Well I'm not sure really...because it had been a long time since my diff had been drained an flushed out..it had just been topped of for years...I bought 3 bottles of the Mobil 1....drained the diff, filled it up, drove about 30mi(let that stuff swish around a bit) drained again..and then refilled...I had an issue where when shifting into gear there was a slight kick and its gone now(knock on wood)..it also felt as though acceleration was less restricted slightly...overall I know it was a good thing b/c it had not been changed in a long time...look at it this way if dmeetro is puttin it in his diff, its a good thing!
If I remember the manual does call for that, however synthetic is more adaptable....just like how Mobil 1 says about thier engine oil that basically if you HAVE to use 10w-40 but you want to use 10w-30 synthetic just go ahead and do it...I'll look for where I read that article......
I would go with synthetic diff oil just because if you are driving a car for 60 on the same oil its better to have something taht lubricated better, and like pomes says it will addapt better to temperature variation.
I live in the south, its fine...it works out great. if you wanna use 80w90 that'd be fine too..don't think gear oil is going to give you extra power...dmeetro said above that he would go with synthetic, and I did as well....so just go ahead and drain it (this oil stinks!) and fill it with the new oil....as I said before, I drained, filled it up, drove a bit, drained and refilled all over again...
I did drain that oil and I had added the high proformence dino oil by valvoline
but I thought since it says high proformance it equal to synthetic.
but I hear you said synthetic is smoother seems interesting.
when do you drain the gear oil? and how long would it last before needing to be
synthetic is synthetic...and nothing else is. However if you drained your diff and put in some new valvoline you're good...as far as smoother, I've heard the same thing...there are opinions on both sides when it comes to syn vs non-syn...its still an open debate really...and its supposed to be drained every 60k...I'll do it more often b/c it only costs a couple of bucks and takes a couple of minutes!! I really don't think the job of gear lube (royal purple, redline, amsoil) is to "give" you horsepower...don't believe the hype IMO...but as dmeetro has said, changing all of your oil/fluids(diff, engine, tranny) you will get minimal gains......its a question of clean and proper lubrication, not some magic fluid that gives you more horsepower....once again IMO!! In most cases, don't believe what the manufacturer says if seems to good to be true...read what other people have to say!
I heard royal purple and some other syntheic redline makes it very smooth in the
car. it seems like a good oil to try out. they got heavy duty gear oil from lucas then they got high performance which one is better? then we got synthetic.
I believe heavy duty gear lube is just that...heavy duty for like tractors and stuff...lucas probably makes good stuff...its not a matter of what's the best gear lube in the world, its an individual based thing(for the most part)..for example, I've also heard about the syns making things awefully smooth and for me its worked out...however if you look hard enough you could find somebody preaching from the top of the mountain that its the worst thing ever made for cars...then they'll ppl who say its "okay"...then they'll be ppl who say its no different than anything else...I'm not a lubrication specialist, so I came on here, trusted a respected member who knew more than me....and it all worked out!! We all want what's best for our cars!
we are just consumers of oil products we just have to try any products to
just see if it works out. the worst thing about it is we dont know if the oil product is doing its job since I found some info saying some oils shear down and and does not have its film on parts. we are just consumer. companies dont give us
detailed info. there was something about lucas foaming up which is not good for the oil. but lucas does not tell us consumers about it.
I went to get some engine flush , oil filter and synthetic engine oil yesterday after reading what my peers (you guys) had to say on it and while chatting to the guy on the floor who told me of his years experience in building engines etc told me that in an engine as old as mine 200+k's putting syn oil in could result in problems like blowing smoke and said to use a non syn oil and add some Moreys heavy duty stabiliser or Lucas oil, which I have used in other cars with good results. Has anyone else heard of this? Not the additive but the possibility of problems of using a syn engine oil?
Yea I used Lucas and it still smokes a little on start up but adding that qt of oil changed from two weeks to two months. It basicaly expands O rings and of course thickins your oil. I would never use syth on a 200k engine. On a new preformance engine, yes, on an oldass stock engine, no.