Does a 3.7:1 diff exist or can I not count?
14 April 2003, 07:05 PM
#1
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37 on crown wheel.
10 on pinion
3.7:1
closest I can see is autobox
David
10 on pinion
3.7:1
closest I can see is autobox
David
14 April 2003, 08:12 PM
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Ive counted so many times.. I even painted the tooth I started on.. Ill post the pics..
David
David
14 April 2003, 10:05 PM
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David,
Just looked up the "Impreza" service manual, and they list two rear diff's wth 3.9's in.
1) 1600/1800cc "VA" type pt.no on case, or lable ends in "XF"
2) 2000cc non-turbo, "T1" on lable or case.
Apart from making sure what you have is as strong as the sport 3.9, 3.7 may just give you that "edge" you were looking for, for top speed
Mark.
Just looked up the "Impreza" service manual, and they list two rear diff's wth 3.9's in.
1) 1600/1800cc "VA" type pt.no on case, or lable ends in "XF"
2) 2000cc non-turbo, "T1" on lable or case.
Apart from making sure what you have is as strong as the sport 3.9, 3.7 may just give you that "edge" you were looking for, for top speed
Mark.
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14 April 2003, 11:49 PM
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Mark do you mean the 3.7 in you first sentence??
Will ring you to discuss tomorrow..
David
Will ring you to discuss tomorrow..
David
15 April 2003, 07:44 PM
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Guys Don't forget that Uk cars have different ratio diffs front to rear because the step off from front to rear is at 1.1 : 1 rather than 1:1 like the JDM versions. SO I reckon that if the rear diff is 3.7:1 then the front will be 3.9:1
Don't even think about asking me WHY ???
David
Don't even think about asking me WHY ???
David
15 April 2003, 08:04 PM
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David (API)
I think you'll find that the UK rear diff' is a 3.54.
Andy,
I guess we need to know what the diff' has come from. The "myths" are based on "Impreza" ratio's. If you want to include Legacy's, Justy's, Foresters, SVX's, + a few more, then I guess we find one, or two other ratio's we weren't aware of
Mark.
I think you'll find that the UK rear diff' is a 3.54.
Andy,
I guess we need to know what the diff' has come from. The "myths" are based on "Impreza" ratio's. If you want to include Legacy's, Justy's, Foresters, SVX's, + a few more, then I guess we find one, or two other ratio's we weren't aware of
Mark.
15 April 2003, 08:16 PM
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Yeah Yeah Mark, I agree, but if the rear on a UK is 3.5 then the front will be 3.7 - don't you think?? Then you could have 3.7 front and rear if you used a JDM 1:1 step off.
David
David
15 April 2003, 08:22 PM
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nope...
UK Turbo runs a 33.545 (39/11)
with 1.1 front drop.
David
UK Turbo runs a 33.545 (39/11)
with 1.1 front drop.
David
15 April 2003, 10:55 PM
#18
Probably for sustained hi speed cruise temperature issues, particularly as it's not a 'UK' ratio but a 'Euro' model ratio...don't forget the official Skyline imports had oil coolers fitted on the transmission becasue of the higher sustained cruising speeds in Europe.
15 April 2003, 11:38 PM
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David,
Just to put a spanner in the works, be it a very useful one, according to the latest service manual, the UK STi7 has 1.1:1 drop gears !!!! Whilst the Jap spec' have 1:1.
This would imply that you would actually need a 3.54 rear CW & P, but I would confirm this.
Mark.
Just to put a spanner in the works, be it a very useful one, according to the latest service manual, the UK STi7 has 1.1:1 drop gears !!!! Whilst the Jap spec' have 1:1.
This would imply that you would actually need a 3.54 rear CW & P, but I would confirm this.
Mark.
16 April 2003, 12:05 AM
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Although it doesnt go into much detail, the Subaru website only mentions a 3.9, even for the UK car.
UK sti 6speed
Still doesnt explain, where the 3.7 comes from ???
UK sti 6speed
Still doesnt explain, where the 3.7 comes from ???
16 April 2003, 09:04 AM
#21
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FFS ARGH..
Im off to park a car on my head
Why is nothing ever simple..
**** it may just run FWD.
Im off to park a car on my head
Why is nothing ever simple..
**** it may just run FWD.
16 April 2003, 09:13 AM
#22
David, check the gearbox first, in any gear compare front drive shaft turns to rear output shaft turns.
If the drop gear is 1:1 then it should be a 3.9:1 ratio, if it's a 1.1:1 it should be 3.545 (not 4.29 which is backwards) I think, brain's a bit slow this morning
Paul
[Edited by Pavlo - 4/16/2003 10:59:16 AM]
If the drop gear is 1:1 then it should be a 3.9:1 ratio, if it's a 1.1:1 it should be 3.545 (not 4.29 which is backwards) I think, brain's a bit slow this morning
Paul
[Edited by Pavlo - 4/16/2003 10:59:16 AM]
16 April 2003, 10:38 AM
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The 3.7:1 rear diff is indeed listed in the Impreza service manual, which kinda implies that it does exist and that it is fitted to the Impreza. It didn't list which Impreza it was fitted to, I guess that I'de need to look at the spec sheet for each model and see if I can find it.
David,
Finding a 3.545:1 rear diff is easy, it's a stock UK rear diff, and there's plenty of them about at breakers yards! With regard to figuring out if it's a 1:1 or a 1.1:1 drop gear in your transfer case, pop the box into a high-ish gear and take note of the positions of the front and rear outputs... it is useful to turn the two front shafts so that the holes are parallel, you'll see if there has been any relative motion in the front diff later... turn the input so that the fronts turn once. If the rear has turned 3.9 times then it's a 1:1, or if the rear has turned 3.545 times it's a 1.1:1
Cheers,
Pat.
David,
Finding a 3.545:1 rear diff is easy, it's a stock UK rear diff, and there's plenty of them about at breakers yards! With regard to figuring out if it's a 1:1 or a 1.1:1 drop gear in your transfer case, pop the box into a high-ish gear and take note of the positions of the front and rear outputs... it is useful to turn the two front shafts so that the holes are parallel, you'll see if there has been any relative motion in the front diff later... turn the input so that the fronts turn once. If the rear has turned 3.9 times then it's a 1:1, or if the rear has turned 3.545 times it's a 1.1:1
Cheers,
Pat.
16 April 2003, 10:47 AM
#24
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Argh.. not so easy without a gear linkage...
Will ring subaru..
David
Will ring subaru..
David
23 April 2003, 10:11 AM
#25
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Forgot to post on here...
I have erm obtai... seen the my02/03 service manual and had a look at the information for the 6MT box.. and the uk cars run a 1.1:1 transfer.. the australian model runs a 1:1...
David
I have erm obtai... seen the my02/03 service manual and had a look at the information for the 6MT box.. and the uk cars run a 1.1:1 transfer.. the australian model runs a 1:1...
David
23 April 2003, 10:32 AM
#26
So are you saying that a UK 6 speed will run with a 3.545:1 rear diff!
If so that's great news.
Gotta find me a 6 speed, no wait, gotta find me some money...
Paul
If so that's great news.
Gotta find me a 6 speed, no wait, gotta find me some money...
Paul
, Im getting Deja Vue and thoughts of RWD Escorts from my youth with all these diff options being the same numbers.