Good luck.

mig.

Wow the quality of the photo's here have really set the high bar for the rest of us!

PasPar2

Its encouraging to see a tranny repair for once. All I hear on these forums is "its broke, git a new one"

Macster

When my 03's transmission was spotted with a leaking selector shaft seal and the discussion started between the dealer and the factory regarding what to do, I asked the techs about the transmission. They told me it shared some parts with the 996 NA car's transmission and was rebuildable.

In the case of my car they estimated the cost to remove the transmission disassemble it and replace the seal and take care of whatever else was found needing attention -- probably not much -- to be in the $5K range.

(As an aside, I said probably not much above, but I do note the replacement transmission's shifting action was much improved over that of the old/original transmission. The original transmission's shifting was a disappointment but the replacement transmission's shifting is like a rifle bolt.)

However, the car was covered by a CPO warranty and the word from the factory was no rebuild but instead to replace the transmission so we waited nearly 2 weeks for one to show up from Germany.

I asked the techs what the cost would have been out of my pocket had I had to pay for the new transmission and the estimate was around $11K.

I note jbossolo reported his transmission rebuild cost $10K so to get a new transmission for $1K or thereabouts seems to make a good argument for replacing rather than rebuilding.

'course, I'd be sure were I faced with this decision to get some current and hard estimates for the new vs. rebuild cost.

jbossolo

The guy that did my tranny is Bill Rader, out of Vegas.

http://www.billradermotorsports.com/

Top notch service, very communicative, reasonable rates. I'd recommend him to anyone.
His pictures and documentation of my job make the pictures on this post look bad by comparison (and those are pretty good!). Just thought I'd share his info, in case anyone needs some work done.
He also drilled and soldered intakes to the case for an oil cooler setup that I later had my indy install.
Running like a babe now.

His shop specializes in motorsports applications, he built the gearboxes that won in the GT class in the 24 hours of Daytona in 2009 and 2011, along with numerous other race wins, and championships in SCCA, World Challenge, Grand Am, and ALMS.

By the way, all my synchros are SS, and were all replaced, my gears are short-ratio, parts are motorsport-spec. Not exactly "OEM", hence, the cost. Had I gone to a full-blown rebuild with all-new parts and a GT3 oil cooler setup (my original plan) the bill would've been in the vicinity of $23K. These cars are not cheap.

"02996ttx50

my trans r&r by a very reputable/known tech here cost 2500 to r&r inspect and replace the thrust/pinion/main bearings and that included machine work to install my wavertrac tbd lsd. it was 600 to R&R the box out and back in the car. so 3100 all in.

even if nothing else fails in the box ( my internals all looked as new )
the bearing WII at some point fail.

simon..fix it all once ( more?? ) right, and be done with it.

jbossolo

Best advise ever.

BRM

Hi Simon,

I can try to answer some of your questions.

I am going to assume that by "lever bearing" he means the bushing that is in the case for the shift levers. Often these wear out because of the long counterweighted levers that are on many of these boxes. These bushings can be replaced, new bushings are available from Porsche as well as the seals that go in after the bushings are changed.

On the 1st and 2nd gear situation, if the dog teeth are really bad yes you will need to replace the gears, but there usually are options. You can replace the main shaft and both gears, or in most cases you should be able to purchase the idler gears with the dog teeth on them separately. Let me know what type your trans is, or the "G" number like "G96/50" for example, and I can get you some part numbers for the individual idler gears.

Feel free to PM me and we can discuss more options.

SimonK

I trust the second rebuilder. First rebuilder was an idiot. But once someone through their incompetence screws you, you question everything. And there is a lot of BS going around about our g-boxes. I worked out they are pretty much bluet proof but the bearings. If you however let an idiot lose in fixing them, you are in trouble.

Kevinmacd

What I understand about the Porsche bearings is they are sealed and greased. Eventually the grease washes out then the bearings go bad because of lack of lube. I have heard of some repair shops removing the bearing seals so the trans oil keeps them lubricated. You usually can find the grease on the bottom of the trans, and at the magnetic pickup located on the bottom.

Kevin

If you track this gearbox, you suck the life out of it.. Strongly recommend fabricating a oil cooler and electric pump. The person that only does 1 to 5 events a season just needs to change the fluid more often. But the dedicated track hound with 12 plus events a year needs to really look at cooling and possibly installing a inline oil filter.