[Francis]

Hey Gang,

I'm trying to locate an LSD for my GT. I have read and have found only 3 types for the GT.

Quaife:
Plus: Supposedly the best for the Opel - much better than the ZF and in a different class than the Phantom Grip. Replaces weak spiders. No clutches to wear out. Proven. limited lifetime warranty.
Minuses: Costs new usually $1495, can be found for $1295 including shipping.

ZF:
Plus: Decent LSD unit. Replaces weak spiders. Note 40% locking.
Minus: Harder and harder to find, costing more and more, never know what condition the clutches are in or if the unit is shot. Also, if you're using gears 3.67 and up you need a 3.67 and up LSD unit, otherwise it won't fit. The cost of these units are now in the $550-900 range.

Phantom Grip:
Plus: It's cheap.
Minuses: Still uses the weak spider gears. $300-400.

My questions:
1) Does the Quaife make sense to buy at 1295 or is it better to take a risk and buy a ZF and not really know what you're getting?
2) I've heard of ZF coming in 75% locking but do these units fit the manta a/opel gt rear? Who rebuilds ZF units? Where can you buy a rebuild kit? Can you rebuild them with 75% lock?
3) Is the Quaife that much better than the ZF?
4) Because of the cheap cost of the Phantom Grip it seems like it can't be all that good of a unit. Not trying to condemn the unit, just skeptical. Almost sounds too good to be true. What's the opinions?
5) If anyone has a good used ZF or Quaife for a 3.67 ratio, I'm interested in buying. Let me know.

As always, thanks for the help,
Francis

 

[RallyBob]

Your assessment is almost perfect, but I would give the nod to the ZF style limited slip over the Quaife for hard driving. I've driven a Quaife-equipped, 40%, and 75% ZF lsd-equipped, and Phantom Grip-equipped Opels.

The Phantom Grip is okay for normal road use but not for high hp or racing.

The Quaife is very non-instrusive and an excellent road differential for the most part. Turn-in is very good with this diff, but if your car lifts an inside rear tire it will NOT put the power down, as a Quaife requires both tires to be on the ground to register torque and therefore an unweighted tire will spin like an open differential. Good for smooth racetracks or well set-up road cars.

The ZF 40% is probably the best all-around diff, it's stronger than stock and puts the power down pretty well even if you lift a tire. Turn-in is not as good as a Quaife, but not bad either. A 75% (or sometimes 80%) ZF is awesome for rallying or for road racing, but for road use or autocrossing it will require a rethink of the suspension tuning since there will be a significant increase in understeer especially at turn-in. But it puts the power down very well.

BTW, any 3.18 or 3.44 differential is different from a 3.67 and numerically higher differential. The ring gear thickness' were altered to work with the different pinion gear diameters, so there are two carriers regardless of brand.

Bob

 

[DaveJ]

A genuine ZF LSD repair kit containing all the plates, costs about £100 (about US$195) in the UK. If you are willing to claim the VAT back from UK Customs & Excise, it would come out at £82.50 + Delivery (£10-20).

 

[Francis]

Hey Dave,

Where can one get a genuine ZF LSD repair kit?

Francis

 

[baz]

http://webcat.zf-trading.com/


you will need to know which car and model but there you go
took me 3 min to find with yapoo and the letters ZF

 

[DaveJ]

The following company can supply genuine ZF LSD repair kits in the UK.

www.motoscope.co.uk , in Northallerton North Yorkshire. They will send stuff worldwide on request.

Contact Address:
Motoscope (Northallerton) Ltd
Standard Way Industrial Estate,
Northallerton
North Yorkshire
DL6 2XE
England

Telephone: +44 (0)1609 780155
Fax: +44 (0)1609 780062

Email: [email protected]

Opening Times:
Mon-Fri: 0900-1800 GMT
Sat: 0900-1700 GMT

 

[azzi]

Got a ZF 80% in my Manta, Certainly makes for a interesting road-ride.

I'll post a few vids I took yesterday, no 0-60 runs though as the roads were damp and I couldn't stop the car going sideways as I pushed the throttle in 2nd.

 

[bear]

Well, some good news for me, and I need some now. Rally Bob kinda endorses the NOS ZF posi for my V-6/T-5 swap on the GT, so I guess the $1100 + it cost me plus the $325 to install it and replace anything inside that looked suspect was a good move. And there are rebuild kits available too, things are looking up in the Opel world.

 

[Francis]

Thanks Dave for that info. I sent an email to the company .... so I'll let the group know of what I hear.

Azzi - would love to see those vids of your car. You mentioned that you have a 80% locking on your manta. This is the standard ZF for the Opel manta a - correct? Did you rebuild it with 80% locking? Or bought it this way? If so, where - looking!!!

Namba - where did you get your LSD? Is it 40 or 75/80% locking?

Francis

 

[bear]

Francis, I got mine from Martin, a contact Gil of OGTS has in England. He made the trip to Germany and picked the NOS unit up for me and shipped it here. That was about 2 years ago and at the time had one other NOS and about 6 used ones. I don't know the % lock-up, I was just glad to get a posi. I had called Quaife USA and Martin called the home office in England and neither had or was interested in building units for the Opels then, although they were listed on both websites as available. HTH.

 

[azzi]

Francis,

The diff in my car was bought seperatly and came as an 80% version.

The Salsbury diff used in Manta's GT's and others are all interchangable, but with a crown wheel and pinion of ratio's above 3.67 there is 4mm diffrence on the LSD face. I forget which way around it is, but one need a 4mm spacer plate made up to run the other ratio's.

Don't know if you have the Rover SD1 over in the States, but they also had a Salsbury diff, but of HUGE BHP potential.

Just change the halfshafts and tubes into the rover diff and away you go. they fit straight in. You open up a whole world of ratio's then.