Starquest Manual Trans Gear Oil GL4 VS. GL5

[Starfighterpilot]

The FSM states that GL-4 Gear Oil is to be used in the Starquest's 5-speed manual trans.

 

I was gonna have my '88's 5-speed's gear oil changed yesterday. The only problem was I could not find a quick oil change place that stocked the GL-4 gear oil. They all only stocked GL-5 gear oil.

 

So I backed off on changing the oil. Then I went skulking around on the WWW to find out if the GL-5 oil could be substituted for the GL - 4.

 

I found this interesting post http://www.automotivehelper.com/topic33390.htm

 

and this one http://www.ratwell.com/technical/GearOil.html

 

If you want use google, it seems as there there is a healthy debate about using GL - 5 oil in older vehicle tranny's that the Manf staes to use GL-4.

 

Does anyone have any real time experience with this?

 

And No I don't want to use the synthetics. I know what's been proven that works over many many years and that's what I want to use.

 

For What It's Worth.

 

KEN

[UlrichWolf]

Seems to be a rather semantic argument, since most lubes I see have the GL-4 and GL-5 both on the package.

 

But, if you want to argue semantics, here's the bottom line.....you can POTENTIALLY have your synchronizers corrode, or you can have your bearings QUICKLY seize.

 

Your call.

 

Tim

[Starfighterpilot]

Not to start an arguement; I went to Advance Auto, O'Rielly's, AutoZone and a couple of Mom and Pop's Auto Parts Stores and looked at all of their tranny gear oils on their shelves. Valvoline, Mobil 1, Castrol, Pennezoil, and Lucas Gear Oil plus all of the off brands only had API GL-5 ratings on the bottles. No mention of compatibility to GL 4. The only store that had GL 4 & GL 5 on the bottle was NAPA. It was NAPA Premium Performance Gear Oil, 80W-85-90, GL-3/GL-4/GL-5, part# 75-210.

 

However, online, I did find that Valvoline still makes a GL 4 gear oil. It's Valvoline Duragear, 75W-85, GL 4, Part Code No. 1264-58.

 

I would have included the Pennzoil GL4 gear oil that's noted in one of my above OP links, but my local Pennzoil Quik Lube place says that Atlanta area Pennzoil distributor quit stocking it.

 

Then I got on line and found that a Valvoline Quik Oil Change place about 3 miles away from me. I just called 'em and they stock it. So Monday I'm on my way there. I forgot that they were there. Old age rearing it's ugly head again.

 

Just so that you guys know of a source of the original MITSU OEM spec'd gear oil that is still available.

 

The main purpose of bringing this issue up is every 3 - 6 mos we get a new Starquester asking what's the best engine oil to use. Seems like the tranny and the diffs are never thought about, except for what type of HP synthetic gear oil to use.

 

Happier than a pig in poop.

 

For What It's Worth.

 

KEN

Edited May 22, 2010 by Starfighterpilot

[lmwii]

interesting stuff here:

http://www.lubrizol....GL5.html#Update

• API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications.
• API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL-PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation.

 

another site i just looked at explained it thusly:

http://www.thesamba....t-276529--.html

 

I sent a tech message to the Amsoil tech guy. His response stated the history of how that myth got started by the ignorant VW people. When GL-5 first came out it was indeed corrosive to brass syncros. But only at temps above 250ºF. Now since it is impossible to get any street driven gear oil to that temp (It is hard to get engine oil that hot!), there will be no problems using regular GL-5. However, just to satisfy the ignorant masses, the API came up with another added rating, called MT-1 which is tacked onto the end of all GL-5 oils you can buy today. With this MT-1, GL-5 oil is not corrosive at any temp.

The difference between GL-4 and GL-5 is the extreme pressure capability. On surfaces that have high pressure where metal to metal contact will happen, the GL-5 is way better at protecting. Spider gear teeth and side gear teeth are one place where GL-5's better EP rating is desperatly needed. I've got 5-6 Bus 091 ZFs in my garage right now that have suffered significant wear on the gear teeth from probably using GL-4.

Edited May 22, 2010 by lmwii

[ucw458]

Going back to my previous thread about lube discussion.

 

So it seems the general concensous among the scientific comunity that GL-5 is reccomended for high speed and high torque and GL-4 seems to be standard gear oil for commuter vehicles. Our cars are high torque and high stress. They get beat on frequently. So it would seem if GL-5 was available when our cars were built that Mitsu would have reccomended GL-5 in the FSM. Since it seems that GL-5 is a superior gear oil perhaps the reason alot of us have trans problems is not just neglect. Maybe another big contributing factor is they all came with inferior GL-4 gear oil. I've got a trans with 90k miles on it and lots of input shaft play. How many times do you think the oil was changed? I would think for at least the first 50k it had GL-4 in it. The car it came out of had not been modified.

 

Perhaps Mitsu reccomended GL-4 because it was the best lube at the time of manufacture. But it may not have been adequate protection for our trans. So perhaps most of out trans problems are from using inadequate gear oil.

 

Just a thought.

[lmwii]

Perhaps Mitsu reccomended GL-4 because it was the best lube at the time of manufacture.

 

that is the impression i got as well. from what i read, there's no reason to think that gl-5 would be harmful, and is likely an upgrade.

[Starfighterpilot]

As some of you may remember, last Nov I wiped out a number of bearings in my ’88 Starion’s 5-speed manual tranny on the way back to Atlanta from my daughter’s house in Tulsa. So I had to get the tranny rebuilt. Root cause of the problem, was the tranny rear seal had had enough sometime during my 22K miles that I put on the car last year on my cross-country trips and started leaking. Enough tranny oil eventually leaked out that it wiped out the bearings. Didn’t have a problem with that seal leaking before all the trips. I checked it.

 

I was at the tranny shop for the tear down, inspection, cleaning and reassembly of the tranny. It was squeaky clean when the shop reassembled it. However I was not at the shop when they reinstalled it. On the way back to Tulsa (876 miles) for Christmas, I noticed a slight buzzing of the trans gear shifter on hard WOT throttle and at the resonance frequency engine RPM’s of between 2850 and 3200. I have a BSE kit installed so I expected that very slight buzzing/vibration and I figured that, “OK the tranny is working itself back in,” and I changed the trans gear oil in Tulsa. However, I forgot to ask the lube place what grade of trans oil they used. DUH!!

 

For the past 5 months (about 6K miles) I have noticed that the gear shifter buzzing/vibration has gradually gotten louder. So Friday I was going to get the trans gear oil changed again. See my OP for what I found THIS TIME when I specified GL-4 trans gear oil to be used.

 

Yesterday evening I checked the trans rebuild and Tulsa tranny gear oil change receipts. Both of the places used GL-5 80W-90W gear oil.

 

This morning I took the old girl into a Valvoline Quick Oil Change place and they dumped the tranny GL-5 Gear Oil and replaced it with dinosaur GL-4, 75W-85W. I had them drain the gear oil through a muslin rag to catch any metal flaks that could have been left over from the tranny rebuild wear in. Hardly any metal showed up.

 

I noticed smoother shifting and the WOT shifter buzzing and the slight shifter vibration had disappeared on the way home.

 

This afternoon I took the old girl on a 60 mile interstate round trip to see if the buzzing and vibration would reappear. I did about 10 hard WOT's and kept her at the engine resonance harmonic RPM's, noted above, and she is as quiet as a church mouse and smooth as silk. NO tranny shifter buzzing/vibration.

 

Tomorrow A.M. I’m taking the old girl back and having the dif gear oil changed using the 80W-90W GL-5 oil and have Valvoline’s LSD additive added. The gear oil in her now has about 28K miles on it, so it's about due by my schedule (every 30K miles). FSM page 0-4, Lube & Maint Chart, says to check it at 48K & 96K miles.

 

I'm posting this just to let you guys know what I found. Personally, I’m going to keep on using the GL-4 75W-85W trans gear oil that I’ve used since she was new. With scheduled gear oil changes it kept the trans in good shape for about 360K miles 'til the rear seal lunched it. I see no reason to change from it, especially upon what I found out this week-end and my experience today.

 

And further skulking around the '88 FSM on page 0-6, and the '84 FSM, page 0-4. Recommended Lubricants Chart, revealed that GL 5 gear oil was available back in '88 and '84. It is specified for use in the differential. However Mitsu specified GL-4 for the 5-speed manual trans. I believe that MITSU knew something or had a damn good reason to make that specific differentiation.

 

For What It's Worth.

 

KEN

Edited May 25, 2010 by Starfighterpilot

[slowquest]

Mitsu STILL says to not use GL-5 in the trans, even in the Evo's and manual trans Eclipses. I'm not buying the argument that GL-5 is an "updated" oil that's ok to use in our trans.

[BLACK88SHP]

As some of you may remember, last Nov I wiped out a number of bearings in my ’88 Starion’s 5-speed manual tranny on the way back to Atlanta from my daughter’s house in Tulsa. So I had to get the tranny rebuilt. Root cause of the problem, was the tranny rear seal had had enough sometime during my 22K miles that I put on the car last year on my cross-country trips and started leaking. Enough tranny oil eventually leaked out that it wiped out the bearings. Didn’t have a problem with that seal leaking before all the trips. I checked it. http://www.starquestclub.com/forum/public/style_emoticons/default/angry.gif

 

I was at the tranny shop for the tear down, inspection, cleaning and reassembly of the tranny. It was squeaky clean when the shop reassembled it. However I was not at the shop when they reinstalled it. On the way back to Tulsa (876 miles) for Christmas, I noticed a slight buzzing of the trans gear shifter on hard WOT throttle and at the resonance frequency engine RPM’s of between 2850 and 3200. I have a BSE kit installed so I expected that very slight buzzing/vibration and I figured that, “OK the tranny is working itself back in,” and I changed the trans gear oil in Tulsa. However, I forgot to ask the lube place what grade of trans oil they used. DUH!! http://www.starquestclub.com/forum/public/style_emoticons/default/wacko.gif http://www.starquestclub.com/forum/public/style_emoticons/default/unsure.gif

 

For the past 5 months (about 6K miles) I have noticed that the gear shifter buzzing/vibration has gradually gotten louder. So Friday I was going to get the trans gear oil changed again. See my OP for what I found THIS TIME when I specified GL-4 trans gear oil to be used.

 

Yesterday evening I checked the trans rebuild and Tulsa tranny gear oil change receipts. Both of the places used GL-5 80W-90W gear oil.

 

This morning I took the old girl into a Valvoline Quick Oil Change place and they dumped the tranny GL-5 Gear Oil and replaced it with dinosaur GL-4, 75W-85W. I had them drain the gear oil through a muslin rag to catch any metal flaks that could have been left over from the tranny rebuild wear in. Hardly any metal showed up. http://www.starquestclub.com/forum/public/style_emoticons/default/smile.gif

 

I noticed smoother shifting and the WOT shifter buzzing and the slight shifter vibration had disappeared on the way home. http://www.starquestclub.com/forum/public/style_emoticons/default/smile.gif

 

This afternoon I took the old girl on a 60 mile interstate round trip to see if the buzzing and vibration would reappear. I did about 10 hard WOT's and kept her at the engine resonance harmonic RPM's, noted above, and she is as quiet as a church mouse and smooth as silk. NO tranny shifter buzzing/vibration.

 

Tomorrow A.M. I’m taking the old girl back and having the dif gear oil changed using the 80W-90W GL-5 oil and have Valvoline’s LSD additive added. The gear oil in her now has about 28K miles on it, so it's about due by my schedule (every 30K miles). FSM page 0-4, Lube & Maint Chart, says to check it at 48K & 96K miles.

 

I'm posting this just to let you guys know what I found. Personally, I’m going to keep on using the GL-4 75W-85W trans gear oil that I’ve used since she was new. With scheduled gear oil changes it kept the trans in good shape for about 360K miles 'til the rear seal lunched it. I see no reason to change from it, especially upon what I found out this week-end and my experience today.

 

And further skulking around the '88 FSM on page 0-6, and the '84 FSM, page 0-4. Recommended Lubricants Chart, revealed that GL 5 gear oil was available back in '88 and '84. It is specified for use in the differential. However Mitsu specified GL-4 for the 5-speed manual trans. I believe that MITSU knew something or had a damn good reason to make that specific differentiation.

 

For What It's Worth.

 

KEN

 

Ken:

 

So glad I found this thread and your post. I am just getting back into these cars with my '88 Conquest and I am having the same harmonic issues between 2500 and 3200 rpm that you described. The engine in my car was rebuilt by *DM for the previous owner about 5K miles ago and I have no idea whether the balance shaft was reinstalled in the rebuild or not. When I got the car I had all of the soft suspension parts replaced with poly, and I decided to do the same with the transmission. My buzzing stick turned into a shrieking banshee within the sympathetic rpm range so I went back to the rubber trans mount.

 

The lighter (but still annoying) buzzing is back and I have thought about a bunch of larger-scale crazy schemes to troubleshoot it (modified fluid dampers, cracking open the engine to see if there even is a balance shaft installed) but I believe I will start with a gear oil change and make sure I use the GL-4. I am cautiously optimistic that the problem I am having is identical to the one you had and that this gear oil change will do the trick. Thanks for sharing. Though it was four years before I joined this forum it may be just what I needed to see.

Edited October 30, 2014 by BLACK88SHP

[JohnnyWadd]

Does anyone have any real time experience with this?

 

 

 

For What It's Worth.

 

KEN

 

Yes.

I have used Sta-Lube gl-4 In three different 5-speeds. One that I sold 9 years is still driving around. Its what they had at a local store (Bi-Mart) and it has a good reputation. As you can see it does come in a gl-4.

http://www.amazon.co...d/dp/B000M8RYMC

 

If you read the label you will see if it covers GL-5 and GL-5 or just one.

http://www.amazon.co...s=sta lube gl-5

 

From my research the only possible issue using a GL-5 spec'd oil is that it happens to be a low quality and has corrosive elements that damge the bearings or brass syncros. Almost every GL-5 I have looked at is backwards compatible.

 

My current oil is Amsoil Severe Gear. Using that in my '89 quest and my 4x4. No issues no leaks no noise smooth shifts etc etc

http://www.amsoil.co.../?code=SVGQT-EA

 

I am curious why not synthetic? Because you can get a sweet deal at Wal-Mart on Synthetic stuff by Valvoline. I have used that stuff in a Dodge Cummins Diesel 5 speed, several other trucks and one Starion that I did a clutch on that drove to Texas from Oregon. Its good stuff. The dodge actually shifted better when I put in the Valvoline.

 

https://static.grain...nger/4NPL1_AS01

 

 

I wonder if the shops just put some low grade bulk oil tat they happen to have on hard in your 5 speed

Edited October 30, 2014 by JohnnyWadd

[TexasQuest]

There is actually a TSB from Mitsubishi from April 1993 cautioning people NOT to use GL5 oils in the transmission due to the oil having additive which may chemically react to the copper synchro rings in the tranny leading to damage.

[JohnnyWadd]

There is actually a TSB from Mitsubishi from April 1993 cautioning people NOT to use GL5 oils in the transmission due to the oil having additive which may chemically react to the copper synchro rings in the tranny leading to damage.

 

I have read similar stuff on that as well.

[Preludedude]

So what chain of stores carry the proper gl4 oil? Carquest? Napa? Etc...

[clow340]

Wait, starfighterpilot, how many miles are on your quest? Btw good information thanks everyone

[BLACK88SHP]

I am newly back to the StarQuest world after a 15 year hiatus. I have read through forum posts on this subject until I have seen just about everyone's opinions and scientific cases made for the "right" gear oil to use. It appears to me that 40-50% of the SQC members are running Royal Purple 75W90. Although it is GL-4/GL-5 rated, it specifically states that the formula was designed to be non-corrosive to yellow metals and is fine for manual transmission synchros.

 

Having had a nasty buzzing in my shifter between 2500 and 3200 RPM since I bought the car a few months ago, I went with the general consensus from SQC members and changed the gear oil this past weekend from whatever was in it to Royal Purple 75W90 - and the buzzing has stopped.

 

That being stated, I have read some other forums related to 240SXs, Eclipses and Evos and am intrigued by the number of people who rave about Redline MT90 (also synthetic) which is GL-4 rated. I've also asked around my local tuner crowd and it seems to be a very popular choice for those willing to spend the money.

Edited November 12, 2014 by BLACK88SHP

[Starfighterpilot]

So what chain of stores carry the proper gl4 oil? Carquest? Napa? Etc...

 

Order online at Amazon http://www.amazon.com/Sta-Lube-SL24239-GL-4-Multi-Purpose-Hypoid/dp/B000M8RYMC

 

For What It's Worth.

 

KEN

[Starfighterpilot]

There is actually a TSB from Mitsubishi from April 1993 cautioning people NOT to use GL5 oils in the transmission due to the oil having additive which may chemically react to the copper synchro rings in the tranny leading to damage.

 

You're right there is. Looking through my complete list of 1988 Mitsu Starion Service bulletins that I printed out from ALLDATA back in 2002 I found that the Technical Service Bulletin number is 9322001, Issue Date April 1993, M/T Fluid Recommedation/Caution. (I think that MT stands for manual transmission)

 

I don't have a print out of that TSB - if any of you guys have access to ALLDATA, could you get a print out of it and post it here. It may be interesting reading and put this debate to rest once and for all.

 

Then I'll post it in the FAQ's.

 

For What It's Worth.

 

KEN

[ucw458]

I don't have a print out of that TSB - if any of you guys have access to ALLDATA, could you get a print out of it and post it here. It may be interesting reading and put this debate to rest once and for all.

 

A 20 year old document isn't gonna prove anything. Especially when oil tech has vastly improved since then.

 

 

The myth that GL5 was bad got started many years ago. When enough people had spread the myth people regarded it as fact even though it wasn't. While it's true that older GL5 had chemicals that could corrode copper and brass the part that was left out was those chemicals had to get to 500+ degrees before they became reactive. You will never see those temps in a street driven car. Newer GL5 does not have those chemicals. It's not reactive to copper or brass and it's a much better lube. Especially if you are upping the power and racing.

 

As far as your buzzing noise is concerned....... I have always run GL5 and have never noticed a buzzing in any of my SQs. Now it could be my ears just aren't picking it up. But it could also be wear inside your transmission that reacts with a higher pressure rated lube like GL5 to make the buzzing noise. Remember none of us but you have 400k+ miles on their trans. That extra mileage could be contributary to the noise.

 

 

Furthermore, car manufacturers look after themselves first. If there was even the slightest chance GL5 could cause a warranty repair then they would make damn sure all their documentation specified GL4. Even if the slightest chance was based on heresay, conjecture or misleading representation of the facts.

 

 

In summary, I'm not saying you are wrong. I'm saying that stating GL4 is the best is like saying brand x in this weight is the best oil for your engine. You can't get everyone to agree on that. Everyone has their own opinion. People's cars have different needs. Scaring people into thinking they should only use GL4 isn't the right thing to do. GL4 works for you and that's great. But GL4 wont work for me because I'm capable of putting down alot more power than you are. Your car is bone stock. Mine is highly modified and needs the higher pressure lube found in GL5.

[JohnnyWadd]

http://i1187.photobucket.com/albums/z388/starionkiller/random%20parts/th_tsboil.jpg

 

Edit in. The corrosive element of gl5 is there all the time. It doesn't need to be superheated . It all happens when the synchros touch regardless of pressure. It's a matter of how much brass scrubbed off at that moment. I am finding some info on newer cars shifting better with gl4 now. gl4 will handle the pressures of a starion rwd transmission. Look up the actual specs. While it does have reduced pressure additives compared to gl5 , it still has them.

Edited November 15, 2014 by JohnnyWadd

[ucw458]

The use of the word "may" many times in that TSB suggests to me they don't know so they are going to recommend not using GL5. What it also tells me is they are laying the groundwork for denying warranty claims. If someone's trans went out they will ask for receipts to prove regular fluid changes have been done. When they see GL5 on the receipt the warranty claim will be denied.