Diffs, FAQ

[Immortality]

I have a 98' v.s holden v.6 ute it has a lsd but doesn't behave like on when its off stands, after reading ur post I tried to find a harrop/eaton 28 spline "early" true trac center but I want to use PayPal to purchase one but I couldn't see that option for there websites so I started looking around and found only 31 spline "early"true trac if any one has one to sell or know of were I can go to get one the way I need too please advise, also my brother seems to think that dropping the oil out, flushing it with diesel, emptying it then putting new oi in might bring it back to life any thoughts?

Sent from my GT-I9100 using Tapatalk

I wouldn't think so, the LSD single pegs when their isn't enough friction between the cones and the LSD housing due to wear. When the cones/housing wears, the cones effectively bottom out in the housing. The only way to fix that is to machine the end face to get the proper clearance. A simple oil change won't fix the mechanical wear.

So my VS static diff (trailing) can't be removed and exchanged for the VS Calias IRS I have sitting in carport?

You can't fit an IRS setup into a chassis manufactured with the live axle diff as the mounting points are different.

Maybe a custom replacement could be Jag diff?

Not sure why you would even want to do this. IF you want IRS, the best option is to buy a vehicle with it fitted from the factory.

 

[_R_J_K_]

Maybe a custom replacement could be Jag diff?

Waste of time and money. If you want IRS that badly, it would be cheaper to get a Commodore that already has it. The Commodore IRS setup isn't really that great either.

Also, if I were to use a custom diff setup I would get an R200 from a Nissan or a BW80 from a late model Commodore. Both of these have heaps of aftermarket support.

 

[Immortality]

Waste of time and money. If you want IRS that badly, it would be cheaper to get a Commodore that already has it. The Commodore IRS setup isn't really that great either.

Also, if I were to use a custom diff setup I would get an R200 from a Nissan or a BW80 from a late model Commodore. Both of these have heaps of aftermarket support.

I wouldn't say the Commodore IRS is that bad. The VR/VS models can use some strengthening of the rear subframe. The biggest problem is that the design was borrowed from another model, however Holden decided they didn't need the toe arm link that was part of the original design. HSV decided that the toe arm link was required and fitted them on the HSV (VT GTS) models, Holden saw the light eventually and fitted the toe link arm as standard equipment from the VX 2 onwards.

I've got both versions (IRS and live axle) of the VS Commodore and the IRS does ride better.

One of the suspension outfits actually worked at designing a kit to retrofit the extra toe link arms to earlier models, unfortunately they decided that it was simply easier to just retrofit a VX 2 rear suspension into the earlier model cars but this doesn't work for those of us who have VR/VS model Commodores.

 

[_R_J_K_]

I wouldn't say the Commodore IRS is that bad.

I mean comparatively to the rest of the automotive world. Most manufacturers stopped using a better version of the swing arm setup in the 80's. For me, toe adjustment doesn't really make up for its lack of adjustability else where.

 

[Immortality]

What other adjust-ability do you need in the rear suspension? Between the toe link adjustment and fitting a 2 way adjustable bush for camber (or the 4 way adjustable bushes for the earlier models) there isn't much more required for the rear end.

 

[_R_J_K_]

The ability to set everything with a turnbuckle or replacement arms. The bushes may be adjustable, but they are hardly easy to set. I'm not really a fan of the separated spring and shock either, it really limits your options in the back. It's a shame that the VE setup didn't come out 10 years earlier.

 

[Immortality]

TBH I'm not a fan of the spring/shock arrangement either (both IRS and live axle) but I guess we can't have everything ( A simple strengthening of the chassis shock mount would have allowed for a proper coil-over type set up in both configurations).

 

[DCEIVDU]

it possibly would, what would you suggest as it covers more then one section. VN/VP or VR/VS. it's also relevant to the modding V6 section and modding V8's as well. i honestly believe having a dedicated "transmission/driveline/differential" subsection would be best solution

I think leave it here. Great write up. Has cleared A lot of unknown territory for me so thanks a bunch

 

[jsnolea12]

a friend of mine has a vr v6 commodore ute, will a diff centre out of a sedan bolt straight in? as having trouble finding a ute diff for it

 

[gluten3]

I wouldn't say the Commodore IRS is that bad. The VR/VS models can use some strengthening of the rear subframe. The biggest problem is that the design was borrowed from another model, however Holden decided they didn't need the toe arm link that was part of the original design. HSV decided that the toe arm link was required and fitted them on the HSV (VT GTS) models, Holden saw the light eventually and fitted the toe link arm as standard equipment from the VX 2 onwards.

It came from Opel Omega. Opel copied simple IRS from BMW 2002 (early 70s). It did not have toe control link. Holden used this from VP-VT. Opel added the toe control link at the end of 1993. Holden did not until VX II, but still made VZ utes without toe links, so they are well and truly lagging behind.