C4S Coupe power distribution?

Hello everyone - just recently joined the forum as I am looking to get a 996.2 C4S Coupe. The car I�m looking at needs a front CV boot replacement, so that got me thinking into making the RWD conversion. Anyone got any idea in what is the AWD power distribution on these cars? Not that I intend to track the car for real difference in drive, but I assume some of you folks have felt a difference in power delivery by doing the conversion.

You can get a whole new GKN whole front axle assembly for $360 from Rock Auto if you wanna press the easy button and keep it AWD.

Quotes source post: 20152390

I have read that only about 10% of the power goes to the front under normal circumstances. Just finished doing my front axles and refreshing control arms, sway, outer tie rods and dif fluid change - easy jobs and all parts for ~$1200. I have always been of the opinion that AWD is a net benefit and can help a driver like me keep from ending up backwards, in a ditch, on fire! Gaining more skill but there is a learning curve to excel at driving these cars properly IMO..

Ive read that its as little as 5% to the front under normal conditions

IIRR, 5-40% torque to front axle on the Turbo depending on rear wheel slip/spin. The more the rear spins the more power the front gets to try and 'pull you out of a problem. It is a good system. Audi way back when won so many races when the same basic awd system came out on the Quarto Rally car, they got penalized.

Any torque to the front assumes the viscous coupling is still working. At 175k mine was completely useless. Capt Obvious on the Turbo forum swapped in a 997 electromagnetic coupling and a standalone controller. He reports that the front wheels actually do something with that hardware. The OG Audi Quattros used a Torsen center diff.

OK, one of the reasons I wanted to make the conversion is from a nasty vibration while at hwy speeds. One possibility was that one of the CV axles may have been completely blown and needing replacing. My first approach however, was to take off the front wheels and have them balanced. After I did this, all vibration went away, which tells me the CV axles are still good, even with a ripped boot. I think this points me into the replacing CV Boot path, and keeping the car as an AWD car.

Three front axle replacement is an easy DIY job. I found it easiest to remove the front diff and do a service on it. Makes taking the half shafts out much easier. I also thought about goint rwd but even on the track I haven't found a down side to the awd. It's pretty seamless and the weight gain removing g the front diff, Carson shafts and front axle just wasn't a good enough reason.

Wondering if someone who switched out an AWD to RWD Pcar also has a poster of Richard Petty in their garage.

Quotes source post: 20161028

I did hear about this before! but surprisingly, all videos I have seen remove the shaft by removing the front suspension members instead of dropping the front diff. I wanted to take that approach, but have not been able to find instructions on how to do or videos. I did buy the Bentley Service Manual and it also points you in the removing suspension for shafts. Do you have any writeups on it by any chance?

I was i.n the same boat as you. I think most folks don't want to remove the cardon shafts on the rear. But my diff had a leak and I wanted to put all new seals in the diff and remove the oil. Once the rear shaft is out and you remove the torx bolts from the output flanges is whn the tricky work starts. There is a strange bracket on the front. (Item 4) in the diagram. Remove the rear mounting bracket with the diff supported. Remove the nuts on the bracket and pry the diff back. Then remove the bolts holding the diff to the bracket. The unit will just come down. Assuming you loosened the axle nuts prior to starting the axles will just slide out.

Quotes source post: 20160790

I have 04-C4S, ~ 100k miles, nice shape, no accidents, reasonable $, PPI ok, but both front outer CV boots ripped. NBD, I have done lots of CV boots on P-VW cars, deducted some $ for that service (to be DIY). The CAUTION! --- I removed the suspension parts and could not get the axle out of the wheel carrier. Heat, Liquid Wrench, beating with sledge hammer on "old giant nut" did nothing. I finally removed the wheel carrier/axle assembly as a single unit. My 20-ton press could NOT press the axle out (both sides!). I took them to local "foreign car shop", dubious about any P-car, let alone a 996, no deal. No 911s/Boxsters/Caymans, only SUV Pcars there. They were vague about the "job" to begin with, as I went there and inquired about it... They couldn't do it either. I ended up finding used new-to-me axle carriers, 1 in Wash DC, another in Portland, Or-e-gun, just under $1000 for the pair. The one from DC was a lot more expensive than the one from Portland. I bought new axles/CV boot assemblies on Amazon, relatively low cost, don't remember $$. While I-was-in-there, I replaced LCAs, Fork pcs, tie-rods, sway bar drops, cleaned the calipers, new "dustless" pads (Wrong/ They Lie). After all of that, reassemble and get alignment, not much cost at ~$140, compared to some places. I checked their align eqip. and they had the latest Hunter (?) stuff that attaches to the tires, not scratching the rim, (on new tires/refurbed 8/11-18" rims), the neat printout of Before/After and compared everything to Bentley Manual, nice work. Anyway, a simple job turned into a costly nightmare. I got so tired of up/down-dance circus with jackstands/floor jack I bought a Quick Jack. I love that QJ, good product and worth in IMO. I got the 7000TL QJ, a little heavier duty than the 5000, and useable on truck and SUV. I bought the C4S BECAUSE it was AWD and the fabulous fat a$$-end. I wanted to keep it that way. Just my experience, but something tat can happen. FWIW, I keep soaking the old carrier/axle assys, and will sell the wheel carriers one of these days. There may be a shop around here that does electron steel discharge/displacement or something like that, I don't remember what it is called to remove a bolt or something from some other part. Any suggestions appreciated to get these things apart.... YMMV

The shafts seize in the hubs because someone didn't torque it up correctly and the parts develop fretting corrision due to relative movement. I had a rear wheel carrier assembly seize up this way. I ended up drilling out the splined shaft until it was almost gone then punching out the remnants. Of course the destroys the outer CV joint and probably the hub too, which is OK because the fretting corrosion has turned them to junk anyway. At least the wheel carrier can be salvaged. I tried everything to get the CV out of the hub. A 50 ton press, heated it with oxyacetylene until the wheel bearing grease caught on fire, nothing could separate it.

You don�t have to remove the diff or any suspension parts to get the front cv axles out. I did it. Ended up removing the plastic shield behind the diff and the 2 straps.

Quotes source post: 20165534

ahhh that rear end� .yes! Thanks for sharing this experience and what an adventure it took you through.

Quotes source post: 20166135

Do you wanna make a trip to WI and help me out with mine then? haha I had never heard of them coming off so easy. I will have to give it a try. I assume you loosened the axle nut first, to give the axles some lateral movement?

Quotes source post: 20165598

Thanks for the definitive answer. On my "new" reassembly, I put Never-Seize (silver moly paste I think?) on splines, bolts, and nuts. Is this gonna work, not detrimental? YMMV

You're supposed to glue the splines into the hubs with Loctite 680 but no one ever does, makes them a real pain to get apart later. If there is any play at all between spline and hub I will use a ring of loctite 242 to fill the gaps. As long as the hub nut is torqued properly it should be ok. Too many guys just give it a zap with the impact or give it a Popeye arm pull with an 18" breaker bar. The nut takes 460 Nm torque - for me that takes my 3/4" drive T handle with a six foot pipe on it.