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MG MGB GT V8 Factory Originals Technical - Need heads-up on limited slip alternatives ...

Please educate me on the various type of limited slip differentials out there ... I'm totally confused. It's my vague understanding that a positraction, which I guess uses some sort of clutch, is fundamentally different from a torque-biasing unit based on gears and springs.

I have an MGC rear end with a 3.07 gearset under my V8 at the moment. Works great, but in things like wet leaves, one wheel will just spin out. Don't like that tendency, and I think a limited slip will solve it. I don't know whether it would be better to pull the C unit out (which would be a shame as it was quite costly) and put something else in there, or just have a Quaife unit (the only LSD of which I know that will pop right in there) put in.

My budget is around $1000. Of course, the less the better.
Sam Peeters

Peter,
Well, you are in UK so shipping might skew things, but you could get a 8 or 8.8 or 9" done up (depending on your skills) for under $1000. BUT posi traction as it has been explained to me would not solve that issue. In fact I have had people warn me to be carefull in wet weather with a posi as if you punch it they both tear loos and your backside is trying to pass your frontside.. Again, could be heresay, but I tend to trust the guys that said that.

The Quaiffe on the other hand does exactly what you are looking for, HOWEVER I only see them for $1400US and I am not sure if they could withstand the power of a V8. Hopefully someone here will chime in on that issue. If it could AND I could get better gearing (say 3.27:1 range) I would have consireder staying with my stock rear end as the axles look plenty strong.

Larry
Larry Embrey

Peter
I've read on this site that one of the Nissan's has an axil with an offset limited slip diff', in a variety of ratios (disc's as well). Mentioned by someone from Adelaide (OZ) I think.
The advantage of this is that one side is just the right length so you merely have to shorten the other side of the tube and can use an axil from the "good" side. Half as much tube shortening, no resplineing and off the shelf parts so it's got to be a fraction of the usual price (and the spare parts aspect is also nice). Try the archives.
If I ever change the back axil thats the route I'll take.
Peter

I too have a 3.07 rear from a C and because it was about the only thing out there, I had a Quaife put in. It just seemed easier than getting a Ford rear made up. Personally I think it's great -- completely solved the severe one-wheel-spinning problem I was having, esp. when I put on a stiffer set of sway bars.

The units are *much* cheaper if you obtain them in the UK -- about 40% less than at Moss, etc. The shipping cost isn't too bad at all if you just allow for surface rather than air, and you need pay no VAT. I received a heavy lump of metal in the mail and I couldn't quite visualize how it goes in, but installed it looks as follows:

http://home.earthlink.net/~davidd_dt/lsd.JPG

Cost me $90 to have it installed (I took the rear end off first and brought it in). You do have to order one specifically for the 3.07 -- it is NOT the same as the regular 3.9 unit. The unit is silent -- Glenn and others had warned that it's quite sensitive to being properly set up or it will whine, but it came out fine. Most of the time you don't feel its presence whatsoever. You really do feel it on dirt roads or slippery surfaces (we have tons of cheapo "chip & seal" roads in rural NJ which have a mix of loose gravel and tamped-down pavement), or as you say when one tire is on wet leaves and the other is on dry pavement.

As far as durability, I called the company and they said it should be fine up to several hundred HP -- so its strength would seem to far exceed that of the C rear end itself.
David

Would it be correct to characterize the Quaife as a Torsen type diff? Interestingly enough, mine spins both rear tires but I'm quite sure it's a normal late B axle.
Jim Blackwood

Jim,
That;s because you always have tou BIG FAT FOOT on the gas pedal!!

Heh I actually put extra thrust washers in my diff when I put it together, made the spider gear action REAL tight. makes it a semi locker, she will squeel around corners etc, and full power no regard for tires takes-offs are a pleasing sideways affair.. heh

Larry Embrey

I have definitely read that a Quaife is indeed a Torsen-type design. But what the heck does that mean?

I don't know about this item in particular, but apparently Quaife makes very, very high quality products. A mechanic friend tells me they are some of the best products in the auto industry today. (I think I even saw Steve S. give 'em a thumbs-up here, and that's saying something!!)

I get the feeling that "Quaife" and "cheap" do not belong in the same sentence, but I would muchly like to have one.
Terrence

Just for drill, I went to www.quaifeamerica.com to see what was there. It's very interesting to see how many applications they have - even for Ford's 8.8 and 9 inch differentials. Now if one of these things in an MGB rear was strong enough to take abuse from a SBF...

Wayne
Wayne Pearson

In a torsen design, instead of spider gears each axle shaft is splined to a pinion gear which is part of a worm and pinion set. Actually several worms for 1 pinion, equally spaced around the carrier. Each worm has spur gears on one or both ends which engage similar gears on an adjacent and parallel worm, which engages the pinion for the other axle shaft. It's not a locking differential in the truest sense like a Detroit is, but the ratios are such that it is far easier to transmit drive torque through the carrier to the pinions than it is to spin all those gears when one wheel is off the ground.
Jim Blackwood

Sam,

You be educated. :)

http://www.torsen.com/products/products.htm
Carl

Since there are obviously no rednecks in this crowd...I feel it is my obligation to inform you of the Lincoln Locker. All you need is a Lincoln welder, a welding stick and about 10 min. Total cost...about $3 for the stick and $200 for the welder.

Galen
G.P. Copes

Hehe there is always that GP. problem is that tends to be hard on diff internals and as I haeve proven, they are not up to the task unlike a ford or other V8 rear-end..

Larry Embrey

Clide and I tried welding up the diff on our truck to make an Eastwood Locker. But then one day a halfshaft broke and that made me say those famous words 'right turn Clyde!' For it sure as hell turned through 90 degrees fast.
Clint

Some of the rock crawler boys will just pour the diff carrier full of lead. It locks but there's a little give, and it'll (maybe) spit out the lead before blowing an axle. Periodic touch ups required.
Jim Blackwood

Lincoln Locker! LMAO!
bill jacobson

This thread was discussed between 27/10/2002 and 07/11/2002

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