Transmission lube
06-01-2001, 04:19 PM
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Transmission lube
Incase you didn't see my question on the old board, what is the best tranny lube to use for my 86' 951? It is getting replaced monday when they replace the broken transmission cooler from my accident 
. Tranny is in excellent condition...never barfed on my once. Let me know...thanks,
ribs
. Tranny is in excellent condition...never barfed on my once. Let me know...thanks,ribs
06-01-2001, 04:25 PM
#2
Drifting
ribs, for my non-LSD I've used Mobil 1 70W90 synthetic, Redline 70W90 synthetic, and Swepco 201 (I think it's 201...). There was no discernible difference between the Mobil 1 and Redline for me, aside that the Redline was cheaper. I did NOT like the Swepco at all. Did not ease the shifting like the other two. And it's not synthetic, if that matters to you.
06-02-2001, 08:12 AM
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I have used Mobil 1 for some time now and find it works well. I did try Redline MTL once, but think the Mobil 1 is smoother. I have a Quaife in my 951 TS trans.
06-09-2001, 01:07 PM
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With the syn. gear oils [espesially the Redline gear oils]some of the trannys are having chatter in the Ltm slip diff. This is because they don't have enough of the additive in their oils that eliminate this chatter. SWEPCO 201 on the other hand does have this additive [Molybdenum Disulfide]and has been quite succesful in solving these problems. Now it may not solve all of your shifting problems but it will allow your tranny the opportunity to last for quite sometime in your car. BTW I have seen a perfectly good tranny fail, actual metal coming off the gears, after switching to Mobil 1 within a few hundred miles.
06-09-2001, 02:09 PM
#6
Nordschleife Master
Lane, you have me a bit concerned here. I have a LSD on an '88 952. I have been running Mobile 1 in it for about 9 years. Last fall I changed out the oil and found tiny metal shavings at the bottom of the case when I stuck my finger in and fished around. Not a lot, I figured it was about to be expected for 5 years of use (but only 15k miles), but now I'm not so sure.
I have no shifting problems but the transmission sure makes that "standard" bucket full of marbles sound in neutral and the clutch out.
Everyone seems to have a different opinion on what is best.
I have no shifting problems but the transmission sure makes that "standard" bucket full of marbles sound in neutral and the clutch out.
Everyone seems to have a different opinion on what is best.
06-09-2001, 04:06 PM
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Dan,
Depending on your shifting habits 'very small' metal shavings after 9 years of use is not uncommon. It would depend on the total mileage on the tranny. You said 15K? Is that total mileage on the tranny? If so, there is most likely a problem inside that box. A properly maintained transmission with proper shifting should last anywhere from 100K-150K. Of course this can be effected by many other factors, total horsepower, clutch condition, hard shifting (poor technic)etc...
I have a hard time believing that the use of a synthetic lubricant would precipitate gear failure. LSD damage possilbly, not enough additive. That could be the source of your metal shavings. Good luck.
Max
Depending on your shifting habits 'very small' metal shavings after 9 years of use is not uncommon. It would depend on the total mileage on the tranny. You said 15K? Is that total mileage on the tranny? If so, there is most likely a problem inside that box. A properly maintained transmission with proper shifting should last anywhere from 100K-150K. Of course this can be effected by many other factors, total horsepower, clutch condition, hard shifting (poor technic)etc...
I have a hard time believing that the use of a synthetic lubricant would precipitate gear failure. LSD damage possilbly, not enough additive. That could be the source of your metal shavings. Good luck.
Max
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06-09-2001, 04:10 PM
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Since this thread came up and they already did the work, I suppose I will let you all know what they ended up doing with it. They replaced the GL5 that was in there with more GL5. I have had no problems with the "natural" gear lube that was in there before, and my mechanic suggested that I use the GL5 because with the # of miles on the tranny (103K) and the fact that it still works very well, why fix it if it ain't broke? Thanks for your responses though. If I ever get the tranny replaced or rebuilt, I will ask this qustion again, but for now I think the GL5 will work fine.
06-09-2001, 05:45 PM
#9
Nordschleife Master
Max, The 5 years and 15k miles was what the old oil (Mobile 1) I changed had on it. Total mileage on the tranny is a bit under 40k.
I'm trying to think back to when I changed it the time before when it had dino oil and how many shavings were present. I think less but who really knows. I shift just fine with proper technique and have never blown a shift and ground the gears, but this LSD angle has me thinking maybe Moblie 1 isn't the way to go.
I'm trying to think back to when I changed it the time before when it had dino oil and how many shavings were present. I think less but who really knows. I shift just fine with proper technique and have never blown a shift and ground the gears, but this LSD angle has me thinking maybe Moblie 1 isn't the way to go.
06-09-2001, 06:51 PM
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Dan,
I have a '91 944S2 and my owner's manual stipulates hypoid oil. Generic term and of course they list the standard viscosity. I have seen several threads on the old boards discussing LSD's and types of gear oils. You might check out the archives for info. I would guess that your shavings might be coming from your LSD. They are ALOT more particular when it comes to gear oils than a regular Diff. Just my 2 cents. Let me know what you find out.
Max
I have a '91 944S2 and my owner's manual stipulates hypoid oil. Generic term and of course they list the standard viscosity. I have seen several threads on the old boards discussing LSD's and types of gear oils. You might check out the archives for info. I would guess that your shavings might be coming from your LSD. They are ALOT more particular when it comes to gear oils than a regular Diff. Just my 2 cents. Let me know what you find out.
Max
06-10-2001, 03:34 AM
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Regarding the post about chatter from certain brands of LSD safe oils... may need to manually add more Friction Modifier. This is one of those "use or driving style" adjustments... if autocrossing or tracking your results will vary bigtime... if street only, then most ovver-the-couter LSD remedies will work fine.
As for the archives... here's some info from Tech-Session that was also posted as a response to Redline MTL use in our cars:
Good Luck!
[ 10-06-2001: Message edited by: Skip ]
As for the archives... here's some info from Tech-Session that was also posted as a response to Redline MTL use in our cars:
The Basics:
Friction Modifier (FM) is slippery stuff. The FM is in place to reduce LSD clutch chatter upon engagement. The amount needed is relative to the application and the age of the differential. In full race cars, you want the clutch to lock up nice and strong while not being so concerned with a little chatter. In high mileage (or worn) LSD cars, the clutches will be worn and need less FM to attain the desired effect. The downside, or catch-22, is that the syncros don't need or even like the FM. In most cars this is not a problem because the differential and transmission are separated and do not share the same lubricant. Our transaxled P-cars do share, so we must prepare for that.
FM options:
FM needs to be used in LSD cars, we know that. It's the amount that is variable. As a general rule, what comes out of the bottle is sufficient for most applications. Some folks will mix FM stuff with non-FM stuff (75W90NS and 75W90) until the desired effect of "no chatter" is attained... the reason for this being again, that syncros don't like FM.
Oil weight:
In high-performance applications where the temperatures may get higher than street use, it is common practice to use a bit higher weight oil (75W90 vs. 70W80), and higher still if the tranny/diff is not externally cooled (80W140).
What about GL-5 vs. GL-4:
The main complaint against GL-5 use in syncro'd trannies is because the chemicals used to provide the extreme pressure protection can be corrosive to synchronizers, which are commonly made of brass or bronze. Here's what the 944 factory manual has this to say: "Filling capacity Approx. 2.0 liters hypoid transmission oil SAE 75W90 to API Class GL5 or MIL-L-2105B, or SAE 80 to API Class GL4 or MIL -L-2105."
Which one is right?:
In the end, it is up to the owner. Though statements of GL-5 use in a syncro'd tranny are somewhat against... history and sales of GL-5 lubricants (like Redline 75W90) continue to be favorable. This is a heavily debated topic, even within the industry. The only things we can assume for sure is: 1. Don't use FM in non-LSD transaxles 2. Don't add FM to make the clutches lock up sooner in LSD equipped cars.
Friction Modifier (FM) is slippery stuff. The FM is in place to reduce LSD clutch chatter upon engagement. The amount needed is relative to the application and the age of the differential. In full race cars, you want the clutch to lock up nice and strong while not being so concerned with a little chatter. In high mileage (or worn) LSD cars, the clutches will be worn and need less FM to attain the desired effect. The downside, or catch-22, is that the syncros don't need or even like the FM. In most cars this is not a problem because the differential and transmission are separated and do not share the same lubricant. Our transaxled P-cars do share, so we must prepare for that.
FM options:
FM needs to be used in LSD cars, we know that. It's the amount that is variable. As a general rule, what comes out of the bottle is sufficient for most applications. Some folks will mix FM stuff with non-FM stuff (75W90NS and 75W90) until the desired effect of "no chatter" is attained... the reason for this being again, that syncros don't like FM.
Oil weight:
In high-performance applications where the temperatures may get higher than street use, it is common practice to use a bit higher weight oil (75W90 vs. 70W80), and higher still if the tranny/diff is not externally cooled (80W140).
What about GL-5 vs. GL-4:
The main complaint against GL-5 use in syncro'd trannies is because the chemicals used to provide the extreme pressure protection can be corrosive to synchronizers, which are commonly made of brass or bronze. Here's what the 944 factory manual has this to say: "Filling capacity Approx. 2.0 liters hypoid transmission oil SAE 75W90 to API Class GL5 or MIL-L-2105B, or SAE 80 to API Class GL4 or MIL -L-2105."
Which one is right?:
In the end, it is up to the owner. Though statements of GL-5 use in a syncro'd tranny are somewhat against... history and sales of GL-5 lubricants (like Redline 75W90) continue to be favorable. This is a heavily debated topic, even within the industry. The only things we can assume for sure is: 1. Don't use FM in non-LSD transaxles 2. Don't add FM to make the clutches lock up sooner in LSD equipped cars.
[ 10-06-2001: Message edited by: Skip ]
