If anybody here is familiar with SAAB classic 900 transmissions, Eiron, they know that they are notorious for pinion bearing failure. I'm convinced that dino oil (SAABs recomendation) is the way to go. However, would 10w-30 or 10w-40 be better? I've become obsessed with not rebuilding this transmission in the foreseeable future.
SAAB Trans Questions
- Thread starter carrera79
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Hi carrera79,
I feel your pain
.
I'm guessing you've read thru my tranny oil experiment on my '90? It's been about 1500 miles since I went thru all that, including Saturday's 325 mile trip to the ski resort (seven hours of freeway & mountain driving for six hours of snowboarding??), & the change-over's still shifting fine.
I also just finished an A-Rx treatment on my son's '85 C900 tranny (8v engine). We just got the car about 6 wks ago, & the PO was already using 10W-30. The old oil had 30k on it, but the inner drivers are leaking a bit & it needs the occassional top-up. I simply added the A-Rx to this oil (& topped up with fresh to reach the "full" mark) & ran it for 1500 miles. When I drained it out yesterday, it looked pretty black for tranny oil.
I refilled with one liter of Saab 5w30 syn blend (for 0°F cold-start shifting) & the rest (1 & 1/2 liters?) Delvac 1300 Super 15w40 (for the hot viscosity, detergent & moly). Since I'm not doing anything "special" as far as the A-Rx treatment goes, I'll be interested to see if the drivers leak any less. I'll drain this out after 10k miles & refill with Rotella syn 5W-40, since it's not a PAO-based oil. At that point, I'll get back on a "normal" change schedule.
I feel your pain
I'm guessing you've read thru my tranny oil experiment on my '90? It's been about 1500 miles since I went thru all that, including Saturday's 325 mile trip to the ski resort (seven hours of freeway & mountain driving for six hours of snowboarding??), & the change-over's still shifting fine.
I also just finished an A-Rx treatment on my son's '85 C900 tranny (8v engine). We just got the car about 6 wks ago, & the PO was already using 10W-30. The old oil had 30k on it, but the inner drivers are leaking a bit & it needs the occassional top-up. I simply added the A-Rx to this oil (& topped up with fresh to reach the "full" mark) & ran it for 1500 miles. When I drained it out yesterday, it looked pretty black for tranny oil.
I refilled with one liter of Saab 5w30 syn blend (for 0°F cold-start shifting) & the rest (1 & 1/2 liters?) Delvac 1300 Super 15w40 (for the hot viscosity, detergent & moly). Since I'm not doing anything "special" as far as the A-Rx treatment goes, I'll be interested to see if the drivers leak any less. I'll drain this out after 10k miles & refill with Rotella syn 5W-40, since it's not a PAO-based oil. At that point, I'll get back on a "normal" change schedule.
Hey! Where's everybody else on this?
I can't be the only one to experiment with tranny lubes!?!
I can't be the only one to experiment with tranny lubes!?!
Thanks Eiron. I've gotten a lot of useful info from your posts. I'm thinking at this point I might just do an Auto Rx treatment and then begin chaning tranny fluid every oil change. BTW-I ran the Neutra through my engine and it worked wonderfully. Seems to be running a lot smoother especially before it warms up. Maybe the Schaeffers has something to do with that.
I've got over 300k miles on my 900 tranny using Mobil 10W-30. Knock on wood.
Shifts smooth as butter.
Shifts smooth as butter.
Really short-term update:
I just drove the '85 for the second time since the change, & I'm not as pleased with this mix as I had hoped. (But, it could be due to the colder weather we've got now.) Even with Mobil's claim of 10W- cold flow & the 40% 5w30 mixed in, morning shifts doen't seem any less stiff than with the old 10W-30 in there. Also, warm shifts aren't as smooth as they were before.
I'm now thinking a "thick" 5w30 would be better for my area. I still want something lower than a 10W- for the 0°F cold shifts, & something heavier when hot (than the average 30 wt) to protect the smaller pinion bearing in this model year. I know Exxon's coming out with a new 5w30 "high mileage" oil, & it might be a thicker 30 wt, but I don't have any specs on it yet. (I know it's futile, but I wish Saab still made their ACEA A3, 12.4 cSt, 5w30 semi-syn. I think this would be perfect!)
If shifting doesn't improve, I'll probably dump it this summer for something else. (Maybe the slightly thinner Rotella Syn, or a lighter home-blend.) Feel free to email me with any questions or "on-the-spot" evaluations of how the tranny's doing.
I just drove the '85 for the second time since the change, & I'm not as pleased with this mix as I had hoped. (But, it could be due to the colder weather we've got now.) Even with Mobil's claim of 10W- cold flow & the 40% 5w30 mixed in, morning shifts doen't seem any less stiff than with the old 10W-30 in there. Also, warm shifts aren't as smooth as they were before.
I'm now thinking a "thick" 5w30 would be better for my area. I still want something lower than a 10W- for the 0°F cold shifts, & something heavier when hot (than the average 30 wt) to protect the smaller pinion bearing in this model year. I know Exxon's coming out with a new 5w30 "high mileage" oil, & it might be a thicker 30 wt, but I don't have any specs on it yet. (I know it's futile, but I wish Saab still made their ACEA A3, 12.4 cSt, 5w30 semi-syn. I think this would be perfect!)
If shifting doesn't improve, I'll probably dump it this summer for something else. (Maybe the slightly thinner Rotella Syn, or a lighter home-blend.) Feel free to email me with any questions or "on-the-spot" evaluations of how the tranny's doing.
IIRC, Saab's recommendation is to NOT use synthetic motor oil in the transmissions. Regular dino oil, period. But, interestingly enough, you can use synthetic manual transmission fluid.
I think your shifting problem is directly related to the use of the semi-syn portion of the motor oil you added to the transmission.
I have had success using Redline MTL (but some folks say that the Honda MTF is the way to go), or BG Synchroshift.
Currently, I'm using the synthetic Saab MTF in my 95 900S--shifts great in the cold (car spent all but the last 5 months of it's life in Colorado).
I think your shifting problem is directly related to the use of the semi-syn portion of the motor oil you added to the transmission.
I have had success using Redline MTL (but some folks say that the Honda MTF is the way to go), or BG Synchroshift.
Currently, I'm using the synthetic Saab MTF in my 95 900S--shifts great in the cold (car spent all but the last 5 months of it's life in Colorado).
I don't think that I'm ever going to run Synth MTL in my C900. I hear too many stories about transmissions going after putting that stuff in, and on the other hand I hear a ton of stories about long life with dino. I don't understand why, but i'll stay with what's recommended in this case.
Are you having problems now, or just trying to avoid future problems?
I think the Rotella Syn's a good choice if you want to stay away from PAOs for any reason. I don't have an aversion to PAOs in the tranny, but I'm not convinced the cost is worth it at short change intervals. Of course, my trannies have 151k & 167k miles on 'em, so I don't think PAOs will give me any drivetrain longevity at this point. Now, if I had a newly rebuilt tranny, I'd probably run Delvac 1 in it for 30k mi intervals from the start.
My experience with cryo-treated metal was that it got harder but not tougher. This made the part stronger during normal use but also more brittle & susceptible to fracturing during hard use. (The part actually exploded under high torque. Lots of tiny bits, kinda like what tempered glass does when it breaks.)
I think the Rotella Syn's a good choice if you want to stay away from PAOs for any reason. I don't have an aversion to PAOs in the tranny, but I'm not convinced the cost is worth it at short change intervals. Of course, my trannies have 151k & 167k miles on 'em, so I don't think PAOs will give me any drivetrain longevity at this point. Now, if I had a newly rebuilt tranny, I'd probably run Delvac 1 in it for 30k mi intervals from the start.
My experience with cryo-treated metal was that it got harder but not tougher. This made the part stronger during normal use but also more brittle & susceptible to fracturing during hard use. (The part actually exploded under high torque. Lots of tiny bits, kinda like what tempered glass does when it breaks.)
Really short-term update #2:
Well, the drive home on the 14th was much better (shifting-wise) than the drive into work. I'm convinced that part of what I'm experiencing is temp/viscosity related, since the drive in was in the teens & the drive home was in the 30's. Yesterday's drives were also better, with inbound temps in the 20's & homeward temps in the 40's. As long as the shifting continues to improve, I feel much better about having the heavier oil (& moly) in there, especially for the bearings. Since the Rotella Syn 5W-40 is roughly 10% lighter than the D1300S, I might try 1 qt of M1 xW-30 (for the moly) & the remainder Rotella.
As a comparison, I drove my '90 this morning & it's now shifting as well as when I had any gear oil in it (it had Castrol dino gear oil for most of its life, & BG SyncroShift II syn for the past 30k-40k mi). It's been 1500 miles since the A-Rx treatment in this car's tranny, & the new oil mix is slightly different from what's in the '85 (maybe 70% D1300S 15w40, with the remainder being M1 10W-30). I also didn't particularly like the shifting in this car when I refilled with my mix, but it's been getting steadily better. This may point to some on-going after-effects of the A-Rx cleaning, or plating of the parts with moly, or some shearing of the oil from the gear train, or ???.
axjohn,
The only reference to gear lubes I've seen is on Townsend's website. It's a very old document (1994? earlier?), & its origins are sketchy at best. It recommends against syn oils solely on the basis of seal integrity (which should be a non-issue with today's oils), but also mentions that gear oils should be changed at half the interval length (15k mi) of motor oils (30k mi). Many have said that Townsend actually recommended M1 15W-50 in all C900 trannies, but I've never seen it on his site.
You're right, the new 900's ('94 to present) are recommended to get Saab's syn lube, & that's what I'd suggest you stay with. But, like carrera79 has said, I think Saab had some good reasons for spec'ing motor oil in these C900 trannies. (IMO, a very high heat load/soak is the biggest reason.) I liked the BG SS2, but it was horribly expensive & my shifting problem (5th gear sticking) came back anyway. I refuse to use RedLine, mostly due to the one local Saab garage that swears by it but also swears that C900 manual trannies are only good for 120k miles under the best conditions. And I think the new Honda stuff is perfect for new Hondas, but probably wasn't spec'ed with a 25 yr old Saab tranny design in mind.
carrera79,
Let us know what you decide to use, & be sure to keep us posted as to how it works out!
Well, the drive home on the 14th was much better (shifting-wise) than the drive into work. I'm convinced that part of what I'm experiencing is temp/viscosity related, since the drive in was in the teens & the drive home was in the 30's. Yesterday's drives were also better, with inbound temps in the 20's & homeward temps in the 40's. As long as the shifting continues to improve, I feel much better about having the heavier oil (& moly) in there, especially for the bearings. Since the Rotella Syn 5W-40 is roughly 10% lighter than the D1300S, I might try 1 qt of M1 xW-30 (for the moly) & the remainder Rotella.
As a comparison, I drove my '90 this morning & it's now shifting as well as when I had any gear oil in it (it had Castrol dino gear oil for most of its life, & BG SyncroShift II syn for the past 30k-40k mi). It's been 1500 miles since the A-Rx treatment in this car's tranny, & the new oil mix is slightly different from what's in the '85 (maybe 70% D1300S 15w40, with the remainder being M1 10W-30). I also didn't particularly like the shifting in this car when I refilled with my mix, but it's been getting steadily better. This may point to some on-going after-effects of the A-Rx cleaning, or plating of the parts with moly, or some shearing of the oil from the gear train, or ???.
axjohn,
The only reference to gear lubes I've seen is on Townsend's website. It's a very old document (1994? earlier?), & its origins are sketchy at best. It recommends against syn oils solely on the basis of seal integrity (which should be a non-issue with today's oils), but also mentions that gear oils should be changed at half the interval length (15k mi) of motor oils (30k mi). Many have said that Townsend actually recommended M1 15W-50 in all C900 trannies, but I've never seen it on his site.
You're right, the new 900's ('94 to present) are recommended to get Saab's syn lube, & that's what I'd suggest you stay with. But, like carrera79 has said, I think Saab had some good reasons for spec'ing motor oil in these C900 trannies. (IMO, a very high heat load/soak is the biggest reason.) I liked the BG SS2, but it was horribly expensive & my shifting problem (5th gear sticking) came back anyway. I refuse to use RedLine, mostly due to the one local Saab garage that swears by it but also swears that C900 manual trannies are only good for 120k miles under the best conditions. And I think the new Honda stuff is perfect for new Hondas, but probably wasn't spec'ed with a 25 yr old Saab tranny design in mind.
carrera79,
Let us know what you decide to use, & be sure to keep us posted as to how it works out!
I think that I'm going to do a change real soon here. I'm thinking of going with some sort of high mileage or long life oil with moly in it. I was thinking about putting in a quart of the Schaeffer's supreme, but I'm intersted in your comments about PAO's in this trans. What is the reasoning behind this? Is it too slippery for the syncros?
I'll tell you what. I'm almost ready to yank this thing out, replace everything with cryo treated stuff and do whatever modifications I can at my friends machine shop to make this thing as reliable as possible.
I'll tell you what. I'm almost ready to yank this thing out, replace everything with cryo treated stuff and do whatever modifications I can at my friends machine shop to make this thing as reliable as possible.
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