[Passion4_900]

Ok, so I had used the Honda MTF in my other c900 and wasnt 100% satisfied with the result and I have a feeling there is better stuff on the market. So I am on a hunt for a solution to c900's tranny problems. After doing an extensive search online through Google searches and archive searches in the saabscene databas and others as well, I have come to a conclusion. Nobody knows for shure exacly what is best for c900 manual trannys.

-Saab recomends regular engine oil
-some say that full synthetic should not be used
-no oils containing traces of sulfur should be used (leaches out copper in the synchros)

-some garages swear by Amsoil Redline MTF.

The 2 main products I have in mind to try is:

1- mobil 1 full synthetic engine oil (or MTF but cant find any from mobil 1)
2 - found a new product when I went to the store today: Lucas 75/90 Synthetic Gear Oil. I have had good results with most of Lucas products and seems that this may be a winner.

Doing further research on the lucas website, mail ingredients are:

Name: Synthetic petroleum hydrocarbons plus additives
Components: hydrocracked, hydroisomorized C-15/ C-55 parafinic oils.

I believe that in plain terms basicaly means synthetic oil with additive. No sign of sulfur.

Anyone have knowledge or would logicaly be able to debate wich oil is best, if either?

maybe they are both not recomended, just let me know.....

on the lucas oil bottle it is marked that will greately reduce gear whine and will mix with other synthetic or petroleum based gear oils.

 

[Smaart Aas Saabr]

What the fuck is a "synthetic petroleum hydrocarbon". That's like a synthetic non-synthetic! :lol:

I know the original spec Saab put into them in the factory was EP75 GL-4 or GL-5, gear oil, with 10w30 / 10w40 motor oil for topping up (basically the same viscosity).

Saab has a special "synthetic Saab MTF" which they use on the cars after model year 1994, save the '94 900 Convertible. They then replaced this with a "new" MTF, which supersedes the old one. But - both TSB's from Saab specifically say "DO NOT USE THIS ON C900".

There are more than a few cars from back then that asked for motor oil in the gearbox, and they didn't seem to get hit as badly as the C900. (ie the transmissions lasted "forever").

One thing that is for sure is the original oil sucks (due to age and milage), and should be replaced on pretty much any C900 right now.

 

[Passion4_900]

I guess as it stands, I'll buy the lucas stuff and flush the tranny with normal fluid then refil with lucas stuff....... unless anyone else has something they'd like to add..... that's why i put up this discussion, so we can come up with a "winning" solution.... or recipe....

 

[DeLorean]

well I have tried a bunch of things... right now, I have mobil 1 engine oil in there, and I do not like it... it does not shift very well and has a bit of a notchy feel to it. I'm not sure what I want to try next, maybe some GM-syncromesch again. that always gave a great shifter feel!

 

[Passion4_900]

Good to know........ I guess I won't try mobil 1 then. Thanks for letting me know.

Honda stuff had a bit of a notchy feel as well and thats why I want to try something different. I'll report my findings with the lucas stuff........ it's kinta expensive tough.... 48$ for 3.75L or 14.99$ for 1L (just a bit over a quart) ....
for you guys here in canada, it can be purchased at Canadian Tire

 

[Smaart Aas Saabr]

Good to know........ I guess I won't try mobil 1 then. Thanks for letting me know.

Honda stuff had a bit of a notchy feel as well and thats why I want to try something different. I'll report my findings with the lucas stuff........ it's kinta expensive tough.... 48$ for 3.75L or 14.99$ for 1L (just a bit over a quart) ....
for you guys here in canada, it can be purchased at Canadian Tire

There's your problem :wink: :wink: Try checking out some independent auto-parts shops, I know I've seen a lot of them who had that Lucas "gears in oil" dealie for you to play with while they copy your credit card :lol:

 

[gm]

synthetic motor oils are to slick for the saab syncro's ESPECIALLY when the car is COLD!!! I tried Mobil 1 as well as Amsoil synthetic motor oil in my SPG's trans & the stuff was HORRIBLE!!!

I personally do not like trying new fluids because these trannies are WEAK & the wrong trans fluid will kill the trans.

Thus, I have used redline MTL for years with excellent luck. I got 50K miles + out of my old SPG with MTL which included several track days & 200-250 crank HP. I would definantly consider this stuff, your car's trans might be past the point of smooth shifting however I feel MTL offers the best protection especially in cold weather which is coming!

I did rescently blow up my trans at the track (the 320+ whp didn't help) & I use the thicker MT-90 fluid in my trans which is BAD for cold weather. From talking to a shop my cause is probably from not having a trans oil cooler which next time around it will have!

If you want to try MTL I have several bottles which I am not going to use. I payed $10 ea & that's what I can sell it for if interested.

 

[Passion4_900]

I realy want to give the Lucas MTL a shot. If it doesnt work out, then I'll replace with redline MTF. At least it will have flushed the tranny in the process!

 

[8valvegrowl]

I ran Mobil 1 Synthetic Gear Lubricant in my c900 trans. (GL-5 EP75-90W). My trans went from newly rebuilt to blown in 6 months! (Not due to hard shifting or high HP/torque, I have a N/A 8-valve).

The EP-type gear lube destroys the brass/copper parts inside the trans.

I run Honda MTF in my rebuilt box now (had RedLine in it as soon as the rebuild was done, then I flushed it with Honda MTF 10K miles later). The Honda MTF is extremely smooth and not notchy at all. I'm flushing it again (it's been about 15K since the last flush) and refilling with Honda MTF.

I think your 'box may be worn enough that it will feel pretty notchy no matter what you do.

Give the Lucas a try! I've seen it around and have been curious if it was worth the price for the c900 'box.

 

[Passion4_900]

The EP-type gear lube destroys the brass/copper parts inside the trans.

EP-type? what does EP stand for? I read that lubes containing sulfure is what leaches out the copper from parts in the trans....

 

[Smaart Aas Saabr]

I think it's Extended Protection, funny enough :lol:

 

[DeLorean]

Extended pressure. you can get EP-90 by the gallon for nearly as cheap as you can get gas :lol: I ran that in my 86 900 for a while, it worked fine for me but would NOT shift when it was very cold outside till the car got warmed up.

 

[Smaart Aas Saabr]

There you go.

Probably cheaper than gas... been wondering if I can run my car on a slight methanol mix, since I just got several gallons of windshield washer fluid for 99 cents a gallon, Canadian cents, and it's Canadian windshield washer stuff (ie freezes at -40 not watered down American stuff, us Canucks like our alkyhol!) :lol:

 

[samberlong]

I've got Dexron III ATF in my c900 manual gearbox, shifts very smoothly indeed. Was a great imporvement over the shift quality of the old oil.

 

[Passion4_900]

I've got Dexron III ATF in my c900 manual gearbox, shifts very smoothly indeed. Was a great imporvement over the shift quality of the old oil.

So, it is safe to put Auto trans fluidin a manual trans?

 

[saabfish]

I'm running Royal Purple synthetic with a quart of the Lucas Synthetic additive as a blend. Shifting smoothed out nicely and the gears seem to just drop in.
Oddly enough, the shift into first seems to need less of the put it in 2nd or 3rd before going into 1st. Since there is no syncro for 1st it does help greatly.

 

[snow4_1man]

I’m also running Royal Purple synthetic. Before my transmission was a little bit harsh, but now it’s fine. It took about a day when I started feeling the difference. It smoothed things up rather nicely. I also run Royal Purple in my Engine excellent stuff I have had no problems since.