I've always been of the opinion that Manual trans fluid should be changed every 30-40k for cars that are driven fairly hard. In my case, I drive my car pretty hard on a regular basis. As such, I first changed my trans fluid at 30k miles with Lubromoly GL-4 75w90. I recently changed it a 2nd time at 74k miles with Lubromoly GL-5 75w90, as I could not locate any GL-4 no matter where I looked. So far, I'm pretty disappointed. My gearbox has always been silky smooth, even with over 70k miles. Well, after changing to GL-5 my gearbox feels about 80% more notchy, especially when it's cold. In fact, when the weather has been less than 50 degrees, the very first 1-2 shift in the morning ALWAYS grinds a little which is very concerning. Even if I shift as light as possible, it still wants to grind 2nd on that very 1st shift of the day. Since the weather has warmed up, it hasn't been AS bad but still not as smooth as it used to be. What did they change from GL-4 to GL-5, or am I just crazy to be changing my fluid so soon? Anything I can add to minimize this?
Just changed Tranny fluid, GL4 to GL5...
- Thread starter GLISHO
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GL-5 fluids should not be used in place of GL-4, at least in the cases I have always been involved with. (Nissan manual trans)
Just find an Amsoil dealer and buy some MTG. The stuff is awesome.
It's GL-4, 75W90.
Just find an Amsoil dealer and buy some MTG. The stuff is awesome.
It's GL-4, 75W90.
+1 Amsoil has some of if not the best gear lubes out there period. I would change back to the GL-4 in the near future.
+2 on the Amsoil MTG 75w-90 GL-4 gear oil.
Only thing that would quiet the bearing rattle in my 96 5spd Metro.
Really, really good stuff.
I've tried at least 4 other name brands.
Only thing that would quiet the bearing rattle in my 96 5spd Metro.
Really, really good stuff.
I've tried at least 4 other name brands.
GL 5 shouldn't be used in place of GL 4 lubes. Something to do with the brass synchros in the tranny.
Yes GL5 is going to eat you syncros....the ep additives in gl5 are corrosive to brass so get it out asap
Redline or Amsoil - both have excellent GL-4 gear oils.
GL-5 has higher amounts of sulfur in it as an EP (Extreme Pressure) additive and it can damage (pit) brass synchros. key word can, not necessarily will it do it though because the temperatures required to do so are quite high. the guys at mobil 1 said so but i cant remember where i read that so technically i have no proof.
that being said...im pleased with my Red Line MT-90.
that being said...im pleased with my Red Line MT-90.
Its because your new fluid is considerably thicker than the old fluid. Best to change out gear oils in the summer and give the fluid a couple months of summer shearing to make it more friendly when its cold out.
BTW, all the GL5 scare tactics said in this thread are [censored]. Please, unless you can post some pictures of damaged transmission components, don't spread rumors. I've used GL5 in manual transmissions for over decades with no synchro problems.
You have a couple options. You can give it a little time to shear. You can add a bottle of Lubegard Gear Oil Supplement to assist. Or, you can change it out for another gear oil.
75w90 GL4 gear oils that are easy to find(mail order) and speed or 4x4 shops are Redline MT90 and Amsoil MTG. The local Ford dealer should have a couple choices of GL4 75w90.
If you don't mind a little thinner, GL4 75w85 is also available.
BTW, all the GL5 scare tactics said in this thread are [censored]. Please, unless you can post some pictures of damaged transmission components, don't spread rumors. I've used GL5 in manual transmissions for over decades with no synchro problems.
You have a couple options. You can give it a little time to shear. You can add a bottle of Lubegard Gear Oil Supplement to assist. Or, you can change it out for another gear oil.
75w90 GL4 gear oils that are easy to find(mail order) and speed or 4x4 shops are Redline MT90 and Amsoil MTG. The local Ford dealer should have a couple choices of GL4 75w90.
If you don't mind a little thinner, GL4 75w85 is also available.
Hey guess what....I've replaced and torn apart failed transmission from running gl5 in a gl4 app......sorry I'm not all 15 year old girlish with a camera and take pics of everything I do
Rough, sounds like the prevailing opinion is that I should change it out. It just sucks that in order to find a good, synthetic fluid (like Redline or Amsoil) I have to order online since there's no dealers in my area (I hate SW Missouri!!!)
Originally Posted By: GLISHO
Rough, sounds like the prevailing opinion is that I should change it out. It just sucks that in order to find a good, synthetic fluid (like Redline or Amsoil) I have to order online since there's no dealers in my area (I hate SW Missouri!!!)
I don't know what your standards are, for a specific synthetic to qualify as good, but there is another option available at Ford dealers. There is the Motorcraft Full Synthetic Manual Transmission Fluid, which is a 75W-90 gear oil that is recommended for transmissions requiring GL-3 and GL-4 type gear oils. The part number for it is XT-M5-QS.
Rough, sounds like the prevailing opinion is that I should change it out. It just sucks that in order to find a good, synthetic fluid (like Redline or Amsoil) I have to order online since there's no dealers in my area (I hate SW Missouri!!!)
I don't know what your standards are, for a specific synthetic to qualify as good, but there is another option available at Ford dealers. There is the Motorcraft Full Synthetic Manual Transmission Fluid, which is a 75W-90 gear oil that is recommended for transmissions requiring GL-3 and GL-4 type gear oils. The part number for it is XT-M5-QS.
My transmission calls for GL5 75w80 but I use GL4/5 75w90.
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Only negative I know of when using GL5`s in manual trannies is the LS modifier which can impede the synchros from doing their job by providing smooth shifts. I`ve heard of GL5 causing notchy or clunky shifts.
Even the buffered sulfur in GL5s is not without problems.
the stuff will attach to the brass synchro faces and does not wer off, but is 'chunked' off in small pieces. This is because of the strong sulfur bond, and it takes metal away with it.
So it can be bad for another reason than simply being corrosive..
the stuff will attach to the brass synchro faces and does not wer off, but is 'chunked' off in small pieces. This is because of the strong sulfur bond, and it takes metal away with it.
So it can be bad for another reason than simply being corrosive..
Yes, GL-5 is corrosive, and will not allow your syncros to work as designed. The GL-4 provides a bit more needed friction for them to catch on to as you change gears. Thats where your clunky shifts come from when you use a GL-5 with the slick additives meant for a diff.
i've seen gl-5 wipe of the little spiral ridges on the inside of the blocker(syncro) rings right off....these spiral ridges squeegee the oil off of the beveled surface on the back of the gear, this allows the blocker ring to 'grab' the gear and synchronize (equalize)the speed of the input shaft to the output shaft to allow the shift collar to smoothly engage the selected gear
Putting GL5 in a transmission is a mistake. Get it outta there and go back to GL4. GL5 oils have high amounts of sulphur based EP additives which cause corrosion of yellow metals in the transmission (synchros).
Also, GL5 oils frequently have LS friction modifier additives, which will interfere with synchro operation. Get the GL5 outta there!
I'd run Redline MTL or MT90.
Also, GL5 oils frequently have LS friction modifier additives, which will interfere with synchro operation. Get the GL5 outta there!
I'd run Redline MTL or MT90.
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I ran GL-5 in a GL-4 transmission for over a year and a half before realizing the mistake I'd made, I have Red Line MT-90 in there now and it shifts just fine.
The sulfur doesn't start to eat up the brass until very high temperatures are used, which aren't all too common in normal driving conditions.
The sulfur doesn't start to eat up the brass until very high temperatures are used, which aren't all too common in normal driving conditions.
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