Transmission rebuild questions
 

I may need to have a some failing parts replaced in the 6spd in my 08 CS. I am after a better, stronger, and smoother shift. What parts should be upgraded while the box is out and are there really upgrades or just new bits and pieces?

This is my first time delving into this so its AAALLLL new to me.

There are little to no aftermarket parts to upgrade the transmission. Guard has suggested new gears being available but they would be meant to improve track performance with more favorable ratios, not improving smoothness. There are vendors selling aftermarket shifters which may help.

Thanks for the reply. How about other transmissions. Are there any that could fit with adapters?

What is the primary use for your car? You're in MD, it might be worth it to give TPC racing a call and see if they have some information for you.

If you're in a stock car and it doesn't feel smooth it's possible you have some issues with engine/trans mounts. Porsche's aren't known for having weak transmissions unless you're dumping your clutch and launching your car.

The car has never been tracked. Just a typical unmodded daily driver. No drag racing or clutch dumping. I thought a Porsche trans. would be stronger too but after talking to two transmission shops I am getting the "pinion bearing" failing diagnosis. The fluid was changed at 45k and 83k. It's really pathetic how cheap these cars are.

Cheap pathetic cars. Give you a dollar for it.

Seriously, what is prompting you to think the tranny needs resbuilding?

While have changed the fluid a couple of times -- and I hoped used the right flux and put in the right amount -- have you flushed/bled the clutch hydraulic system recently (within two years or less)?

A while back my Boxster's tranny was getting a bit hard to shift smoothly. Also, the clutch was grabby and felt like it wasn't disengaging fully.

Talking to the SM at the dealer and he mentioned clutch fluid bleed. I couldn't remember when it was last done but he looked it up and noted it had been around 2.5 years ago. Had the brake and clutch fluid flushed/bled and the clutch action was 100% better as was the shifting. The brakes felt the same as before. They always feel good.

So my Boxster and its pathetic cheap transmission soldier on with now just over 287K miles on the tranny (and original clutch).

Give you two dollars for your cheap pathetic Cayman.

Settle down Macster. Of course you would give me a dollar for it so it would only cost you 4001.00 to fix the trans with 85k on it.

I paid more so I expect more especially from Porsche that trans problems should not happen at 85k. Should I expect the same as I do a Toyota? If so, then I expect the trans to last at least 187k with almost no problems.

What's prompting me is the spinning sound that recently started under light throttle or deceleration and the box of rocks sounding trans at idle.

When I described to two shops they both said sounds like the pinion bearing is going and that this is typical around this many miles. Typical around 85K?! And since the same bearing goes back in the same problem can be expected again down the road.

Has this been properly diagnosed yet?

Have these shops that diagnosed it actually seen the car, only diagnosed over the phone?

Cheers

Over the phone so far. But, they are all stating the same thing whether is round-gossip or not - that the pinion bearing goes around 80-85k. So far they all also say there are no other options except to put the same bearing back in and expect to do it at another 85k...

I may try to get the clutch fluid changed tomorrow since it has not been done - only the brakes.

If the brakes were flushed the clutch should have been at the same time, they share the same fluid.

i believe john tecce at BGB can rebuild these things.

Mr. Mooty,

Thanks for the referral!

Mr. Wanderer, pinion shaft damage is not uncommon on these cars HOWEVER, it is uncommon on a car where the OP does not track it. That is cause for concern and he has a right to think that a stock street car with no track abuse should at least be able to handle 100K miles on the gearbox.

Herein lies the problem; if you're R&P are eating themselves, then you need a new pinion shaft and therefore you need a new gearbox. The newer style Getrag transmission that is in the 987.2 is much more robust but it will not bolt up to your engine and even then it's not 100% bulletproof. We have never had an R&P fail in our transmission but my gearbox guy is pretty OCD about pinion depth and the setup so we are fortunate to have someone with my level of concern poking around in there.

If the R&P is going, new gears and sliders won't help you, only a new gearbox will or a reman from Porsche. Obviously you're looking for better news but the reality is that we can't source the parts that are breaking so we need a new gearbox. A new pinion shaft and the labor to replace would equate almost to a reman transmission from the dealership. Unfortunately this might be your only option. Sometimes some setups just aren't ideal and I fear that this is one of them.

Thanks for the reply John. Pretty disappointing but it is what it is.

Is the problem there are no better internals for this gearbox? So if I contacted some bearing manufacturers they would not have anything that would work?

I would like to learn how to rebuild the transmission but you eluded that the R&P are not available for purchase yet? Are there better syncros etc etc. to put in?

The plan was to keep the car forever and make it better as the old parts wear out. Having to put the same quality parts back in and get the same result really rubs the wrong way if you know what I mean.

Lots of questions...

^ i am sure b/n guards transmission and BGB, these cars will get the much needed gearboxes and maybe even different gearsets. but in the short time, you are against a tall wall.

These are not weak gearboxes. They are a derivative of a gearbox originally designed for an Audi turbo diesel with a ton of torque. You experience is an outlier and not standard. The shops telling you it happens all the time have something to sell you. Based on our conversations I'm still not convinced it isn't your TO bearing.

That said, there are no strength upgrades for the gearbox. No better synchros. Nada. It is a fruitless search.

Has your gear oil ever been changed? It is way past due. That alone could account for your synchro concerns. If it was changed what was put in? If they used something like Redline, again your synchro issues would be fluid based and no fault of the gearbox itself. Also a bad TO bearing could hinder your shift quality because the clutch may not fully release.

Step 1 at this point is get the gearbox out of the car.