gm limited slip additive

**godless-phoenix** · 12-02-2010, 01:02 PM

hey-lo my friends, i was wondering if the gm limited slip additive would be ok to add after i put the diff. fluid in already...i forgot to add it when i put in new diff. fluid, witch was a few months ago, and it whines at lower speeds, so i was just going to go ahead and add it, if thats ok...dont want to mess anything up of course

**Too Fast** · 12-02-2010, 01:33 PM

Won't hurt. But probably won't help a whine either. The only problem I see is getting it in, since your already full. Siphon some out, maybe, but no too much. The additive is there mostly to prevent the limited slip clutches from making noise in tight corners.

**godless-phoenix** · 12-02-2010, 02:01 PM

ahh i see ok...so, what do u think would help the whining, its bad when im in reverse, but i can hear it at lower speeds... i had my diff. repaired a couple years ago and i have a mac rear end gurdle if any of this info helps

**KMdef9** · 12-02-2010, 02:26 PM

You need to check the fluid you added into it. If it already contains additive, DON'T add anymore additive.

I know most Lucas products have it, but double check none the less.

**godless-phoenix** · 12-02-2010, 02:49 PM

Originally Posted by KMdef9

You need to check the fluid you added into it. If it already contains additive, DON'T add anymore additive.

I know most Lucas products have it, but double check none the less.

it was mobil synthetic 75/90 i believe

**pajeff02** · 12-02-2010, 07:04 PM

Clutch type or torsen posi? Even with torsen they recommend the limited slip additive -- had to look it up for another member not too long ago.

**98maro** · 12-02-2010, 07:16 PM

i put some on mine twice... it didnt work..
still whines starts at 35mph and stops at 80..
why? i dont know

**godless-phoenix** · 12-02-2010, 08:44 PM

Originally Posted by pajeff02

Clutch type or torsen posi? Even with torsen they recommend the limited slip additive -- had to look it up for another member not too long ago.

shit, i dunno...im assuming the stock diff. and axle is the clutch type?

**Too Fast** · 12-03-2010, 02:25 AM

Here's how to tell the difference between a clutch type and a torsen equuipped diff, if you can get both rear wheels off the ground at the same time:

Spin one of them forward. If the other side goes forward with it, you have a cltuch type.

If the other side doesn't move, or spins in reverse roatation, then either you clutch type limited slip is completely worn out or your car has the torsen style. This always jacked people up at my shop, they said "You car doesn't even have a posi???" Tryed to explain that a torsen works differently, but they still had a hard time believing me.

And, again, the additive most likely won't stop any kind of whine, but it won't hurt to try.

**pajeff02** · 12-03-2010, 03:01 AM

From what I have read on here, '99 was the transition year to the torsen differential. Here's the quip about additive: http://www.torsen.com/general/genera...modifier added

**godless-phoenix** · 12-03-2010, 07:24 AM

Originally Posted by pajeff02

From what I have read on here, '99 was the transition year to the torsen differential. Here's the quip about additive: http://www.torsen.com/general/genera...modifier added

i just assumed it was clutch type, cause i had no idea,haha...but ill take your word for it

so i have the torsen style...from burn-outs, i can tell when im going straight, both tires will make marks, but if im turning right lets say, and burning out, i only see one tire mark...im going to adjust my rear lower control arms this weekend, so when i have the car up ill spin the tires just for piece of mind

**99'CajunFirehawk157** · 12-04-2010, 07:22 PM

FWIW, some diffs don't like synthetic oil, mine is one (auburn) and I run two bottles of gm additive in mine with dino oil, runs quiet. Also, I have heard of people running ford posi additive too.

**godless-phoenix** · 12-04-2010, 08:57 PM

i put in the additive today, let you guys know in a day or 2 what happens...also i turned the wheel when i had it jacked up, and the other wheel does turn the opposite way. so i do have a torsen

i also noticed some "play" in the axle. when i was turning the wheel forward, and then went to turn it backwards, the axle would take second to "lock up" it seemed like, dont know if thats good or bad...