Just make sure if have the scan tool to check transmission temp. if you are going to diy.

 

Noted with thanks.

Will give it to indy when I replace tensioner damper, pulley and ribbed belt.

Thanks

J

 

Bentleytech, would it be possible to clarify what is meant by "you have to drive up thru the range at 20-25% throttle and then let it coast to down shift"
Speeds, duration or ??

Thanks, Bill

 

what it means is from standstill, apply 20-25% throttle, let the car go up through each gear till top and then coast to let car slow down and down shift on its own, this is why it is hard ti do. not many roads apart from the freeway give you enough space and the speed you reach is pretty fast before you can start the coasting to slow down.

 

Thanks, Bentleytech. I was able to run through the gears as you suggested on the freeway from a dead stop from the onramp up until 6th gear. I could only coast down to 3rd or 4th before having to speed up due to following traffic. I thought I would have to try it again but yesterday after leaving home to drive around town, the shift was smooth as can be. Don't thing it's a coincidence. Saved me a trip to the dealer and maybe a big repair bill.

To repeat the symptoms, the transmission would always shift from first to second with a hesitation and a "clunk" which seem to get progressively worse. The slower I accelerated, the more pronounced the "clunk". All other shifts were OK.

Is there a simple explanation for what was happening to cause it to heal itself?

Thanks again to Bentleytech!!

 

reviving an oldie but a goodie (hopefully)
so I'm trying to replicate this drive cycle to hopefully solve the same set of issues discussed. harsh 3-2 slowing to a stoplight and hesitation on the 1-2 all else is fine and dandy.

A couple questions

was the 20-25% throttle a "by feel" thing or did you hold while watching 25% by use of a obd2 scanner or sort?

possibly interrelated issue but maybe not... when the obd2 scanner is plugged in and the car is off or at idle it shows 13-14 % throttle position. when WOT is applied (when car not running) shows 89% or so
I'll go for another drive tomorrow to see what happens in each case.

 

Any closure on this? I am diagnosing something similar on my '05.

 

Most likely the accumulator values are bad. They buffer shifts and especially down shifts. There are 6 and they get compressed with age. The sonnax replacements are more robust. The valves are within the transmission throttle body. I've done this project and eliminated the harsh down shift. The job isn't a typical DIY.

https://www.sonnax.com/parts/2678-ac...tor-piston-kit

 

​​​​​​Thanks! My shifts are okay for the first few KMs, but when I come to a dead stop in traffic, and then creep forward with gentle throttle in d1, it jerks heavy and all tranny indicators light up on the dash and car only has one gear.
​​​​​The sonnax job would require a full fluid drain and fill, right?

 

Well it's more involved.. briefly: drain fluid, drop pan, remove tranmission electronic couple, drop tranmission throttle body, remove the tranmission control unit from the tranmission throttle body, separate the two halves of the transmission throttle body and don't loose orientation of the small check *****. Now remove the accumulators and install the new ones. You need to replace the separator plate between the transmission throttle body halves... etc. There is more, this is just a synopsis.

Furthermore I would like to see a clean scan of the transmission control unit since it's defaulting to limp mode. So erase all pre existing codes and than replicate the driving pattern that causes these issues and re scan after a limp mode (all shift lights on) occurrence. This requires RT. VCDS or an equivalent scanner.