RON

Guys, i have a my00 turbo, i broke the gearbox, surprise surprise..... anyways, i have now fitted a gearbox from a blobeye, code ends is ty754vn5aa..... anyways, having now fitted it all up, filled with oil etc, when i drive it, it feels fine in a straight line, but on corners it feels as though the front tyres are on marbles...... which is not nice...LOL


Do i now need the rear diff out of the same car the box came from..??? i suspect i can get it of i do...
Oh, AND if i do get said diff, will the shafts etc fit the same as mine...... cos the gearbox didn;t and it was a bit of a pain!!
Thanks.

Ron.

RON

Forgot to say, that the gearbox casing also gets so hot you can barely touch it..... i suspect this is due to the centre diff working too hard.... i've put redline shockproof oil in it.... damn expensive stuff!! don;t wanna cook it!!

RON

Or toask the same question a different way..... does anyone know what REAR diff was in the ukmy00's..... cos i believe the newage cars have a 4.111 diff.... pretty sure the earlier uk cars didnlt have that....

merlin24

iTrader: (1)

You are probably better off emailing or phoning David @ API Engines or the info you need and possible solutions.

Mick

172sport

iTrader: (6)

AFAIK uk cars have a 3.9 front diff 1.1:1 drop gear and run a 3.54 rear diff

Stu.

RON

Thanks Stu.. as i suspected... different diff....ARGH!!!

I originally asked if the 5AA box would fit my car, and all i got was confusing answers, most said, it was a straight fit, but it was far from it..... and now it seems the diff is different aswell......

I should add, i blame no-one, only myself, i went this route to try and save a bit of money, and all it's done is make the job more complicated.... i should have just got my old box rebuilt and been happy with that eh....

172sport

iTrader: (6)

whats your original box code?

APIDavid

iTrader: (4)

Ron, you are confusing yourself with this; 172 is correct UK cars ORIGINALLY have a front ratio of 3.9:1 with 1.1:1 drop gears and a 3.54 rear diff. If you multiply 3.54 by 1.1 you get 3.9. Geddit??

I understand that it is done that way to cut down prop shaft speed and reduce vibration and harshness through the frame. There is no other obvious reason to do so.

NOW, to your problem; Diffs and gearboxes always get phenomenally hot and the first time anyone ever notices, is when they have a problem and rest a hand on the box. Then they panic. But it has always been red hot it is just you never needed to know until now.

That is not to say that you do or don't have a problem but what I am saying is that it is not conclusive proof of a problem.

You need to get the original box stripped to find out if it is still standard, as Subaru supplied. Part of a rebuilders problem is always to know whether the item in question is original or changed. No one out ' THERE' would think to take off the ID sticker if they rebuilt a box with different ratios. We do it as a matter of course but others may not be so diligent.

Once confirmed that you have indeed fitted like for like then we can all move on.
What tends to happen when a wrong rear diff or front final drive is fitted is that there is a large vibration in 3rd gear. Soon after, if you keep driving, there is an audible clunk [ similar to the sound of a wheel weight flying off and hitting the under floor ] Then all vibration stops.

That is when the centre diff just broke - now you have a 2WD Impreza......

To establish what rear final drive you have: drain out the diff oil, take out the filler plug mark a tooth with white paint or Tippex rotate and count the teeth. 37 is 4.1 ratio; 40 is 4.4 anything else [ I am not sure of 3.54 set up, yeah, I know, you caught me out ] must be 3.54

Call me anytime for further info - good luck

David

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01926 614333

JohnD

iTrader: (5)

[QUOTE=APIDavid;8166081]Ron, you are confusing yourself with this; 172 is correct UK cars ORIGINALLY have a front ratio of 3.9:1 with 1.1:1 drop gears and a 3.54 rear diff. If you multiply 3.54 by 1.1 you get 3.9. Geddit??

I understand that it is done that way to cut down prop shaft speed and reduce vibration and harshness through the frame. There is no other obvious reason to do so.
QUOTE]

An interesting point when you consider gear ratios is why you often see 1.1:1 or say, 8.14:1 The main reason is that if for instance you had 1:1 the same teeth will mesh every revolution creating a set wear pattern and resonance. By sticking in an extra tooth or two on one of the gears (called a "hunting" tooth) the wear pattern becomes much more random as two particular teeth will only mate after so many revs. It also reduces the possibility of "hetrodyne" in a gear train. In most cases altering the ratio by such a small amount is acceptable (as in a gear box) You couldn't do this in a valve train, however!
I wonder if, during development, Subaru used a 1:1 drop gear with the same ratios at each end, and found problems!

JohnD

APIDavid

iTrader: (4)

John, JDM cars are all 1:1 drop gears and they don't have a problem with excess wear or noise. So for that reason I went with the prop shaft thing. I understand perfectly your argument and concur that is a recognised way to go to even out wear.

If you consider the circumstances of driving in Japan and say Europe. Cars in Japan are regulated severely to 70 mph on the freeways and as we all know have a 112mph limiter fitted.

Road speeds in the rest of the world are much higher on motorways and freeways etc. and put the comfort cruising speed into a different resonance zone.

Hence a reduction in prop speed may well change that resonance and the problem goes away.

There may well be another perfectly good reason that I haven't considered, but that is my reasoning for the 1.1:1 drop set.

Maybe some Subaru / IM tecchies may be out there watching and can offer a reason that will put us all out of our misery...............

Where are you when we need you Mike Wood ??

David APi

RON

Blimey... Thankyou david for taking such a long time to type all that, (if like me you type with 2 fingers..LOL)....

I have contacted the people i got the box from, and they are sending me the rear diff from the same vehicle that the box came from, so it'll be matched whatever....

I am still slightly confused..... I can gaurentee that the original box in my car was standard gearing, as i bought the car NEW, and i am pretty much the only driver, and certainly the only driver!

So, do you know what front diff, a transfer gears the 5AA box would have..... as thats what i have fitted..... something is definately amiss, as like i say, when cornering the inside fron wheel feels as if it's skipping.... or on marbles..... i have heard the odd slight clunk.... not too loud..... i am pretty sure the centre diff hasn't broken, as i jacked one front wheel up, and even with the gearbox in nuetral, it was quite stiff to turn just the one wheel..... ie, the viscous diff was creating drag..... i also put both front wheels in the air and spun them, to check that the front diff was free.... and also, not broken........ so, when the 'new' diff arrives, i will count the teeth as per your instructions, i shall then drain the oil from mine, and count that one..... if they're different, (which i am now praying they are) then i will simply fit the new diff..... and keep the old one with the old gearbox.....

I thought buying another box would be simpler.... if only i'd thought a bit more about it...LOL!!

Thanks again David ... much appreciated...!!!!

RON

Original (and standard) box code was TY754VN1AA

new box code is TY754VN5AA

stockcar

is it possible you have actually got a Forester g/box (prev fitted to the donor car??), that may explain your issues

cbr337

I went though the same sort of problem i had a uk car and fitted a wrx rear diff not realising that it was a diffrent ratio and wound the diff up so ive now got another wrx diff and fitted and matching gearbox wot a pain as i could'nt find uk diff in time

RON

I guess that is an option Alyn... are they basically the same box... ie, strength wise....

I've just been scouring ebay, and found an 06 wrx rear diff, with (it says) a 4.111:1 ratio....... so assuming my car has the 3.54 one as per uk classics... and assuming that the 'new' gearbox came froma car with the same gearing as an 06wrx..... that might hopefully be why mines not right...... i hope it's not a forester box.... mind you, if they send me the diff from the same vehicle, and it travels at the same speed when it's all sorted i guess it doesn't matter much....... won;t be pleased if the overall gearing reduces my speed though......!!

APIDavid

iTrader: (4)

Ron, I would not rely upon anyone on Ebay knowing what the ratio of a Subaru diff is. To the very best of my knowledge ALL as in EVERY ONE of the UK VN series 5 speeders are 3.9 front diff ratio and 3.545 rear axle ratio.

So your original car will definitely be that spec and the 06 in my opinion, ditto. Going back to a 4.1 ratio will take the gearing rather lower and I cannot see why Fuji would do that. More revs being used at cruising speed, etc., etc.,

The front diff on a UK / Euro car is open unless converted after sale. So up in the air turning a front wheel will be free to rotate and the opposite side front wheel will rotate the opposite direction There should be no stiffness or resistance. A damaged front diff will cause the problem you describe.

Do the counting trick and see what happens. It is possible to count the front diff teeth in the same manner as the rear through the drain plug hole on the box - but is awfully messy, as the oil drips on you whilst counting.

Good luck David

Forester boxes can be TY753 Vn??? or TY 755Vn ??? Never TY754.

172sport

iTrader: (6)

Forester box info

Note the use of a 1.081:1 drop ratio (4.444 front diff) (4.111 rear)

Subaru Forester Owners Forum

RON

Well, now i'm totally confused...... and praying the front diff in the 'new' box isn;t broken........... the 'new' diff has arrived, and i've counted the teeth on the crownwheel, and there are 39...... so, as thats not a number that David gave as an option, i'm guessing it must be 3.54...... the next job is to drain the oil from my existing diff, and count that...... if that proves to be the same, then i guess i need to count the front diff teeth.... which will mean draining £80 worth of oil from the box..... however, it will go into a clean container, and go back in at some point......!! unless bits of centre diff come out in it....

will update later when i've counted the existing rear diff.....

172sport

iTrader: (6)

Oh the code for that box is ty755vn1aa, just been supplied to me by grade A.
Also has the benefit of an oil cooler too. Suitable for a rear diff of 4.111.

Ill let you know how it goes as im in the process of fitting it........

smokingkills

iTrader: (3)

You also need to count the teeth on the pinion, you need 11 on there too to make 3.54 ie 39/11= 3.54. Some diffs have 10 on the pinion wheel making 3.9 final ratio

RON

Can't do that without taking the back off the diff though can i...... i'm sure David would have said if that were needed....

GC8

Has anyone identified the code? Its not on my reference, but it rings a bell. I believe that Ive seen one before that allegedly came out of a New Age UK300.

RON

When i originally spoke to the gearbox provider, they did tell me it was from a UK300..... however, that is no different to a WRX of the same vintage..... (or is it?)....






I have now counted the teeth on my old rear diff, you guessed it, 39...... the same as the new one....ARGH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

So, lets assume that the gearbox i bought and got, was froma uk wrx, as the code would suggest...... and therefore the diff were all matched.... what the hell would cause the odd feeling and 'skipping' effect i was getting on the front wheels...... if the centre diff was broken when i got it, (due to accident imapct lets say..... ) what would the centre diff being broken feel like......???


I am now at my whits end, and considering removing the new box, driving it up to Norfolk along with the diff they sent me, and tryiong to get my money, (or most of it) back.... and dropping my old broken box off at API for a rebuild in the same journey...... i've just about had it.... why the hell do we modify cars until they break!!!

smokingkills

iTrader: (3)

Wot David dunno about boxes & diffs ain't wurf knowing.

If you are sure you have your hands on a uk diff & not jdm one you'll be fine

GC8

Now Im beginning to wonder whether it was your post that I saw the type number on and couldnt find it in any references.....? I didnt remember that actual type nmber, but it was similar to a US '04, but a VN as opposed to their VV.

Devildog

What about the teeth on the pinion?

Without obviously driving the car, the most likely cause of the front end "skipping" would be that the front diff was locking.

Does it feel like torque steer under power, or is it happening at light throttle openings too?

Either jack the front of the car up, in a high gear and turn one front wheel - the other should turn freely in the opposite direction, or to test under load, find some hard dirt/gravel, stop the car, wind on full lock and drive forward slowly. if the front diff is locking up, you'll soon know about it as either the inside wheel will spin as it matches the speed of the outside, or the outside will drag as it matches the speed of the inside.

If it does, and doesn't turn very well your front diff is knackered.

To be honest, even missmatched front and rear diffs (within reason) shouldn't cause the problem you appear to be describing as the centre diff should be able to take up some of the difference, unless it too was locked, or starts locking up as the viscous fluid heats up due to the shear.

Does it do it from cold? Or only when you've been driiving for a while?

APIDavid

iTrader: (4)

The problem must be in either the front diff or the centre diff. Either way box out and a looking at by someone.. No matter whether the wrong front ratio, or damaged front planetary set, or damaged centre diff.

APi springs to mind Ron, I seem to have heard that name a few times .

If that is an option bring both busted box and 'new ' one and we'll get into it.

Good Luck no matter what, David

01926 614333

RON

Right............. off to API for me tomorrow then...LOL!!!



Many thanks for everyones help in this matter..... hopefully it'll be resolved in a day or two....!!

APIDavid

iTrader: (4)

RON

Slight change of Plan David.... i'll be with you AM..... then going on to norwich..... driveshafts all sorted, so nothing to do there...!!!