Need a GL-4 Lube!

Jelly · Jul 28, 2004

Need four quarts for my NP4500 5-spd. transmission.

Supposedly, the factory GM fill is 75W-90 Castrol Syntorque. It's not widely available and the cost is quite high.

Now, it's the not the synthetic part that is important here...it's the GL-4 part.

My 'ol beater truck's transmission has been running for awhile on "improper fluids" and it's time to get the right fluid in there to do the job.

Has anyone seen a GL-4 lube that is available locally?

How about this stuff...anyone seen it?:
http://pennzoil.com/products/gear_oil/gearplus8090g4.html

[ July 29, 2004, 02:40 AM: Message edited by: Jelly ]

MolaKule · Jul 29, 2004

Are you sure your transmission doesn't need this:

http://pennzoil.com/products/gear_oil/syncro_fluid.html

Jelly · Jul 29, 2004

Positive Mola.

The NV3500 series transmissions specify GM # 12345349 which is the Synchromesh you mention.

I have the NV4500.

Bror Jace · Jul 29, 2004

Jelly, need a 90 weight?

Red Line, Amsoil and (I think) Royal Purple make a GL-4 90 weight (75W-90, etc ...).

Looking for some cheapo GL-4 stuff on the store shelves? Good luck!

--- Bror Jace

Bror Jace · Jul 29, 2004

Fine Jelly, you just go ahead and make a liar out of me!

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=001228

Of course, this goes along with my prediction(s) that we'll see more and more dual-rated GL-4 & GL-5 as non corrosive additives become more and more prevalent.

--- Bror Jace

HardbodyLoyalist · Sep 1, 2004

I remember reading a thread on one of the Nissan boards a few weeks ago concerning this. Nissan transmissions are notorious for their GL-4 requirement due to their bronze syncronizers. One guy finally made a phone call to Coastal, who said that their multi-rated GL-3/GL-4/GL-5 gear oils do not contain enough sulfur to attack yellow metals and SHOULD be safe to run in a "GL-4 only" transmission.

Whether or not anybody is willing to try this is an open question. Personally, I run Redline MT-90 in my 1994 Hardbody manual transmission.

1sttruck · Sep 2, 2004

http://www.standardtransmission.com/ has Castrol Syntorq for $54 a gallon, for the NV4500.

Ed · Sep 5, 2004

My79 Toyota specs GL4 for the transmission. I've been using GL5 for the last 20 or so years with absolutely no problems. I think modern GL5 is backward compatible with just about any gear oil.

XS650 · Sep 5, 2004

quote:

Originally posted by Ed:
My79 Toyota specs GL4 for the transmission. I've been using GL5 for the last 20 or so years with absolutely no problems. I think modern GL5 is backward compatible with just about any gear oil.

Wouldn't you think that if the people making the GL5 were confident that it would never cause problems in a GL4 application that they would broaden their market base by dual labeling it?

I have an uncle that smoked two or three packs of cigarettes a day and drank a bottle of gin a day, I never saw him sober, but he lived to be nearly 80. However, I don't recommend his behavior to anyone who wants to live to be nearly 80.

tenderloin · Sep 5, 2004

http://www.torcoracingoils.com/assets/files/mtf_man_trans_fluid_tech.pdf

pgtr · Sep 27, 2004

Finding a straight GL-4 is a tall order even in a large metropolitan area.

The most widely easily available GL-4 specific lube I am aware of is probably Sta-Lube's 80W90 GL4 (conventional). In fact in many cases it may very well be the ONLY GL4 specific lube available short of mail order.

Other options include boutique brand synthetic GL4s or GL4/5 'combos': Royal Purple from NAPA (who also sells StaLube), Redline from local 'performance' shops or Amsoil from a local dealer. These can also be mail-ordered including some vendors here on the boards.

Unfortunately the 'biggee' oil companies have largely abandoned GL4 solutions - at least as far as the general public is concerned. While a few do 'have' a few products they are mostly not available or have only limited availability at onerous prices thru distributors that also mandate they be bought in bulk (on top of the inflated price).

It's been like this for a number of years. I don't know why the GL4s have been practically abandoned by the majors. But the boutique brands are smart to keep this niche filled. Perhaps if enough of us continue to demand lubes meet GL4 standards for our transmissions that spec it or API get's off it's butt and updates a new manual transmission lube standard things will get better. But frankly I'm not holding my breath.

A couple possible explanations? A) In the US automatics have been king for a long long time. The manual transmission segment is probably much smaller from a 'big picture' view. B) Perhaps a modern GL5 is 'good enough'. It may (or not depending on brand and additives) be yellow metal unfriendly but it may take years or even decades before corrosion makes a difference and by then they may figure 'who cares'? C) Retailers and oil companies may be averse to assume add'l liability by stocking GL4 on shelves - A GL4 in the diffy can ruin it in short order and in our litigious society if it matters all that much what the bottle or owner's manual says all that much. You know sooner or later some idiot will dump GL4 in a hypoid rear end.

So perhaps by definition a GL4 is a 'niche' player...? Just a thought.

Spector · Oct 7, 2004

RedLine Mt-90 and MTL are both GL-4 gear oils. I switched to them with good success.

Shannow · Oct 8, 2004

I use Mobilgear XHP 75W-90. reputedly an XHVI type basestock.

BTW, why do the Japanese insist on building GL-4 gearboxes ?

Al · Oct 11, 2004

I have been following the GL-4/GL-5 threads for quite a while.

I suppose a Transmission requiring GL-4 would be OK on this oil but no one would want to accept liability.

http://www.pennzoil.com/TechData/Pd...ng/Gear&Transmission/pdf/SynchromeshFluid.PDF The fact that it has "Excellent compatability with Yellow metals (Brass, bronze, and copper)" Is a good sign

Any thoughts???

Jelly · Oct 11, 2004

I have a very-rare C1500 with the NV4500 (well, actually NP4500, but same thing), and while these are Dodge links, they have the same lubricant requirements...

http://www.turbodieselregister.com/LIQUIDS.pdf
http://dodgeram.org/tech/transmission/nv4500_spec.htm

I have Coastal 80w-90 GL-4/GL-5 in there right now, and shifting performance is subpar.

So what do you think Al...Synchromesh the way to go with my transmission?

[ October 11, 2004, 08:02 PM: Message edited by: Jelly ]

Al · Oct 11, 2004

quote:

Originally posted by Jelly:
So what do you think Al...Synchromesh the way to go with my transmission?

Well the reason I was posting was to try to receive information. So I am sorta in the dark in this one. I do know that the GM verson of "Synchromesh" does work really well. I drained it out of my son's Cavalier after 75K and there was almost no metal on the magnetic plug. It appeared to shift well also. I then made the mistake of filling it with the Mobil 1 GL-5. I drained it out after a couple of weeks bc I just was unsure of whether it would be O.K. Went back with the Synchromesh.

TomH · Oct 12, 2004

Your local Saturn dealer also carries a GL-4 lube. Part number is 21018899 for a one quart bottle, retail price is $11.68. No weight is specified on the bottle, but it looks to be about a 75/80W90.

fractal · Oct 13, 2004

I bought a gallon of Sta-Lube SAE 85w90 gl4 gear oil for 17 dollars from the local auto parts store. It was on the shelf right next to a gallon of SAE 80w90 gl5 gear oil which was 18 dollars. Quarts were 7 bucks a bottle and I needed 3 quarts so the gallon was cheaper. I have heard horror stories of gl5 gear oil destroying older equipment so saved the dollar and bought the gl4 gear oil for my kubota. The user manual does not even specify a GL for the gear oil so I figured better safe than sorry. Besides, it was a buck cheaper.

weatherdude · Nov 21, 2004

quote:

Originally posted by Jelly:
Need four quarts for my NP4500 5-spd. transmission.

Supposedly, the factory GM fill is 75W-90 Castrol Syntorque. It's not widely available and the cost is quite high.

Now, it's the not the synthetic part that is important here...it's the GL-4 part.

My 'ol beater truck's transmission has been running for awhile on "improper fluids" and it's time to get the right fluid in there to do the job.

Has anyone seen a GL-4 lube that is available locally?

How about this stuff...anyone seen it?:
http://pennzoil.com/products/gear_oil/gearplus8090g4.html

Jelly, I know this thread is a bit old, but I found myself in the same situation (different transmission, same fluid) and I talked with RedLine about the situation. Here's the response I got back:

quote:

Email reply from Dave@Redline:
Jeramy,

The Syntorq LT is a 75W85 GL-4 gear lube, lower in viscosity than a
typical 80W90 and not as slippery.

I would recommend a blend of MTL and MT-90 about equal parts, this
will give the viscosity called for.

Regards, Dave
Red Line Oil

I was in a pinch and needed a solution fast. Since only RedLine MT-90 could be obtained localy on a Sunday evening, I went with straight MT-90. Shifts a great deal better than the stock Syntorq LT that came in it. That and I don't think the difference between the 85 and 90 weights at operating temperature will make a big difference. If anything, I hope it will provide a little more protection.

heyjay · Nov 21, 2004

Before I sold my fleet, I used to use Mobil commercial lubes, including Mobil Mobiltrans SHC 50 in the Roadranger transmissions. You can see the specs at http://www.mobil.com/USA-English/Lubes/PDS/NAUSE2CVLMOMobiltrans_SHC_50.asp. Unfortunately, the smallest container I've seen it in is a 5 gal pail. Mobil does mention it's better for transmissions than gear oils with sulphur-phosphorus additives.

Need a GL-4 Lube!

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