I've read a few threads about Sportshift and engine braking (the threads are pretty old so i don't want to resurrect them). A lot of people seem to be against the idea of using SS for engine braking because they say it'll damage the transmission and engine. I agree with that, that engine braking probably leads to more wear and tear for both the engine and transmission but don't TL's come with a 7-year powertrain warranty? If something went wrong with either the engine or transmission (within 7 years), a person wouldn't have to pay for much at all, just bring it to Acura and they'll fix it right? Or maybe I'm missing something.

Yes, but it's not like you drive into the dealership, get a coffee, wait 30 minutes, and drive out with the new transmission. It takes a couple weeks to take out the transmission, rebuild it, and put it back in, depending on how busy the shop is. Also, I can't imagine engine braking with an auto is particularly effective.

But isn't Acura really good about loaner cars? Or do they charge a fee for using them?

Also, I agree using the brakes is a much more practical and effective way to slow a car but, IMO, using engine braking to occasionally slow (not necessarily stop) a car is really fun. Especially on Honda engines that sound so good at high rpm's.

What kind of damage will incur by downshifting?

I don't believe that downshifting to slow down your car is going to damage the transmission. Not even premature wear. If we go by this logic, we don't want the transmission to downshift or upshift at all then.

The transmission is engineered to do what? Exactly, shift. If downshifting were going to damage the transmission prematurely, Honda would have put a warning label on the dash.

I have a Honda Accord with 233k miles. It's still got the original transmission. I have done thousands of engine braking and the tranny is still working good.

My brother's '03 TL-S got a new tranny in 3 days. That's 3 days after dropping it off. They ordered it, overnight'd the part, replaced it, and called him back. He had an 05 TL as a loaner.

Why do you want to downshift to slow down? You'd have to drop 2 gears to be effective, but it'd be jerky. I'd just stick to using the brakes - that's what they're for, and while you slow down, the ECU will automatically downshift accordingly.

P.S. I don't think it'll damage the tranny if you really insist on doing it. There's no proof for/against it as far as I know.

It is nice to hear the engine as you downshift, but I feel that SS on the TL doesn't provide much manual control as my previous car. I had a Volvo s40 T5 (geartronic tranny), which seemed to have a more precise sport shift, both up and down. Like mentioned above, you would have downshift twice just to have an effect with the TL... I don't think it would hurt the trans., but I prefer the brakes due to the lower level of control.

I engine brake with my SS on nearly a daily basis in heavy traffic. I did this with both my 2G and 3G TLs, and it has never led to any kind of trouble. This is a legitimate issue with 2G TL trannys, but not with 3G TL trannys (yet). I've got nearly 45k on my car and I've had no tranny issues. Don't worry, I'll let you all know if I do! I think that the 3G's SS provides adequate control as that that nice wide powerband in third gear is refined. It's not a 6MT by any means, but it works.

I drive this way because my first three cars were manual trannys and that was how I drove then, too.

Then there is the other side of the story, downshifting to slow down creates a lot of engine vacuum which sucks oil to the top end parts and lubes them.

So the trans MAY wear out faster, but the engine will last longer.

I tend to drive/ride things like I want, good or not, the car serves me, not the other way around. I will gladly pay to repair something after lots of fun, then run something very carefully to get 500,000 miles out of it.

And come on, 3/4 of the people here will dump the car for some fancy new model well before anything would wear out.

Brett

Not much on an auto tranny, but the money shift on a manual can be very expensive as the rev limiter is not effective in downshifting.

I actually was talking about downshifting auto tranny.

So what about Grade Logic Control? It essentially is the same idea, but I guess it doesnt downshift at a very high rpm.

Grade Logic Control doesn't downshift during braking, unless you are going downhill and the computer thinks you are still accelerating while the throttle pedal isn't depressed or if you touch the brakes lightly.

It also holds the lower gear when going uphill to reduce gear hunting.

Bottom line is, it's your car and you can do whatever you want with it. I drive a manual, and I usually only downshift like that to slow the car if I'm setting up for a turn, or just in general if I'm doing some spirited driving. I like my brakes slow the car down 99.9% of the time, I think that's why they put brakes on the car. I don't think the car was designed to take the abuse of boy racer driving all the time. I just don't see any need when you're just cruising to slow the car with the transmission???

You have an interesting point, but you're forgetting about the amount of power going through the transmission. When you upshift, the transmission goes into a numerically lower gear, which means the car can maintain the same speed at a lower RPM. There's not much drivetrain shock, because at the lower RPM, there's not as much torque being produced.

Now when you downshift, the current gear disengages from the main shaft and downshifts into a numerically higher gear, which multiplies the power at a greater ratio, while the engine is forced to rev at a higher RPM which is accompanied by more torque. In this case, there IS a lot of drivetrain shock. And stuff like engine mounts can go because of this drivetrain shock. And the internals take the most beating, so imagine how much stress it's going through.


There's a lot of things that we can do to harm the car, but they don't put a label for every little thing. Just because there isn't a label, it doesn't mean they encourage doing it.

Bottom line is, do whatever you want. It's your car. Personally, I still downshift using SS, especially when I'm doing some spirited driving because it helps slow the car down much quicker.

I'm not forgetting the amount of power that goes through the tranny. That's true that the tranny has to withstand a lot of torque when we force it do downshift. However, my question is, don't the engineers design the transmission to take that much torque though? If not, there will be a lot more failed transmission around us. Everyone would be driving manuals if automatics break too often.

The car has a lot of computers that will not allow the transmission kill itself by doing what the driver wants. The transmission won't even downshift if the speed is too high. The torque converter disengage when you are downshifting, so the gear change is not very abrupt. Some cars even rev match when you downshift.

I know that there is a lot of things that can harm the car and there's no warning labels on them. But if the tranny is made of glass, that will break on repeated engine braking, I'm sure a warning will be posted. Either on the dash or in the owner's manual.

My TL is 6MT so it doesn't really relate to it, but I'm talking from my experience with my 95 Accord that its original tranny is still good after almost 12 years and 200+ miles and with thousands of forced downshift.

My question is still unanswered though. What part or parts of the transmission are going to give because of repeated forced downshifting? I genuinely want to know if my opinion is correct or not. I have a 5AT Mazda6 and some people actually also have concerns about its weak transmission.

I downshift with SS quite often, but I always depress the accelerator a bit to "rev match" when doing it so I don't get a violent *clunk* when it finally shifts down. I just did it this morning when I noticed a CHP coming up a few cars back and I didn't want him to see me brake.


I'm less worried about jolting the transmission than I am about jolting the CV joints on the subaxles. On previous FWD cars, I've had to replace them as a wear item and I don't want to have to do that on my TL for at least 150k miles.

I agree.

I'm sorry but the argument that downshifting puts excessive, harmful torque on the torque converter is idiotic. If the TL's torque converter (or any other part of the TL's powertrain) is so wimpy then why do people put superchargers on automatic TL's? If the TL's torque converter/powertrain were so weak and fragile don't you think we would see the trannies of TL's with SC's break in a matter of months due to all the additional torque SC's put on them?

260 HP and xuimod --

You can say that if there would be a problem, then they would've warned us... or that they built these things to handle it.

But you're forgetting that you're talking about the same people who brought us the glass transmission in the 2G CL and 2G TL, along with the Accord, Odyssey, MDX, and the Pilot. Then deny there's a problem and won't do the right thing. They aren't perfect.



xuimod --

I'm specifically talking about the transmission. I haven't seen too many failures with the TC itself in these cars. The main problem lies with the gear shafts and the clutchpacks, it seems.




Once again, I'm not saying you shouldn't downshift using the SS. Hell, I do it, too -- on the streets and on the course. That's just how I drive. But it is not good for the transmission.

My brother's '03 TL-S got a new tranny in 3 days. That's 3 days after dropping it off. They ordered it, overnight'd the part, replaced it, and called him back. He had an 05 TL as a loaner.

This is really dependent on the dealer. Both the local acura dealers over the phone said the tranny shouldn't be having problems, and if it "broke" it's probably something I did. (At least that's what they told my wife. Maybe they're just sexist).

First dealership refused to install the oil jet, because they said I needed the recall letter in hand, even though you could lookup the vin and see it was part of it.

When the tranny finally did let go, the other dealer tried to void the warranty saying that because I didn't flush the fluid, it voided the warranty. When I called them on that (I only had 30k miles on the car, and manual didn't even recommend it until 60k miles), then they tried to void the warranty because I didn't have the dealer perform any of the scheduled maintenence items (I did them myself). When I called them on that bs/bluff too (nowhere in the warranty disclaimer did it say I have to have the dealer perform maintenence. Heck, it didn't even require you to do the maintenence if you go by the exact text, as the maintenence guide used the word "Recommended" and "should", instead of "must" and "mandatory/required"). Needless to say, they reinstated my warranty and replaced my tranny free of charge.

They had to order it first, so it took a few days to get the parts in. They also said they don't give out Acura Loaners when they need to be out more than 24 hours. So I had a POS ford rental.

Why do you want to downshift to slow down? You'd have to drop 2 gears to be effective, but it'd be jerky.
Which is why Infiniti's 5AT is better, because it rev-matches for you. Acura shoudl've implemented this feature into their SS mode like Infiniti did.

P.S. I don't think it'll damage the tranny if you really insist on doing it. There's no proof for/against it as far as I know.
Exactly. The only time it would put extra wear, would be if you had a manual, in which case it would wear your clutch. In that case, yes, I'd rather replace $50 brakes, than pay for a $1700 clutch job. (At least that's how much it was on the Supra)

On an auto, I think the only harm it could do, is generate excess heat in the torque converter, but I don't think this would do anything in the short term. It's not like you're constantly running too hot.

ACtually... A couple years ago, Motor Trend had an HKS Supercharged Accord V6. They actually complained about the tranny, because it kept overheating. They had to dial down the boost to keep the tranny from self-destructing. (Apparently the first test car gave up the ghost) At least that's how they explained away the dissapointing test results.

Now I'm not saying the TL's tranny is weak in this regard, just pointing out what happened. Motor Trend (which typically doesn't like GM cars), pointed out that even with the HKS kit, this V6 put out less torque than the supercharged V6 in the Grand Prix GTP, but the GTP's tranny didn't have overheating problems. I mean, the TL's tranny only drains about 3 or 4 quarts when you remove the drain. The tranny in the GTP drains 8 quarts when you drain it, and 13 if you drop the torque converter. Now keep in mind, this was a supercharged version of the 200hp J30. MT hypothesised that the tranny in that application wasn't built to withstand that much power.

I guess all I'm saying is that if you beat on the tranny that much, at least install an auxillary tranny cooler.

Besides, didn't people say that Acura "fixed" the 2G tranny problems by playing some ECU trickery to cut power on the shifts? Wouldn't that mean the tranny is weaker than you think?

I can smell flame war coming miles and miles away.

I'm not forgetting the tranny problem on those cars. I had a V6 Accord and while my transmission didn't break on me, it caused enough concern to me that I sold it before it hit 100k miles.

My point is this: an auto transmission is designed (or supposed to be designed) to handle enough drivetrain shock during forced downshifts.

Back to Honda's glass transmissions, didn't (don't) they fail just because they were used? The transmission, whether it was abused or not, have the same fate, fail at about the same time, or even before, the tires need replacing. In this case, I think it's safe to call it bad engineering or design. Therefore, it's safe to call it an exception to the norm.

But look at the norm: auto tranny should be able to handle forced downshift with next to no bad impact. If it is the norm that drivers should not force-downshift their auto transmissions, a warning will be seen, especially in a country of lawsuits like the US.

Of course, it's just my

Good post, I wasn't aware of that. Have to admit, you have a lot of good, hard-core automotive knowledge in that head of yours (knowing the number of quarts of transmission fluid in different cars ...that's pretty hard-core).

BTW, here's the article you mentioned...supercharged 1998 Accord V6 does 0-60 in 7.1secs vs. 7.4 stock

http://www.motortrend.com/features/p..._honda_accord/

If and when I get a TL (most likely certified used) I'll just make sure the powertrain warranty still has 10's of thousands of miles and a few years left on it. And if the tranny to croaks then, after Acura replaces it, I'll change my driving habits.

Lol! I only knew the number of quarts because I changed the tranny fluid on my TL and GTP every year. I always thought the "Drain, fill, drive, drain, fill, drive, drain, fill, drive, rinse/repeat" procedure in the Acura service manual was strange, so it stuck in my head that it only drains like 3 quarts. Whereas when I drained my GTP it drained so much fluid, it overflowed my catch pan and spilled tranny fluid all over the garage, so that stuck in my memory too, lol....