Hey guys, I have a 2001 Tiburon SE. Automatic. Anyways, its only done this 2x now in the past 5 weeks. It actually did it the firt time when I had cruise control on. Started to go up a hill, and when it downshifted, huge clunk, u could feel it thru the enitre car, but it never actually downshifted, its almost as if it tried to, and then gave up. I shut the cruise off Immediately, and then the car was fine. It did it again today to me, goin up a slight hill, I gave it a bit of gas to speed up & it clunked, I let off the gas, it seemed fine, then I stepped on the gas alot harder, and it worked fine. The only 2x this has happened, was on the highway doin around 110 - 120 KM/H, 70 - 75MPH for the americnas on here.

Other then that tho, the tranny always shifts perfectly fine, no issues ever. The cor only has 115,000KM on it.

 

that's weird, i've gone down plenty of hills with the cruise on and nothings happened...

 

It was goin uphill tho, not down.

 

How is the fluid level? I hear these transmissions are very sensitive to the level being accurate. You might want to add a fluid cooler. Especially in the hills or mountains.

EDIT: While you're under the hood, check your engine and transmission mounts.

 

Ill have to check the fluid level, I havnt yet. I plan to get the fluid changed shortly anyways.

Thanks.

 

^ Make sure it's Hyundai brand ATF.. Seriously...