New 8 speed transmission... (9 Viewers)

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I would make sure your driveshaft and U-joints are all greased well. I thought I had tranny issues (especially 1 to 2 shifting), but once I got the U-joints and slip yoke greased well, the shifting issue went away. It seems the factory does not grease these well or at all?
 
It sounds to me like what they are describing as "normal..." *might* be a legitimate problem...and could actually be the "NORM."
As in... A design flaw. Time will tell... Don't know, and don't want to assume...but when several people are saying it's that seriously rough in the first several gears? Hmmm... I'd be seriously following up on this.
 
Have you tried shifting manually from 1 to 2 to 3, etc.? I'd be curious if the shifts were still hard when you shifted manually up.
 
I would make sure your driveshaft and U-joints are all greased well. I thought I had tranny issues (especially 1 to 2 shifting), but once I got the U-joints and slip yoke greased well, the shifting issue went away. It seems the factory does not grease these well or at all?

I definitely noticed that with my 4th Gen 4Runner. If the driveshafts were not properly greased, the shifts would feel very firm. Once the driveshafts were greased, that all went away (for about 3,000 miles or so...).
 
My 13 shifts fine. That are instances where drive line tolerances stack up and that will cause a jerk on almost any vehicle. Imagine descending a long grade in 4th using compression braking and then hit accelerator and shift up to fifth simultaneously. The entire drive train has to take a new set. The jolts in low range are just gear ratio induced. Torque is snatching you a bit. Whether it applies to the OP (rough shifting) --I have no idea without actually driving the vehicle. Toyota sought a balance between durability of clutch packs and shopping mall smooth.
 
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Silicon carbide can catalyze steel production and serve as a 'fuel' but whether it is somehow embedded in steel as a wear inhibitor (???) by Toyota as opposed to a ceramic matrix like a brake rotor---I have no data. Not my field of study. Slippage (exceeding the friction threshold) leads to consumption and heat and does allow for smoothness. To answer the question directly, I don't know.
 
New member and 16' owner.
I don't have experience with older models, but i can say the 8 speed transmission in my 2016 shifts ROUGH! I mean, like jolts you back in the seat every shift through the first few gears.

Not normal. Just got a 16' and was happily surprised at Toyota's first go of an 8-speed. Compared to the German counterparts, upshifts are as smooth albeit a little slower. Downshifts, while still smooth, are brutally slow/clumsy but fine for hill speed or towing use only.
 
After purchasing my 2016 with 16k miles and putting 7k more miles on it (now at approx 23k), I feel like the transmission is okay, not great, and I have noticed two very reliable experiences with the transmission:

  • Cold shifting from 1-2 is always going to be a big jerk. If I let the vehicle sit until the warning menus go away on the nav screen, then it's usually going to be smooth 1-2. If cold start, go right away, 1-2 is jerky. (of course, anecdotal statistics)
  • Driving above 50mph, if I tell the cruise to drop >5 mph the car will do one of two things: the vehicle will either slam on the brakes and get me to my new speed very quickly or it will coast while it shifts into 3 or 4 different gears seemingly not knowing where it should be. Yesterday, it abruptly shifted once then shifted again and sat at 3500 rpm's (not towing, coasting down to lower cruise setting) for about 30 seconds before shifting into what felt like the right gear and coasting the few mph down to get to the correct cruise mph setting. It's very offputting when this happens and it's very offputting that it's not a predictable experience when I decrease my cruise speed.


I drove an 8-speed 2-series M235i BMW before this and I literally never felt the car shift unless I was flooring it. With the LC, I feel every single shift. That's not to say it's uncomfortable or a problem in any way, just surprised the difference in the feel considering this vehicle was almost twice the price of my brand new 2-series BMW. I was expecting more luxury in ride feel, not less.
 
Generally a more abrupt shift is going to cause less wear. It could just be that Toyota has decided to optimize for longevity over smoothness. The 8 speed is also fairly new in the LC so it could also be that they haven't got the optimization quite right and it could be addressed in future updates.
 
While I don't have a newer LC with 8-speed, I am an engineer and enjoy postulating about various things.

I'm thinking the 8-speed is rougher, particularly in the lower gears, due to the lower first gear ratio. Not quite, but think of tractor trailers with their incredibly low gears and jerky take-offs.

LCratios.JPG


The 8-speed has a much lower first gear. Effective ratio with the diff, makes the 8-speed something like 15.8 vs 13 for the 6-speed. Add in the off-road oriented driveline, with transfer case, 4x4, and soft bushings, and that makes for a recipe for slack and jerkiness. It's incredibly hard to make something smooth against light load and slack.

That lower first gear could be a great advantage for hard core off-roaders, especially ones that fit larger tires. Funny enough, larger tires in itself might help smooth out shifts, as it puts a larger constant load against the driveline slack.
 
So I'm new to the Toyota Land Cruiser as of 10 days ago, picked up a new 2017 200 and I couldn't be more in love. That being said, I was just thinking about how the shifting is "rough" at lower speeds (between 1st/2nd gears). It's almost like you can get it into a quasi state where you're just between gears and the slightest bit of skinny pedal triggers 2nd gear to kick in and you're off to the races. This is my third vehicle with a 8 speed auto trans (2014 Grand Cherokee and 2016 LR4) and what I think is interesting is that all three have displayed similiar characteristics. I'm coming to the conclusion that it's simply the dynamics of how these new transmissions are built and operate than a general overall problem, per say.

Anyways, just my $.02.
 
Hmmm.....interesting thread. One of the reasons I liked the '17 was the smoothness of the transmission. On our tests drives prior to purchase, my wife noted she couldn't even feel the transmission shifts in the '17. Our other vehicles are an '04 LC and a '13 Outback, both with 5-speed transmissions, and you can feel the shifts in both. I do find 1st gear very low and with the idle torque of the 5.7L it really wants to go. If you look at the ratios @TeCKis300 posted you can see the large ratio differences in the lower gears and small ratio differences in the higher gears. Seems like that would inherently make for more noticeable shifts in the lower gears. I'll pay more attention and try different acceleration scenarios to see if I can duplicate the "rough" shifting others have experiences.
 
I would make sure your driveshaft and U-joints are all greased well. I thought I had tranny issues (especially 1 to 2 shifting), but once I got the U-joints and slip yoke greased well, the shifting issue went away. It seems the factory does not grease these well or at all?

I thought my transmission had issues as well on my 16LC. After grease up all perfect.
 
I wonder if part of the reason why people are having different experiences could be due to whether or not the driver is using ECT.
 
I can say for sure that I do not use ECT for daily driving.
 
I've had a 2016 since August. After 7 months, 14K miles, some travel trailer towing, some light off-roading (which I nearly always do in low range) and after having driven an 8-speed 2014 for 2 years it is only on rare occasions where the transmission seems to get lost for a single shift. It happened today. Felt like a "thunk". Like it hesitated before committing. It it is unusual for me to notice this and I often think it is because I have been "noncommittal" with the accelerator- sort of faking it out. I found the same thing would happen with my LR4. Almost like it skips a gear sometimes. But I find if I am smooth then it is smooth. And I never put it in gear until the nav system warnings have cleared. I've always thought it best to let a little warm up occur before driving away.

I have also experienced the downshifting and use of engine compression to decelerate when using cruise control. I would think it would be tough to get that right. It has to be influenced by vehicle weight and road grade. It tries but it's definitely not perfect.
 
While I don't have a newer LC with 8-speed, I am an engineer and enjoy postulating about various things.

I'm thinking the 8-speed is rougher, particularly in the lower gears, due to the lower first gear ratio. Not quite, but think of tractor trailers with their incredibly low gears and jerky take-offs.

View attachment 1415432

The 8-speed has a much lower first gear. Effective ratio with the diff, makes the 8-speed something like 15.8 vs 13 for the 6-speed. Add in the off-road oriented driveline, with transfer case, 4x4, and soft bushings, and that makes for a recipe for slack and jerkiness. It's incredibly hard to make something smooth against light load and slack.

That lower first gear could be a great advantage for hard core off-roaders, especially ones that fit larger tires. Funny enough, larger tires in itself might help smooth out shifts, as it puts a larger constant load against the driveline slack.


@TeCKis300, I found this chart very interesting. So I put the data in a simple spreadsheet to make it easier for me to see the numbers and the "effective ratio" (which, though this may not be correct, I calculated by multiplying the gear ratio by the differential ratio.) I then looked at the difference between successive gears (difference between 1st and 2nd, 2nd and 3rd, etc.). Here is that spreadsheet.

LC Gear Ratios 6 vs 8.png


I noticed that not only is the "effective ratio" (I made up that term) lower for first gear, it is lower for first through the first 6 gears (if you compare 1 to 1, 2 to 2, etc. which shouldn't be done when you are working with 6 vs 8 total gears.) Though I have not owned a 6-speed LC, I seem to remember that they recommend, when pulling a trailer, to shift into S4 which has a effective ratio of 3.9. For the 8-speed they recommend towing a trailer in S6 which has an effective ratio of 3.3. If you compare the "overdrive gears" which, IIRC are 5/6 and 7/8 then those on the 8-speed are overall "higher" gears possibly resulting in better gas mileage? And possibly more significant to the issue raised on this thread is the jumpt from first gear to second. On the 6-speed that jump is ~5.37. On the 8-speed it is ~6.56. The jump between second and third is also noticeably higher with the 8-speed. In other words, rather than using the 8-speed transmission to "smooth out" the shifting with smaller increments between gears, they have used it to widen the range of the gears with lower gears in the low end and higher gears in the high end.

This makes me think of my road bikes where the move to an 11-speed cassette allows some riders to choose closer/smoother gear ratios and others (like me) to forsake those closer gear ratios for a couple more "granny gears".

Then again, this may all be bogus if my math isn't right.
 
Great job laying out the numbers. I did these calculations adhoc, but seeing them side by side really starts telling the story. You'd think with more gears that'd it be closer ratios everywhere. But those are quite big steps on the lower gears. And tight ratios up higher for just the right cruising gear (efficiency) at speed.

Another neat thing to understand is the max spread of ratios between the trannies (lowest vs highest gear). 6-speed covers a 5.66 spread. 8-speed 7.13. That's a better than a 20% improvement!

The 8-speed really is a nice step up as there's practically a gear for everything. For day to day, it might seem overkill of too many ratios. When talking really mixed use like towing and off-roading is when it really shines. Or for those doing large tires like 33s or 35s, there's practically no need to re-gear anymore with the breadth of ratios offered.
 
Not needing to re-gear was one of the first things I noticed. So I agree. Overall more capability, not merely smoother shifting (which wasn't a problem needing fixing on the 6-speed.) And of course there is alway low range when you want even more control, engine compression and low end power when going off road. And since I tow a travel trailer, I use the Toyota recommendation to tow in S6 whereas if I had an earlier, 6-speed model the recommendation would be S4. When comparing the ratios for the two, I could use S5 and get a closer ratio to the S4 recommendation on the 6-speed. If I use the the new 8-speed recommendation of S6 I am getting a higher gear for towing - and again presumably better mileage.
 

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