F3ARED

Firstly let me preface this by saying I have spent ages reading information on RL, the other Porsche forum, and GT40s regarding how strong the 016 is or rather isnt. I am well aware that a 951 or S2 box is substantially stronger, or that an 01E is infinitely stronger than both of those options. Unfortunately neither of those transaxles are cost effective in Aus so im faced with either building an 016 and crossing my fingers or going full-send and fitting a Cayman G86/02. I know that the general failure modes to an 016 revolve around the standard diff center and the ability for the case to flex, and that fitting a Quaif centre and a strengthening plate will make it better but not bulletproof - what I would like is feedback from anyone who has actually gone down this route and how it ultimately fared with how you treated it or how much power you fed it. Most info out there seems to center either on kit-car builders dropping some form of V8 in front of it with 315 section tyres, or 944 guys who have thrown one behind an LS swapped track car on semi slick 275s - needless to say my goals for the car [street driven, 400-odd hp 1.8t] arent going to put the same strain on the driveline that one of those examples would but in saying that, id like to be able to drive it hard without sh*tting myself that im going to punch the pinion out the rear of the trans.

So - if youve run one, what were you running infront of it, what tyres were on it, how little or long did it last or how did you treat it?

Any help/advice appreciated.

N-

V2Rocket

I can't comment on the "strengthened" part, though I have certainly seen that info over the years as well.
What i can offer, which is what a lot of folks have experienced, is that even a stock 944 engine and stock size tires can be enough to make the gearbox pop.

In my case, I was about 60 miles into an 80-mile highway drive, around 70mph and not going very hard, when the pinion gear decided it had 2-3 too many teeth and the whole thing locked up.
I had owned the car for 4 years before that and never really beat on the transmission/diff.

KevinGross

I am having a hard time understanding parts of your post. You seem to want to build a robust transmission, but are unwilling for some reason to consider an S2 or Turbo transmission.

I don't know what you mean by a Cayman G86/02. The Cayman never came with a G86 transmission. If you mean a G86.20 transmission as used in the first generation Boxster, plan to spend a whole more lot on purchasing and rebuilding it than you would on a S2 or Turbo box. Or a 968 G44 / 01E transmission.

Also don't know what strengthening plate you are referring to.

I've built hundreds of 016 transmissions (literally), a large portion of them for club racers. The key to transmission survival is:

• Get it built correctly: new parts, pinion depth, ring-to-pinion backlash and carrier bearing preload, on down the line. Get it serviced on a schedule.
• Use a quality lube, and avoid getting advice on this from the Internet. Change it at the right intervals.
• Shift properly, esp heel-toe downshifts. If your style is clutch-side-step Fast and Furious, you will break synchros and everything else in the transmission.
• If you are driving on track, monitor fluid temps and install a cooler if temps rise much above 204F.

Cheers,

F3ARED

When yours failed, how exactly did it fail? Ie were you on throttle and hit a bump or just coasting along?

It's not that I am unwilling to consider an S2 or Turbo box; in fact, that would be the preferred choice. The problem is a lack of availability in Aus and the cost; in 18 months of searching I've come across just one S2 box locally and at 5k AUD for a used box in unknown condition with an open centre it's just not a viable option. By the time and LSD is fitted, box is rebuilt etc we are talking a 10k proposition at which point the G86/20 (I meant Boxster, not sure why I said Cayman) becomes a better option. For the cost of that S2 box I can acquire a new crown wheel and pinion, synchros and a quaif LSD centre for the 016 so I guess what my question should have read was can an 016 be built to be as strong as a standard turbo/S2 box?

The strengthening plate was something Renegade was doing with their V8 conversions; basically a steel or billet plate to go between the two halves of the casing to prevent the case from flexing and or allowing the pinion to move rewards.

Given your experience building them, would a properly built 016 survive 400hp, or be as strong as a standard turbo box?

N-

V2Rocket

Just cruising on a fairly smooth highway/motorway. It had been driving fine for an hour and then crunch crunch pop bang *coffee grinder noises* pull over tow truck.

KevinGross

Any 944 or G86.20 transmission you purchase will, at its age, need to be rebuilt. You'll spend about twice as much rebuilding the G86.20, and you need to find someone with a 50-ton press to remove the gears from the pinion shaft to replace its (notorious) front bearing. I do this work, have the press, and lemme tell you, the G96 / G86.20 transmission is a joyless experience to rebuild for this and other reasons.

The weak point in the base 944 transmission is the pinion gear, specifically the dimensions of its tooth root. The S2 and Turbo transmissions benefit from pinion teeth that are axially longer and radially wider at their root. That said, I have customers who make their base 944 transmissions endure racing because they maintain them, they cool them, and they shift up and down carefully. The base 944 transmission also has thinner gears than the S, S2, and Turbo, and their strength is another factor. Bottom line is that the base 016 will never be as strong as an S2 or Turbo.

Is this the plate that goes between the steel center section and the aluminum end cover, requiring the end cover to be milled down? If so, I don't get it. I recently evicted one of these from an Audi 016 (type AAZ) being used in a GT40 replica. The plate provides no discernible benefit: it does not tie or locate anything mechanically, What's worse, it requires milling the end cover to the point that its dowel pins no longer locate the cover: they float. Since the end cover's 44F bearing locates the back end of the input shaft and its gears, not a good thing.

Sorry to be a buzz kill, good luck with the project!

F3ARED

The reasoning behind the G86.20 was actually pretty simple; its far easier and cheaper to get one of these in Aus than it is any of the Audi 01E/01X variants or the S2/951 box. From what ive read these are pretty strong and can handle a bit of abuse which was what got my attention. Unfortunate that 012 boxes are a dime a dozen here but arent considered strong and info is pretty scarce other than "i blew one up in my Boxster".

Yeah that is the plate, supposedly it stops the case halves from moving or twisting. Not sure how much it does or doesnt do, just seems to be a lot of people doing it.

Haha, better to be a buzz kill than to spend money rebuilding a transmission that just wont be up to the job. Back to the drawing board I think.

Cheers

N-

Tiger03447

Kevin: Is it possible when o/hauling an 016 box to put the later ring and pinion gears in it for added strength and less failure potential? TIA

KevinGross

Yes, there is a ring-and-pinion set that has the same, larger pinion geometry as the 944S. It requires replacing the differential carrier (large aluminum case section) with an updated design that accommodates the wider ring gear. However, the case is ridiculously inexpensive, last time I purchased one. Same final drive ratio.

Tiger03447

Thanks for the reply, Kevin!