Anybody used Lubrimatic 75/140 synthetic gear oil for the 30K service?The 75/140 wt seems to be hard to find in synthetic, but would rather go with this in the rear and stick with 75/90 for the front.

 

Why don't you mailorder either Redline or Royal Purple off the internet? That's what I did and was able to get Royal Purple 75w-140 for less than $8 a quart.

MikeyB

 

I'm with MikeyB on this one. I like to support my local business's, but with these kinds of oil/lubes, its often highway robbery what they charge.

I can buy a quart of Redline online for $7.00; and the guy down the street sells the same thing for $11.40. He says "Redline's recently bumped up their prices" yeah right.

I told him thanks, but I'll wait for the UPS man .......

 

does it do any good/harm to introduce synthetics to a truck that has never used synthetics and has 113,000 on it ?

 

I wouldn't hesitate a moment to introduce syn oil to a used vehicle - especially in differentials.

You might read a bad story about someone introducing syn oil to a badly sludged engine, and the high detergent syn oil loosening it up and plugging the oil pump screen - but I've never seen that happen in person. If you are worried about sludge in an engine, then I'd do a half and half mix with dino and syn to help flush it out gradually.

If you took half way reasonable care of an engine, I'd go syn and not look back.

 

Depends on how long you're going to keep the truck. With 113k on the clock and you're planning to drive it another 200k miles I say go for it.

MikeyB

 

unless it starts nickel and dimeing me to death , hope to get thru next winter with it

 

I've been using LE's 9920 in both my F150 for ~80k miles and my Wife's Dakota for ~20k. I have had absolutely no issues. I did run the 90wt in the ford for about 10k; I switched back to 75/140 and noticed better mileage (~1/2mpg) in the winter.

Another thought: The oil looks pretty clean when I drain it every year. I am thinking about going to an extended drain interval, but before I do that, I need to start oil analysis to ensure the oil is sill in good shape.

HTH

Tony

 

What is the skinny on the lube weight ? I have an 03 dually, I was planning to use Mobil1 75/90 on both diffs... What are the pro's/con's of going 75/140 ?

 

Unless the changed the specs' according to the owner's manual it states use 75w/90 both front and rear for all types of service. That's what I run and if it goes south on me then DC will have to replace it and or the truck because that's what they(DC) states to run.
Oh yeah, been running AMSOIL synthetics from about 7k miles. I've got 37k now and did a 30 k service just to make sure they were G to G

 

I am using the Amsoil Severe Gear 80w90 front and rear.

 

There's a TSB out that states 75w-140 can be used in the rear end now.
Highly recommended for towing in the hot weather.

MikeyB

 

Yeah, when I did my first change, the guy at the dealership told me that they now recommend 75-140 for people that tow. He also said they have Redline for less than the DC stuff, and it wouldn't effect the warranty. His price for Redline wasn't that bad, so I went for it.

 

just the rear or front and rear ?

 

Just the rear only. The front is still 75w-90.

MikeyB