Gear lube question

I have become spoiled by shopping on the net. I hate so much going to a store to look for something on their shelves they typically don't carry, that my go to thing now is to order it online. I do it too much, I know, I should be supporting local brick and mortar stores more, I'm just to time-constrained these days, I don't have any to waste shopping for something the stores don't carry in stock. I hate that I give so much of my money to Amazon when I really despise the people that run it. But it's so easy...

 

Try finding some GL-4 when you're on a road trip in an old car....

 

That was worth the look up.

Would you say demagraphics has a large part in this? What I mean is when I’m in farming communities I get jealous over all the hardware and goods offered in their hardware and auto parts stores. Los Angeles County ****s when it comes to finding what one really wants.

 

Could be that it's just where I live, but I doubt it.

 

This I can buy locally, or on the road. I have zero qualms about using it in old manual transmissions. Has caused zero problems so far.

 

And walking into the parts store is traditional lol. I can pay with cash, which is still traditional also! I just run 10w30 with zinc additive in mine. Makes it go faster

 

That's odd. I have been fooling with trucks for 40+ years, dating back to 70's models. We always used 75 to 90w gear oil in the transmissions, and 140W in the drive axles. The newer 90's models did move to synthetics, but still used the same weights. Maybe they used 50W in medium range trucks, I don't know, don't have any experience with them. Never ran an auto shift, either {although I knew a few guys that did, and had the shop bills to prove it}. Those were for women drivers, LOL!

 

Now you did it. You left the last sentence in.

 

Next time you go racing wipe a film of Vasoline over the whole Elco.

 

Are you making fun of my time slip man?

 

No man, shine gel I tell ya. It has anti wear stuff in it so patina won’t wear off.

 

Shew! Almost had my feelings hurt for a minute there

 

It may be somewhat geographic, people in areas tend to do things alike, but across the US the overwhelming most common oil used in truck transmissions (for those NOT using synthetic) has been SAE 50 engine oil. And even the CD50 synthetic oil for transmissions is pretty much a synthetic version of a straight grade 50 engine oil. This has been the practice going back to the 80's at least when I started in the business. Check out the recommendations here: https://www.globaltransmissionsuppl...roubleshooting-guide/transmission-lubrication

Here's another one, check out the approved oils for Eaton Roadranger transmissions, all of them SAE 50 grade http://www.roadranger.com/ecm/group...@roadranger/do***ents/content/pct_1174384.pdf

 

I was cruising the internets looking for more info on MT-1, and happened upon some old discussion on this subject a****st some military vehicle guys. One fellow was sure that using GL-5 was the end of the world for their trucks, but another one pointed out that the Army changed their own spec to use GL-5 in all the transmissions on these trucks starting in the 80s...and Uncle has been using it ever since, and no one seems to have found any issues with it, at all. Which kind of shows my position isn't as idiotic as it appears.

 

I've seen synchro-mesh in the parts stores, one has a GM part number on it. My buddy swears by it for all stick shift transmissions.

 

I just run 50% 80/90 gear oil, 50% auto trans fluid. Recommended to me by a reputable gearbox rebuilder. Shifts easy when cold.

 

I agree with Squirrel.

There has been much hype over this GL4, GL5 issue.

There may be some truth over this in a laboratory setting.

Maybe failures in a zillion miles?

But I have yet to see any photographic evidence that the GL5 will destroy yellow metal parts (syncro rings), that can be directly linked to GL5 being used, and not just being hearsay or an excuse to cover up a bad rebuild or poor quality parts.

There are many top manual transmission rebuilders, that also have the same opinion on GL5, me included.

I will admit, that due to all the hype over this issue, I now error on the side of caution and use GL4 in older manual transmissions, but dont really believe it.

I have been building transmissions for more than 40 years and NEVER had an issue with using GL5.

Show me the proof and I will believe.

Bill

 

Blues, I was going to mention 50w engine oil in truck manual transmissions, but I didn’t want to start another **** storm. Thank you for bringing it up.

 

As far as I am concerned, the vast majority of NWC T-5 failures had nothing to do with the syncro ring design or bearing designs or the kind of oil that was in it.

We also put ATF in NWC T-5s to make them shift easier when it was 0 degrees in Chicago, and never saw one come back with lubrication issues (gears on the mainshaft).

We saw WC T-5 failures with the same results also.

We also did rebuild both types that had over 100,000 miles on them or more, that were just plain worn out.
Why did these not fail early?
Because a sane person was driving it.

It had to do with the ***hole driving it. They all thought that if it was a Z-28 or a Mustang GT it was an instant race car and beat the **** out of them. Bang shifting, speed shifting, clutch-less shifting, half *** releasing the clutch shifting, downshifting like they were on a road co**** instead of using the brakes, or just didn't know how to drive a manual trans car properly.

Back in the day, we saw cases blown out on the bottom, exploded cluster gears (side stepping the clutch) and torn up engaging teeth on the gears and reverse chewed up. The most common gear/syncro failure was 3rd gear because when they were BANGING through the gears, 3rd is shifting away from them and couldn't reach that far to solidly get it into gear before re-engaging the clutch.

Bill

 

I love it when an OP joins, posts a question then immediately disappears for 3 days...so far...

 

Nice to hear from someone who works/worked on manual transmissions for a living. Good insight.

 

like gimpy stated , the fluid recommendation from the oem is there for a reason and there is also a reason for the mul***ude of different oils on the market .

but as squirrel stated , I’ve never seen a failure in a manual trans that was not related to abuse .

either running it low on whatever fluid , contamination or the biggest one I have seen Abuse by the operator.

I’ve seen manual trans filled from the factory with engine oil , gear oil , synthetic gear oil , mineral oil , hydraulic fluid , atf ,some weird blue **** that looked and had the viscosity of windshield wiper fluid in a euro car . My point is follow what the oem says should be in there . Don’t loose sleep over it and if your driving responsibly any type of fluid is better than nothing and won’t be catastrophic.

 

I am a former GM Engineer, I can ***ure you your options in the matter of lubrication in a T5 are incorrect.

 

Was GL-4 specified for the T5? Or possibly Dexron II? or it would depend on when it was made, and which manual you refer to?

Pretty far off topic for the OPs question, either way....

 

Dexron II was for WC T5's, with needle roller bearings between the gears and main shaft.

50W gear oil (Ford insisted 70W, until cold climate complaints pushed them to 50) was specified for the NWC T5's, and yes, the original published specification was for GL-4.

Middle weight gear oil is used in NWC T5's because the gears are metal-to-metal on the main shaft.

They are effectively NOT the same transmission.

I refer to the original do***ents submitted from the Borg-Warner test facility, to GM Corporate headquarters. They are in the archives at The Heritage Center.

 

Interesting....reading on the internets about people trying to figure out what oil to use in their 80s T5 equipped cars, seems that ATF ended up in a lot of the NWC transmissions.

Still have no idea how this relates to the old junk we drive from the days when gear oil was gear oil, there were no API cl***ifications.

 

There weren't so many over educated opinionated experts either !

 

I have badly abused a lot of manual transmission cars and trucks. I've even broken a few (OK maybe more then that).
I believe I can honestly say I have probably never had a transmission failure due to the lube I used in it.

Back in my younger days, 80/90 was the standard gear lube in rear ends and manual transmissions. That changed after I had to drive one through a bitter cold winter. I believe ATF was what I put in it then. When it broke, I don't think the missing teeth off the gears was lube related, most likely powershift related, because that was when it broke. Maybe I should blame the failure on the lube...

I did just replace the 5 speed AX15 that was in my coupe. It had a slight vibration in 4th ever since I've owned it, but I swapped it out when it started getting a slight vibration in 5th gear. I haven't pulled it apart (and don't intend to). That trans also saw abuse, but not at the level of those of my younger days. That trans had several different lubes used in it. The 1st change was from ATF to a gear lube. Then a few years later another change from the gear lube to motor oil. The last time was back to gear lube.

 

The American Petroleum Ins***ute started grading oils in the 1930's.

 

So....the API grade of 90wt "Multi-Purpose Gear Lubricant", as specified in the owners manual for my 62 Corvette, is....??????