TheSamba.com :: View topic - GL 4 or GL 5

Mon Sep 07, 2015 12:50 pm

I've read many pages of this discussion and thought I would add my personal experience with GL 4 and the VW G 005 000 gear oil.

After a co-worker rebuilt my 091 he recommended GL 4. So, I went to our parts counter at the dealership and purchased the G 005 000 and ran it for 10 years. No problems, shifted fine in warm and cold conditions.

Last December I thought it might be prudent to change out the fluid after 40,000 miles. Drained it and then went to get more. Unfortunately we only had 2 liters in stock.

No worries. Walked over to the parts store down the street and bought a gallon of GL 4 and refilled the gearbox.

The next 2 weeks were cold (Arizona 'cold') and the transmission was terrible to get into gear especially first thing in the morning.

After ordering 4 liters of the VW stuff, I drained and refilled the gear box. Immediately the shifting was easier and like it was before.

On an oil discussion forum I read that the VW G 005 000 is referred to as GL 4+. A synthetic type of GL 4.

Has there been any discussion on here regarding a GL 4+? I have done a search but haven't found anything.

Tue Sep 08, 2015 9:40 am

That is something I will have to look into. I've heard about stiff shifting after transmission oil changes and some had to do with the fill level. VW ended up suggesting the fill height to be 1cm below the fill hole. Not sure if the stiff shifting came out only when the oil was cold or if it was all the time

Tue Sep 08, 2015 7:22 pm

When I switched to GL-5 synthetic, I noticed the shifting was smoother. Especially nice on the drag strip :wink:

Wed Sep 09, 2015 3:00 am

neil68 wrote: When I switched to GL-5 synthetic, I noticed the shifting was smoother. Especially nice on the drag strip :wink:

The problem comes in that not all GL-5 oils including synthetics work well in these transmissions. To say that your GL-5 shifts well is pretty meaningless unless you mentions which exact product they are using.

Wed Sep 09, 2015 7:42 pm

Wildthings wrote: neil68 wrote: When I switched to GL-5 synthetic, I noticed the shifting was smoother. Especially nice on the drag strip :wink:

The problem comes in that not all GL-5 oils including synthetics work well in these transmissions. To say that your GL-5 shifts well is pretty meaningless unless you mentions which exact product they are using.

Please name one GL-5 synthetic that does not work well in a VW gearbox, and explain what you mean by not working well.

It was several years ago that I switched to using GL-5 and I've used several brands. Currently using MotoMaster 75W90 synthetic.

Wed Sep 09, 2015 7:54 pm

neil68 wrote: Wildthings wrote: neil68 wrote: When I switched to GL-5 synthetic, I noticed the shifting was smoother. Especially nice on the drag strip :wink:

The problem comes in that not all GL-5 oils including synthetics work well in these transmissions. To say that your GL-5 shifts well is pretty meaningless unless you mentions which exact product they are using.

Please name one GL-5 synthetic that does not work well in a VW gearbox, and explain what you mean by not working well.

It was several years ago that I switched to using GL-5 and I've used several brands. Currently using MotoMaster 75W90 synthetic.

BG Ultra Guard, as I posted before this GL-5 crap required about four times as much force on the shifter to get into gear on an upshift and made downshifting close to impossible.

Wed Sep 09, 2015 8:15 pm

Was it a 75W90 synthetic GL-5?

Are you sure you don't have a gearbox problem?

Wed Sep 09, 2015 8:36 pm

neil68 wrote: Was it a 75W90 synthetic GL-5?

Are you sure you don't have a gearbox problem?

Newly rebuilt gear box that was initially filled for GL-4 which was switched to the crap GL-5 at around 4-5000 miles. Shifting instantly went to $hit, not after 100 miles or even 10 miles, but on the first shift. Shifting improved greatly when I dropped the GL-5 crap after a couple of thousand miles and went back to a GL-4 but isn't as good as it was prior to running the GL-5 crap. Note that the BG website strongly implies that Ultra Guard should not be used in a transaxle with yellow metal yet the rebuilder who did my tranny now requires this oil for warranty purposes.

Wed Sep 09, 2015 9:25 pm

My original comment, which you took exception to, was regarding GL-5 SYNTHETIC. I already asked if you used GL-5 SYNTHETIC, but you still haven't confirmed it yet.

It doesn't sound like it was synthetic, as you didn't gain the smoother shifting.

The yellow metal issue is old news. Most gear oil companies tidied that up many years ago. Perhaps BG didn't upgrade their products...

Thu Sep 10, 2015 4:57 am

neil68 wrote: My original comment, which you took exception to, was regarding GL-5 SYNTHETIC. I already asked if you used GL-5 SYNTHETIC, but you still haven't confirmed it yet.

It doesn't sound like it was synthetic, as you didn't gain the smoother shifting.

The yellow metal issue is old news. Most gear oil companies tidied that up many years ago. Perhaps BG didn't upgrade their products...

The crap is synthetic, expensive, and causes shifting problems. I would be more inclined to say that a few oil companies have GL-5 oils that are well suited for use in transaxles as that is specifically why they engineer, manufacture, and sell GL-4 oils. You guys haven't posted anything at all to make me think that a modern top of the line Gl-4 oil isn't equal to or better than a GL-5 oil in all categories. As I have posted before, in the 4 ball wear test, the info I have found shows that GL-4 oils seem to offer the same level of wear protection or are superior to GL-5 oils in the same price range. And as I have said before the online sources for this info, being manufactures sales data for the GL-4 oils may not be all that reliable.

Thu Sep 10, 2015 11:12 am

Generally synthetics shift much smoother than conventional...whether GL-4 or GL-5. I've never heard of this BG company, but that sounds odd that their GL-5 synthetic worsened your shifting!

Regarding your second point, information regarding the superiority of GL-5 is amply available and outlined in this thread and elsewhere. Soon GL-4 will no longer be available...

Thu Sep 10, 2015 11:55 am

neil68 wrote:

Regarding your second point, information regarding the superiority of GL-5 is amply available and outlined in this thread and elsewhere..

I haven't seen anything but anecdotal evidence of this, anecdotal evidence which surely isn't supported by the manufactures claims I have found and previously posted.

Quote: Soon GL-4 will no longer be available...

I have heard this over and over as well. Strange as GL-4 is being specced by quite a few manufacturers these days.

Thu Sep 10, 2015 7:33 pm

[quote="Wildthings"] neil68 wrote:

Quote: Soon GL-4 will no longer be available...

I have heard this over and over as well. Strange as GL-4 is being specced by quite a few manufacturers these days.

Here's a couple of quotes from one of my off-road Jeep sources:

The API GL-4 has been given this status: "service designation not in current use". In other words, obsolete.

"The GL-4 category for gear oil was created primarily for non-hypoid gears and for transmission applications which needed protection for yellow-metal compatibility (primarily in synchronizers). It did not contain highly active sulfur-phosphorous EP additives. GL-5 gear lubricants do not contain those types of additives and can be used in transmissions and other gearboxes which call for GL-4 gear oils while providing more protection."

I could list multiple other sources, but that's already been done on the preceding pages, so you can peruse those for more info.

Thu Sep 10, 2015 10:37 pm

You could provide information from other sources like the API instead of The Samba or a Jeep forun, so yes please do provide evidence from the API that GL-4 isn't a hypoid gear oil and also provide evidence from the API that the GL-4 spec is inactive.

Thu Sep 10, 2015 11:40 pm

It's not only API.

SAE declared GL-4 "inactive" in 2010...according to Rudnick's Chemistry & Technology textbook: "Synthetics, Oils and Bio Based Lubricants", 2nd Edition.

Almost everyone has moved on to the superior GL-5 gear oil, especially since the old issue of yellow metal corrosion was remedied many years ago.

Of course, there are still a few who will continue to go kicking and screaming and searching for GL-4 for years to come :wink: Just check out some of the Mazda (my brother-in-law), Jeep (my neighbour) and other forums. The same arguments go back and forth...

Fri Sep 11, 2015 1:17 am

Well your source is not the API as asked for or even the SAE so we can discount its accuracy in saying that GL-4 has been declared inactive. If you want to take it as gospel though it does also says: "GL-4 Lubricants in this service contain active EP additives for passenger car or moderately loaded hypoid axle gears" and "(Automotive) Transaxles are still predominately filled with petroleum engine oils, ATF, or GL-4 gear oils", so I am not very worried that GL-4 gear oil will soon disappear from the shelves or will fail to protect the parts in my low offset angle hypoid gear boxes just as well or better than it has done for decades at this point. This source certainly doesn't support your claim that "Almost everyone has moved on to the superior GL-5 gear oil" in fact it could hardly contradict it more.

The same source also says that: "the amount and activity of the EP additive will also negatively impact bearing life and elastomer durability in the transmission or axle", which suggest that using a GL-5 oil where it is not specified may actually lead to early bearing wear and thus increased gear wear.

Sun Sep 13, 2015 9:33 am

Wildthings wrote: I had a used tranny that I picked up rebuilt by GTA a few years ago to have as a spare. Since it was a 002 and I was putting in an older 1800 I decided to give the rebuild a go. GTA now recommends a fairly expensive synthetic GL-5 which I bought, but I first filled the gear box with some GL-4 which I had around and drove it with that oil in it for 4-5 thousand miles. The tranny shifted absolutely fine with the GL-4 oil in it, the shifts were light and smooth, including the downshifts. I then drained the gear box and refilled it with the synthetic BG Ultra Guard GL-5 supplied by GTA. The upshifts instantly became hard and slow, taking maybe 4 times the force and several times at long to get into gear and the downshifts were worse. Downshifting into 3rd was slow and hard and downshifting into 2nd at any speed was pretty much impossible without double clutching and still even then not very easy. Downshifting into 1st at any speed above 5 mph required so much force that it felt like the shift lever and linkage would bend or break if sufficient force were applied to get it to go in.

I ran the tranny with GTA recommend oil for about 2K miles and then dropped the oil and replaced it with Pennzoil Gl-4. The shifing instantly improved but did not go back to being as easy as it had been before, it being a bit more apt to grind going into gear.

Since the problem happened instantly when switching over to the BG Ultra Guard GL-5 oil I don't think that the problem is corrosion related, though corrosion damage could happen over the long run. I can't see where anything has changed for the better with GL-5 oil over the years that I have been driving VW's. What happened with this 002 is almost identical to what I experienced almost 30 years back when I tried running a GL-5 oil in a rebuilt 091 tranny after having broken it in with Gl-4, and is similar to what I have found on various boxes in other VW's I have bought and run over the years.

The BG Ultra Guard website does say their product will aggressively attach yellow metal, though as I say the shifting problem occurred immediately after the tranny was filled with this product.

I had a very similar experience as Wildthings. Back in the '90s I purchased an '85 vanagon; shifted fine. Drove for while before I figured I better do some maintainence, mainly gear box oil, who knows how long or what was in there. Grabbed some castrol hypoy-c and threw it in there. Shifting started to degrade quickly. Only later did I see it was rated gl-5. Parted that van at 250,000 miles due to lack of available main bearings. Fast forward to '06, slapped that tranny into my '88 and drove for a while, till I couldn't stand the shifting. Stuck some Sta-lube GL-4 in it and gained some shiftablity back.... but not like it was. Going from first to second when cold is an exercise in patients. In cold weather I have to pull out of the driveway in second. Gets a little better when warm.

I learned my lesson. I use GL-4 in my VW transaxles.

And you should too....... and if you don't do what I tell you to do, yer a big stupidhead so there!

Sun Sep 13, 2015 11:54 am

Wildthings wrote: Well your source is not the API as asked for or even the SAE so we can discount its accuracy in saying that GL-4 has been declared inactive. If you want to take it as gospel though it does also says: "GL-4 Lubricants in this service contain active EP additives for passenger car or moderately loaded hypoid axle gears" and "(Automotive) Transaxles are still predominately filled with petroleum engine oils, ATF, or GL-4 gear oils", so I am not very worried that GL-4 gear oil will soon disappear from the shelves or will fail to protect the parts in my low offset angle hypoid gear boxes just as well or better than it has done for decades at this point. This source certainly doesn't support your claim that "Almost everyone has moved on to the superior GL-5 gear oil" in fact it could hardly contradict it more.

The same source also says that: "the amount and activity of the EP additive will also negatively impact bearing life and elastomer durability in the transmission or axle", which suggest that using a GL-5 oil where it is not specified may actually lead to early bearing wear and thus increased gear wear.

You have made it clear that you only want to believe what you already believe. The fact is that GL4 is already becoming more difficult to find...just read some of the previous posts. Both SAE and API have weighed in on the fact that GL4 is on it's way out. GL5 was long ago adjusted for the potential risk to yellow metals, and yet you continue to cite old news.

I'll stick with the superior protection of GL5, as many of our OEM parts are no longer being manufactured...

Sun Sep 13, 2015 12:02 pm

neil68 wrote: Wildthings wrote: Well your source is not the API as asked for or even the SAE so we can discount its accuracy in saying that GL-4 has been declared inactive. If you want to take it as gospel though it does also says: "GL-4 Lubricants in this service contain active EP additives for passenger car or moderately loaded hypoid axle gears" and "(Automotive) Transaxles are still predominately filled with petroleum engine oils, ATF, or GL-4 gear oils", so I am not very worried that GL-4 gear oil will soon disappear from the shelves or will fail to protect the parts in my low offset angle hypoid gear boxes just as well or better than it has done for decades at this point. This source certainly doesn't support your claim that "Almost everyone has moved on to the superior GL-5 gear oil" in fact it could hardly contradict it more.

The same source also says that: "the amount and activity of the EP additive will also negatively impact bearing life and elastomer durability in the transmission or axle", which suggest that using a GL-5 oil where it is not specified may actually lead to early bearing wear and thus increased gear wear.

You have made it clear that you only want to believe what you already believe. The fact is that GL4 is already becoming more difficult to find...just read some of the previous posts. Both SAE and API have weighed in on the fact that GL4 is on it's way out. GL5 was long ago adjusted for the potential risk to yellow metals, and yet you continue to cite old news...

I am not having any trouble finding GL-4 and as the report you referred to says it is still being commonly used and will be available for a long time to come. Please support your statement that the SAE and API have said that GL-4 is on the way out, obsolete, or inactive with something from either the SAE or API themselves. Aping what others claim counts for nothing.

Fri Oct 30, 2015 7:24 am

Did not read all, but todays its not gl4 OR gl5, it is gl4 and gl5.

http://www.reifendirekt.de/cgi-bin/oshop.pl?item_i...disabled=1

"Fully synthetic multigrade gear oil for manual transmissions and rear axles of passenger cars, trucks, buses and off-road vehicles. High Performer gear oil 75W-90 GL4 / 5 (fully synthetic) is produced on synthetic base Universal high performance gear oil of SAE grade 75W-90 with a specially selected additive combination.

Advantages:

Thermally highly resilient and provides even under permanent stress of +180 ° C a safe lubrication film. Even under such extreme conditions, it does not constitute impermissible aging products.

The High Performer gear oil 75W-90 GL4 / 5 (fully synthetic) meets and exceeds the following specifications:

API: GL4 / GL5

MIL-L2105D

SAE 75W / 80W / 85W / SAE 80W-90 / SAE 90

Mercedes-Benz 235.0

MF 1134

MAN 342

GM-M 75/1

FORD SQM-2C-9002 AA

VW TL 727

The practical advantages:

Excellent wear protection and high oxidation stability

No lack of lubrication due to viscous or thin oil

reduced gear noise even in very hot oil as a result of well-adhering lubricant film

high wear protection, absolutely shear stable, ie the SAE class does not change

Full lubrication even at temperatures down to -50 ° C

universal application in manual transmissions, Hypoidachsgetrieben, planetary gears, side drives, auxiliary drives and steering gears"