I have been having issues with my front inner CV boots boiling over and exploding within 100-150 miles after installation. First was with a re-built CV boot and after failing we then installed completely new OEM axles, once again, failed within 150 highway miles.

We are now thinking something has failed with the front differential, potentially a bearing or race, thus causing excessive heat. We have been keeping an eye on the diff fluid....levels are good, but we are seeing fluid seeping out of the breather/overflow vent at the top of the diff.

Unfortunately the front diff is not re-buildable nor can we order bearings or races to trouble shoot. The cost for a new front diff is stupid crazy....$6,500ish! I do not see the value in replacing it. Therefore, we are considering removing it altogether.

Has anyone ever perform such surgery on a 997.1? In doing so, is their anything we need to be aware of? Is this really just a simple process of removing the diff and transfer case, etc...as sighted in many 996TT AWD to RWD conversion threads, or is there way more involved with doing so with a 997.1? i.e. electronic sensors dictating the amount of drive to the front wheels, left or right, Traction Control, ABS, etc...

The vehicle is primarily used on road courses. ie: its a "Track RAT" with plates.

Concerns from the shop that might be performing the surgery:
"There is some concern here that the tranny may also have to be changed, once the front driveshaft is removed. If there is no load on the front driveshaft (it would be gone), then we believe the transfer case may be set up to transfer all load to the unload front or rear, which now would be the front, and there would be no power to the rear...."

Thanks in advance for any insight on this matter.
VID997

 

Subscribed.


How about sensors also?

 

Its easy to do on a turbo but according to my guy everyone goes back and puts the AWD back.

 

Hey squat, do you happen to know why this is the case? Also, do you. Know what is involved with this conversion?

 

You disconnect the front driveshaft, you need the part from the gt2 to hold the pieces in the front. The handling changes too much is why

 

^^^ FYI: My vehicle is a heavily modified track machine and is not very usable as a street car. It has one purpose....that being... going around in kinky circles, () which requires one to turn the steering wheel left and right while controlling the throttle....not just left, or holding it straight while keeping the pedal flat.

 

Squat, alignment and suspension wise...everything has been replace with CUP car bits and in 2013 it spent an entire season fine tuning the suspension and alignments with everything based on Ohlins TTX 46 & 36's.

We have already began bench marking set-up with a GT-2RS and feel we are at a very good starting point (if we eliminate the front wheel drive system).

 

Then buy the piece in the front front a GT2 and take out the driveshaft. I forget what its clled

 

Hence, my subscription. I am in the same boat with the cup car parts and monoball bushings.

Great thread! Looking for some answers.

 

My guess is most people don't like the 997TT RWD conversion because in order to do it correctly and see a benefit you need to do more than just rip out the front diff. Ideally you'll want to correct the front geometry by installing GT2/3 uprights which turns into a costly exercise. At the very least, you will need different spring rates with a smaller front to rear split which will necessitate new shocks. This is a perfect excuse for a good set of motorsport coil overs. Finally, a quality Motorsport type LSD like a Guard or a CUP 40/60 LSD is virtually a must because you need an effective way to put the power to the ground now that the front drive is gone. Adjustable front and rear sways are a given but you already have all those goodies. I'm not sure what type of LSD the 997TT comes with but even the LSD that Porsche puts on stock GT2/3s (their track car) is very weak and wears out in a few track days. Most guys rebuild the stock LSDs with Guard guts. I would imagine the stock 997TT LSD will be even weaker as the car is designed as a GT cruiser and not a track car. The biggest obstacle I see is defeating the electronics on the 7TT. I'm not sure if the car would go haywire if the front drive is removed. Maybe not, only one way to find out, right? On the 996TT it's easy. You pull one plug and all you have is ABS. If someone could figure out how to fully defeat the PSM on the 7TT, this would be a killer conversion. About $10K worth of stuff (Suspension and LSD) would get you close to a GT2 for a fraction of the price. I'd love to see it...

 

you can do it easily, and I don't think you need to modify your transmission.
its more fun than AWD specially once the turbo kicks off, but YOU HAVE to consider the LSD


I Had a problem with my front differential earlier this year, and unfortunately I replaced it with a new one and the cost was around $7500 including labor


All the best

 

^^PowderHound,

The car currently has a Guard GT2 PRO 40/60 LSD, AASCO Lightweight Aluminum Fly Wheel, SACHS RACE Clutch, CUP Cables, Numeric Shifter, GMG Semi Solid Tranny Mounts, RSS Semi Solid Engine Mounts, Ohlins TTX Fully Adjustable Coilovers, RSS Adjustable Control Arms (Front), GT3 CUP Adjustable Control Arms (Rear), RSS Adjustable Front Toe/Bump Steer Kit, RSS Adjustable Rear Links, RSS Adjustable Rear Toe Steer Kit, TRG Adjustable Drop Links (Front), Champion Adjustable Sway bars (Front and Rear), Turbo Kraft Monoball Camber Plates (Front & Rear), and I am sure I am forgetting to mention some other bits...

We are more concerned about electronics and what to do with the output drive on the transmission which powers the transfer case for the front wheels.

Thanks,
VID

 

I was more referring to someone trying to do a RWD mod a stock 997TT. You are 90% there. As I said, the hurdle is the electronics. Or is it a hurdle at all? Maybe it will work just fine. I'm not sure if anyone really knows but it seems like it should be easy enough to try. Someone has to know the electronic feedback from the front diff to the ECU. On the 996TT, the front diff is purely mechanical so it's a no brainer. As far as the output drive on the gearbox, there is nothing do do. You just unbolt the cardan shaft, and remover the whole front drive including the axles. You will have to disassemble the front axles to use the stub axles in the uprights.

 

you can disconnect the front drive and go RWD, but you wont be able to get into sport mode.

the right way to do RWD is by changing the front up rights to gt3/gt2 spec. the handling will be night and day.

as far as transmission issues, you wont have any.

if/when my front diff dies i will go rwd as well.

 

you do nothing to the tranny output just leave it there and let it spin. that in no way will impact anything. take the front drive out, cut the axels and make stub axels out of them. for the electronics you can get a proffessional version of duramtric and code out the AWD and make the car think its a gt2. simple. just need the Pro cable, enthusiast cable will not do it.