A nice Swedish whine

[escalator guru]

If I experience a whistling noise at high speeds in any gear on my 88 with over 200k on the clock and the original trans... it's just air noise, right?


How do I nurse my transmission so I don't have to replace it anytime soon (or ever, preferably)?

[eggsngrits]

First of all -- new fluids all around!! Keep them fresh.

Second -- no engine braking downshifts! Everytime you engage the clutch and the engine revs to catch up, your pinion spins up almost instantly -- this can kill your tranny.

After that, I think that you're good. Someone else may know better.

[woywitka]

Originally Posted by eggsngrits

First of all -- new fluids all around!! Keep them fresh.

Second -- no engine braking downshifts! Everytime you engage the clutch and the engine revs to catch up, your pinion spins up almost instantly -- this can kill your tranny.

After that, I think that you're good. Someone else may know better.

wait explain this for a sec if you don't mind please. i don't understand.

[therealturbofan]

i think he means to match revs on downshifts. very good idea.

[Jezzadee]

I'll have a go. Brake pads are cheaper than a transmission. You should use your brakes to slow down to the correct speed before engaging the right gear. The only time you would use gears to slow down is when descending a steep hill or on a slippery surface. This puts far less wear on the transmission.

Originally Posted by EG

If I experience a whistling noise at high speeds in any gear on my 88 with over 200k on the clock and the original trans... it's just air noise, right?

Probably. On mine the whistle comes from the passenger air vent. I've been trying to solve it for two years

[therealturbofan]

jezza, do you mean that loud, annoying high-pitched whistle from behind the dash that happens only once in a while, and usually on the 2nd or 3rd fan setting?

i think engine braking is fine, but just match revs to the gear.

[Jezzadee]

It doesn't seem to matter what the fan is set to, I just get a whistle from near the far left dash vent which is especially noticeable on the motorway. I've had the vent out and it closes fully, so I've got no idea where air could be getting through. One place I've yet to check is the hole on the bulkhead/firewall below the brake booster where the vacuum hose from the overpressure switch passes from behind the dash into the engine bay. There might be a gap there that could cause a whistle.

[eggsngrits]

Originally Posted by therealturbofan

i think he means to match revs on downshifts. very good idea.

Yes. But yes is too short.

[jetman]

Further explanation, I guess the real wear on the pinion is on the downshifts when it goes from a standstill to 4000+RPM on a downshift. Slow down, match your speed, ease it in. Avoid running up AND down all gears, as fun as that's not.

[therealturbofan]

WHY THE CRAP DID THEY PUT SUCH FLIPPIN' WEAK TRANSMISSIONS IN THESE CARS?!?!?!!?!?!?!?

*calms down* no, mine hasn't blown, but with my luck, give it a week.

if there's still somebody reading this that doesn't understand matching revs, i promise you'll be a lot better off asking one of your friends what it is and having them describe it in person...

[eggsngrits]

Believe me, as one who has had a major transmission rebuild, I feel your pain.


On the other hand, my tranny was 16 years old! How tough do they need to be?

I think the better question is: Why did they build it so that you have to pull the freakin' engine to work on the transmission?

But, then again, that's one of the things that I like about the C900 -- it is very different!!

[DrSquirley]

Originally Posted by eggsngrits

I think the better question is: Why did they build it so that you have to pull the freakin' engine to work on the transmission?

Yeah. But yeah is too short.

-Alex

[therealturbofan]

yeah isn't too short. just type "yeah" then put about 5 spaces after it, then type a period... like this: "yeah ." it'll let you post it

anyway, yeah i like that saabs are different... unique design, unique sound, unique interior... etc. but different=you have to pull the engine to touch the back of it, NO.

[jetman]

Sometimes I think the engineers at Saab just couldnt comprehend that people would abuse their perfect machines the way we do!

[Matthew]

Originally Posted by Jezzadee

You should use your brakes to slow down to the correct speed before engaging the right gear. The only time you would use gears to slow down is when descending a steep hill or on a slippery surface.

But then the car is in the incorrect gear for its speed.

I know that rule comes from Roadcraft but it is one with which I strongly disagree. Engine braking keeps the vehicle better balanced, especially around corners IMHO.

[ProfZ]

Originally Posted by eggsngrits

Everytime you engage the clutch and the engine revs to catch up, your pinion spins up almost instantly -- this can kill your tranny.

Um..not quite. What happens at a downshift is that the roadwheels attempt to spin the engine up, via the crown gear and pinion, to the rpm required by the just-selected lower gear.

Some of the shock of this change is absorbed by the clutch disk's friction lining and cushion springs, but the rest has to be taken by the trans. This puts a sharply greater side loading on the bearings of all moving parts in the trans, including the 2 pinion bearings. These are weaker than the others and take more side loading, so fail sooner.

One way to minimize this shock is to double-declutch if you're shifting down at high speeds, and to accelerate and shift smoothly when shifting up.

[therealturbofan]

what's the point of more power if you can't use it?

[Jezzadee]

Originally Posted by Matthew

But then the car is in the incorrect gear for its speed.

I only ever find that to be noticeable if I were for example doing 60 mph in 5th and approached a junction where I was going to have to stop. By the time I've braked to 25 mph, still in 5th, I have to engage the clutch and roll on it for quite a distance to stop the engine labouring. My IAM observer thinks it is fine for me to change into 3rd in this situation as long as I am not using gears to slow down, which I am technically not as I am still braking. In every other gear it is not a problem as the distance I roll with clutch down is very short - the engine should not labour at all if it is done correctly.

Engine braking keeps the vehicle better balanced, especially around corners IMHO.

What I've found keeps the vehicle more stable still is to brake in advance to the right speed, then engage the right gear to enable you to keep a steady pressure on the accelerator round the bend so you are driving the car through it, rather than using the engine to brake while going round it.

I know that rule comes from Roadcraft but it is one with which I strongly disagree.

I found it difficult at first, and as I say, with 5th gear on my car I find it helpful to negotiate a lower gear on a long braking manoeuvre, but as a rule I find that the car seems happy with 'braking to slow' and the drive is smoother as a result. I think as a general rule it is valid, but of course you should do what feels right for the car, and this is acknowledged by the IAM.

[eggsngrits]

Originally Posted by ProfZ

Um..not quite. What happens at a downshift is that the roadwheels attempt to spin the engine up, via the crown gear and pinion, to the rpm required by the just-selected lower gear.

Some of the shock of this change is absorbed by the clutch disk's friction lining and cushion springs, but the rest has to be taken by the trans. This puts a sharply greater side loading on the bearings of all moving parts in the trans, including the 2 pinion bearings. These are weaker than the others and take more side loading, so fail sooner.

One way to minimize this shock is to double-declutch if you're shifting down at high speeds, and to accelerate and shift smoothly when shifting up.

Thanks for the correction. The point remains: quick downshift and clutch engage can mean bad stuff for the pinion.

Oh, and 'Fan: This doesn't mean that you can't use the power, it just means that you have to know how to use it properly.

Everything has a weak link -- it just so happens that here it's the transmission in many cases (although, again, mine was 16-years-old before it went!). If it we owned 9000's, we be lamenting the DI cassette, if we owned Nissan Maximas we'd be crying about the bearings in the differential and oil sender leaks/failure (which can lead to REAL disaster). It's a part of having a car the age of ours.

[jetman]

I drive awefully fast (actually not right now,trying to save gas) but in general I do. I try to avoid accelerating too fast or braking to hard. Average speed and momentum are what count anyway.

Be nice to your car so you can both enjoy the experience.