39 replies to this topic

[antelopeslr5000]

From my limited knowledge, a Hydratrak differential is a LSD. However, it's a speed sensitive rather than torque sensitive LSD.

[TerrA LX]

Hydratrak limited-slip differential uses a cartridge-type
fluid coupling, which progressively and smoothly increases torque transfer to
the wheel with traction. This is in direct response to the reactive speed
difference between the wheel with traction and the opposing, faster rotating
wheel -- the wheel that is slipping. Thus, the more one wheel slips, the more
useful traction that is transferred to the opposing wheel.

The standard holden/BW lsd is a plate-type (act just like little sprung clutch plates) that locks up fairly rapidly and sharply if one wheel spins faster than the other. They can be taken out and torqued up tighter if you want less slip before it starts turning the other wheel as well. The downside is that they lock up just as sharply at low speed, which the viscous type don't, so the rear drifts out more easily if you provoke it in a corner at low speed - but fun as long as you're ready for it!

[REDA9X]

Great diff, I have one in my Senator. The VT1 stroker HSV's were the last cars to have them fitted. They were introduced with the VR GTS

[REDA9X]

it fits in the standard housing, but it's expensive. Look at the prices for a full house VT Senator series one, then look at a full house VT 2 Senator from new you will see more than a $10,000 price drop, mainly due t hand bulit stroker engines, 6 speed conversion and Hydratrac

[ls2lxhatch]

I have read more bad reviews of the hydra track than positive reviews. Apparently once the oil overheats they turn into an open centre.

This site explains how the different types of diff centres work.
http://auto.howstuff...ifferential.htm

[Toranamat69]

If you are after traction a hydratrack is a poor idea - the worst thing you can do to try and get traction is to let 1 wheel lose grip before trying to bring the other wheel into play - it is already to late to ever get back the optimum traction unless you lift off the go pedal.

The reason car manufacturers use these is because they are maintenance free.
Clutch LSD's do a better job but are a wearing item which you can kill pretty quickly if you drive them too hard and have really grippy tires.

With a car like a commodore where they don't suffer anything like the weight transfer issues on the rear end they will work fine as you have similar weight over both rear wheels. With a weight transferring bastard like a Torana, they will be shit and will act much more like an open centre.

You can get hydratracks for 9" too if you want but I wouldn't ever bother to use one.

M@

[TerrA LX]

BW standard fitment to fraud since 1970's

[TerrA LX]

Ford was using BW a good 10 years before holden did.

[Dr Terry]

Ford was using BW a good 10 years before holden did.

Hi Guys.

Ford have been using Borg Warner diffs since the 1966 release of the XR Falcon. That's about 18 years before Holden.

Dr Terry

[ls2lxhatch]

The reason why i was asking about Hydra Trac is because I want a diff that isn't a F..d 9". Purely for the reason I'm stubborn and there will be no parts from that manufacturer in my car!

You can build a 9" without using any parts from Ford if you want. The 9" LSD design is superior to the BW LSD design.

It all depends on your budget and application.

[Gump]

i got a quote for a 9" for my hj they wanted $3200 31 spline axles everything new bar the housing.

gump

[ls2lxhatch]

John Taverna Chassis
9� Housing with used 31 spline axles suit commodore discs $1150

3.55 LSD new gears $1350
3.55 Detroit Locker $1700

Final Drive Diff Conversions
9" housing with new 31 spline Moser axles $1400.
4" tailshaft with uni's and yoke $400