I have spent hours searching but couldn't find the info i need on my vn diff conversion into lx Torana . I need this diff to be 15-20mm wider wider than standard per side . I have 2 options #1.is knock an even amount off each side which will require at least 1 axle to be shortened and resplined, or #2 use two short axles and hope i can get the diff the right width for my wheel offset I need to know how wide would a vn diff be (BUF to BUF) if i used 2 short axles?? , and will the tailshaft clear the tunnel??. i would much prefer to use unmodified axles and would like if the upper mounts were evenly attached to the axle tubes . I would go with a skyline diff but i cant get one without paying too much and i have vn rear ends coming out of my rear end. I would appreciate any advice i can get on this conversion because i want to get it right first time. cheers, Rob.
need advice for my diff conversion
Started by
_robslxhatch_
, Oct 09 2010 11:07 PM
48 replies to this topic
#2
Posted 09 October 2010 - 11:10 PM
The VN short axles are very close to standard Torana axle length if I recall correctly. If you have a VN diff sitting around why not measure it for yourself?
#3
_robslxhatch_
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Posted 10 October 2010 - 07:07 AM
The VN short axles are very close to standard Torana axle length if I recall correctly. If you have a VN diff sitting around why not measure it for yourself?
the axles are close to torana length but how do i know how wide the space between them ?? unless i put the 2 short axles into an old diff hemisphere , (i think i just answered my own question)but i am concerned about the tailshaft tunnel though.
#4
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Posted 10 October 2010 - 07:15 AM
If you use the standard short axle as the new long axle on the cut diff and the old long axle cut and re splined as the new short one you can achieve a diff around 10mm shorter than standard so I can not see how you could get a diff 20mm wider unless you use two long VN axles cut and re splined as the standard short axle would be 20mm or so short.
I would think trying to equal out the axles would push the centre out too far causing the tailshaft to run into something.
I would think trying to equal out the axles would push the centre out too far causing the tailshaft to run into something.
#5
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Posted 10 October 2010 - 12:16 PM
If you use the standard short axle as the new long axle on the cut diff and the old long axle cut and re splined as the new short one you can achieve a diff around 10mm shorter than standard so I can not see how you could get a diff 20mm wider unless you use two long VN axles cut and re splined as the standard short axle would be 20mm or so short.
I would think trying to equal out the axles would push the centre out too far causing the tailshaft to run into something.
correct me if i am wrong but the short axle is around 100mm (this is a rough guess as the axles are at work) shorter than the long one , and if you used that as the long axle then cut the long one to make it even shorter again then you would be taking 200mm off the length of the diff (100mm each side) i only want 100mm or so off the width of the long side only. i am hoping that if i use two untouched short axles which seem to be around an inch or so longer than a standard torana axle (again this is a guess) then it will get me somewhere around 1460- 1480mm from BUF to BUF. Surely someone here can tell me whether or not the tailshaft will clear. In the meantime i got some measuring to do.
#6
Posted 10 October 2010 - 06:31 PM
I think you did answer your own question - if you have a VN diff there you can measure the short side from the cast centre in the housing, if you assume this measurement for both sides then you get your overall width with two short axles.
The VN short axles are very close to standard Torana axle length if I recall correctly. If you have a VN diff sitting around why not measure it for yourself?
the axles are close to torana length but how do i know how wide the space between them ?? unless i put the 2 short axles into an old diff hemisphere , (i think i just answered my own question)but i am concerned about the tailshaft tunnel though.
I think the VN short side axles are quite close to Torana axle length. Adding disc brakes might get you some extra width but basically that configuration is going to be very similar width to Torana.correct me if i am wrong but the short axle is around 100mm (this is a rough guess as the axles are at work) shorter than the long one , and if you used that as the long axle then cut the long one to make it even shorter again then you would be taking 200mm off the length of the diff (100mm each side) i only want 100mm or so off the width of the long side only. i am hoping that if i use two untouched short axles which seem to be around an inch or so longer than a standard torana axle (again this is a guess) then it will get me somewhere around 1460- 1480mm from BUF to BUF. Surely someone here can tell me whether or not the tailshaft will clear. In the meantime i got some measuring to do.
Again you can find the position of the tail shaft by taking your own measurements - you already have enough parts on hand to determine the overall width and pinion position. This way you know for certain too!
#7
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Posted 10 October 2010 - 08:51 PM
would the borgy axles sit fit further apart than the banjo ones in the housing ?? this would add width too ..I was just hoping that someone has done the conversion this way and could tell me if they had any dramas. I will let those who are interested know my results.
#8
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Posted 10 October 2010 - 08:56 PM
the tailshaft shouldnt come close to fowling anything if it does obviously your diff yolk is not inline with the output shaft of the box. i think maybe you might be better off getting an expert to tackle this one for you mate. a torana tailshaft runs down the centre of the tunnel but it is offset in the housing, one side is longer from the centre of the diff yolk. make your measurements off the banjo.
#9
Posted 11 October 2010 - 06:09 AM
Could be a few mm perhaps, basically all you have between the two axles in either diff is the spider gear pin(s), in the Borg Warner the 4 spider pin setup is a bit chunkierwould the borgy axles sit fit further apart than the banjo ones in the housing ?? this would add width too ..
#10
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Posted 12 October 2010 - 06:22 AM
I will do some more measurements later but the commo short axles are exactly 12mm longer than the Torana ones. by the looks of it the pinion will move over approx 50mm.I cant believe no one knows whether this can be done , surely someone has looked into it, or done it.
#11
Posted 12 October 2010 - 07:35 AM
Of course it can be done, just shorten the long side of the housing and use two short axles.
I'm just saying that you need to do your measurements first to make sure the end result is what you wanted!
I'm just saying that you need to do your measurements first to make sure the end result is what you wanted!
#12
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Posted 12 October 2010 - 10:11 AM
I just can't understand why you would want to run your tailshaft on such an angle just so you can use two short VN axles when there are many better options.
#13
Posted 12 October 2010 - 12:56 PM
The angle can't be that bad? The Borg Warner gearset isn't actually much bigger than the Banjo one, so if the Banjo uses equal length axles then a Borg Warner with equal length axles won't have much more pinion offset than factory?
#14
_robslxhatch_
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Posted 12 October 2010 - 01:00 PM
I just can't understand why you would want to run your tailshaft on such an angle just so you can use two short VN axles when there are many better options.
what are those better options??? two short axles enables me to have the upper mounts evenly welded onto the axle tubes and i would not be running a crappy re-sline. I have vn diffs already, Its 300 bucks cheaper to shorten 1 side and maintain the commodore stud pattern, and it looks like if my initial measurements are correct that it will go pretty close to the width i need. The tailshaft , it seems, will move over approx 30-40mm toward the drivers side than the standard torana flange.
The angle can't be that bad? The Borg Warner gearset isn't actually much bigger than the Banjo one, so if the Banjo uses equal length axles then a Borg Warner with equal length axles won't have much more pinion offset than factory?
thats what i am thinking it seems that it will only move over around 30mm more than the banjo flange.
#15
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Posted 13 October 2010 - 11:47 AM
I have recently been looking at doing exactly the same thing for my UC conversion.
I am running commodore wheels so a bit of extra lenght is desirable.
From the measurements I have taken, the pinion will be ~40mm further to the drivers side.
I need the housing centered because the UC top arm mounts are closer together and will both be welded to the cast steel centre.
I should have both diff's stripped and measured tonight, and will report back.
I am running commodore wheels so a bit of extra lenght is desirable.
From the measurements I have taken, the pinion will be ~40mm further to the drivers side.
I need the housing centered because the UC top arm mounts are closer together and will both be welded to the cast steel centre.
I should have both diff's stripped and measured tonight, and will report back.
#16
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Posted 13 October 2010 - 12:46 PM
ok ,from what i can gather so far. the commodore short axle is 17mm longer than the Tory one . when pushed into the centre 2 short axles measure 1465mm from hub to hub , add disc rotor thickness and you have approx 1475mm. The pinion will move over around 40mm ,yes, but only 30mm ,or so,more than the Torana one which is itself off centre.
#17
Heath
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Posted 13 October 2010 - 05:56 PM
Thrashing an axle in one direction for 10 years and then wanting to thrash it in the opposite direction for a few more doesn't sound very good for longevity. And if you wanted to drive it like a grandma I'd guess you'd keep the Banjo?
#18
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Posted 13 October 2010 - 07:37 PM
I need the housing centered because the UC top arm mounts are closer together and will both be welded to the cast steel centre.
Ah eh? arn't the UC top mounts further apart?
From the measurements I have taken, the pinion will be ~40mm further to the drivers side.
Won't the uni's be running at excessive angles?
#19
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Posted 13 October 2010 - 08:02 PM
i would think that if the tailshaft was 40 mm across then things with brake. like gearbox casings. and using a old axel that spun one way its hole life them load it up and make it go in the other direction is a good way to brake it
#20
_robslxhatch_
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Posted 13 October 2010 - 08:26 PM
i would think that if the tailshaft was 40 mm across then things with brake. like gearbox casings. and using a old axel that spun one way its hole life them load it up and make it go in the other direction is a good way to brake it
err , what about raised 4wds where the gearbox is a meter higher than the diff??. nah the only thing i have to worry about is the angles not being exactly the same and causing some kind of vibration.Also there is a possibility that an axle being put in the opposite side may fail easier than a new one, but it is still better than a re-spline and because they are cheap/free ,hell, i dont care if i bust one a week. a re-spline will cost me $160 per side and billet ones $600 per side.
Edited by robslxhatch, 13 October 2010 - 08:28 PM.
#21
Posted 14 October 2010 - 06:46 AM
You can still look at the driveshaft angles in a single plane, its just that this is no longer perpendicular to the floor. Any sideways movement of the rear uni is going to automatically be matched by a cancelling angle at the front uni so that part is fine. And to address your specific point, a lowered Torana usually ends up with not enough up/down uni angle so this could help make up for it. As long as it fits in the tunnel I don't see any real down side other than being a little more difficult to measure the total angles.Won't the uni's be running at excessive angles?
#22
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Posted 14 October 2010 - 02:39 PM
Not my cup of tea for a performance application.
Keep us updated with how you get on with this one.
Keep us updated with how you get on with this one.
#23
_coupe202_
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Posted 14 October 2010 - 05:15 PM
What the big deal with having the top mount welded onto the centre housing not on the tubes, have you looked into VL commmodore axles
for the length you chasing they are shorter than the VN commmodores by how much not sure, another way is VK commodore salisbury 28 spline they are shorter than the VL commodore ones by how much I cant answer that.
for the length you chasing they are shorter than the VN commmodores by how much not sure, another way is VK commodore salisbury 28 spline they are shorter than the VL commodore ones by how much I cant answer that.
#24
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Posted 14 October 2010 - 06:04 PM
What the big deal with having the top mount welded onto the centre housing not on the tubes, have you looked into VL commmodore axles
for the length you chasing they are shorter than the VN commmodores by how much not sure, another way is VK commodore salisbury 28 spline they are shorter than the VL commodore ones by how much I cant answer that.
i have certainly given thought to using different axles but the reason i am thinking about the vn style short axle is people cant give them away , i wish i had a tone of different axles to chose from but the only thing i have a few of is vn diffs. i would love it if someone here could measure a few commodore axles and let us know the different lengths .Either way i can get the width i need without using resplines, cheaply , with commodore stud pattern, for use with commodore rear brakes.
#25
_gmlj6_
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Posted 14 October 2010 - 06:05 PM
your completly right. i got hi tuf axels for 650 all up icluding bearings. there not billet but there not std second handers either.
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