What's stronger, 4 spider or welded center differentials? I've heard that welded lose traction or at least chirps when shift gears and the 4 spider has more traction. But other than this, which can take on more torque?

A welded diff is stronger, because it's welded, IE there is nothing to break internally, except strip the drive gear on the outside of the diff.

A 4 spider diff is basically an open diff like the stock one, but has 4 mounting points for the gears inside the diff housing, instead of 2 like the stock diff. A lot stronger, but can still break.

With the welded diff your car is essentially 4wd instead of AWD which isn't fun for street driveability or turn radius.

As far as traction, I'm not sure as I have no first hand experience with either.

In turn's the inner wheel's must turn slower then the outter tires due to shorter distance to travel. With a welded diff. both rear tires turn at the same speed, so you will go through rear tires quicker due to the fact that you will be essentially dragging the rear outter tire, and the rear end will hop. Welded diff. is more of a straight line deal. If your going to be driving on the street, and more mileage on your tires then go with the 4 spider over the welded differential. In all honesty you probably won't make enough power to be breaking the 4 spider so don't worry about it.

fourreGsixty3 said:

In turn's the inner wheel's must turn slower then the outter tires due to shorter distance to travel. With a welded diff. both rear tires turn at the same speed, so you will go through rear tires quicker due to the fact that you will be essentially dragging the rear outter tire, and the rear end will hop. Welded diff. is more of a straight line deal. If your going to be driving on the street, and more mileage on your tires then go with the 4 spider over the welded differential. In all honesty you probably won't make enough power to be breaking the 4 spider so don't worry about it.

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Welded diffs suck for daily driving. Id go with the 4 gear spider if its street driven. If its just a track car then a welded would be fine.

ANother choice would be an lsd, i do beleive they make them for the center diffs.

You just said what I said . Yes as far as LSDs go there are 2 real choices Quaife, and KAAZ.

Quaife... http://www.optionimports.com/quaife.html

KAAZ...http://www.kaazusa.com/KAAZ USA - faq_files/content_faq.htm

Hope those can help for your possible choices.

fourreGsixty3 said:

You just said what I said . Yes as far as LSDs go there are 2 real choices Quaife, and KAAZ.

Quaife... http://www.optionimports.com/quaife.html

KAAZ...http://www.kaazusa.com/KAAZ USA - faq_files/content_faq.htm

Hope those can help for your possible choices.

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Im a little out of it right now.

fourreGsixty3 said:

In turn's the inner wheel's must turn slower then the outer tires due to shorter distance to travel. With a welded diff. both rear tires turn at the same speed, so you will go through rear tires quicker due to the fact that you will be essentially dragging the rear outter tire, and the rear end will hop. Welded diff. is more of a straight line deal. If your going to be driving on the street, and more mileage on your tires then go with the 4 spider over the welded differential. In all honesty you probably won't make enough power to be breaking the 4 spider so don't worry about it.

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How will a welded center diff cause the back tires to turn at the samw speed? you still have a diff in the back. All welding the center diff does is give you a true 50/50 split between the front and rear. The front and rear diffs will still function the same letting one tire spin faster than the other..

p.s. I still would not recommend it for a street car. You need to be making alot of power to even worry about a center lsd, or welding one up.

just my .02

The 2 and 4 spider diffs still have a factory LSD using the VCU that you see when you pull the tranny end cover off. It IS NOT an open diff. The Quaife center diff LSD is known the break the outer lower housing gear, and it also uses the factory VCU anyway. It is geared internaly to work a little better though, but with so many of them breaking, it's not worth it IMO. The Quaife front LSD units are really good though. If you have 600hp or less, the 4 spider will laugh at you and will not break. We machine them if you want to send us yours

http://www.jackstransmissions.com/p...d=300&osCsid=8e960dd0ef55b51d026c7286d5abb4fc

Jack

luvmygst said:

How will a welded center diff cause the back tires to turn at the samw speed? you still have a diff in the back. All welding the center diff does is give you a true 50/50 split between the front and rear. The front and rear diffs will still function the same letting one tire spin faster than the other..

p.s. I still would not recommend it for a street car. You need to be making alot of power to even worry about a center lsd, or welding one up.

just my .02

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It does cause the rear tires to spin the same. So parking is a bi*** and it feels wierd turning sharp at low speeds. Our cars already have a 50/50 split of power from the factory.

To the OP yes the welded diff is strong as hell, but very annoying for a daily driver. I would go with the 4 spider gears if this is a DD.

luvmygst said:

How will a welded center diff cause the back tires to turn at the samw speed? you still have a diff in the back. All welding the center diff does is give you a true 50/50 split between the front and rear. The front and rear diffs will still function the same letting one tire spin faster than the other..

p.s. I still would not recommend it for a street car. You need to be making alot of power to even worry about a center lsd, or welding one up.

just my .02

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I said "slower" because the front tires are traveling a shorter distance so need less rotation's to make a turn, and the rear traveling a longer distance will need more rotation's to keep speed, and keep a smooth turn. This won't be AS obvious with the rear/front diff.'s still splitting power.

But as we have said...we both don't recommend it for street car's...more for straight lines only Jack's 4 spider gear's with dual torrington bearing's look very nice, and top notch quality.

JayRolla said:

Our cars already have a 50/50 split of power from the factory. DD.

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Actually its 60 to the front and 40 to the rear.

PSI NRG said:

Actually its 60 to the front and 40 to the rear.

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I can't count the number of times Defiant has come into a thread and re-explained that we all have a 50/50 split.

PSI NRG said:

Actually its 60 to the front and 40 to the rear.

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You are wrong and I dont feel like proving it because yes Defiant has already. He would slap you for saying this.

The right answer is that under normal driving conditions the car is at a complete 50/50 split but... Under a hard launch it becomes 60/40 becuase of the viscous coupling. So which are we talking about? This would make sence because then if we already had a 50/50 split why would people weld the center difs other then to make it stronger?

PSI NRG said:

The right answer is that under normal driving conditions the car is at a complete 50/50 split but... Under a hard launch it becomes 60/40 becuase of the viscous coupling. So which are we talking about? This would make sence because then if we already had a 50/50 split why would people weld the center difs other then to make it stronger?

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Just for anyone searching around like i am, this information is incorrect. DSMs have a 50/50 split front to rear from the factory.

why would people weld the center difs other then to make it stronger?

to also get better traction, in order to drop your 60' times. also if you rally the car will understeer less through turns.

So i got a question, didnt feel the need to start a thread, and its related to the 4 spider so i thought id post here.i have a 4 spyder center diff on my shep stage 3, has about 5-6k miles on it.. Is the 4 spider diffs louder then the stock? When i accelerate before the exhaust notes kick in, at a higher gear low RPM (1st-4th) around 2-3krpm i hear a sort of drive train rattling 5th gear i dont hear it as much at all could be because of less vibration and more momentum, no noise on decel from high rpm in any gear that i can tell. it seems to go quiter once the trans and diffs are fully warm but i can still hear it. Could it also be carrier bearings/bushings? It sounds like the noise would be as fast as the drive shaft turning. deep clacking sort of? just changed trans fluid and it was perfectly clear. not sure if anyone else notices their drive train being louder with a stage 3 or if its just me but im curious if its normal or not. the car makes no noises coasting, no noises idling.
clutch is a sprung 6 puck ACT 2600, stock from the Tcase back with most likely origional bushings and bearings back there. 135k on the chassis.

Verified AWD is still working cause i had some snow fun btw. so i don't think anything in the rear diff is toast.. Yet.

I have no idea if a 4-spider is louder, but, I have to say, of all the 4-spider threads to revive, this was not the one. More than half of the posts are utter nonsense.

Thank google for that one

So if I go with the quiafe lsd I dont need the 4 spider?

JackM said:

The 2 and 4 spider diffs still have a factory LSD using the VCU that you see when you pull the tranny end cover off. It IS NOT an open diff. The Quaife center diff LSD is known the break the outer lower housing gear, and it also uses the factory VCU anyway. It is geared internaly to work a little better though, but with so many of them breaking, it's not worth it IMO. The Quaife front LSD units are really good though. If you have 600hp or less, the 4 spider will laugh at you and will not break. We machine them if you want to send us yours

http://www.jackstransmissions.com/p...d=300&osCsid=8e960dd0ef55b51d026c7286d5abb4fc

Jack

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Mine is on its way to you! My trust is always put on jackstransmissions.com