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Hi All,

After breaking a few different 5 speeds now, I'm taking the route of fitting an STi 6 speed into my my00 turbo, and to hell with the additional weight and gear change.

I've never like the 4th to 5th step on the Euro fugly STi's I've worked on, so sourced a JDM version which has better spaced 5th and 6th (IMHO - time will tell ), especially for track work.

The problem with fitting the JDM box, is that it uses different drop gears to Euro ones (1:1 instead of 1.1:1?), meaning you also need to change the rear diff crown wheel/pinion to a 3.9 item. While doing this it would be rude not to fit a plated diff too

Many thanks to David at API for his help and patience...after loads of emails and advice I received the following (received in double quick time!);

(David - you want your dog back )



It is very f*cking heavy.....I can lift a 5MT OK, but gave myself a hernia moving this one....

A small amount of transit damage, easily fixed - especially as I'll need to remove the edges from this bracket anyway to fit my APS tmic intercooler (only big remaining question mark - will it still fit? Otherwise I'll be raising the bonnet a bit....). Question - is that the correct location for that breather pipe?;



In addition I sourced a quickshift linkage and gearknob from Rallispec (no photos yet). I also sent the prop (chucked on the pallet at the last minute by David!) away to have 60mm removed from it's length (thanks JB & T-uk!) - cost me ~60 pounds with balancing (at mates rates), I'll do photos before fitting.

Richard

 

Next up is replacing the open diff that came with the 3.9 casing (from a Sport?) with the STi V3 plated diff (last of the r160's). This was not as simple as I first imagined......

Open diff;



With new plated;



Different view of both side by side - note oil dispersers;



First problems came removing the bearing carrier covers - they're alloy and have reacted with the bolts causing oxide corrosion......snapped first bolt off, soaked the rest and they all freed up OK. Lots of cleanup work afterwards though;



After this, things got real interesting - when swapping the crown wheel you realise that these 8 bolts have a lot of work to do....it's at times like this I wish I'd given the job to professionals With luck, I torqued the bolts up correctly at 75lb/ft each, along with thread lock. But....

The b*stard assembly would not fit back into the casing - the plated diff doesn't have the cut away in the middle. I ended up taking it to a proper workshop and press removing one of the bearings. Still didn't fit. Removed the crown wheel again (30 minutes just to clean the bolts of thread lock....). Still didn't fit. Refitted crown wheel and ground two of the carrier threads down inside the case (can't really see it in the above, but each thread is raised slightly to ensure it's oil tight). Hey Presto! Refit bearing and carriers and do some measuring - play is correct between pinion & crown wheel, but there's not enough play on one of the carrier bearings. Subaru CH don't have stock, and I go home The 2 threads I removed metal from will need to be sealed with silicon on re-assembly.

A selection of spacers arrive next week - I reckon I only need .2mm. If all OK, then the box/diff will go in next weekend. I'm taking the opportunity to also fit all the Powerflex bushing I have for the rear end (all 16 of them....been afraid to change them since buying 18 months ago ), so it's going to be a day long job I guess.

Another question - I saw David mention removing the lower two bolts before mating gearbox to engine. I don't really fancy doing this, what do people think about opening out the holes on the gearbox to give additional free play (at least like that I can still refit nuts with special washers). Would this provide enough room to mate it together? Worse case, I'll remove engine mounts and twist the bugger

Richard

 

Good work fella. Taking a diff apart and reassembling sounds like a professional job for sure to me, but there again so does filling the petrol tank

 

We did not remove the two lower bolts, it was a squeeze, engine needed tipping backwards. Make sure you grind off the lifting eye if there is one as it can foul the floor of the car. The breather looks correctly located.

 

Thanks John

Richard

 

Richard, We endeavour to send a free dog with every order over £1000.00 as a matter of good business public relations. However, sometimes we run short and have to substitute a cat or in times of real hardship a rabbit.......

Please feel free to keep the dog and ENJOY as they say in the States.

David API

PS Thanks for the plug Richard

 

Remind me never to order a dog box from you David.

 

a draper 150 kg floor transmission jack , made life much easier when fitting john's box. I think this is why we got away with leaving the lower studs in the housing.

will see how you get on with the rear diff. I have sourced a 3.9 sport diff , ready for 5mt failure or if a 6 speed comes up at the right money but your probably right doing the job right, first time with a plated version.

 

the lifiting eye unbolts...

the breather is correct..

and its more for allignment I remove the studs and replace them with bolts..

David

 

Cheers David, sounds sensible.

Richard

 

Nice one dowser, interesting read

 

Just as a note before I throw the packet away:

Clutch release spring needed is 30546AA060

 

Thanks John. How different is it from the 5 speed one then? Is this the spring attaching to the hydraulic assembly?

Cheers, Richard

 

It is shorter, it goes from the clutch release fork to a tie point.

 

not needed.. 5 speed works.. if you use a combination of bits...

the only parts I bought were the box, and a s/hand linkage...

all the rest were hit with a hammer or modified...

 

It only costs c.£1 and is the correct item though.

Farmyard Performance (T-uk) modified my 5 speed one and I used that for a few weeks without event.

 

think i just hammered the bracket.. I was pissed iirc.

 

LOL @ David. The rear lifting eye unbolts, front needs to be removed...or hammered flat

Received the bearing carrier spacers today - as far as I can tell, .2mm is good and .25 too much.......but do you know how hard it is to measure backlash with a ruler butted up against the casing while I turn the crown with pinion locked? It's more than 0, and less than .3... Will do it properly (back to the proper garage....with proper tools) tomorrow night....in between tuning a WRX and Evo.....

Interesting to note that Subaru manual states that a plated diff requires threadlock on the bearing carrier bolts. Given that I'll be running somewhere over 170% of stock torque through this assembly, should I also raise the torque settings of the bolts themselves? I'd appreciate replies from people who understand this stuff (aluminium carriers bolting to cast iron casing).....if I could do it again, I'd make sure the plated 3.9 came as a pre-built assembly

Current plan is to replace diff & bushes, plus strip everything ready for gearbox, on Friday night. Then sleep at garage and replace box Saturday morning while doing a classic turbo swap/pump/decat and remap. New season is approaching, gotta' get moving......

Richard
PS: photos to follow, if I remember the camera tomorrow.

 

Richard, The torque setting is the optimum for the bolt size and thread, increasing will wring the neck of the bolt and make it MORE likely to snap off. The threads in the crown wheel are extremely hard as they were treated with the wheel when it was heat treated. The bolts will be case hardened and after the thread stretches [when tightened too much ] there will be surface cracks in the rings of the thread. Any doubts use new. [ If you can get em......]

Clean all thread surfaces with an air drying cleaner, I always used cellulose thinners when I was building transmissions. Use a strong loctite, it used to be #636 but after, ahem, a number of years it's probably changed. you'll need to get it from a specialist engineers shop not some rip of such as Swiss Halfords. 270 was the regular stuff.

If you put too much on the bolt it will spew out of the threads and get under the cap thus not allowing the proper seating. If you put it down the bolt hole you'll chase it down the thread and risk hydraulic lock at the bottom of the hole.

Just enough and not too much is never a truer statement with loctite. Hopefully you have a recently calibrated torque wrench?, they soften after about six months use and read all over the place. We have 6 in our system two in use, two at the shop and two unused calibrated ones in the cupboard. Overkill maybe but we do build a lot of engines and so on. If you have any serious doubts about your wrenches buy new again - the cost in relation to the cost of parts etc is negligible. Or, ask the Snap on man to call and 'test' a wrench off his van to see if it's suitable. Of course it won't be, but by then the bolts are done up.....

Good luck David API

 

648 is the Engineering Loctite and the strongest one iirc.


bob

 

Cheers both - crown wheel bolts are done already, to the recommended torque. My question was more related to the bearing carrier bolts torque setting, but you answered that question too

Thanks, Richard

 

Diff rebuild complete - but forgot camera, so no photo's. Swap starts tonight

A thought occurs to me - how do I set-up the AVC-R for 6 gears? Must dig out the PDF again!

Richard

 

Richard, I'm off to the States tonight, so if you have any questions for me, I'm afraid they'll have to wait until the 24th. l'll check then to see if you have tried to get me. Hope all goes well, Good Luck David

 

Started working on car at 6pm Friday evening - stopped at 2pm Saturday afternoon, very tired

It took 14 hours to replace all rear end bushing and swap the diff - a real fun job, hope it's worth it. I suppose I'll need to do the geometry again now

Diff and box is in, but box must come back out...... In my frazzled state Saturday morning I remember holding both 5mt and 6mt clutch forks in my hand, and thinking they're the same. Which is, of course, totally wrong!

Fork is located correctly on the release bearing, but is way too far back to allow fitting the hydraulic actuator.

And, just to confirm, I can use the 6mt with the 5mt clutch/flywheel? I was sure this is what Dave and Skassa had done? Dave/Skassa - which fork did you use? And John, which for you (having run the STi clutch/flywheel too)?

Oh, at around the same time as checking the forks, I also looked at the selector bracket that attach's the shifter to the box (the quick shift kit I bought had a new one for the 6mt). They both looked the same as well. Luckily, I managed to swap this without removing the box....it's around 1mm wider, and I'm a real dipsh*t...as the guys who helped me mate the box up (I could barely lift a feather by this point) will continue to remind me of for some time! The quickshift seems incredibly short, but need to drive to confirm really.

We'll drop the box again on Tuesday evening to (hopefully ) sort the remaining issue.

Richard

PS: can anyone recommend a good stud removing tool? I ended up needing to cut a bolt off one of my turbo studs, and I've decided it's time to do all the studs now (15 minute d/p removal took 1.5 hours )

 

What are you doing, or have others done, about the speedo drive?
The drive on a 6mt has a 3 pin plug if i am right, and a classic drive has 2 wires but does not fit in the hole.

 

Speedo drive and plug is the same but in a different location, just swap it (with the cable from the 5MT) over.

Richard

 

Superb thread... Richard, I look forward to meeting you this weekend! Will you be coming up in the Scooby? i.e. will it be running by then, or will you have to take the Evo?

Cheers
Richard

 

the late classic model(MY00) has a 3 pin connector I just switch it over from the 5 to the 6 speed box it works ok.

One thing I needed to change was the pin from the slave cylinder it was to sort.
I use the 5 speed slave cylinder on the 6 speed box.

kurt

 

One thing I needed to change was the pin from the slave cylinder it was to sort.


Strange ,mine fitted without a change of anything

Skassa

 

So did mine....in the end I used the existing hydraulics bolted onto the new box. No problems bar having to shorten the spring.

Didn't need to remove the box again, just got a professional to put the bearing in the right place and fit the fork correctly (that's the last time I leave the release bearing in the clutch assembly ).

After that it was straight forward...except for the propshaft of course! Turns out the centre bearing was crushed on the spare one (can't complain, David chucked it on the pallet for me at last moment).....don't know how I didn't notice it before getting it shortened....DOH! There was a fun hour or so splitting the props and swapping the centre bearings over.

You lose the d/p support bracket - I'll need to make something proper (we bodged it for now....but it's vibrating), or check how it's done on the STi's.

The short shift kit has around a 50% shorter neutral gate than a stock STi shifter, brutally short but great...very <snick>, <snick>.

Gearing is perfect for track work I reckon - you are always rushing through peak torque and power, car flies. I now need 4k3rpm for 100 mph, previously was 4k - but I don't like autobahns anyway!

Rear diff impressions are harder to gauge - the geometry is out after stripping the whole rear end to do the bushes, but a fast t-junction launch see's my benchmark time equalled....be interesting to see what happens at 100%

The bushes, while adding a huge amount of NVH, makes for an incredibly solid rear end - it's not so much a loss of compliance (well, OK, it is stiffer than before), as a huge increase in control. I now feel absolutely everything the rear end is doing!

Altogether a great package - I'll get geometry redone ASAP so I can give it a better work out. Thanks to everyone who helped, on this thread and via email - especially to David for sorting out all the bits so efficiently

Oh, sorry - no more photos, kept forgetting camera.....

Richard...wanders off to talk to engine builder about EJ25 build

PS: Richard - sorry, but I wont be making it this weekend, I'm so far behind on everything after tha last week that I *really* need to score some brownie points with my wife..... But email me, I can sort it to come over (Stuttgart, right - ~2 hours from Zurich?) one weekday evening or on another weekend. Have fun