Ever since I replaced my LSD oil with mobil 1 I have had this ERRRRRRRRRR noise in the rear when I accelerate (no its not the normal exhaust noise, its a very weird noise).

I heard that you dont need LSD additives because the LSD part is sealed etc. So what would cause this noise???? Is mobil 1 a bad oil to use in the differential? Should I replace it with something else? Or do I need a LSD additive for some strange reason?? Or could mobil 1 having LSD additive cause the problem??

Thanks for any advice

 

was the noise there before the oil change? i would replace it with nissan oem oil or whatever the spec indicates.

 

no it wasnt.... I went to nissan dealership and they pulled out pennzoil 80w90...... I guess I could put non synthetic in there, but I figured synthetic would be better.

 

I assume you used the M1 LS 75W-90? The write-up I found says it's ok for LSDs. But from your description it sounds like something isn't happy.

 

Ya 75W-90 is what I used....... Maybe I should switch to a non synthetic or maybe try some LSD additive for the heck of it????

 

You didn't overfill it, did you?

Car should have been level (on four jack stands or a lift) when you filled it.

 

well i was lazy, I only lifted one side of the rear, drained and then filled it, but then I put the car flat on the ground and let the excess oil flow out. So it shouldnt be over filled

 

i changed mine with a hand pump earlier this year with a synthetic blend/ oem weight(generic brand). No issues whatsoever.

 

Well, there goes my theory.

Here's what I'd do: Go to the dealer and buy from them whatever fluid they'd put in the car. If they don't have any to sell you, ask them exactly what they use, and go buy it at your friendly parts store. Swap out the fluid, and see if you still have the noise. If you do, make an appointment for ASAP at the service department. Keep your receipt for the last fluid purchase. Good luck, and I'll be curious to know what the outcome is.

 

I went to O'Reillys Auto parts (were i bought the mobil 1 gear oil) and told them my situation to see if they had any recommendations (figured why not). They said they never heard of any problems with mobil 1 gear oil, and said its one of the best on the market. They mentioned royal purple being good to, and then I asked if they had any. They had to go back to the back to see if they had any, and they came back with there last 2 quarts. I asked them how much, and they said free (WOOHOO). So i will be putting that in later and seeing if it fixes the problem..

 

Does the noise get louder as you speed up?? Does it sound like rattling??

 

no its not a rattle, its more of a hollow ERRRRRR noise....

 

O'Reillys gave me Royal Purple 75W-140, I have read that thicker protects better (in diffs) but will give worse gas mileage. I didn't care about the small gas mileage decrease so I put it in, so far I haven't heard any weird noises from the rear since. It has fixed the problem, at least as far as i can tell. Maybe I just needed a thicker oil, or maybe Mobil 1 75W90 isn't very good