Hi all,

Only when driving above 75 mph occurs.
I did a little experiment, and at 75mph I pressed the gas just a bit, then I saw the rpm went high which means it downshifted but it was very very smootly, almost fell it. But then (after 1-2 seconds) I push the gas harder and it will downshift again (into the third gear) and this time quite hard, like a bad transmition.

At 75mph rpm is as below:
5'th gear - 3100
4'th gear - 3500
3'th gear - 3900 (this is the faulty gear at downshifting)

I am not pushing it so often, hence I am not sure if this issue was there before.
Could you guys tell me if it happens the same with your Tls?

Thanks.

Catalin

 

explain what you mean by "quite hard" - it's normal for car to down shift "roughly", if that's what you mean, when your pedal's to the floor. i'm not quite too sure what you mean...is the car hesitating? does the car jerk?

 

when the car is at lower RPM's below 3.5K, the torque convert can slowly lock up and the shift will be buttery smooth, but when you are above that, you are already at the locked point and it will give you the feeling of a hard shift.

 

Hi erik3,

Yes the car jerks when it downshifts from 4th to 3rd gear.
But if I reduce the speed below 70-75mph I will not feel any jerk at all for the same transition from 4th to 3rd gear.

Catalin

 

I'll explain this a little bit more just so you understand what I am talking about. In a manual transmission, you have a clutch that engages to connect the motor to the transmission. In an automatic, you have a torque converter. It is fluid filled and has a lock point. basically when you go near a certain RPM, it will lock and deliver 100% power, which results in the rough shift since during the shift there is no power, then suddenly bam, 230 WHP of power.

 

Hi csmeance,

Your explanation make some sense, but could you please tell me, your TL is 2006 and does the same hard shift under above conditions?
I tried to repeat the same scenario with my other car (2005 odyssey) and the entire shifting (up and down) is just fine and I drove it up to 80-85mph, i was affraid to go higher.
I have one more question to you but I'll wait for your response first.

Thanks, Catalin

 

Oh, ok, now it makes more sense. You know what I am going to do?
I will create the same rpm that gives me trouble for other downshifts let's say for 3 to 2 or for 2 to 1 and according to that theory I should be feeling the same shock.
Will keep you posted then.

 

aye. my TL will shift harsh also under the same conditions, I have an 2004 with the glass transmission...

 

when you were going 75mph and you press the gas and the rpm's rise without a shift its the tourqe converter, dont confuse that with a smooth shift....the same thing happens when your in sport shift and you keep it in one gear and let the rpms drop...when you touch the gas the rpms will rise like it down shifted, but it didnt....

 

vinnier6,

Are you sure a difference of 400 rpms generated in .1 seconds when I press the gas, can come from the torque converter?

 

Same shift harsh regardless which gear it is downshifting from or to, but only if rpms are above 3k.

Interesting, my 05 odyssey, shifts and downshifts very smothly when rpms are even 3500+, why tl does not do it so?
It makes me feel I have a shity trainsmision on tl compared to odyssey. But I guess I will have to live with it.

 

Well the odyssey is more comfort oriented than a TL which is sport luxury...

 

Hey boss, curious what regiment you use to maintain your glass tranny. Is it the IHC pressure and Redline fluid plan?

I replaced my 06 tranny at 95K. It was a Jasper rebuild. It's been butter until the last 2-3 mos. I feel like the shift point has changed a little bit like it's struggling under torque (low... I don't floor it). If I just let up on the gas a little bit it would shift, but then jerk, slightly. Prior to that it was all butter. My rebuilt warranty require that I use DW1 and change it every 25K. I've been changing it every 15K (3-4 engine oil changes).

I am just wondering if I should now be changing out the 3rd and 4th pressure switch and then switching over to Redline.

What are you using?

 

Of course when you're downshifting from 75mph to 3rd it will give a strong kick. It's at those RPMs that the car is in ideal condition to show you its full power.

What I can suggest you to do is get an OBDII Bluetooth adapter, I got mine off ebay a few years ago, cost me about 20$, today they go at half that price. I got a Vgate ELM327 which has been working quite well since then. 2nd part is (if you have an android phone) get an app called Torque Pro which will be the interface to interpret the information given by the car and its only 5$. It's a very useful combo as you can analyse gear ratios, verify what that CEL means and clear it if needed, you can analyze gas consumption, air pressure, oil pressure and temperatures in the engine and transmission...the TL has pretty much every sensor the app can handle and interpret. A lot of it will be gibberish for any of us, but there are a few useful extensions you can download such as knock detectors, torque line charts, fuel economy charts, shift lights and warning.

One of the extension allows you to set specific gear thresholds and compare to those of your car. You can find official numbers of the TL's gear thresholds somewhere around here and set them in the app. If your transmission deviates too much from the mean, the app will sound an alarm and warn you. You can also configure the hysteresis range and overtime set a benchmark of how your transmission reacts and how those changes deviate overtime. I've been using this system for many years and on 2 different cars and it's gotta be the best 25$ (15$ today) i spent. If you use this app on a regular basis, you will start to know your car beyond of what you can feel in the steering wheel or gas pedal.

Thanks to this app, I had an early warning that my transmission was on its way out, the app warned me 9 months in advance that my gears were slightly slipping, I was able to determine what was causing the idle vibrations in my TL (EGR valve), diagnose many problems and saved a ton of money on diagnosis costs. There are many of free or low cost CEL code readers on Google Play, but this app is WAY more than that. It's an entire monitoring system for your car. It even precisely calculates your 0-60, 1/8m, 1/4mi, 0-100.