do I need an additive in my 8 3/4 sure grip?

-
jefframin

jefframin

http://www.jefframin.org
Joined
May 23, 2004
Messages
25
Reaction score
5
Hi folks.

I have a (very) slow leak from my 8 3/4. I want to top off the fluid.

Question - do I need to worry about the limited slip additive? When I first filled it, I know I used a bottle of the skunk oil, but I've read online that if I find gear lube that states it's good for limited slip diffs that it isn't necessary?

Thoughts?
 
jefframin said:
................. I find gear lube that states it's good for limited slip diffs that it isn't necessary?

Thoughts?
Click to expand...

Not necessarily true. At least not true for my '05 Ram 9-1/4" LSD (corporate) when I changed it. Clicked and chattered without the stuff.
 
Daves69 said:
Not necessarily true. At least not true for my '05 Ram 9-1/4" LSD (corporate) when I changed it. Clicked and chattered without the stuff.
Click to expand...

Depends on what oil they used. Generally speaking factory uses crude gear oil and some additive when doing changes. Full synthetic gear lubes (like AMSOIL) generally don't need an additive. With that being said there are some case where a small amount of gear additive is needed even with synthetic lube.
 
BlueDream said:
I'd fix the leak first and then put in the correct oil with the limited slip additive.
Click to expand...

Ultimately, this ^^ is the best route.

Jeff, keep in mind that it's a must to have the additive, it lets the suregrip 'slip', if you will, during normal driving conditions, it helps the unit to not wear out prematurely.
 
Bad Sport said:
Ultimately, this ^^ is the best route.

Jeff, keep in mind that it's a must to have the additive, it lets the suregrip 'slip', if you will, during normal driving conditions, it helps the unit to not wear out prematurely.
Click to expand...

Well, I'm not going to remove the chunk. Too much work for such a small problem.

Anybody know what the ratio from oil to additive is, if I was filling one from scratch?
 
jefframin said:
Well, I'm not going to remove the chunk. Too much work for such a small problem.

Anybody know what the ratio from oil to additive is, if I was filling one from scratch?
Click to expand...


Where is it leaking? It's quite possible you could fix it without doing that. Is it an axle seal or something?

Secondly, I don't know the exact mix, but I think if you top it off and add just a bit of the additive, it should be fine.
 
charger426 said:
................ With that being said there are some case where a small amount of gear additive is needed even with synthetic lube.
Click to expand...

Here's one of those then.
Straight Mobil 1 Synthetic LS lube didn't happen for me. Night and day difference with the additive.
 
Simple answer, if it pops and chatters, add some additive. If it doesn't when making turns, your good to go.
 
jefframin said:
Anybody know what the ratio from oil to additive is, if I was filling one from scratch?
Click to expand...

I bought a bottle from the local dealer and IIRC the instructions say add the bottle then fill it with lube.
 
off topic sorry but had to ask, was looking at your restoration page. What size wheels and tires are you using? are they factory 5.5 steel wheels? what size rubber? I am getting ready to put new tires on mine and like the way yours fill the wheel well.
 
salinasjoel said:
off topic sorry but had to ask, was looking at your restoration page. What size wheels and tires are you using? are they factory 5.5 steel wheels? what size rubber? I am getting ready to put new tires on mine and like the way yours fill the wheel well.
Click to expand...

I'll correct this post later if I'm wrong; I need to double-check when I get home.

Fronts are 195/70 on the stock HD wheels (14 x 5.5).

Rears are 235/60 on custom made 14 x 6.
 
Daves69 said:
Here's one of those then.
Straight Mobil 1 Synthetic LS lube didn't happen for me. Night and day difference with the additive.
Click to expand...

Yeah I have no idea why some do and some don't and the run it to find out really sucks. Oh and if you have to much it won't lock up....there has to be a better way lol.
 
I would add it if you have a clutch type, the cone is not as critical even though it's recommend. Use the ford stuff it's like $6 for 4 oz.
 
the 8.75 holds 2.25 quarts. if your just topping it of a little no need to add more additive. I would also try cleaning it very well and smearing some silicone to stop leak
 
Regardless of what the label on the bottle of lube implies, you must add friction modifier when used with a good limited slip differential.

If gear lube does not smell like friction modifier, it contains very little, if any, additive.
 
Can somebody tell me where I can get this additive? :banghead:

My 98 Dodge Dually is making noise in the rear. Would like to drain current fluid, add some of the Lucas Rear Oil and add the additive.

Rear gets noisy towing in 90+ degree heat in Summer. Has knocking sound when I pull into refuel. I think it is on the DOWNWARD SPIRAL.

I hear the Ford additive is the best, containing whale oil.
 

Attachments

  • 81-RAM-custom2.jpg
    46.2 KB · Views: 290
partsmonsta said:
Can somebody tell me where I can get this additive? :banghead:

My 98 Dodge Dually is making noise in the rear. Would like to drain current fluid, add some of the Lucas Rear Oil and add the additive.

Rear gets noisy towing in 90+ degree heat in Summer. Has knocking sound when I pull into refuel. I think it is on the DOWNWARD SPIRAL.

I hear the Ford additive is the best, containing whale oil.
Click to expand...

I do believe this is it: http://www.amazon.com/Ford-XL-3-Friction-Modifier-Additive/dp/B000NU5LP6
 
partsmonsta said:
Can somebody tell me where I can get this additive? :banghead:

My 98 Dodge Dually is making noise in the rear. Would like to drain current fluid, add some of the Lucas Rear Oil and add the additive.

Rear gets noisy towing in 90+ degree heat in Summer. Has knocking sound when I pull into refuel. I think it is on the DOWNWARD SPIRAL.

I hear the Ford additive is the best, containing whale oil.
Click to expand...

My rear in the dakota was quietest with 75/140 mobil 1 and a bottle of FM that napa sells on the shelf maybe CRC or sta lube??
 
You must log in or register to reply here.
-

Back
Top