Are synthetics all their cracked up to be?

So here is my story. All my life I've had 4 speeds and drove the living hell out of all of them. Never had a problem. When I redid my Sprint I jumped on the synthetic bandwagon and filled it with the stuff. Well, the toploader is now sitting on the garage floor, draining.
About a week ago I was out driving the Sprint when I notice something just didn't sound right. Like a wining noise, especially in 1st and 2nd. Its hard to tell for sure because the car is pretty loud. Soon I could not get it in 3rd at all and it started vibrating really bad. Eventually I had to use only 2nd and 4th. But true to its nature, the Sprint limped home and still kept its record of never leaving me stranded.
So now it sits with its synthetic blood, dripping in a pan. Initial inspection showed no damage but spinning the shafts makes me think there is a set of roller bearings that quit and went home.
As soon as I take it apart I will let you know. I can tell you this, I dont care what the laboratory data says, Straight gear oil will do my lubricating from now on.

 

Yea problem is shortly everything will be at least a simi synthetic blend. I know with Nissan almost every new auto trans is a full synthetic. Yea it may go 60k before it needs to be changed but you better have 250-400 bucks saved to change it. And dont get me started on those crap CVT trans. I agree with you striaght gear oil for the old stuff.

 

Dennis; I hear ya'. I have a T5, and when I had it installed, I used the Valvoline synthetic gear oil (substitute for Dextron lll). The trans wouldn't shift smooth, and the thing whined and grumbled from the start. I called D&D Performance in Detroit, and they said to get the stuff out of there and use straight Dextron lll. After doing that, it runs and shifts smooth and I have had no problem since. I'm with you, it ain't what its cracked up to be!

 

Not supposed to run gear oil in t-5s,I learned that years ago I did the same thing,thought I had a bad tranny.Gave it to my friend he put it in his car with atf and still running til this day I like synthetic in engines,but in anything else I havent tried

 

The oil I used was the substitute for the Dextron. I thought it would make the trans shift smoother. I also used the B&M Slickshift synthetic, and it did the same thing. The Dextron was the ticket, works like a champ.

 

we have found in differentials that the gears wear out in about 15000 miles with synthetic gear oil. we have found the stickyest gear oil that we can get for a reasonable price. its schafers brand gear oil. we run a streight 140wt in differentials. i belive that synthetics are too slipery to stay between the gears under high pressure.

 

they also seem to find ways past the older style gaskets, you really need newer synthetic style gaskets to keep them from dripping i was told the gaskets would work but my rear end would not stop leaking ( LOL, on the truck ;P)

 

If you can find it in your area, MYSTIC brand oil is one of the best I have ever used. May have to go to big truck supply to find it. And Lucas oil treatment will make it cling even more. I usually run a 25%/75% mix, 25% Lucas and 75% oil in rears and trannys. I've ran them over 1,000,000 miles using that combo without a failed gear or bearing.

 

Well all I can say is that before we put ATF+4 in Chryslers we didnt have big issues with leaks. Once they started using the +4 we started doing more warranty leaks than I have ever seen. The same in the steering. Switched from steering fluid to +4 and the flood gates opened. Pumps,lines,coolers racks all leaking. Most of us techs have switched our chryslers back to steering fluid with no issues. It makes more noise cold but we dont mind. I'd rather have a few minutes of noise than leaks.
I have ran synthetic engine oil and diff oil in my Jeeps and it works great. No leaks or failures for 200 000 km. I truly think it depends on the vehicle and application.
If I run synthetic oil in my 3.5 300m it burns almost 2 liters in an oil change interval. Non-synthetic maybe half a liter. Once again I think it depends on the application.
My Mav. does not get synthetic.

 

Just got this off the David Kee Toploader websight:

The biggest determining factor as to whether it will work or not is the driver. If you drive your car normally and shift it normally synthetic would be a great choice. If you drive aggressively or want to shift fast then synthetic may not work well.

 

You're not saying you drive aggressively. Are you Dennis???

Not sure on the sticks, but I read an article once that said do not use it in the autos. I've used synthetic in the race car engine and the rear end with no problems, but i stick with regular Castrol type F in my c-4.

 

I found out in a forum that dino oil is best for tranny synchronizers and related parts... in part due to synthetics being so slippery and making the tranny hard to shift... my mercedes benz uses synthetic oil and that stuff over here is over 15 bucks a liter !!!!

 

In my rearend business,a lot of rears go 100k before having any bearing trouble (non-synthetic lube) I've had to do quite a few 50-70 mi. rears recently with synthetic in them from the factory,now when I order a bearing kit ,it's the same one for both,and your gear lube is 4.00 a qt.vs 24.00 a qt.,I talk the customer into reg.gear oil,I'm personally not sold on it.

 

I have been running synthetic in my 4 speed and differential since 2000. I do have certain opinions about synthetic motor oils, but for the gear box and rear end I have changed my mind about the cling to factor. Talked to Mavaholic tonite and I am switching back to regular gear oil for the trans and rear end.
Dan

 

the best dino motor oil I used was from the motor pool !!!! good old 15-40WD... the grease-monkies(track mechanics) would sling the 5gl's can in the recycling bins and I would drain them dry into and old jerrycan I had and on a good day I would have almost half a can of free oil !!!! 2.5 gallons of diesel 15-40WD motor oil... on a M60A1 main battle tank; 15 gallons for the engine of 15-40WD and 17 gallons of 10WD for the transmission .... then in the 80's, M1,M1A1,M1A1C, turbo-shaft turbine oil at 30.00 USD a quart !!!!! sorry got off topic, but synthetics lubricants has there place and applications specially in modern engines/transmissions ...