You can technically switch at any time. Synthetic in older engines tends to find weak spots which causes the engine to leak, but with 50k you shouldnt have a problem. Me personally, I stick with conventional and swap it every 3k.

 

i"ve been a 3 month 3000 mile person since I started driving, back in the 1900's (that sure does sounds bad)...no reason to stop now, never had a problem. The Nissan I had before this on was 7500 miles between changes, I could never make it that far....

 

Ive researched on BITOG and sythetic proves no benifit unless you are looking to run high performance applications or long intervals. In the first 3k with conventional oil, the wear properties are almost identical in an n/a engine. Ill stick with my Castrol GTX. I put Valvoline Synpower after I got the truck and I started getting oil out of the crank shaft seal ...... that was my lesson learned.

 

At about what mileage do we need the different drivetrain fluids changed? I think my manual had 2 different scenarios, one was normal and one was hard driving conditions. I just drive mine normally around town with the occasional longer ride somewhere, and I think that city part fell under harder driving conditions... almost to 19k now.

 

I think it starts calling for fluid changes at 60k. I just read about the transfer case and I believe it said check it every 30k and replace the fluid at 75k. Don't quote me on that though.

 

I believe the book says every 15K for differential and 30 K for trans.and transfere case

 

My OM states change the front and rear axle fluids every15000 miles, check the transfer case fluid every 30000 miles and to change the auto trans fluid every 60000 miles. I didnt see anything about changing the transfer case fluids, just to check the level.

 

Lets see a show of hands from everyone who actually changes their axle fluids every 15k miles.....

 

EVERY 15k!?!?!?! Are they nuts? The rear axle has synthetic fluid in it. I would think that should be able to go 30k easy. And the front doesnt have power going to it for at least 50% of the time, more like 90% with me.

I too, would like to see a show of hands; who changes their axle fluid every 15k miles?

 

I'm close to that on the rear diff. Changed it around 18k, then it got changed with all the other fluids around 26k when the transmission shop got mixed up and thought they were changing everything (I told them everything except the rear diff).