AlanG

I was hoping it would be that Tim, but it wasn't unfortunately.
I checked the springs for the detents and they were fine. I believe there are different springs (stronger) which are available as opposed to the greens that are in there, but haven't got a set to try.
It now ocurs within 40 miles of motorway use, but the latest thing i've found which is odd, is that when it happens, it'll crunch for like 3 or 4 times in a row, then the next 3 or 4 times it won't
I went up and down the box from 3rd to 4th and vice versa deliberately to see *exactly* what was happening and that's what i found.

The oil is still hot while this is going on,, hence i'm wondering if it could be a specific oil it's needing or better synchro's.

Danny Boy

iTrader: (2)

Its wierd that on mine at normal shift speeds the up change from 2nd to 3rd is probably the smoothest in the box, its just at high revs that it crunches.

Aztec Performance Ltd

iTrader: (234)

I'll point Zen this way so he can add his input.

He may remember what oil is in mine.


Bob

ZEN Performance

It does sound like the oils isn't helping these issues. In Alan's case, he has not only new gears, but new synchro rings and synchro hub assembly, in short everything concerned with changing 3rd and 4th gear is brand new.

911

So needs 'running in'?

While you are watching Paul:

Would you say a Zen semi helical 1st to 4th, stock 5th on sysnchro with Sti ratios is available via ppg/you.

Is there a strength advantage in straight cut 1st/2nd with 3rd.4th in Semi helical and stock 5th? I thought 3rd was the weak gear with respect to resistance to torque levels.

Maybe a bit off-thread but of interest to the readers I think.
Graham.

Danny Boy

iTrader: (2)

Go for your life Graham, no problem with some chat here

Dan retire's from the keyboard to watch his thread grow to 500 pages long

Danny Boy

iTrader: (2)

Paul, Isn't it 3rd gear that has brand new Syncro rings on it anyway, as it needed a 4th gear style one to work?

Dan.

AlanG

Have you heard anything from PPG yet Paul? Maybe they've got a recommended oil?

ZEN Performance

Normally, but Alan's box has complete new synchro assembly for 3-4 too, not just a new synchro in 3rd.

Paul

Aztec Performance Ltd

iTrader: (234)

Paul,

Do you recall what oil was used in mine?

David_Wallis

just to add, I drove stevens car at the weekend and to be honest I wasnt that impressed with the gearbox due to the same problems as mentioned above, certainly did it on at least two or three changes, I could 'Feel' the syncro's and these were 7000(+-100)RPM changes and they werent slow changes either, certainly not as fast as I would normally change gear though whilst drag racing.

Would be interested to hear recommended oils as this is on the blue/green redline shockproof.

AlanG

My synchro problem happens at low and medium revs as well as high revs, but you get an idea it's going to crunch cause when you go from 3rd to 4th, the gearlever feels like it is being pulled away from you to get into 4th gear. It becomes very very light in action from 3rd to 4th whereas the other gears you need to deliberately change into gear.
I haven't had any issues from 4th to 3rd or 5th down into 4th, only 3rd up into 4th.

Aztec Performance Ltd

iTrader: (234)

David: How was down****ing into 1st at high rpm? Thats the biggest problem on mine - it wont engage until revs drop. I get an irregular crunch from 2nd to 3rd high rpm too.

911

Dropping down to 1st from 2nd at high rpm (in 2nd) is a crucial change in hill climbing..a 6 speeder will do this easy?

I still think this is the rotational mass of the heavy duty gears with synchro engagement.
I bet dog change boxes are fine.
Graham

Aztec Performance Ltd

iTrader: (234)

Whatever the problem is Graham it isnt right and will cost valuable time in competition and be a PITA on the road. Had I have known.....

I would assume that an OE box would be fine (my OE 5 speed certainly was).

David_Wallis

Bob, I wouldnt consider that in my car unless trying to loose someone with blue lights or having a race around the streets (maybe on a circuit I would) so there was no need to test it in stevens car, the short is I wouldnt do it in mine so deffo wouldnt in stevens car, 2nd is fine for me.

However my OE 5 spd would never drop into first at any decent revs, much to my annoyance as not many people use this trick on the road

Its fair to say I am NOT at all impressed with the PPG Kit as yet, but Im going to wait and see what a decent (sorry Different) oil does as subaru gearboxes are temperemental at the best of times!.

However its safe to say that I suspect my new PPG syncro kit will be for sale very shortly.

Graham, what makes you suspect this, I hardly think the rotational mass will be substancially different, after all you arent going to fit much bigger in the given space..

Damn right, theres no fooking syncro's you fool

David

911

That's my point.
The dog box will engage no matter what.
As I recall, the pics of Danny's gears showed a substantial increase in size over stock.
Unles I am wrong a synchro locks by taper/oil film to the gear you are selecting to go to to align to the one you are in. The selector can then engage the gear just stopped for the moment and the task is done, and the sychro ring releases as there is no pressure on it.
In that split second, the ring/oil film has to slow down a mass that is greater in possibly the same time or quicker during a 'race change'.

Maybe an oil that has better characteristics will help, experiment will tell for a given box.
The better the fit between the gear cone and the ring the better the lock-up at the moment of selection.

With the dog engagement the change is not so delicate for sure.
The Possum Bourne dog box i once drove with on a sprint track(Sti RA) was better the harder you changed, but awful if changed in a relaxed manner ie road gearbox style.

Graham.

ps: Is there an alternative to the ppg?
Seems there are several ppg boxes here that are not right with synchro but fine as dog changes.
Can you have strength and synchro changes?

AlanG

I've just had word back from PPG regards my issue and here's the oil they recommend:
"Redline Shockproof Lightweight (blue) gear oil.. And if crunching issues was still there, to use Heavyweight (red) Redline"

Comments?
Can anyone remind me why Redline HSP shouldn't be used in these boxes? (There was a debate some time ago IIRC).

They also mentioned that if you run the earlier box i.e. pre 98, then you will find the synchros aren't up to the job.
In my case, the later/larger synchro cones/hubs were used and problem still there.

mikeesingh

iTrader: (3)

i had the Redline Shockproof Lightweight gear oil in my ppg kit, i had problems going into one gear i think it was 3rd or 4th (not sure which one) was only a problem on slow gear changes.

andy97

iTrader: (1)

I am/was about to commit to going ppg syncro. I shall now put this on hold for a while until the issue of gear selection is resolved- I shall watch this thread develop with interest

Andy

911

Snap.
Graham

Danny Boy

iTrader: (2)

Hmm it seems others are having problems with other gears too, yet mine is only in the 2nd to 3rd upshift at high rpm. I think the first port of call is to overfill the box slightly with the current oil to see if that makes any difference as the 3rd/4th syncro is on the upper shaft.

andy97

iTrader: (1)

Hi Danny

It would be useful, if you could update your thread with all the details on what attempts you have/ will be making to eradicate the gear selection hiccup.

What type of gear oil are you using at present?

Andy

AlanG

This is a shame about the PPG gearkits cause i'm more than happy with mine in every way bar this one issue, which only surfaces when the oil is hot and is only the one gear (so far..)
I don't think we should write the kit off too readily. After all, no one i've heard of has broken any of these gears yet, which was a common problem before these kits were available.
I've sent another mail to PPG regards this. If anyone's interested , i'll update, but i'm disappointed this has happened and find it a bit strange that there's all of a sudden been a "rash" of synchro problems with these kits, unless we all bought the kits at the same time and are the first real "users" out there!!

AlanG

Bought Tuesday11thApril, posted 12th April
"Bought a PPG kit with billet forks yesterday "

posted 12th April
"Its fair to say I am NOT at all impressed with the PPG Kit as yet"

"However its safe to say that I suspect my new PPG syncro kit will be for sale very shortly"


Why the quick change of mind David if you don't mind me asking? What is that doesn't impress? Is it just the synchro problem?

Danny Boy

iTrader: (2)

Alan i must say that im very happy on the whole with the PPG kit too, i felt that the shift quality is no better or worse than an OE 5MT, a bit notchy but there all like that sir

As you say there is only one problem and it only occurs on high rpm shifts. In day to day driving the box behaves perfectly, infact i tried today to provoke it with fast shifts at lower rpm and less than subtle clutch work and nothing untoward happened.
Im sure we will find a solution with a few of us using the product, it's just a bit of a learning curve.

Hopefully next week i will have a chance to take 5mins away from work to have a bit of an experiment with the oil levels and will report back with my findings.

Dan.

Danny Boy

iTrader: (2)

Andy im currently using the new version of castrol Syntrax called driveline. Its a 75W-90 as reccomended in the suabru owners manual, its also in my rear diff too. The origninal version of syntrax cured a crunching 4th to 5th shift in my original 5MT when i first bought the car, so i have stuck with it as it has performed very well.
I have heard some roumour on scoobynet that the formulation has changed and the new version is not as good, can't say that i noticed any difference in the standard box between the new and old formulation (if indeed anything has changed other than the packaging!) as far as i know there has been no hard evidence to prove this roumour though.

ZEN Performance

I ran heavyweight shockproof in mine. I drove 7000 miles on the kit including at times a daily commute of over 80miles each way to work. The only time I experienced synchro problems was on track at rockingham, upon stripping the box, I found a worn out baulk ring causing the problem. I had no issues at the 'Ring earlier in the year with Felly driving, including the GP circuit which was pretty hard without the long straights of the North loop.

Redline oil is perhaps worth a try, although very expensive at double the cost or more. There is an equivalent from Millers although it specifically states it's not for use with synchro boxes.

Graham,

The gears are the same weight as the OE parts, while the teeth may be bigger, so are the gaps! The baulk (synchro) ring wears it way to a perfect fit onto the cone of the gear. The cone of the baulk ring is grooved so the contact area is very small, during a gearchange the small surface area allows the oil to be displaced and a metal to metal contact to be made. It is this positive contact that allows the baulk ring to grip the gear and spin it up to speed. If the oil is too good, and too stable, it can lead to the film not being displaced and the baulk ring not to properly grip the gear.

I am beginning to wonder if the steel forks are having an effect on the gearchange. While you would naturally assume it has no part to play. There is a noticable difference in the design, critically, in the way it holds the syncho hub (the bit that slides and loads up the baulk ring aswell as engage the gear). The stock fork holds the hub in 2 places with plastic wear pads that allow a little give.

I suspect the hub is over constrained by the fork, and without perfect alignment is not giving an even pressure onto the baulk ring.

The way forward, for a long term fix, well I have my ideas, but first I would lile to confirm it's the issue. My own box only had factory forks that somehow managed not to break.

Paul

Aztec Performance Ltd

iTrader: (234)

Mine is on OE forks.

911

Thanks Paul.
This was the point I was trying to make in that the box needs 'running in'; that is to bed the ring to the gear cone (etc).

Could these high grade, impact resistant oils actually be the issue?

Even though the gears weigh the same , is the rotational mass distribution very different, that is a greater mass on the periphery compared to stock?

I am certainly no gearbox king here, just a very interested party.

My hill climb season kick's off with a higher torque than last year and I'm waiting for the box to pop.
Repairs will need to be quick, but i would rather invest in a box that will allow slicks later.

You know where I am coming from.

Graham