1995 850, 180,000 miles. Trans shifts fine unless it is hot. Cool weather no issues but when it gets warm outdoors I get clunk when it downshifts, like appraching a stop. Does not happen every time. After it does the clunk it kind of slips when starting out for a second or two. It moves but not much, then it "catches".

So, transmission has a problem when hot. Been doing this about 20K miles. I change the fluid about every 5-10K using bay 13 flush method. This helps but does not fix. First few times I used synthetic fluid but last time decided I wasn't getting much benefit from $100+ cost since I dump it often.

Wondering if it is worth putting on a transmission cooler. Thinking is it makes the tranny work 50 degrees cooler then it ought to work at 100 degrees as it does not at 50. I made up the 50 degree drop but you get the idea.

Opinions, success stories, disaster stories?

Thanks,

Terry