Are synthetics all their cracked up to be?

I have been running a semi-synthetic 90 weight that has Royal Purple additive in it for 70,000+ miles now with good results. This is in a Suzuki Sidekick with a 5 speed stick. I run this in the rear axle and the transmission.

I changed them at different times and each time it really helped it roll easier in a neutral coasting. It rolled much further than with the original oil. Helped fuel mileage a bit ... it is right at 30 mpg highway now.

The transmission seemed to shift a bit smoother, too.

There was a small demonstrator at the parts store that showed oil with Royal Purple in it climbing higher on a series of gears than straight oil alone. It had better cling.

Doesn't prove anything about really high shock loads, but I doubt that it would hurt anything.

 

Here is the failure. The main input bearing. I tore the transmission down completely and all needle bearings are fine. So luckily all the damage is basically one bearing. This bearing must of gotten real hot because it took an unbelievable amount of pressure to press it off the input shaft. Again I believe it is because of inadequate lubrication. The transmission was filled to proper level and all passage ways were clear. So all I need is to dress up the input shaft, clean everything up, get one bearing, some gaskets, and GEAR OIL

 

agreed! ran synthetic in my rear end leaked like mad. put regular in it. it stoppped.

synthetic oil works well on newer cars they are build for it. tighter clearances! the some new toyotas use 0W20 synthetic!!!!! though some older motors built with newer parts sythetic works well! however IMO trannies and rearends on older cars i'd just use regular oil.

My Original Maverick i use regular 10W40 Gear and tranny Oil

Race car and other Street Maverick - Synthetic 10w30 Regular Gear and Tranny Oil

my cars newer then 2000 everything Synthetic! no leaks!

 

[FONT=Verdana, Arial, Helvetica]USA[/FONT]
[FONT=Verdana, Arial, Helvetica]812 Posts[/FONT]
[FONT=Verdana, Arial, Helvetica]Posted - 04/30/2009 : 12:46:32 PM[/FONT] [FONT=Verdana, Arial, Helvetica]I'd run std 75w-90 wt grease in it. 85w-140 is a bit too thick if you want it to shift easy in cool weather.

I'd stay away from any synthetic or ATF, as it will not shift well due to brass blocker rings not getting enough grip to match gear speeds.
[/FONT]this was a discussion on what lube for toploader's at the UMTR forum...

 

I run 100% Lucas oil in my trans & rear axle.

 

I spoke with David Kee Toploader Transmissions. He said that front bearing is the weak link in these transmissions. Its not like there are a lot of failures, but when they do occur, the bearing is at the top of the list. He feels the synthetic did not cause this failure, it was just one of those things. He says the synthetics cause more of a shifting problem, (as mentioned above) than anything else. Still, I'm going back to the old technology. It matches me better. They also offer a much improved front bearing, which is what I ordered for mine.

 

Did you ask if he sold his Maverick?
http://mmb.maverick.to/showthread.php?t=52895

 

Ran a 2.8 chebby motor once off of 100% of their heavy duty oil stabalizer... made the really loud rod knock go away for about half an hour..

Dino oil all the way for all of my vehicles! (dont have anything newer then an 88, so no point switching now)

 

I started running Synthetic oil and gear lube in the late 1970's. Started it in a H/Prod. Bugeye sprite in SCCA racing. Better engine life and trans/diff life. Picked up MPH, oil presure, shifting became easy. Never had a leak issue. Still run it today in all my cars. Castrol Syntec5W50 in the older cars and Mobile 1 in the new stuff. Never had an oil related problem. Picked up MPG on my street cars and they run a bit cooler.

 

I use to run Mobil 1 in all my stuff then my brother became an Amsoil dealer now I get a good discount on that.

 

I run 10w40 mobil 1 synthetic with lucas stabilizer in mine,picked up some horsees and oil pressure


gabe

 

The old top loaders should not have anything but reg gear lube installed.

 

I have two top loaders in the past few years and they were clunky shifting with slow syncro's. Replaced the dyno lube with Amsoil and the shifted like new. Ran it in a '64 Dodge 4 spd and worked great. Trans shop told me it needed a rebuild. I change to Amsoil and took it back to them and they were amazed at the difference. No rebuild needed and it's still going strong 10 years later. Used it in my '63 Ranchero 2:77 trans and same results.

T-5's do require ATF. That trans was designed for ATF. I have not tried a synthetic ATF yet, but we use in on the assembly line and Allison will provide an unlimited mileage warranty when it is used in heavy duty truck applications.

 

Tranny Lube

Mav

Were you brown shoe or black shoe?

I have Petron Gear Box Conditioner, the company had been around for circa 30 years. In the past I have had customers with gear noise and they came back very happy, no noise.

Texasjack

 

Now thats thiken with yer dip stik jimmi! Lol