sonu

Hi all

I know that there have been many noted problems with the gearbox, but I thought I'd add my experience.

I have a '99 UK Scoob. It's done about 9500 miles.

Recently, I've started to get a loud crunching noise when I try to move down from 5th gear to 4rth gear as a result I cannot move into the 4rth gear.

Does anyone know if the 'gearbox problems' have been rectified by Subaru?

Thanks

Sonu

Tony Quinn

Hello again Sonu,

My MY99 is going to the dealer on Saturday, also with what appears to be a 4th gear synchro problem. The service manager says he is not aware of this being a common fault, but that it may emerge as one because he did have a car in last week with a similar fault. My problem is with changing from 3 to 4, 5 to 4 is OK.

I can let you know what he says next week but maybe somebody else has already had this fixed. So it appears not to have been recognised as a problem yet, hence no permanent fix?

Tony

coolhand

Hi all, anyone heard of G/box failure? Well, the gears for Subarus are pretty weak for the WRXs. Becareful when U're trashing the gears.

Tony Quinn

Nothing to do with thrashing the gears. This car has only 6,500 miles on the clock and has been driven very gently for most of them. I've driven other cars (in my youth) with far less mechanical sympathy over many, many more miles and never managed to damage a gearbox before. I think that we are going to hear of many more gearbox problems on MY99 cars.

I was immediately unimpressed by the gearbox and hoped that it might improve. However, it has become worse or I have started to want to change more quickly now that the car has had plenty of running-in time. This is very definitely a design or manufacturing problem in my opinion. I just hope that the problem is due to a faulty batch of parts and nothing more fundamental. Anyhow, now I will find out whether Subaru really deserve their JD Power awards.

coolhand

Ok, since yr car's new n hasn't been trashed abt, why not get the oil changed first n see how? sometimes, it's the grade of the oil n not other problems...we usually go for the easiest n cheapest first.

Tony Quinn

Thanks Coolhand (Luke?),

Easiest and cheapest, we think alike. That's what I'm doing, still under warranty you see. I'm not convinced that just an oil upgrade will resolve the problem because 4th gear is far worse than any other. Although I would not underestimate the difference that a good synthetic oil can make, especially on cold mornings.

sonu

Thanks for your input.

The Scooby is supposed to be a 'sports' car and therefore the gearbox should withstand quick gear changes.

My car's going to the dealer on Monday. Tony, please keep us informed of any developments.

Thanks

Sonu

pilch

Sonu,

I have a problem putting the car (MY94 WRX) in reverse from stationary. I always seem to crunch. I thought it was lazy foot syndrome, but there is definitely something amiss. Every other gear is fine.

No help at all, but just thought I'd mention it to make you feel better!

pilch

Ellie

I thought i would let you know that the MY99 gearbox is the weakest i have ever come across in my driving days. I have gone through 3, YES, 3 gearboxes in the past month alone after modifying my car to output more than 280bhp. I have many friends with (almost)non-modified turbos and they have also had problems (mainly with 3rd gear breaking to bits).
I, for one, am totally unhappy wih the quality of the 'boxes and i am quickly losing faith in the car.
Could it be time to try an EVO ???

Unimpressed, sad, disappointed and now skint......

Ellie.

coolhand

Hi all Subaru drivers,
I'm going to say something, the gears are very weak for the car...any mods to the engine to gain more torque will be sending the gears to it's grave much much faster...I'm sorry to say but I don't drive a Subaru. The Evo's box is a very good design, anything else fails except the box. Sorry, don't drive a Mitsu too. I drive a GTi-R. It's sad n frustrating but I've seen n heard of many broken gears for the scooby. In fact, I've got a broken to bits n forward unmovable V3 box in my workshop now waiting for an operation. We had to use reverse to get the car back into the workshop.

Tony Quinn

Sonu,

One of the mechanics took my car for a short test drive on Saturday. He confirmed that 4th gear synchro was faulty and I am just waiting for the dealership to call me back with parts availability so that I can book the car in for repairs.

Do you have this month's Evo? They suspect that their Forester has problems with its 5th gear synchro. Same box?

Tony

sonu

Tony

I've just picked up my turbo. They replaced the clutch and took a look at the gearbox but could not find anything wrong with it.

I'll give it a few blasts to check the box . Maybe I was a bit heavy handed on the gearbox when I was travelling back from De Nurburg Ringa ...

Thanks

Sonu

musclenut

I used to have a problem with MY97 car. Everytime when i went into either first gear or reverse the synchro's would crunch. Finally, i changed to an STI MY96 gearbox that seems to have no problems at all,even with quickshifting.

stv555

Same problem with MY99, noticed it from day one...thought the box may need running in and then a change of oil. Now at 8k noticeable above 70 when shifting from 4th to 5th, no crunching just baulking slightly as 5th engages. Am returning to the dealer next week bulletins in hand....let's test this JD pOwer thing out !!!!!

sunilp

STV555 - plese explain what "baulking" is?

Thanks

Ian Cook

Mines going into my dealer on Monday as well, mine jumps out of 5th gear on the motorway on the over run, and then crunches like crazy when you try to put it back in. Also i have caught the syncro out on 3rd on several occasions it sounds like a syncro problem, hope its nothing more, I dont really want to be driving a Justy about for weeks

Nigel M

My 99 Turbo is very reluctant to go into reverse without graunching? The dealerssays to blip the throttle and try again if there is resistance in moving the lever into reverse. Still graunches, any ideas?

mark245

Nigel M, wont solve your gearbox problems, but as your foot depressing the clutch go into first gear with the gearlever then try reverse. This usually helps,
Mark

Nigel M

Thanks Mark

Dino555

Tony me English mate,

No more gearbox problems, does this mean that we will meet again on The Green Hell???

By the way, my gearbox also crunches sometimes, should I use the clutch when I change gears ???

Bye

Dino

DYNT

Bulk Ring problem .... and dirty syncro... reason for hard engagement.

This is how everything started ...... the helical gearing is to steep ... for noise/smooth reason. This in turn made it 'weak'

Everytime it turns .... some 'grinding paste' got stuck at the bulk ring and syncro.

When U strip the gearbox .. everything is fine except that the syncro and bulk ring is dirty ..... even the Heel and toe of the gearing is correct.

firefox

Watchya...

The proper/long term solution is to fit the STI box... or fit a Prodrive Grp N Box... about 6K for the Prodrive one....

Or just keep having a replacement box fitted underwarranty until FHI resolves the problem

J.

stv555

Sunlip

Early gearboxes used baulk rings, which in modern times have been replaced by synchro cones or rings. Gearboxes are known as constant mesh gearboxes where all gear clusters are in constant mesh but disengaged from the mainshaft. Selecting gear in effect is a process of locking the appropriate gear to the shaft which in turn drives the wheels. Baulking is a term used to describe the snatching of a gear when the synchronisation need to engage gears is not perfect...you feel a kick back in the gear lever, normally described as not having a clean shift. Crunching of the gears is an extreme form of this. Baulking is normally associated with worn gear parts, old or incorrect transmission oil.

AlexM

Jay,

Just out of curiosity, what goes into a Prodrive group N box?.

Presumably, it is a standard Sti box rebuilt with better gears etc, but essentially the same as standard. What else would be allowed by Group N regs.

Cheers,

Alex

P.S. a standard UK MY98 'box is £2700

stv555

Dog boxes and modified internals - beware !

Dog boxes use straight cut gears which are up to 50% stronger than helical gears. The manin reason for using helical gears is noise, during use the torque is transmitted through a small contact patch on each tooth, thus mechanical contact is kept to minimum and they run quiet. This contact patch is normally some way away from the root of the tooth and breakage can occur halfway up the tooth.

Additionally a percentage of the torque is used to try and push the gearsets in opposite directions, not away from each other but in the direction of the supporting mainshaft and layshaft, hence the need for thrust washers at each end of the clusters.

Straight gears look like a gear found in a clock, but much thicker, contact area is greater, hence the whining sound, and the load on each tooth is supported by the root of each tooth, hence their strength. You lose more power with a dog-box, but now the torque is used to drive the gear clusters away from each other. Now the weak points are as follows : the bearings the gearsets run on, the main and layshaft strength, the bearings the two shafts are supported on and the casing which supports the bearings. You can get to a situation where everything has been modified and the gearbox casing splits apart.

It is a rewarding though tough drive with a dog-box but the noise can become unbearable.
Straig

Darren Soothill

I wouldnt say that the STI box was fixed! Im not entirely happy with my box and am looking into alternative internals which is where my question starts!

Has any one driven a road car with a dog box and what are the downsides of this and how liveable is it on a day to day basis?

Does anyone know of any other companies other than Quaife who make replacement internals?

Quaife at the moment have a new box in the prototype phase.

Darren

AlexM

Darren,

Tell us more about the Quaife prototype box, if you know. I presume that these bits are for the STI box - Is the casing/internal layout very different from the UK box?.

With a fairly modest re-boost, a MY98 UK could be producing 250-260lb/ft torque, which could be terminal for the gearbox fairly quickly.

Would an equivilant STI gearbox (STI IV?) go onto a MY98 UK?. I presume you would need an STI rear diff too. Sounds expensive

Cheers,

Alex

Darren Soothill

I dont know much more about it at the moment I have just mailed them to ask if they can send me some more details.

With previous boxes they have just replaced the internals and quite often allow you to choose the ratios. I dont know if they are aiming this box as a replacement for the UK or the Type R box. The only STI with a substantially different diff is the Type R.

Darren

AlexM

Hmmm... Interesting.

I would have thought that it should be possible to improve on the stength of the gears, bearings and mainshaft without going for Straight cut gears.

Better material selection, quality control, stress relieving treatments (shot peening, tempering etc) should make it possible to improve on the standard gears. Subaru will have chosen the cheapest component that will do the job - it all comes down to cost I suppose, and it should be possible to build a stronger box with non subaru parts.

The gearbox case is a long casting, so that may be the limiting factor after fitting stronger shafts, gears and bearings.
You're right about straight cut-gears on a road car - the noise would drive you crazy in no time at all.

Are straight-cut gears allowed for group N?

Cheers,

Alex