Diff additive question...

Poopie D · #1 (**permalink**) 11-07-06, 04:11 PM

I am getting my new diff installed on thursday. I asked the shop foreman if they would be adding the additive and he said they do not need to as it already has all the fluids in it. Can someone let me know where the dealer can find out if they need to add it or not? I searched the bulletins and did not find anything.

Also, do you know if they do an alignment after the new diff is installed and if no, should I get one done anyways? And if I do, should I bring the settings off of cadillacfaq's or will the dealership alredy know what the alignment should be set to?

Thanks!!!

**The Tony Show** · #2 (**permalink**) 11-07-06, 04:25 PM

Bring your own alignment specs. Many techs will just reset it to "within factory tolerance", which is "between -1.4 and -0.6 camber" and "between 0 and 0.2 deg toe". That's a big range.

Gear lube:

Part # 000 089021677 - Gear Lube, 4 quarts
Part # 000 001052358 - Additive, 1 bottle

Have fun!

*edited to add* If you don't mind rotating your tires every 5-8k miles, try these alignment specs to really sharpen up the handling:

Front:

-1.0 camber
4.3 caster
.05 toe

Rear:

-1.5 camber
.15 toe

That baby will stick with those settings. I know. Plus, it's within factory tolerance so no one can blame anything on your alignment.

Poopie D · #3 (**permalink**) 11-07-06, 06:48 PM

They are saying that the additive will not be put in. Is there a bulletin I can bring them that says they are supposed to?

Also, do they do the alignment under warranty?

v-ape · #4 (**permalink**) 11-07-06, 07:11 PM

They put the additive in at Lindsay when I had mine done.

**The Tony Show** · #5 (**permalink**) 11-07-06, 07:25 PM

Quote:

Originally Posted by Poopie D

They are saying that the additive will not be put in. Is there a bulletin I can bring them that says they are supposed to?

Also, do they do the alignment under warranty?

Take your spare tire cover off and show them option code G80 (limited slip differential) on the bottom of it. All limited slip differentials require the additive.

joshdctsv · #6 (**permalink**) 11-07-06, 08:14 PM

How sad that they STILL dont have their service departments on the right page regarding the additive. I contend this is a contributor to the continual failures.

Poopie D · #7 (**permalink**) 11-07-06, 08:27 PM

Quote:

Originally Posted by Tony Orlando

Take your spare tire cover off and show them option code G80 (limited slip differential) on the bottom of it. All limited slip differentials require the additive.

I think the problem that I am having is that they think the additive is already in the diff...

I can't imagine them shipping the diff full of fluid...or would they?

Lindsay Cadillac · #8 (**permalink**) 11-07-06, 08:51 PM

The differential is shipped with some fluid in it but it's not filled to the proper level. We drain whatever fluid is in it from assembly and fill it with the proper amount of gear oil and the limited slip additive.

The G80 code is not on the V so you won't be able to use that as leverage.

If your dealer is adamant about not putting the additive in. Do yourself a favor and buy yourself a container for $5 or $6 and save yourself the hassle.

I can not believe that there are dealers that are so resistant to putting this in the differential. What is the big deal??? It's a $5 bottle of fluid that even if wasn't necesary would not have any adverse effect on the differential...

**The Tony Show** · #9 (**permalink**) 11-07-06, 08:57 PM

Quote:

Originally Posted by Lindsay Cadillac

The G80 code is not on the V so you won't be able to use that as leverage.

D'oh! I knew that, too. Time for another beer....

Lindsay Cadillac · #10 (**permalink**) 11-07-06, 09:03 PM

Quote:

Originally Posted by Tony Orlando

D'oh! I knew that, too. Time for another beer....

Tell them to take the differential apart that they take out of your car and if they don't find limited slip clutch plates in there that Tony and I will drive over and put it back together for them...

What do you say Tony?? We can take 'em...

Lindsay Cadillac · #11 (**permalink**) 11-07-06, 09:06 PM

Oh and if they are saying that the "new" differential fluid has the additive in it already. Have them get verification from TAC (Technical Assistance Center) and that you want it noted on your repair order that it's in the "new" fluid...

Poopie D · #12 (**permalink**) 11-07-06, 09:41 PM

Quote:

Originally Posted by Lindsay Cadillac

The differential is shipped with some fluid in it but it's not filled to the proper level. We drain whatever fluid is in it from assembly and fill it with the proper amount of gear oil and the limited slip additive.

The G80 code is not on the V so you won't be able to use that as leverage.

If your dealer is adamant about not putting the additive in. Do yourself a favor and buy yourself a container for $5 or $6 and save yourself the hassle.

I can not believe that there are dealers that are so resistant to putting this in the differential. What is the big deal??? It's a $5 bottle of fluid that even if wasn't necesary would not have any adverse effect on the differential...

I may have to call you and ask how to put it in! And one other question...will they need to do an alignemnet?

Also, would you mind if I gave my service advisor your phone number if they have any questions? They do not fix many V's up here...

P.S. You rock James!!!

Lindsay Cadillac · #13 (**permalink**) 11-07-06, 09:58 PM

Quote:

Originally Posted by Poopie D

I may have to call you and ask how to put it in! And one other question...will they need to do an alignemnet?

Also, would you mind if I gave my service advisor your phone number if they have any questions? They do not fix many V's up here...

P.S. You rock James!!!

No problem... Give me a call and I'll help where I can... Alignment will depend on what they loosen/remove when taking the differential out... It can be done without disturbing the alignment...

C66 Racing · #14 (**permalink**) 11-08-06, 11:15 PM

Quote:

Originally Posted by Poopie D

I am getting my new diff installed on thursday. I asked the shop foreman if they would be adding the additive and he said they do not need to as it already has all the fluids in it.

Limited slip differentials do need friction modifier. That said, they may be right but it bears some additional questions of your dealer and my confidence in them isn't high based on reading this thread.

The GM differential fluid does not come with friction modifier in it and thus does need the friction modifier additive. However, some fluids such as the AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 that I use in my 02 Z06 already has the friction modifier in it and adding more is not normally required. So if they are using a fluid similar to this one, they may be correct.

rlj5 · #15 (**permalink**) 11-09-06, 07:52 PM

I had a new diff installed recently & after driving for few days I noticed alotta noise on turns. I questioned the mechanic that did the work about weather he put additive in it. He gave me the story that it already had additive in the fluid but he added a little extra anyway. But I sure do get alotta noise on turns, otherwise the diff is fine, Guess I'll just have to put my own in and see what happens.
Do these guys at the dealership think it really is in the fluid or are they just to damn lazy to put it in or what ? Oh yeh, He told me the V's had really tight clutches in the diffs & that wasn't unusual.