Tranny Q

[sfo1]

When I stop at a stop sign on a downhill, then accelerate from the stop, the transmission consistently mis-shifts. I am not sure if its a programming issue (i.e. forward movement before using the accelerator freaks out the computer), nothing or something that can be adjusted.

Anyone experience similar in their 200 model?

 

[tempestv8]

What exactly do you mean by a "mis-shift"? Does it pick 3rd gear instead of 2nd gear?

Or are you simply referring to the shunt you feel, as if the transmission shifted way too roughly from 1st gear to 2nd?

If it's the latter, I think this is a trait of the gearbox. It seems to have a jerky shift quality when going from 1st to 2nd on very light throttle. Well, at least that's how it is on my diesel engine.

I'd imagine Toyota use the same 6 speed auto gearbox on the 5.7 litre gasoline V8, so same shifting trait.

 

[mark71]

you might be feeling driveshaft clunk.

 

[sfo1]

What exactly do you mean by a "mis-shift"? Does it pick 3rd gear instead of 2nd gear?

Or are you simply referring to the shunt you feel, as if the transmission shifted way too roughly from 1st gear to 2nd?

If it's the latter, I think this is a trait of the gearbox. It seems to have a jerky shift quality when going from 1st to 2nd on very light throttle. Well, at least that's how it is on my diesel engine.

I'd imagine Toyota use the same 6 speed auto gearbox on the 5.7 litre gasoline V8, so same shifting trait.

I'd say it the latter. Its not going from 1st to 3rd.

you might be feeling driveshaft clunk.

I don't have the clunk issue. Other than this, the drivetrain is very smooth.

I am going to take it to the dealer to get it on record just in case something happens after the warranty is up.

 

[04UZJ100]

you might be feeling driveshaft clunk.

Yea, it's this.

 

[brussum]

It's kind of a quirky tranny, in my opinion. Mine shifts great if I'm giving it plenty of throttle, but it seems to lag between gears when shifting with less applied power. On a downhill, it's almost like it's not in gear as the engine revs then, all of the sudden, it feels like it pops into gear and away we go with a surge. I've always attributed it to the tranny and the way it downshifts coming into the stop. I've never had a problem with the Cruiser though, so I'm not losing sleep over it.

 

[brussum]

you might be feeling driveshaft clunk.

Is there a recall or service bulletin for the driveshaft clunk? Seems common and I thought I read somewhere that Daddy Toyota was working to fix it. Just a rumor? Any bulletin numbers I can give my service dudes?

 

[tempestv8]

The fix for the tailshaft clunk is simply to drive the vehicle more and getting it serviced reguarly.

Once the splines in the tailshaft have bedded in, the clunk goes away. This is because a new tailshaft has splines that are so tight that the tailshaft does not extend and compress easily. When under lots of torque during standing start, the new tailshaft binds, and then emits a single clunk when the shaft finally changes its length.

With a well worn in shaft, there is no binding, so no clunk.

 

[brussum]

For real? Mine is an '08 with about 50,000 miles on it. It's serviced as regularly as Toyota recommends. When is it officially broken in enough that the clunk goes away? What is it that the mechanic does during the service that helps the tail shaft splines? Im not doubting you, but if it's a recognized defect, then I'd like to get it resolved while I still have a warranty rather than postponing in the hopes that time and mileage will resolve the irritating clunk.

 

[tempestv8]

Hi John,

As it can be a challenge to determine via an internet forum whether the clunk that you're experiencing is the same tailshaft clunk that most new owners experience with their new 200 Series (and same for Lexus LX570, LX470, etc).

Recently a colleague of mine driving a (5 year old) 100 Series reported a clunk issue when taking off from standstill. Diagnosis was still the tailshaft, only that the dealer had NOT been greasing the tailshaft, and the splines had completely dried out.

When they put the grease gun to the tailshaft, the clunk situation was noticeably improved. No doubt for his situation, as the grease finds its way to the right places, the clunk will go away.

The issue now for him is that the grease was pumped in, but grease is not like penetrating oil - it doesn't naturally creep into all places, so the best way of greasing the tail shaft would be to disconnect one end, apply grease, then extend and compress the tailshaft so that the grease evenly goes everywhere inside.

But no one will do that for you as it's a bit of work just to get grease in properly.

You should inspect your tailshaft to see if the dealer has actually applied any grease to it.

If they have, then your clunk may be some clunk other than the "new tailshaft clunk" issue.

 

[brussum]

Excellent info. Thanks! The clunk seems more pronounced lately (truthfully, I never noticed it or it wasn't doing it until recently), so you are probably right on the money. The dealer probably cut corners during the last few services. I'll have to crawl under it and check it out. Thanks again!