A friend of mine says the the spartan locker (ratchet type) is going to trash the t56 that I just got. Its not in the truck right now. Its going to replace a nv3500.
Is that true?
If so he also said the Best kind of posi to replace it with is the GM 'S-spring' clutch type.
Is that true or should I argue that its a bunch of BS

 

People run Detroit lockers in t-56 manual equip cars and I haven't read about any issues and the Detroit is an automatic ratchet type locker. I don't see the correlation between the diff destroying the transmission. I have also never personally heard of using a factory gm posi for an upgrade. I think the only downside to running the locker it it will be noisy "ratcheting" noises around corners and depending whether you are coasting or on the gas around the corner it will load and unload.

 

is there any kind of proof of this? He is going to say that I am crazy and just makin' stuff up or 'I don't know what im talking about' when i thought the same thing. The transmission just sees a load from the rear end regardless of what the actual wheels or axles are doing.
Right?

 

Well not once in this thread did anyone mention the locker being bad for the transmission and these guys are running standards with some serious hp. The people in that thread are very knowledgeable when it comes to vehicles.

 

Depends on how you drive. If you are on it a bit in a corner and the diff is locked up, the bucking from the tires chirping it's great for the trans but it certainly isn't anywhere near the load of a clutch dump.

I'm sure it would be fine. You won't find that combo much. Maybe on a 4x4 site. Not many lockers used here. I know of folks that use spools with their T-56 and they hold up fine.

 

Lockers DO affect synchronized transmissions.....been there done that and will never go back. It has to do with the way the locker "freewheels" and the amount of slop built into them to operate like they do. It affects the way the trans blocker rings slow/speed the drive gears during shifts. I ran a detroit locker behind a synchro'd t56 for a few years and I would always get a random synchro clash here and there during normal driving and it drove like crap in general. Put a spool in and the same trans shifted much smoother all around and never clashed again. I'd put a clutch type posi in it if I were you....

 

Ok, sounds good enough for me. Now, Does anyone know what the name of the rear end that was used in the second gen f-bodys that is clutch type and has the big s spring? I can't afford a $500 truetrack or $400 eaton unit and I see these clutch s spring units here and there but i don't know the name of of them and I want to look them up/find them for sale.
Or does anyone else have a recommendation for a rear end unit that's not a bazillion dollars?

 

I believe "Auburn" makes the "limited slip" diffs in GM. They are a cone type vs disc clutch pack.

My $02 is a Eaton 400lb LS

if $ are tight, could hit a junkyard...but condition of unit is ?

 

I second what JMM said... years ago when I went to a spool in my GTA it was T56 equipped. Much research told me NOT to use a locker... plenty of people told me not to so I went with a spool and never looked back.

 

My God.........

 

I have a locker in my car and it does seem to create havoc with the T-56. during normal driving it takes a lot of finesse to not get clunking between shifts. If I would have looked into it more I would have never got the locker.

 

When you normally shift with a locker, it seems that about the time the synchros speed match the gear selected, the locker hits the coast side of the castelation in the differential, momentarily changing the speed of the output shaft.. The solution, if you choose to go with a locker, is to consciously shift either faster or slower. This way, you wont upset the speed match job that the synchro has to perform. Consider that under just about any other differential, the synchro assembly is only speeding up or slowing down gear speeds with the output shaft remaining at a fairly constant speed while the input speed may vary. With a locker, the moment you depress the clutch, the differential freewheels UNTIL the locker hits the coast side. this causes a slight momentary, but sudden change in the speed of the output shaft. Granted, not everyone has this problem, but it is common. If you grab the drive shaft of a car equipped with a locker, you can turn it back and forth 1/8th of a turn while the car is in neutral. Thats gobs more then with any other properly functioning differential. The other thing with a 6 speed and a locker is that the car can feel like it has a broken panhard bar when you apply power and then let it off again in a curve or turn. My tuner was convinced I had left the panhard bar in my car completely disconnected while we were getting on the highway a couple of years ago!
I continue to use my locker despite its bad behavior because while it feels broken, it hasnt broken while others have had problems even with the most expensive differentials.