Bandit TA

Hey,

I have a question about synthetic tranny and gear oil. Now I'm getting a V6 Camaro from my unlce for free and it has kinda high miles, so I'm about to do a complete tune up on it. I've already decided to stay away from synthetic oil in the engine cause of the high miles and am afraid of it starting to generate leaks or burn oil.

My question is, are there any negative affects with switching to synthetic tranny and gear oil late in a car's life??

Thanks for the help

jpk91rs

It won't correct the wear that is already there, but it will stop any new wear. It shouldn't hurt anything.

RB83L69

There are no negative effects. Go ahead and do it.

It will not cause a motor to burn oil, and it will not create leaks. It may make some leaks worse by cleaning the grunge that is acting as a gasket out of existing leaks. Even that is rare.

I would recommend using synthetic fluids throughout the car.

4L60bliss

LOL, true that. I hate when you get a car w/ tons of crap in the cooling system, so you do a flush. After the flush, you get tons of coolant leaks, since you flushed out all the crap and "Stop Leak" that was clogging the leak.

chacane67

Synthetic in the engine or transmission is fine, but I wouldnt even consider it for the differential.

4L60bliss

And why is that?

Many of the RWD GM vehicles come from the factory w/ synthetic now.

Danno

The real issue with any synthetic fluid be it oil, atf or gear oil is simply this. It is all dependent on seal condition. All fluids have a swell agent incorporated into their formula to condition seals. The different characteristics of synthetic will take time to be absorbed by older seals and that's what generally causes weeping as well as large leaks. I did my 89 with Mobil 1 diff lube, never leaked at all and within 2 wks I had a mess on the garage floor. I was going to change it back but never got around to it, just kept it full and within about 2 months it cleared up. And it's not empty, just not leaking. As Bliss stated many GM vehicles are coming through with it. It's becoming a trend for increased service intervals as environmental concerns increase.

chacane67

Some are shipped with a SEMI- synthetic, not a full synthetic. (Ford was the first to ship with a full syn and had SO many oil related brakedowns, the warranty issue was killing them). Full syn's do not have enough 'film pressure strength' for the impact loading associated with hypoid gears. Dont get me wrong, syn's are good, but in a differential the oil will have to be changed at a much higher frequency, persay in a race car where you would change the oil on a regular basis. A good parafin or crude based oil can go 100,000 miles without worry.

4L60bliss

Actually, the service interval for 80-90W is 15,000 miles. The Service interval for FULL synthetic, like what comes in GM vehicles, is 100,000 miles. I'm not saying your full of crap, but GM spends millions in R&D trying to cut warranty costs, and people like me reap the benefits of there studies. I use synthetic in my rearend.

JERRYWHO

The only time I will use full synthetic gear lube is if you have a gear driven, locker or open type diffs. On cone or clutch type diffs that's factory to our cars i use what the diff calls for.


From Auburn install manual

-IMPORTANT LUBRICANT NOTE-The
Auburn Gear limited-slip differential design has been extensively tested with high quality
non-synthetic 80W90 hypoid oils treated with GM or Ford friction additives (3 oz. of additive
will treat 1 quart of oil). To avoid differential clutch chatter (noise) and for optimum
performance, use the oil and additive described above. Use of other additive and oil types may
cause differential clutch chatter.
! Ford Part Number: C8A219B546A
! GM Part Number: 1052358


Jerry

chacane67

Now tell me, how many of you really change you differential fluid every 15,000 miles?

Just to squeeze this in so I dont sound like I may have nothing to back this up.....I have done failure analysis for GM, Ford, Chrys, Jeep, AM General and a few others here and there, specifically dealing with drivetrain. I have also been building differentials for about 15 years and have even cracked out enough to change a given oil's formulation to squeeze out another 2-3 MPH in land speed record cars (and burnt up money in failures there too).

There are more considerations to diff oil. Climate, ambient temp, GVW, vechicle load and the habbits of the loose nut behind the wheel. The 'Big Three' put a low cost, readily available oil in the vechicle and expect you to follow the book to the 'T', when it come to servicing. In reality, it just doesnt happen. Not to mention that the 'Big Three' are installing devices (differentials, transmissions, t cases, etc....) into platforms that are under rated to begin with. Just look at the 7.5" in you F-body's. They take that chance of being wrong in warranty, because they will make up for it in other ways. Just like some parts are "dealership" only, yeah, they have to retain some parts for making money on the backside of warranty.

Look, being that I'm an FNG around here, I dont really expect you to just swallow what you hear, but more would expect you to ask questions to back up theroies. I also dont see that some of you have had the luck to have the experience that I am blessed with. I'm not here to get into little pissing contests with the 'locals'. I am just here to share a hobby and exchange ideas, opinions and information.

Those who are full of their own opinions will be deaf to words of wisdom from others. In a discussion between two persons, what often happens is that each is intent on asserting his own views.
As a result, apart from hearing his own voice or views, he does not learn anything else.

Peace out~

Danno

You share the thought's of my neighbor and good friend. He is a mechanical eng in an aircraft related industry. In our case it was slightly unrelated to cars. My notice was caused by using syn oil in my sportbike. Engine oil is also used for the clutch and gearbox. Transmission action was WORSE with a full syn than with any 99 cent oil. The gearbox was more noisey, shifting was rougher. He maintains that in certain high stress applications the fact that the lube is a parafin base provides better "cushioning" as he like to call it. Keep the information flowing, I love to communicate with experts in thier fields. It's pretty much the same with the bike crowd, not much in the way of facts to back up discussion. TNX for the input. Dan

five7kid

iTrader: (14)

I have to think two or three times before responding to a thread like this, because people never seem to let facts get in the way of their opinions.

First thing that most people don't accept is there are differences between synthetics. So, most of the above discussion is worthless because the brand and type of synthetic isn't given.

Having said that, I've been using AMSOIL synthetic products since 1983, including engine oil, transmission fluid, and gear lube. I haven't had the leakage or oil consumption problems people long associated with "synthetics". The two "failures" I've observed were: 1) 1985 Olds 98 my dad had. It had been in a flood, and hadn't been maintained by the previous "trailer trash" owners. The engine had so much built-up sludge that it plugged the oil pump pickup as the AMSOIL loosened it up. If we had flushed and changed the oil more at first, it probably wouldn't have failed. 2) 1980 Citation transmission in which 2nd gear band failed at 140k miles. It was switched to synthetic at 130k. After rebuild (which I did myself), it went another 100k+ miles (not sure exactly, because the speedo quit at 215k miles, and my brother who then had the car didn't bother fixing it). I also suspect the band wore out more quickly because I engine braked in 2nd for a block before my house every night on the way back home when we lived in San Diego.

I've been using AMSOIL synthetic gear lube in many, many vehicles (most of them GM), without any leakage or wear problems. I have it now in my locker '57 rear, and factory posi in the Camaro. No wear or chatter problems, and without any additives.

I won't give blanket endorsement for any Tom/Dick/Harry synthetic. I would only reserve recommendation of AMSOIL in high-mileage engines if they have not been treated to at least average maintenance (I switched the Camaro over at 123k miles, and after valve seal replacement, didn't have any consumption problems, and no leakage problems). Auto trannies are hard to predict because they will seem to work fine up to the point where they start slipping, with no real warning. But, as said earlier, synthetic ATF will at least slow down the wear that is occurring.

FWIW, Dana at Pro Built says to stay away from Mobil 1 ATF, but their petroleum Dexron is okay.

Bandit TA

FWIW, Dana at Pro Built says to stay away from Mobil 1 ATF, but their petroleum Dexron is okay. [/B][/QUOTE]



I was not aware of that.........but I have to say, I've never heard anything bad about AMSOIL

Pro Built Automatics

As far as synthetics go, Amsoil is the best followed by Red Line.

Danno

As usual it's a lively topic. 5/7 sounds like a poster child for Amsoil, I'll bet he sells it on the side. Fact is, there are no facts other than what the manufacturers publish in their data sheets. Gotta think about this Amsoil . Two failures shortly after switching doesn't go very far in convincing me to pay through the nose for it. What facts are presented other than his using it since 1983, and by the way it's the only fact worth mentioning. Sounds to me like the old bomb's did better with "dino" based product than with this $6/quart snake oil. Everything on this subject is conjecture or personal opinion because none of us know whether it's worth it or not to use synthetics. Do any of us know for sure that that engine would have stayed together if it had syn. oil in it? Hell no. Does Dana at Pro-Built have a reason to prefer one brand of syn. ATF over another other than his personal opinion. In order to be accurate you would have to take 20 engines to allow for tolerance differences and run 10 with "dino" and 10 with syn. Then see if makes any difference. Same thing with transmissions. That's the ONLY way to get fact's about any products relative worth. A failure analysis guy is one who could give a few opinions that I would take seriously assuming he has some facts to back it up. Facts, fact's I need fact's. I think I'll watch an infomercial. By the way, I want all 20 engines and transmissions from the same plant and shift. Gadzooks-there is a guy on TV running his car with NO oil, gotta run I have to get the fact's on that.

breathment

really.. why is that? what about Mobil 1 ATF in a manual tranny? (t-56)

chacane67

Hear hear Danno!

five7kid

iTrader: (14)

You want data? Most data sheets don't include standardized test results such as four-ball wear (which most people have never even heard of). If you want those numbers as well as comparisons between their products and others, AMSOIL will be happy to provide them. They have also run several fleet-type comparisons (10 to 20 or more like vehicles with like service), and have always shown favorable results from both a wear and operating cost standpoint.

"Poster boy for AMSOIL"? Perhaps. I'll admit I have more experience with theirs than any other products, but I am only a dealer so I can get the products at a lower price (I will sell to friends & family if they want, but I don't advertise or try to make money at it). Except for the two problems that I already related (with high mileage vehicles, that I included because this thread was started with a question about high mileage change-over), I have never had any issues or had anything with AMSOIL in it wear out. Over 19+ years, that's a pretty good record - I've had more failures in that time when petroleum was in the crankcase. And, I'm not totally biased - I know of some impressive long-lasting vehicles that had used Mobil 1 (although those people did say they seemed to burn a lot of it).

Do I know what would have happened in those two cases if petroleum would have been continued? No. Neither do you. I can speculate, though, that the transmission would have failed, and probably earlier. The engine may have gone longer (it was driven for 9 months after change-over before the engine had its problem). Had we realized how crudded up it was, we would have flushed/changed more often, and it would then probably have lasted longer on synthetic than it would have on petroleum. But, AMSOIL didn't "cause" these failures - The tranny lasted longer than a lot of those TH125's did (I had a rental Fiero once with 15k on it with no 2nd gear); and the engine had been abused for the majority of its life by the previous owners, to say nothing about the flood.

Back to the original question: You won't "cause" any problems by switching over. You may have some issues already that synthetics may expose, but the worst that could happen is you'll have to fix something that will have to be fixed eventually, anyway.

chacane67

I can taste the difference.....

Bandit TA

I've decided on definitly using synthetic in the diff, still not sure about the tranny though.......maybe after the rebuild.

I was just wondering, if I go with Mobil 1 in the diff do I have to add the posi additive?

Stingraye

I used valvoline 80-90 synthetic gear oil in my locking posi, and so far has worked fine. Any of you guys have any inputs on Valvoline Durablend synthetic oil?? That's what i've been usin for a while and I like it so far. And anyone have experience with the B&M TrickShift ATF?? I just got a 350 rebuilt and i'm lookin to probably dump 10 Qts of the stuff in there. Thanks

Bandit TA

Stay away from Trick Shift........it's junk, just Type F with a blue color, it'll do more harm then good

Stingraye

how would it do more harm then good?

breathment

because if i remember correctly.. the way it makes ur shifts harder is by increasing the friction in within the tranny which makes more heat which makes ur tranny go boom..

Danno

I love stirring the pot. Actually I was trying to be humorous while still trying to make a point. One of the guy's I ride with is in the oil industry and when you give him a pointed question even he pleads the 5th. I think with some of these synthetics you reach a point of diminishing return. I run them because I can get a longer interval between changes, but I am not honestly convinced that in the real world it makes any difference. My 65 chevy impala(396/powerglide) had well over 100k when I dumped it and all it had was 60's technology motor oil.

MuttandJeff

I know this thread has been dead for awhile, but thought I'd put in my testimonial.

I've been using Mobil 1 synthetic in both engine (5W-30) and tranny (ATF-race approved) on my 98 S-10 for a couple of years now, and I'll have to say it was a dramatic improvement over conventional oil. I haven't tried the gear oil yet, maybe I will when I do change the oil in that one. I also use Mobil 1 5W-30 in my 88 T/A and recently switched the tranny fluid over to Mobil 1 synthetic ATF. Right off, the switch to synthetic ATF was noticeable in its smoothness of operation. But I just did it this weekend, I'll have to wait a week or so for the full testimonial.

For a high mileage vehicle (especially if you suspect abuse by a former owner), you may want to ease into it by adding a quart of synthetic at fluid change, then increase the ratio of sythetic fluid to conventional by a quart for each successive change until you reach full synthetic capacity. As for gear oil, proportion it similarly for the fluid capacity of the rear diff. (I forget the capacity) until you're putting in full synthetic fluid.

That seems to be the safe method if you want to go full synthetic in your vehicle. Also, by easing into it you can detect problems easier and sooner than shocking the system by using something other than conventional oil. I think this has been mentioned before on here by others so I know I'm not the first to state this.

wesilva

iTrader: (35)

This is a great thread. Wish I could have been more involved during it's run....but to the facts. Synthetic oils have an advantage over petroleum lubes because the manufacturer can control the molecular structure. Specifically, the size of the molecules. Petroleum molecules are a range of sizes, as they should be...they derived from different animal and plant material. This standardization of molecules allows the engineer to control the design for specific duties. Can the engineer fail in his choice of molecular structure versus it's intended use? Damn straight....but good design will bring good result. So...another vote for synthetics. I'll also go with Redline Products.