[turbo1992]

Last night I siphoned the oil out of my 92 manual tranny. I did this after a day of driving. Took about 2 hours [slow siphon]. Then I changed over to Redline MT-90. I prefer Redline after seeing great performance on my quirky 308 gearbox.

After the drainage I added 2 quarts and checked the dip stick...just about touched the bottom, so I added about 1/3 quart more. This took it just above the full mark. Took it for a drive...shifted nicely...so I parked it. This afternoon I checked the stick again and now it reads at the mid point, so now I'm under slightly.

From what I have read on the forum some suggest when draining to let the car sit overnight...I prefer to let it sit after it's been driven for a bit and drain it warm. In addition they have said it will only take back 2-2.3 qts or so due to the residule oil left behind. It appears from my results so far this may not be true...my guess is I got most of the old oil out...which was my goal...or the Redline "clings" better...hmmm.

Let the comments begin!

 

[saabreur]

Hi turbo1992, glad to see your post as I'm about to do the same, except I'm thinking of using Amsoil synthetic (see http://townsendimports.com/Web/transmission_folder/trans_image/Amsoil.gif) to refill the box, and using 0W30 as it gets very cold here in Canada (sometimes -30C), and shifting has to be done sloooowly until the oil in the box warms up in the morning! Amsoil probably has similar characteristics to your Redline MT-90 synthetic.

I read somewhere that about 1 L of the 3 L specified as being in the box is left in the box after draining through the axle opening, but with slow syphon that may not be the case; and now I can't find the original reference!

From the Townsend site (http://townsendimports.com/Web/transmission_folder/spovgearboxlube.htm) it would seem that flushing the box before the final fill to remove all particles from the gears and case before they get to the gear shaft bearings, is very advisable. Did you?

Comments from anyone who has experience on these issues will be much appreciated.

 

[saabreur]

Found one reference (at http://wiki.answers.com/Q/Where_is_...n_plug_on_a_1993_Saab_900_Manual_Transmission) as follows:
"Note from a professional: It is not possible to properly drain all of the oil through the dipstick tube. It is preferable and recommended by SAAB to remove the stamped steel differential cover (8 bolts). With the car jacked up from the front, full draining is assured. The differential cover contains an oil "catcher" and filter which should be dismantled and cleaned--you will find bits of metal and junk here. Look for an excessive number of larger metal chips or "mud" which would indicate harsh use of the transmission and/or incipient pinion bearing failure. Be sure to use a new gasket when you put the cover back on." It also noted that Saab recommend not using synthetic oil, but that recommendation was made 30 years or longer ago, when synthetics were not as good as today!

Perhaps the filter reduces the need to flush the box? Any thoughts?

 

[mmoe]

Last night I siphoned the oil out of my 92 manual tranny. I did this after a day of driving. Took about 2 hours [slow siphon]. Then I changed over to Redline MT-90. I prefer Redline after seeing great performance on my quirky 308 gearbox.

After the drainage I added 2 quarts and checked the dip stick...just about touched the bottom, so I added about 1/3 quart more. This took it just above the full mark. Took it for a drive...shifted nicely...so I parked it. This afternoon I checked the stick again and now it reads at the mid point, so now I'm under slightly.

From what I have read on the forum some suggest when draining to let the car sit overnight...I prefer to let it sit after it's been driven for a bit and drain it warm. In addition they have said it will only take back 2-2.3 qts or so due to the residule oil left behind. It appears from my results so far this may not be true...my guess is I got most of the old oil out...which was my goal...or the Redline "clings" better...hmmm.

Let the comments begin!

You haven't taken into account the primary gear case or the various other places that the oil pools without being able to drain. Oil moves in and out of the primaries and the amount that is in there varies a little during use even. This is why there is a plug that prevents the oil from the transmission proper from draining into the primary case when on a downward incline.

The only way to remove all the oil is by removing all the cover plates. If you were to do so after draining the transmission, you would probably be very surprised how much oil is left in the transmission after draining. Probably a full quart or so.

 

[Jim Mesthene]

A truly empty transmission takes 6 pints of oil.
If you drain it hot, and let it sit a few minutes, you can fit about 5 1/2 pints in.

 

[racerx0140]

I drain mine hot and can get up to 4 quarts. i move my pump all around and try to get as much as possible. darn you saab for taking away the drain plug :evil:

 

[saabreur]

I've heard, as mmoe states, that it is not possible to properly drain all of the oil through the dipstick tube. <start of hearsay>It is preferable and recommended by SAAB to remove the stamped steel differential cover (8 bolts). With the car jacked up from the front, full draining is "assured" (but just how confident we can be of this I don't know). The differential cover contains an oil "catcher" and filter which should be dismantled and cleaned--you will find bits of metal and junk there. Look for an excessive number of larger metal chips or "mud" which would indicate harsh use of the transmission and/or incipient pinion bearing failure. Be sure to use a new gasket when you put the cover back on. <end of hearsay>

Has anyone tried this and can comment?

The capacity of the manual gearbox is 3 litres (about 3.2 US quarts) according to my C900 manual. So draining less than this amount leaves quite a lot behind. Is there no easier way than the cover removal?

Also, does the synthetic oil perform OK in the gearbox? Does it cause difficult shifting because of problems with older, likely worn synchro rings/gears having difficulty cutting the oil film?

 

[mmoe]

I've heard, as mmoe states, that it is not possible to properly drain all of the oil through the dipstick tube. <start of hearsay>It is preferable and recommended by SAAB to remove the stamped steel differential cover (8 bolts). With the car jacked up from the front, full draining is "assured" (but just how confident we can be of this I don't know). The differential cover contains an oil "catcher" and filter which should be dismantled and cleaned--you will find bits of metal and junk there. Look for an excessive number of larger metal chips or "mud" which would indicate harsh use of the transmission and/or incipient pinion bearing failure. Be sure to use a new gasket when you put the cover back on. <end of hearsay>

Has anyone tried this and can comment?

The capacity of the manual gearbox is 3 litres (about 3.2 US quarts) according to my C900 manual. So draining less than this amount leaves quite a lot behind. Is there no easier way than the cover removal?

Also, does the synthetic oil perform OK in the gearbox? Does it cause difficult shifting because of problems with older, likely worn synchro rings/gears having difficulty cutting the oil film?

Removing the rear differential cover and jacking the car up from the front is probably the best way short of having the transmission out of the car. It's really not much trouble to remove this cover and cleaning out the filter is not a bad idea either, if equipped. There is also a magnet in the back of the filter, so be sure to clean it off well.

I've been using Redline MTF with excellent results. I think the film is thinner than conventional oil, which allows the syncros to work more effectively, but I'm not an expert either so take that worth a grain of salt.

 

[Jim Mesthene]

Save your time and money

It is preferable and recommended by SAAB to.......

SAAB does not recommend Transmission oil changes except for at the 1000 Mile Service.
It's been my experience that changing, or not changing the oil, or using plain Motor Oil or "Racing Manual Transmission Lube" et al.,makes no difference in the lifespan of the Transmission.
I worked at Dealers that changed the Oil every 15k, and others that followed the factory recommendation. I saw no difference in Transmission lifespan. These Dealers sold and serviced 200 new 900s per year, and thousands of older ones.

 

[turbo1992]

I notice a difference with the Redline MTF in the tranny. I was able to get just over 2.5 qt's into it. That's abbout the amount of oil that came out. The changes I notice the most...smoother shifting and when going into reverse it is much easier than before.

Now the question is...after more input...do I need to go back and remove the cover and do it again. Prior to this post my searches told me the capacity was [and the Bentley] 3.1 gts. Not sure if the mixture will cause any problems down the road. I have the later tranny and so far it's pretty healthy.

I respect to frequency...I can't see the harm in changing it at least a few times during the lifespan.

 

[TooMany2cvs]

These Dealers sold and serviced 200 new 900s per year, and thousands of older ones.

By "older"...?

I notice a difference with the Redline MTF in the tranny. I was able to get just over 2.5 qt's into it. That's abbout the amount of oil that came out. The changes I notice the most...smoother shifting and when going into reverse it is much easier than before.

Yep, that's exactly what I noticed, too - except that was just using nice fresh engine oil.

Sure, changing it every ten minutes is going to make no difference. But if what's in there is 20yr/200k miles old thick black goop with bits of swarf and synchro ring in, nice fresh clean oil is hardly going to be harmful.

It's not as if it's a difficult or expensive procedure, so even if the benefit is purely psychosomatic, it's good value.

 

[Jim Mesthene]

By "older"...?

In the Olden Days (1982-1990), about 50% of our customers still serviced at the Dealer at 100k; there weren't as many Independents working on SAABs back then. We had many customers with 120k-150k.
So, in 1985 for example, we would have 200 new cars: 175 1 year-old cars, 140 2 year-old cars and-so-on back to a couple of dozen 99s. Almost all Transmission repairs came back to the Dealer, there were few Independents who would mess with them; we probably did 100 a year.
So, 100 a year for about 12 years...I probably saw 1200 Transmission repairs (98% of them overhauls) at the Dealers.....Maybe another 100 at my shop. Some Dealers used Motor Oil, some used 75w Gear Oil, one used BG Synchro-shift. Given a choice, I always used Motor Oil.
Those numbers are obviously estimates, but that's my statistical base.

It should be equally obvious that the oil should be changed if it looks or smells bad; God knows what the last guy did to it. I know it "feels different" when you use different oils, but the "feel" is almost all in the Poppet Springs and Balls that make it "Pop" into gear; it means nothing for wear and longevity.
Change the oil if you like, it can do no harm (except to your wallet), but there's no point in discussing "good oil" or change intervals.

 

[saabreur]

Thanks for the good discussion points, everyone; much to think about!

One issue that affects/concerns me is difficult gear engagement (first to second mainly) in cold weather until the gear oil warms up. Here in Canada we often get below minus 10 C, and I have difficulty getting from first to second, second grinds and doesn't engage freely until the gear oil has warmed up. I was thinking that using synthetic 0W40 or 0W50 would give the low temp viscosity to get into gear on starting with a cold tranny, and the protection necessary for safer operation once the box is hot.

Any thoughts or experience on anyone's part?

 

[turbo1992]

Well...based on the last few comments it is only a question of cost and better performance. Longevity is not an issue. If spending $20.00 - $40.00 changing the oil or mtf makes it a better performer it's worth it.

 

[saabreur]

Here in Canada, winter temps are often well below minus 10 C, and until gearbox warms up, I have difficulty shifting into second - have to make a very slow shift to avoid grinding. I wonder whether synthetic oil such as Amsoil 0W40 (or 0W 50 to get better hot weather/high temp protection) would solve the slow shifting on startup without damage to tranny?

Has anyone else had this problem, or tried this solution?

 

[turbo1992]

I have had good luck with Redline. For winters I have heard some go with a lighter oil. I owned a Ferrai 308 2 years ago and the gearbox was famous for having the same problem you do...second gear was a problem when cold. Most owners just avoided 2nd gear until the box was warm. I never had the problem myself.

 

[saabreur]

Since the winter seems to have broken here, although the weather office warns that ain't necessarily so, I expect that it'll be next winter before I'll be able to comment on any benefits on second gear shifting, of using a 0W40 or 0W50 synthetic oil. But if there are any negatives, I'll know a lot sooner and will post accordingly.

Seems like a really good idea to pull the rear differential cover plate and clean the filter! Regardless of what oil you choose to refill.

I would think that if any regular motor oil is mixed with a large quantity of synthetic because one couldn't drain out all the old oil, it wouldn't do any harm; would be just like using semi-synth in your engine... And if you did an annual change, after a few changes, the amount of original oil would be inconsequential.

Thanks for all your comments.

 

[Neil_G]

Gearbox Feel

Hi Jim

I know it "feels different" when you use different oils, but the "feel" is almost all in the Poppet Springs and Balls that make it "Pop" into gear; it means nothing for wear and longevity.

Have you got any advice on what changes that can be made to the springs and balls to change the feel of the gearbox e.g. stronger / weaker spring etc.

regards
Neil

 

[Jim Mesthene]

Have you got any advice on what changes that can be made to the springs and balls to change the feel of the gearbox e.g. stronger / weaker spring etc.

Weaken the Spring a little and it will "fall out of gear" on deceleration, stiffen it and it's almost impossible to shift.
Remove the Ball, apply some MOS2 grease to the Ball and the Shift Rod at the bottom of the hole where the Spring and Ball live. It will feel wonderfully smooth; so smooth you'll write long internet posts about SAAB transmission oils. This will last until the oil washes the grease away in a few weeks.

 

[dobrosaab]

no difference here

This is the first year my 91 SPG has seen upstate NY winter. During the cold just as others have said it grinds into second and third if I'm not careful. I thought I would be smart and put in 10W40 to help my 190k trans with 140k miles on it(rebuilt just before I bought it at 56k mi).

WOW did it hate 10W40!!! The next weekend I went to 10W30 it was back to where I started, no better no worse than 140k mile oil. Oh well - I learned how to shift and skip second for the first few miles till she warms up.

M