Diff additive a 100% MUST?

[Mervz]

I did a rear diff fluid change today.

We put in VP Racing GL100. A few folks said (as well as VP), that i didn't need the GM limited slip additive when using it.

Was i wrong to not use it? I'm worried now i'm going to hurt it becuase i didn't put it in.

 

[muddywaters]

Diff. additive

Mervz, Hi, From my experience, every time i used something other than the Gm lube and additive i developed a chatter in tight turns. Now i haven't tried every after market lube , so if the chatter doesn't occur you lucked out, otherwise drain ,refill with the GM type.

 

[Mervz]

Re: Diff. additive

Mervz, Hi, From my experience, every time i used something other than the Gm lube and additive i developed a chatter in tight turns. Now i haven't tried every after market lube , so if the chatter doesn't occur you lucked out, otherwise drain ,refill with the GM type.

Couldn't i just add the additive into the diff?

 

[Full Bull]

if VP you added is a synthetic, than the additive's not needed...if it's not, then put the additive in...it''ll cut down on the noise.

 

[Mervz]

th VP GL100 is a semi-synth

It says its for limited-slip diffs.

 

[scorp508]

Drive it... see how it is. If it chatters try something else.

 

[Full Bull]

agree....my bet is, however, that you'll need the additive to help cut down on the noise...

 

[Mervz]

thanks Gents. I was reading over at CF.com ( i know, i know), and one of the guys over there (BBE i think) swears by this stuff. He's actually the person who made me try it. He claims no need for the additive.

Oh well, i guess the only way is to try it!

 

[muddywaters]

Additive

Hi, Just a thought, Would the GM additive be any benefit
if it was added to a 1988 manual tranny?

 

[Mervz]

Re: Additive

Hi, Just a thought, Would the GM additive be any benefit
if it was added to a 1988 manual tranny?

I don't think so. The additive only makes the clutch disks spin easier in the diff so that the car can make tight turns. I'm not quite sure what effect it would have on a transmission. :confused

 

[CKA_Racing]

Here's the way i see it. It won't hurt to have added the additive.
Better safe than sorry.

 

[yellow91]

I hae a different question, can I use Mobil 1 75 90w and additive in my 91 vette?

 

[muddywaters]

Additive

I assume Mobil 1 75-90w is synthetic and might not be compatible w/GM additive.

 

[vms4evr]

I'm using the Mobil 1 75W-90 synthetic in the diff with no problems. I have the additive in it. I've also used Red Line synthetic with no additives and that works fine too. The Red Line says the additive is built in. Mobil 1 doesn't. The synthetic is supposed to keep the diff a little cooler.
Graham