Hmm..

Kind of a strange occurrence this morning.. I was at a highway on-ramp.. traffic.. and I was at a slight decline.

It was stop and go.. but I noticed when I'd stop, the rear end of my '04 TL-AT would bounce. Think Juvie - Back that Thang Up.

It was harmonic about 1-2 oscillations a second. Now it was a suspended on-ramp and there were some heavy trucks, no wind, 38F outside, so it may have been externally influenced, but I'm 80-90% it wasn't because when I'd move it would stop.

I couldn't reproduce it once I got into the city.. but was really curious about what would cause it. I'll check my mounts and rear suspension after work.. (maybe during lunch - I always carry tools & flashlight / Semper Paratus) .

Anyone have this occur? clues about the culprit?

 

I've noticed this on bridges. If it's not that, I would start at the shocks.

 

Thanks IHC.. I checked last night and noticed some fluid leak on my rear right shock (not too bad though)..

The mounts seem to be okay. I guess I'll mark this up as external.. I'll post any updates if it occurs again. Hopefully it'll be an excuse to do some mods.

I noticed you are running an external ATF Cooler.. How's it working for you? any advice on which company to look into?

 

Any external leak= a bad shock or soon to be bad shock.

The cooler seems to be working great. 69,000 miles and counting. It's a DIY, no one makes a kit for our cars. Order one of the B&M style stacked plate coolers, not the tube and fin coolers, and use 3/8" fuel injection hose at a minimum. Metal line is preferred. Summit usually has the best prices on the coolers.

I'll try and find the old post with a couple pictures.

 

Wow.. 69k and strong.. yeah I saw your old post and then that external link to the 2G TL install.

Did you ever get around to installing a larger cooler? I posted a similar question in another post but is there a trade-off with cooler size or is bigger better?

Thanks for the advice IHC.. I'm trying to keep my car in good shape yet have some fun with it at the same time. I've been bouncing a few ideas around but the more I search I find that mods and reliability are a real hit & miss but the external ATF cooler seems like a no-brainer though to improve tranny life and reliabilty.

 

The only potential downside to a bigger cooler is running the fluid too cool. This would be nearly impossible to do. Besides the heat generated by the torque convertor, the TL has the factory heater/cooler to stabilize temps. If the fluid temps get below the engine coolant temp of 190-ish degrees, the factory cooler acts like a heater. The external cooler is there to keep temps from getting out of the factory cooler's control.

I haven't gotten around to installing the bigger cooler out of pure laziness. I have it and it's one off the giant 11x13x1.5".

 

That's nuts.. How much ATF fluid would you need to add? 1 qt?.. hmm.. and do you think the factory cooler / heater has a problem heating up a larger volume of ATF?

You are the go to guy IHC.. Thanks for all your advice.. I'm fairly new to the TL, but I think I'm getting a better grasp of the limits and what my future additions will be.

 

My 6MT does the exact same thing when im going less than 10km/h over like a parking lot speed bump. I find it kind of amusing.

 

If I remember correctly, there was a thread or threads about rear bounce on 04TL's and it had to do with alignment (tow) and rear bump stops. It was worse when the rear seat was loaded. I think this TSB was the fix:
http://www.in.honda.com/Rjanisis/pubs/SB/B05-050.PDF.

You might want to have your alignment checked.

 

Awesome.. Thanks, I may change out the rear bump stops if I notice this again. I haven't noticed it with passengers but I rarely have passengers in the back. I'm going to do a front and rear alignment some time soon. I feel the car pulling to the right.. I haven't noticed atypical tread wear but hopefully it's just misaligned.