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)
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.
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.
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.
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.
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.
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.
Originally posted by fierofool: Over the years there have been considerable posts here that said Pennzoil or even John Deere produces the GM Synchromesh fluid.
John Deere does same thing as GM Ford etc and Does Not make parts or fluids but gets Top $ for anything w/ JD Logo. JD is as bad or even worse then buying anything from GM dealer parts network. Is part of Why many old Trackers are getting a premium price at auctions etc. that doesn't need OE JD parts that's Installed only by JD Dealers w/ Proprietary JD "Scan Tools" to fix nearly everything having Tractors down for days to weeks if your lucky. Other "Tractor" brands are moving or have done to JD business model locking down "ECMs" w/ DRM etc too to rake over farmers.
Maybe a mistake or something in it make it a HAZMAT. Seems many other trans oil can be shipped.
Many places won't ship HAZMAT items to anywhere of a number of reasons. If they did, normal shipping cost + making sure the bottle will not leak even w/ crushing the package + often HAZMAT fees by UPS (I think is currently $37.50 for Ground) etc. = shipping cost to you can be high to very high. Plus many sites have Free Shipping > X total and won't eat the extra fees by UPS etc.
Many auto parts stores near you should have this. Many others can order and get same or next day delivery depending on time of order.
They list it as not available, anyway I saw it on amazon listed twice, one for 9 bucks the other 37 bucks, but that one came from another vendor , go figure. you may be right..
I'll get it local, no rush, got a broken hand and its still winter, at least two months from working on the car.
[This message has been edited by hunter29 (edited 02-26-2020).]
GM originally spec'd 5w30 motor oil or Dexron ATF for these gearboxes. But those were superseded by Synchromesh manual transmission oil. There are several brands, for example Pennzoil, Valvoline, and Amsoil. Royal Purple calls their version Synchromax. But they all work in these gearboxes. Also, the Synchromesh oil provides smoother shifts than the older stuff.
GM originally spec'd 5w30 motor oil or Dexron ATF for these gearboxes. But those were superseded by Synchromesh manual transmission oil. There are several brands, for example Pennzoil, Valvoline, and Amsoil. Royal Purple calls their version Synchromax. But they all work in these gearboxes. Also, the Synchromesh oil provides smoother shifts than the older stuff.
Originally posted by hunter29: When did Synchromesh hit the market ?
GM likely ~ early to mid of 80's. Many TSB for it pushed out to dealer network in 87-88 for use in other cars didn't come with. Normal retail like under Pennzoil brand for auto parts stores a bit later.
Very likely Many GM vehicles had this loaded at the factory w/o bothering to update many OM FSM and other docs except for TSBs that few read even when work for GM and Dealers.
You can still find old packs of old types but shouldn't used them. Synchromesh for GM stick cars and many others. Dexron III or VI for GM autos. While many stores still carry "D3 fluid" under various names, GM end licensing D3 ~10 years ago and now only licenses D6 and newer.
Note: Don't know who actually make GM sync oil. Maybe Pennzoil or anyone that meets GM specs. Maybe Chevron now since bought out Texaco who made many fluids for GM for 70+ years. 1 ACDelco bottle on Amazon says Made in Canada but don't know if picture is current.
If you look at the descriptions on the bottles, GM Synchromesh uses the terminology "semi-synthetic" while Pennzoil Synchromesh does not.
I realize that this might come down to marketing, and they could be the exact same fluid. But, I always wondered if there was a chance they were different and thus had different coefficients of friction.
Several years ago, I drained the OEM fluid from my 86 four speed transmission and refilled it with Mobil ONE 5w-30. There was a noticible improvement in shifting ease. The transmission was butter smooth. It was in there for an additional 100,000 miles. I saw no need for going to a Synchromesh type fluid.
