doo doo

The ball runs into indents in the single shaft that moves back and forward for all gears, so yep, a stuck ball or spring will affect all gears in the forward/back (ie 1-2, 2-1, 3-4, 4-3) by letting them slip out of gear (The stick will still move from side to side no probs as this is a separate pair of springs)

if the ball is stuck then yes it shouldn't drop into the box, but best to be absolutely certain first. It might not roll out as it's sitting flat, but using a magnetic tipped tool or similar to try to draw it out should tell you whether it's stuck enough not to drop. I imagine a gearbox shop or nissan will have a replacement ball.

wear will come from difference in wheel speeds while clutches are engaged. 50/50 is a strong enough engagement to break front drive gear on track powered cars.....you'd be spinning both front and back wheels before clutches are slipping when engaged at 50/50. The transfer is not like a viscous coupling which slips before you get traction, but that it grips to create traction for the front. More grip (more hydraulic pressure), less slip.

The preload in the 33's and 34's is hydraulic, and not in the mechanical setup of the system. Mechanically, the transfer case for the 32 and 33 is pretty much identical. Later 32's (april 93 on i think) have a pull type clutch so identical system to 33's. The 33's run about 10% preload in the hydraulic system so running a set preload shouldn't be problematic- the wear in the clutches will come from different wheel speeds front and back and when there's load on the clutches through the hydraulic system. Heat in the system is in the electric pump itself- if it runs for more than 10 seconds in bleed mode it will shut itself off to protect from overheating, but pressure pumped into the system seems to be stored so it doesn't have to keep pumping to maintain pressure. You see this when bleeding the system, when you pull the white fuse and turn the key you hear the pump and watch the pressure gauge, then the pump stops but the pressure remains. When you crack the bleed valve the pressure starts to drop and the pump goes again- if you open the valve enough the pump goes continually, but will shut itself off after 10 seconds to stop itself from overheating as mentioned. Ok, so this to me means you should be able to run a preset hydraulic pressure to the hydraulic actuator to have a continual percentage split. this can be variable- I don't think you'll be able to really accurately determine a percentage, just vary the pressure setting till you get the split that you need. If you get rear wheel spin and you have preload then you will start wearing the clutches more quickly- electronically controlled system would up the pressure in this scenario and there would be less rear wheel spin. Transferring all the electronics to control it would make the most of the system, this is how it was designed after all. A 32 attessa computer won't have preload and is slower in computing torque split (but this enables more oversteer characteristics and is more 'engaging for the driver' IMO) and I assume a 33 attessa computer will be responsible for the preload (and computes info quicker).

So I also thought that helical gears only had one point of contact that is transfered across the gear surface as it rotates, whereas the straight cut has full contact across the gear surface, this being part of the strength-in-design difference- the load on the straight cut is distributed across the whole gear face (better load distribution)whereas the helicals have a concentration of stress on the gear face at the point of loading. Correct me if i'm wrong. I've read that PPG have dealt with issues of gear design, strength and noise and as far as I'm aware it's the dog engagement that needs servicing rather than the straight cut gears. Yet to deal with this issue personally so simply info I've read but not yet experienced.

You'll have to run the same ratio diffs front and rear with the GTR transfer case, having not seen the ford AWD box transfer system I would also check the front diff is going to be turning the correct way too.

The centre clutch is going to wear clutches before it breaks, Mine has 700hp at the fly and you can see the wear in my previous case, it was running RWD before I bought it though, plus that's 15 years of wear. Remember the attessa only transfers power in certain running conditions, not all the time so it's not going to wear like an auto box. Plus the GTR was designed for group A homologation racing and the strength of the stock driveline reflects this. Just remember the diff ratio scenario when running your stock diffs.

GTR diffs are pretty strong, the front is open and the rear is a mechanical LSD, a tighter centre on the rear is probably better for track, you can get LSD centres for the front. The centre clutch system is the only thing activated by attessa hydraulic system and is completely separate to the diffs.

Pics of disassembled transfer case..... you can see the main shaft passes through the hub which the chain drives off. This shaft is one piece from gearbox so you have all-time RWD. you can see the clutch plates act like an wet plate auto box to grip up the hub with the chain drive on it and transfer drive to the front diff. The 3rd shot shows the hydraulic actuation mechanism that pushes the plates together, and I've taken a shot which shows the hub spinning on the shaft. Also chucked in the completely buggered plates that just came out of the case which was previously in the car, you can imagine that putting in new plates has made a fair bit of difference to the drive. If you can swap all the GTR attessa stuff over then that'd give you the best use of the system, the 2 diffs need to be the same ratio (you see it's a 1:1 drive from mainshaft to front drive shaft, GTR diffs are 4.111). Not sure what the cossie setup was like but with my GTiR AWD converted bluebird the diffs were different- the torque split of 60/40 was in the centre diff gearing. Just another thing to check but i'm sure you'll be on to it. You could potentially use a hydraulic handbrake setup to set pressure on the back of the case, you can use different pressures then too. While you sort out putting the rest of the attessa of course. If you need more disassembly pics let me know

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Heard mixed reports about the ikeya shifter, but PPG is the go for gears, why not straight cut? You'll need to get in contact with the dude at PPG and see what he says about using that shifter with his dog box, I'm not sure he'll recommend it. I'm sure I've read that in forums here recently, do a bit of a search. Have got a transfer case teady to pull apart so will be able to get some pics up for you soon. Would love to see some pics of your awd set up and how you're getting the GTR system fitted up, so post em if you've got em.

Hi Jono- standard thrust should be .03-08mm, this is for RB26

Have you tried Ray Hall? He used to do autronic- to set up a whole new map that price sounds in the ball park, cost me around 900 for a complete map set up on both my autronic and motec. He might also be making allowances for any extra little expenses you might run into with autronic, it's very particular about it's senders (although that might have changed with the latest model)

I'll have to dissassemble the case for you first then take some pics, will be overseas for about a month so might not have time till i get back, but i'll try to get some pics in the next week. Not sure about the boxes, heard of a few R33 boxes stripping 3rd, and most boxes have worn 4th gear synchros. Dragging with the attessa is varied, you can burnout in RWD then switch to a preset split with a controller if you've set it up for this, or let the system work itself when you launch. But the track is different- I've read the earlier aussie racing (Gibson motorsport) skylines actually had a half second delay in the transfer off the start line so that the engine would be in it's best power band before the front wheels were engaged- they would spin the rears then suddenly launch forward as AWD engaged. The system is designed for track not strip. Just remember that the rear wheel drive component is completely independent of the front wheel drive component, imagine that the fwd is added to the rwd. I'll get some pics up as they will explain much better.

You might have to do a little guesstimating about what pressure constitutes 70/30 split. As you've read the test mode will produce between 40 and 70 psi, but the system is able to run at 228psi. You have 100% RWD when the system is not engaged at all. If your hydraulic actuation is adjustable then you might have a little experimentation to find your optimum constant torque split value (i would personally start with about 40psi as i don't think the test mode produces full pressure) Would it be helpful to have some pics of a disassembled transfer case all laid out?

still going

The hydraulic system uses power steering fluid. The GTR hydraulic pump is not designed for continual operation, it burns out if left to run. There's also inputs that dictate what pressure it runs via the attessa computer. I'm not really sure what sort of end product you want re cost etc so maybe you could devise a way to keep the clutch pack preloaded either hydraulically or mechanically, you could also devise it in a way that it is adjustable in it's torque split, anything's possible with enough time and money. The clutch packs should take the load, there's a chain drive i the transfer case but it's pretty strong, you'll more likely wear the clutches than break it for your application at a guess.

Get on the net and find 'tune to win' by carrol smith. buy it. Then you might also be interested in 'design to win', and 'engineer to win'. Here's a sample page.

Hey Jase, my mechanic can supply new o-rings (injectors don't usually come with them, always a good idea to use new ones) for a decent price. I'm running 700cc sards and they fit factory, got a bosch 044 external fed by standard in-tank, 540hp atw. Where are you heading power wise? Any fuel mods you do now might as well take into account where you want to end up power wise.

Have you converted your cossie to AWD? The 'centre clutch' is a wet plate setup involving 7 friction plates and 14 drive plates, there's no aftermarket option. It's activated by hydraulic pressure from a pump triggered by the attessa computer in a GTR. Assuming you're running RWD then you don't need to worry about the centre clutch as it is only used in transferring power to the front wheels, and has no involvement with transferring any drive to the rear. Having said that, there's still bearings in the transfer case that the RWD driveshaft passes through- the transfer case has it's own oil pump for these so you need to keep the auto trans fluid topped up in the transfer case.

Some snaps. The 2 outdoors shots show prior to rolling guards front and rear, shocks removed and car lowered to get an idea of how tight it was. The one in the garage is after guards lipped and a little flaring to accommodate the rubber. Ride height is 340 rear and 350 front- hope this helps. (the last photo has the original GTR wheel on the front just in case that's confusing)

Cheers mate, they are indeed. Forgive me if I don't feel too bad........

Should be ok with those tyres, I have the same size wheels but with 265/35/18's and needed to roll the lip up on all the guards. I can get a more indicative pic if you like.

if the wastegate flap is catching on the dump pipe it will be stopping it from opening properly for the mentioned symptoms- you'd then be able to check it is opening properly by taking the actuator rod off and opening it by hand, no need to take the dump off to do this (the dump would need to be on to see if this was a problem). Or you could pressurize the boost line to the gate and see if it opens properly.

Just put 18x 9.5's on my R32 GTR, offset of +12. Tyres are 265/35/18 and had to do a little lipping to fit them under.