synthetic lube and sure grip

[CKnoop]

I'm sure this topic has been covered before. I'm thinking of changing rear end lube to synthetic lube I have sure grip. do I need to put any additive in it like the reg stuff? or is the synthetic stuff ok without it ? thanks for any info

 

[cerberusiam]

Yes, you will need the LSD additive with synth. Put in 2 bottles of the DC reccomended additive and you should be good. You can add a third if it still wants to chatter on corners but if that doesn't cure it it is time to look at the clutches. Several people have tried other types of lubes and got them to work. The only luck I have had is with the DC additive.

 

[Phil Stuart]

CKnoop,



I've changed a few rears with sure grip over to synthetic and have NOT needed the friction modifier. Try it first without it and go from there.

After you fill with synthetic, do about eight figure 8 turns and this should tell you whether you need it or not. You probably won't.

I'm planning on changing out the old lube in my 89 and going synthetic.



What are you going to do with the 89 chassis after you pull the motor?



Phil

 

[CKnoop]

thanks for the info I will try it first without and see what happens
I am going to keep any good and usable parts most body parts are rusty planning on making a trailer out of the back half of the frame and bed that way I can use it for storage and have a spare rear end if I need it

 

[bgilbert]

I'd suggest trying it WITH the friction modifier/additive FIRST. Your rear end doesnt have a drain hole, so its tougher to get 8 ounces of additive into it when its already full. Lets say in the end your truck didnt need it, just call the additive cheap insurance. Or instead of calling it an additive, which some look at that word as something added but not necessarily needed, call it what it is, a friction modifier, which, I'm just a dumb truck driver and not an english teacher, I imagine modifier means to modify, change, alter, or lessin the friction?? I could be wrong... Bill

 

[Phil Stuart]

Originally posted by bgilbert

I'd suggest trying it WITH the friction modifier/additive FIRST. Your rear end doesnt have a drain hole, so its tougher to get 8 ounces of additive into it when its already full. Lets say in the end your truck didnt need it, just call the additive cheap insurance. Or instead of calling it an additive, which some look at that word as something added but not necessarily needed, call it what it is, a friction modifier, which, I'm just a dumb truck driver and not an english teacher, I imagine modifier means to modify, change, alter, or lessin the friction?? I could be wrong... Bill

Just don't fill it all the way to the bottom of the hole and that will leave room if you need to add any modifier to it. Even so, it shouldn't be THAT difficult to siphon a bit out if needed

What you don't want is too much friction modifier in the lube or else the clutches will slip and you'll have NO limited slip function at all!



Phil

 

[bgilbert]

Phil, I never thought about having too much additive in the LSD rearend. Hmmm, I believe I have 7-8 ounces of additive in it, I wonder if its making my limited slip function useless. Because my right rear tire doesnt hesitate to slip and spin on just about any surface. Very embarrasing when I have to get out and lock the hubs in, engage 4WD, just to pull in the garage when theres a little snow on the ground or on a slight incline in a grassy yard and right rear tire just spins. Maybe my LSD isnt working properly? Bill

 

[RGT]

it sounds like you LSD is not functioning right, both my tires always break loose togethor, especially on snowy or wet surfaces. It is fun being able to put this thing sideways with almost no effort though... .

 

[cerberusiam]

I am running 2 1/2 bottles of additive with synthetic to keep the LSD from popping on turns. This is due to using an additive that was "supposed" to be the same thing as the DC stuff and with straight synthetic it skidded the outside tire on turns. The LSD will still pop a little on a hard turn when warm. Even on slick pavement it will leave a double spin track. To much modifier is probably dependent on the condition of the clutch pack. If you have an LSD and only one tire is spinning there is a definite problem. You might check the bolts that hold the LSD together as they have a habit of loosening up. Too loose and it will be time to rebuild the diff.