Diff centers.

[Shaun_VK]

Hey,
Im currently half way through doing a v6 convertion to my 1985 VK and with my donor VN series one i also picked up an LSD diff, i am awear that putting the full VN LSD onto my vk will widen the track by 3.8mm either side. so i was just wondering if it was possible the remove the LSD center from the VN diff and put it into my vk as they are both bog warners. any help would be great, thanks.

[vkberlina]

yes it will fit then you have a problem with axels The later diff im pretty sure is 28 spline and odds are your VK borgwarner is 25 spline. Good news is you should be able to have the axels shortened and splines extended by an engineering shop.

Once you have checked the crwon & pinion contact area when your assembling the diff you will need to check preload on your axel bearings to make sure the axels arent jammed in tight else you will break axels and pull bearings off the axel. You also dont want them too short either.

I would try setting up a jig off the back of the housing with the original centre in and measure the length of the centre and take measurements of where the original axels sit. Then once you assemble the new centre and gears in slide in the VN axels in and start measuring.
Before you get into this too far talk to an engineering shop for two and make sure they can machine the splines up the axels further without weakening them.

EDIT: Also I dont know about the later VN centres and how they compare with the VL and earlier borgwarner centres gut there are subtle differences between the V6 & V8 IRS diff centres between the M78 V6 ones and the V8 M80 ones.

cheers
Scott

[VBRED]

Mate It is more then 3.8 mm it is about 30mm either side. As long as the splines on the axles and the ratios are the same it should be ok. It is not a simple mater of just changing the centres they have to be set up correctly. That is something best left to experts otherwise it could sound like a fire truck.

[vkberlina]

Diffs are easier than gearboxes
When setting up the crown & pinion you use a grease on the contacts of the teeth to make sure the crown and pinion are shimmed correctly and you torque up the bearing caps and check again its more time consuming than anything. When I built my diff it took me a weekend to fully rebuild it in a reasonably well equiped home workshop. The big thing to have is a hydraulic press I had to go down the road to borrow one.

cheers
Scott

[VK SL 3800]

You can also buy a brand new 25 spline lsd center fairly cheap, thats what road im going down, all you do is swap over the crown wheel pop it in setup your crown to pinion gears and your set.

[GunnVK]

Sorry to hijack this thread but i bought a 28 spline borgwarner diff from a VL 5L To go in my vk and my brother has a 28 spline borgwarner LSD out of his VS 5L wagon and he wants to swap the centeres over so he can minispool his diff wit the single spinner from mine and I get the LSD. Will this be a straight swap or will my track widen with the VS LSD center?

Thanks

[vkberlina]

Your cant swap entire diffs just the centres, theory is the centres just swaps straight over just check the width of the centres.

scott

[GunnVK]

Yeah it will be just the centres. Will put it in tonight and see.

Thanks!