Holden V6 CONVERSION

[NeilsTransit]

G'day SOS, My Tranny is a VG120 Mid Roof SWB 1999 vintage with a Series 1 VN +GM Hydramatic 700 autobox, 5 stud 14" wheels and an 8 stud 4.56/1 diff. As far as I know there were 3 diffs that would fit this model...4.11,4.56 and 5.14 ratios. I've searched high and low for a 4.11 but they seem not to have made it to OZ and they're old as as well. Anyways the Commodore diff is about 3.9/1 so the 4.11 not really the best ratio I would think. So you reckon an F100 axle would fit, what about the wheel size on the F100 and would there be a problem with the brake connections? I've had a few old Holdens in the past and changed just about everything on them but never done this mixing and matching stuff with different manufacturers before. I'm currently in Victoria atm.

[sos recovery]

a mate of mine told me the F 100 axle would fit ..
the 3 axles you state are the rear loading axles yes? not the 2 types of solid axles fitted to the swb [which btw dont our lwb vans ] ..
i used to work at the factory these came out of in the UK ....so ill find out a bit more about the F100 thing i reckon youd have to change the hubs which shouldnt be too much hassle but it gives you a 9 inch diff with a variety of ratios pretty much indestructible ..

im running a 4.11 diff but i think the internals were shipped over here as i bought it with the supercharged lump and running gear in it ..it seems to cruise pretty well at 110 kph ive yet to fit the tacho interface so i dont know what rpm the engine is turning at that speed but it feels right
my only concern is i bought this to run my bikes to the drags and track days and run it up the 1/4 mile to see how quick the old girl can go and i wanna see if the prop and diff can stand a thrashing ..ill let you know lol .. ..
ive had the old girl upto about 175kph with a fair bit left in her but the van weaved a bit much so i slowed down untill i can improve the handling [maybe just the tyres]

[NeilsTransit]

My SWB is a front loading diff. The info about what axles will fit I got from Minormatt here on the Forum. At one point I tried getting a 4.11 diff shipped out but Customs here wanted a kings ransom in tax and I had no idea if the diff was any good in the first place so after much research I gave up on the idea. I like the Commy V6 as it is not too complicated compared to the original DOHC 2lt Twink engine as there is seems to be a lot of them around for sale with blown head gaskets (90's vintage).My rev counter shows 4,300rpm at 100k's which is nearly double what it should be so apart from overheating issues it's extremely heavy on fuel. Yes keep me posted on your drag speed over the distance

[sos recovery]

ok you have the "H" Timken axle which comes with 4ratio choices 3.9:1,4.11:1,4.56:1and 5.14:1
the "G" Salisbury axle which fits the lwb wont fit your van as far as i know
you should be able to work out with a bit of maths which ratio youve got ..if i were you id be taking a tape measure to my van and susing out which.. if any ..axles would fit the van ..that are readily available here such as older ford capris ,cortinas, mk 1 and 2 transits .any of the Jap stuff, Ford xd falcon rear end ?

[sos recovery]

ive just given my mate up in qld a petrol swb if that has a 3.9:1 diff in it your welcome to contact him hes Transitdan on here where are you based /

[sos recovery]

http://www.ebay.com.au/itm/FORD-TRANSIT ... SwSHZWce4v
check this out

[NeilsTransit]

G'day SOS, The diff on my Tranny has a metal tag which has 4.56/1 stamped on it and I've looked at other Smiley SWB's and they are the same and it also seems like a high ratio diff by the high RPM showing on the rev counter. I was wondering if you've given a SWB to your mate did it have the original engine in it and wouldn't he need the diff for himself anyway but I will contact him just in case? Your Tranny has been modified so doesn't have the original diff as the original engine would have been the DOHC Twink 2l engine which needed the high ratio diff to get the power up. So with your Tranny what is the RPM when your doing 100k's but it actually sounds like from what you say in previous posts that a 4.11 diff would be ok

[sos recovery]

Dannys breaking the swb anyway for bits for his lwb
it was bog standard so i reckon you can tell from the vin what ratio the diff is ..and the axles is no good to him
He s worth a try anyway ,i dunno what rpm my engines doing mainly cos i still need to connect the tacho interface to get the tacho working but ....it doesnt dound like the engines labouring or overreving so im guessing its been sorted [thats what i understand anyway]

[NeilsTransit]

Thanks SOS for all your info. In my previous post I meant to say low ratio diff for more power not high ratio

[DodgeRover]

NeilsTransit I'm running the 4.56 diff in my Mk2 in 4th gear (1:1) i'm doing about 3400rpm at 60mph, are you sure your auto transmission is selecting the last gear or going into lockup properly?

[sos recovery]

3400 for a Buick V6 is a bit high normally itd be around 1000rpm lower @60mph [96kph]

[DodgeRover]

3400 for a Buick V6 is a bit high normally itd be around 1000rpm lower @60mph [96kph]

Neil says his is doing 4300 at roughly the same speed! I wonder it the auto box is shifting out of 2nd or 3rd? Either that or his axle tag is very wrong.
Assuming the box is shifting ok and final drive when it's in lockup is the usual 1:1 the diff ratio sounds more like a 5.8 to be pulling that many rpms.

[sos recovery]

the engine in a commodore is usually pulling about 2000rpm @100kph[approx 60mph]
mine sounds slightly higher but ill let you know as soon as i get the tacho hooked up exactly what its pulling ..
and ill have a look at my diff tag

[NeilsTransit]

The autobox is definitely going through 4 gears but I'm not sure about lockup as the 4th gear is 0.73/1 according to the manual. This is my first autobox ever so I'm not overly familiar with the terminology. If you have overdrive is that what 0.73/1 means? If so how can you have lockup if that means it's 1/1 in overdrive/4th gear? The diff could be 5.14/1 but I don't think so because the road speed at 60k's for example matches the odometer speed, I gauge this by the fact that I'm going at the same speed as the other road users when in 60k zones and 60'ks is what my odometer speed is reading. Another clue that all the gears are being used is that in 4th gear the vehicle can go from a low speed to a high speed without the revs changing a lot so there must be a big gap in ratios between 3rd and 4th gear. This causes towing problems due to this big difference, the original manual gearbox had 5 gears which makes towing a lot easier I would think but hey what would I know,I'm only a gardener!

[DodgeRover]

If that's the ratio in 4th then it's definitely not the diff you think, try jacking it up and turning a rear wheel and count how many turns the prop makes.
Lock up just means it acts like a manual box when the clutch is up rather than slipping slightly