lubrication questions
Thread Starter
Burning Brakes
Joined: May 2005
Posts: 826
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From: Pearl MS
lubrication questions
I got a couple of questions that I have been brewing over.
I am in the middle of going thru the rear suspension and will have the diff out. When replacing the posi lube and diff fluid, should I use the GM stuff or go syn (Lucas or something)?
How often should I change the trany fluid (4 speed) ? What should I use in it?
I am in the middle of going thru the rear suspension and will have the diff out. When replacing the posi lube and diff fluid, should I use the GM stuff or go syn (Lucas or something)?
How often should I change the trany fluid (4 speed) ? What should I use in it?
Melting Slicks
Joined: Jun 2001
Posts: 2,429
Likes: 14
From: CA
You should get the GM Posi additive at any Chevy parts counter. I think it requires 2 bottles, can't remember. As for lube, in the diff use API GL-5 (80W-90), & in the trans use API GL-4 (75W-90). Not too sure of the oil weights, but make sure you use a GL-4 in the manual trans. GL-5 has chemicals which may harm syncros. As for Dino vs. Synthetic, that's up to you. Regular non-syn gear lube has been used in millions of cars for millions of miles with no wear problems. Fluids are good for 75,000 miles / 5 years, (at least that's when I flush the fluids from my car).
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
Volunteer Vette sell the diff lube as a kit. You get two bottles of diff lube and two bottles of posi additive; just enough for one diff change. I believe most vendors sell it like that and it is usually the original GM product. Of course the local chevy dealer would have what you need.
Bernie
Bernie
Thread Starter
Burning Brakes
Joined: May 2005
Posts: 826
Likes: 0
From: Pearl MS
So you guys dont see any benefit (pros-cons) on synthetic in the trany and diff.
I had a guy at work telling me that the synthetics do not have much of a viscosity change over the life of the oil like the regular oils do - something to do with the single size molecular chains in the synthetic vs. random and multilpe size molecular chains in the oils from the crude oil distillation process. He esentially said that the synthetics wont sludge up.
I had a guy at work telling me that the synthetics do not have much of a viscosity change over the life of the oil like the regular oils do - something to do with the single size molecular chains in the synthetic vs. random and multilpe size molecular chains in the oils from the crude oil distillation process. He esentially said that the synthetics wont sludge up.
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
Why buy something more expensive when it doesn't do any better job than the original and doesn't last any longer? Some contend that Mobile 1 is the best oil you can use in your engine; but I change every 3,000 miles and, for my driving, I can't see the benefit. However,, I'm sure in certain applications it is valid.
Bernie
Bernie
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Originally Posted by skydaddy
So you guys dont see any benefit (pros-cons) on synthetic in the trany and diff.
Been wrenching on cars and bikes since the early 60's and it took a long time to get me away from dino oil in everything. I'll never go back now - synthetics are just plain better.
I won't argue at all with those who claim that dino is fine if you change it often - it is "fine". For me though, for however long I do leave the lubricants in, I want them to be the best available and to me, that would be synthetics - primarily Mobil 1.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
I have a manual on rebuilding T5's and it says in their the advantage of synethetic is longer intervals between oil changes but at a cost of increased noise.
I also read the Dino oil clings better on engines that are only driven weekends. Synthetic oil is for engines used regularly in high mileage.
I stick to Dino oil.
I also read the Dino oil clings better on engines that are only driven weekends. Synthetic oil is for engines used regularly in high mileage.
I stick to Dino oil.
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Le Mans Master
Joined: Oct 2002
Posts: 5,714
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From: Silver City NM
St. Jude Donor '05-'07
Here's the Amsoil location for info on syn gear lubes.
Do a search online and you'll find THOUSANDS of websites with the info you require. Some folks just can't let go of that GM loyalty. Me, I use whatever works BEST
Dep
Do a search online and you'll find THOUSANDS of websites with the info you require. Some folks just can't let go of that GM loyalty. Me, I use whatever works BEST
Dep