Gear Oil (Page 1/3)
hunter29 FEB 25, 06:16 PM
Hello, again, thanks for the reply's to my first thread.

So 5w-30 engine oil for the 4 speed, is there any point in running full syn oil ?

thanks
theogre FEB 25, 06:26 PM
GM doesn't used engine oil in trans but name made a lot of confusion.
Use synchromesh oil available at most local stores.
See my Cave, Manual Trans Fluid

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

hunter29 FEB 25, 07:07 PM
Ok checking out Synchromesh, on that page it asked where did they get the idea of motor oil, in my manual it states 5w 30 engine oil, same for my 84 fiero which ran fine on it. But I guess you can get better today.

thanks
theogre FEB 25, 08:19 PM
Owner books has many problem and made more confusing here. Worse, the owners doesn't get new data for updated fluids etc.
Like many GM OM say Auto Tranies get Dexron II fluid but GM and most others haven't made D2 in 3+ Decades yet many still try to get it claim old books say only use this...

Engine oil will work but isn't same as oils used in the trans at factory.
GM push out many TSB not only numbers in my cave saying then only use Synchromesh oil.

Likely GM or Alldata missed a TSB for 4 speed in Fiero.
hunter29 FEB 25, 08:42 PM
Does it matter what brand I use, AC Delco Ok ?
fierofool FEB 25, 09:07 PM
Save yourself some money over buying GM Synchromesh. Go to your parts store and get some Pennzoil Synchromesh Manual Transmission Fluid. It's the same stuff except cheaper.
hunter29 FEB 25, 09:20 PM
No need for Amsoil ay.
hunter29 FEB 25, 09:49 PM

quote
Originally posted by fierofool:

Save yourself some money over buying GM Synchromesh. Go to your parts store and get some Pennzoil Synchromesh Manual Transmission Fluid. It's the same stuff except cheaper.



Is that a fact ? Do they make it for AC Delco ?
theogre FEB 25, 11:03 PM

quote
Originally posted by hunter29:
Is that a fact ? Do they make it for AC Delco ?

Maybe. All GM Fluids are made under contract w/ big names like Dexcool and others where make by Texaco in 80's and 90's. Dexcool... is likely a contraction of Delco Texaco coolant for easy to TM and © the name.

As to ACDelco... Now is nothing more then a GM Brand Name that's contracted out often everything mark to lowest bidder. Is same crap that Sears Kenmore and others has done for decades.
Worse most ACDelco parts have 0 - 90 days warranty yet wants Top $ to sell them.

GM stopped making parts near 30 years ago when spun off parts divisions as Delphi that finally went bankrupt. short history see https://en.wikipedia.org/wiki/Aptiv

I get most parts from AZ because many have lifetime warranty and only a Phone # to track it nationwide.
fierofool FEB 26, 05:41 AM

quote
Originally posted by hunter29:


Is that a fact ? Do they make it for AC Delco ?



Over the years there have been considerable posts here that said Pennzoil or even John Deere produces the GM Synchromesh fluid.

I agree with Ogre about the GM warranties. I bought an ICM at $85. It lasted less than a month. When I returned it, they said that they didn't warrant electrical parts if they had been installed and used. I purchase my ICM's (I avoid BWD) from the discount auto parts stores and have been running my current ones for probably 10 years. $35 when I bought them.