VN or VL DIFF ?

FCOV6 · Post by **FCOV6** » Wed Oct 29, 2008 11:35 pm

I have a VN diff i have stripped ready to shorten for my FC but have been reading that VL diffs are about 2" shorter ? Does anyone have a VL diff fitted with stock or commo size rims say 16 or 17x7".

Sammy · Post by **Sammy** » Thu Oct 30, 2008 2:14 pm

its like this .... do you want to make the diff the same length as the standard or not ?

if yes then use the vn diff, shorten it and use 2 x short vn axles ....

if no then use the vl diff and shorten it with 2 x short vl axles ....

BUT .. if the vl diff is from any vl other than a turbo or v8 its a fair chance its going to be a 25 spline diff, whereas the vn's are all 28 spline.

FCOV6 · Post by **FCOV6** » Thu Oct 30, 2008 4:23 pm

Sammy wrote:its like this .... do you want to make the diff the same length as the standard or not ?

if yes then use the vn diff, shorten it and use 2 x short vn axles ....

if no then use the vl diff and shorten it with 2 x short vl axles ....

BUT .. if the vl diff is from any vl other than a turbo or v8 its a fair chance its going to be a 25 spline diff, whereas the vn's are all 28 spline.

The way i see it is i need it to be wider than a stock diff to accomodate the offset of commodore rims ( i would prefer to use stock offset rims and not custom). One thing i am concerned about using 2 axles the same length is the pinion will be offset which isnt ideal as it leads to premature uni wear and vibrations.

I have been reading all the related posts and are aware of the 25/28 spline issue, i was hoping i could use 1x short VN and 1x short VL axle with the VN housing.

Sammy · Post by **Sammy** » Sun Nov 02, 2008 5:16 pm

i don't know that the offset degrees (over the length of the tailshaft) is enough that its going to cause unis to fail ... i mean have a look under some 4x4's!! but it quite possibly could be an issue. i see it this way, i'd prefer to pay for a few extra sets of unis over the life of the car then lots more for custom axles ....

also the vl 28 spline axles are hard to get, i got a short vl axle for my torana and it cost me $170 .....

i hope they don't break!!

now as far as offsets with commodore rims go, if i were you i would get a commodore rim and rears discs (i assume your using vn type rear discs) aswell as the axle, throw the whole lot in the banjo housing and see where it sits, because the commodore brakes are a fair bit wider than the standard drums and this helps to offset the offset .....

i have 15x7 with 215's on the back of my car at the moment and if anything theres more clearance on the inside than i would like and a possibilty i will need to roll the guards as a minimum and maybe even pump them slightly (hoping not)

i have been told the vl diff is about 1.5 inchs shorter ... so if you use a short vn and vl axle then i'd guess the diff would end up about .5 to 1 inch shorter than a stock housing .... big question would be brakes etc as i've mentioned above ... also using a short vn and vl will only move the pinion back to the centre of the car by about the .5 to 1 inch....

another thing to think about ... i have been told that a standard r31 skyline housing is the same borg warner and they are only a few cm longer than a stock housing ... so you might be able to use an axle from one of them to get the right lengths and just get it re-drilled to suit commodore stud pattern .....

alternatively you could probably use an entire r31 diff and brakes etc and then you'd only need to change stud pattern and probably lop an inch or so off the ends depending what you need to suit your wheels....

one thing to keep in mind, you probably have 1cm to play with on the end of the axles spline wise ... for example my diff uses the two short vn axles as mentioned but there is about 8-10mm cut off the ends of them so they don't bottom out on the centre. this would obviously depend on what you end up with length wise but if you wanted to go just a bit wider to suit commodore offset then that might be all you need.

i hope i haven't confused everything too much hahaha

FCOV6 · Post by **FCOV6** » Sun Nov 02, 2008 6:15 pm

Sammy wrote:i don't know that the offset degrees (over the length of the tailshaft) is enough that its going to cause unis to fail ... i mean have a look under some 4x4's!! but it quite possibly could be an issue. i see it this way, i'd prefer to pay for a few extra sets of unis over the life of the car then lots more for custom axles ....

also the vl 28 spline axles are hard to get, i got a short vl axle for my torana and it cost me $170 ..... i hope they don't break!!

now as far as offsets with commodore rims go, if i were you i would get a commodore rim and rears discs (i assume your using vn type rear discs) aswell as the axle, throw the whole lot in the banjo housing and see where it sits, because the commodore brakes are a fair bit wider than the standard drums and this helps to offset the offset .....

i have 15x7 with 215's on the back of my car at the moment and if anything theres more clearance on the inside than i would like and a possibilty i will need to roll the guards as a minimum and maybe even pump them slightly (hoping not)

i have been told the vl diff is about 1.5 inchs shorter ... so if you use a short vn and vl axle then i'd guess the diff would end up about .5 to 1 inch shorter than a stock housing .... big question would be brakes etc as i've mentioned above ... also using a short vn and vl will only move the pinion back to the centre of the car by about the .5 to 1 inch....

another thing to think about ... i have been told that a standard r31 skyline housing is the same borg warner and they are only a few cm longer than a stock housing ... so you might be able to use an axle from one of them to get the right lengths and just get it re-drilled to suit commodore stud pattern .....

alternatively you could probably use an entire r31 diff and brakes etc and then you'd only need to change stud pattern and probably lop an inch or so off the ends depending what you need to suit your wheels....

one thing to keep in mind, you probably have 1cm to play with on the end of the axles spline wise ... for example my diff uses the two short vn axles as mentioned but there is about 8-10mm cut off the ends of them so they don't bottom out on the centre. this would obviously depend on what you end up with length wise but if you wanted to go just a bit wider to suit commodore offset then that might be all you need.

i hope i haven't confused everything too much hahaha

Thanks Sammy, that helps a lot and hasnt confused me more. I think i'll give the brakes on the banjo a go and see how it all sits and then make a plan of attack.

regards,
Nick.

matches · Post by **matches** » Tue Nov 04, 2008 11:50 pm

will putting the commodore brakes and axles fit the original ek diff housing? i'm not sure if i've understood this correctly, will doing this change the stud pattern to commodore without having to change the housing?
L&K

FCOV6 · Post by **FCOV6** » Wed Nov 05, 2008 12:23 pm

matches wrote:will putting the commodore brakes and axles fit the original ek diff housing? i'm not sure if i've understood this correctly, will doing this change the stud pattern to commodore without having to change the housing?
L&K

The brake backing plate will bolt to the housing (not sure what years) so you can mount the brakes and work out what width/offset wheels will fit - basically a mock up of how things sit. Although i did read on the EH site that they fit VN rear disc brakes onto EH housings but it doesnt mention how you fit the rotors over the studs without redrilling the rotors.

Sammy · Post by **Sammy** » Wed Nov 05, 2008 1:32 pm

you'd either have to change the axles to commodore or re-drill the stand axles ... but the standard axles might not have the right offset between the bearing and the disc mounting face....

also the old beasts use a different bearing assembly.... you could machine the end of a housing down to fit into the hr housing and then fit the taper roller bearing cup to it etc ....

torana have the right bearings that it will just bolt up....

the only thing you'll find in the hr housing is that the axle will be a bit loose, but it will be good enough to give you a rough idea of where everything is going to sit.

matches · Post by **matches** » Sun Nov 09, 2008 8:05 pm

okay cool thanks, i wasn't sure.

FCOV6 · Post by **FCOV6** » Sun Nov 09, 2008 8:56 pm

matches wrote:okay cool thanks, i wasn't sure.

I had some photo's emailed to me from the EHCC and they get the disc's drilled to early holden stud pattern so the rest is a bolt up deal.

matches · Post by **matches** » Tue Nov 11, 2008 3:46 pm

thanks, i'm wanting to run vr commodore brakes but i don't have the knowledge/ experience to shorten a commodore diff, or the money to get someone else to do it for me. just looking for an easy way to change it over. is there enough room to redrill the original ek axles so the studs will go through the rotors?
L&K

FCOV6 · Post by **FCOV6** » Tue Nov 11, 2008 4:33 pm

matches wrote:thanks, i'm wanting to run vr commodore brakes but i don't have the knowledge/ experience to shorten a commodore diff, or the money to get someone else to do it for me. just looking for an easy way to change it over. is there enough room to redrill the original ek axles so the studs will go through the rotors?
L&K

There doesnt look like enough space to re drill for commo stud pattern, you could get commodore axles resplined to suit but it would work out easier to just use the whole diff.

matches · Post by **matches** » Sun Nov 16, 2008 12:21 am

i'm not really able to shorten a diff myself (too useless) which model torana have the right housing for the commodore axle bearings? i'd rather get commodore axles resplined than even attempt to shorten a diff.

Sammy · Post by **Sammy** » Mon Nov 17, 2008 12:57 pm

if you get a diff housing out of a uc torana these should be the right length and will go straight into the ek (that is assuming the brakes don't change things too much....) i put a complete uc diff in my ek wagon years ago, it was slightly stronger than the banjo and width was spot on with the uc drums ....

however shortening commodore axles i not something i've had much luck with ... twisted the ends off the axles in no time!

matches · Post by **matches** » Tue Nov 18, 2008 5:37 pm

cool thanks, did you have a fairly serious engine in front of that setup or is it just not strong enough when shortening/ resplining axles? with using a uc diff housing did you use 2 short vr commodore axles or didn't it matter with having to shorten anyway?
sorry for so many questions,
L&K