dual gl4 and gl5 when requirement gl4 (manual trans)
- Thread starter miawsers
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Some transmissions can be picky about their lube. Probably won't hurt anything, but might cause yuck shift quality. I never had good luck using a gear oil in my MT car, always went back to a MT lube.
Of course, lots of different cars, lots of different transmissions, might work just fine. Shouldn't hurt anything.
Of course, lots of different cars, lots of different transmissions, might work just fine. Shouldn't hurt anything.
I'm pretty sure that Lucas is not going to give the best service. It's MT-1 rated for non-synchronized truck type transmissions, but a syncrohized transmission won't like it.
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Do yourself a favor and also save time and effort and go to the local GM dealer and buy the proper 75W85 GL-4 gearbox oil. This oil is P/N 88862472 (superseded by 19351859) and is relatively affordable. I believe your capacity is 4.5 pints or thereabouts so it won't hurt too badly.
The viscosity requirements for the 75W-85 are minimum cSt of 11.0 and maximum of 13.5 cSt. The product that you're showing is 18.4 cSt and very far from the specific requirements of your vehicles gearbox.
The viscosity requirements for the 75W-85 are minimum cSt of 11.0 and maximum of 13.5 cSt. The product that you're showing is 18.4 cSt and very far from the specific requirements of your vehicles gearbox.
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Ditto for a GL4 only. Red Line has a few MT offerings that will suit your application. Probably hard to find at a local retailer, but Amazon can have it to your door in a couple days. GL4 is brass friendly, which your Saab likely has in the gearbox.
Probably it calls for MTF 0063. It's 75w85 GL4 classic ZDDP.
GL4/GL5 will work, but it's not the same. First visco is different, second formulation will be different too.
I'd buy original or MTF 75w85 or 75w90 GL4 ZDDP as:
75w85
Redline MT-85
Castrol BOT 402
-Hyundai MTF 75w85
-KIA MTF 75w85
-Castrol Syntrans 75w85
75w90
BMW LT-4
Castrol BOT 328
- Castrol 130M
- Ford 75w90 BO
- Motorcraft XT-M5-QS
- Castrol Multivehicle
- Volvo 1161723
GL4/GL5 will work, but it's not the same. First visco is different, second formulation will be different too.
I'd buy original or MTF 75w85 or 75w90 GL4 ZDDP as:
75w85
Redline MT-85
Castrol BOT 402
-Hyundai MTF 75w85
-KIA MTF 75w85
-Castrol Syntrans 75w85
75w90
BMW LT-4
Castrol BOT 328
- Castrol 130M
- Ford 75w90 BO
- Motorcraft XT-M5-QS
- Castrol Multivehicle
- Volvo 1161723
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If your car calls for a GL4 specifically, stick with that spec. A good MT fluid usually has to be ordered or bought at a dealership. I recommend Redline MT90 for your Saab if it specs a 75W-90 GL4 fluid. If you use a dual rated GL4/5, you car's gears will probably grind and crunch with every shift, especially the 1>2 shift.
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I'm going to do a bit of trial and error with my Nissan Frontier before the cold weather sets in. My Frontier specifies a GL-4 75W-85 lubricant for the manual gearbox. I have used the OEM Nissan fluid as first fill, Ravenol 75W-85 MTF and Redline MT-85. None of these fluids made any appreciable difference in the way my transmission shifted (horribly) or in the amount of gear whine experienced (completely acceptable).
I am going to experiment next month with Amsoil's Manual Synchromesh Fluid. It is published to be a 10.1 cSt fluid which is below the minimum for a 75W-85 product but far above other synchromesh fluids.
After a winter of using this product, and if the shifting quality is not better than with the OEM fluid, I intend to try Royal Purple HPS 10W-40 or their Euro 5W-40 motor oil.
If any of these products make an improvement to shift quality or cause any negative sounds or detectable actions I'll certainly poke out a comment on here.
TO THE OP: please let us know what route you take and how the transmission feels after your fluid change.
I am going to experiment next month with Amsoil's Manual Synchromesh Fluid. It is published to be a 10.1 cSt fluid which is below the minimum for a 75W-85 product but far above other synchromesh fluids.
After a winter of using this product, and if the shifting quality is not better than with the OEM fluid, I intend to try Royal Purple HPS 10W-40 or their Euro 5W-40 motor oil.
If any of these products make an improvement to shift quality or cause any negative sounds or detectable actions I'll certainly poke out a comment on here.
TO THE OP: please let us know what route you take and how the transmission feels after your fluid change.
Thanks. I'll get back to what I used.
Once upon a time, the magic go-to elixer for the Miata world was the Motorcraft XT-M5-QS. Apparently it was made of unicorn tears and most people loved it in their manual boxes. I never got around to trying it as I sold the car, but I had always intended to. From memory it was some made in Germany lube that was designed to deal with some balky shifting Ford transmissions.
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That Motorcraft fluid is a 75W90 product with a viscosity of 15.4cSt@100ºC. This is a bit viscous for my application and I'd prefer to stay within the 75W85 range or slightly under. I don't see a benefit to using a more viscous fluid than what is prescribed.
Probably yes. If the manufacturer specifies API GL-4 I'd prefer using GL-4.
If shift quality suffers synchro wear WILL increase.
Personally I'd give Redline MT-85 a try when living in the US. In a more northern climate
Castrol Syntrans V-FE 75W-80 and Ravenol MTF-2 are worthwhile options. All GL-4 only.
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Yea, should have been more specific. I was more thinking yellow metal damage when I typed that, but yea, yuck shifting will wear the synchros more.
Sure it says GL4? What am I looking at differently? Sometimes I really have to doubt myself and triple check. It says GL5 here.
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Amsoil 75W-90
www.amsoil.com
Manual Transmission & Transaxle Gear Lube 75W-90
Shop Manual Transmission & Transaxle Gear Lube 75W-90 at AMSOIL. Find premium synthetic oil, filters and more online. Fast, free shipping available.
www.amsoil.com
Try Motul Gl4 75w85. Has worked very well in my cars/pickups with synchro trans.
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