My 01 Tacoma 4x4 has developed a loud clunk whenever I put it in drive or reverse or when the transmission shifts gears, up or down. The clunk is loud and I can really feel it, too. It only happens when the transmission is cold, though. After driving for 5-10 miles, the clunk goes away and doesn't come back until after the truck has sat for a few hours. I recently drained and filled the fluid but the problem persists. I'm worried now that I may be in for a very expensive tranny repair.

Does anyone have the same problem or any info on what might be causing this? I'd really appreciate any advice.

 

Are you sure it's coming from the trans, could be worn U joints or maybe try greasing the driveshaft. Mine makes a bit of a clunk going into drive or reverse when the slip yoke needs lubed.

 

I'm not sure it's the transmission. I'll check the drive shaft and lube the zerks next. It puzzles me that it only happens when it's cold.

 

metal expands and contracts with heat, when hot it is expanded, simple for the difference....

 

Did you ever figure out what was causing the "clunk". I have had similar type problems with my 99 4Runner downshifting when cold.

 

check for strawberry milkshake. this is one of the first symptoms when it starts
to mix and before it blows wide open

 

x2, I agree. My 4runner clunked before the coolant mixed with the trans fluid (stawberry milkshake). I caught it fairly early. After a new radiator (koyo A1998) and a power flush with 60 quarts of castrol ATF, my trans is functioning normal.

 

I am pretty confident mine is not in the early stages of the tranny & coolant mixture happening. Reason is say this is because it has been going on for around 34-35K miles. It has recently gotten a little worse, but more annoying than anything. I have done two drain & fills with mobile 1 over the past month and plan to do one more in the next week. Fluid change doesn't seem to make any difference in the condition. Clunk only happens when the vehicle has been sitting over night. It usually occurs on the first downshift to 1st after you have reached speeds for the vehicle to get into OD with the torque converter locking up. I tried turning the OD off and and reaching the same speeds and it never does it. I am wondering if it has something to do with a problem in the TC or some type of shift relay. Any thoughts?