Nomis

I'm not yelling at anyone here but hope it grabs the attention of someone with an answer:

HAS ANYONE SOLVED THIS ISSUE?

Many of us have the 40-42 mph "Shudder" or "washboard" or "rumble strip" problem. This occurs when the torque converter locks-up. This is exacerbated when the enine is at part throttle. Needless to say it is very annoying. Per advice on this board and elsewhere I have done the following in an attempt to remedy the problem:

Trans fluid flush with Toyota Type IV fluid - careful not to overfill.
Replaced Trans mount
Replaced both left and right engine mounts
Unplugged battery to allow ECM to reset and "re-learn"
Replaced and balanced tires (although not specifically related to this)

After all of this the TCC still has a slight bucking action at low speed lock-up @ 40-42 mph - sometimes it is more pronounced than others.

Other than this, it is a joy to drive my SC. Please help.

SupraCoup3

did you just drain the pain via the drain plug, or did you get a power flush at the dealership?

you're only replacing 2 quarts out of 8 when you go the drain plug route. When I had my 400 and got the 40 MPH rumble strip, I changed 2 quarts of fluid. It didn't fix the problem, but it helped. I got a complete powerflush about 2 months before the car was... well, we don't talk about that.

Anyhow, powerflush or 2 quart change?

Nomis

Pulled off the cooler line and pumped all of the old fluid out while replacing with new T-IV fluid. The fluid is nice and red.

SupraCoup3

you may be looking at a new torque converter then.

not changing the ATF fluid every 15k (like the manual says) catches up with an higher milage SC4


John


EDIT: but if you're going to change the TC, I'd go aftermarket -- I've heard it cuts about a second off of your quarter mile time.

VSsc400

iTrader: (1)

could the TC lockup problem also occur in the 60-70mph range?

Nomis

I see you asked this in a couple other related threads, sorry for not answering sooner. The problem seems to be most pronounced at the 42mph-45mph range. I have noticed a slight, very slight shudder at 60mph. But I would think if you had the same issue we're having you would definately have the 45mph shuddering/bucking as well. I'm guessing you don't, so your's may be a different issue? Describe the problem you have at 60mph, is it bucking or shuddering or vibrating? If it's vibration then maybe the wheels and or driveshaft are out of balance. Maybe it's a combination of the two and you have some sort of harmonic vibration? If you don't have the bucking at 45mph, consider yourself lucky, cause it sucks.

VSsc400

iTrader: (1)

mine doesn't buck and miss in the 40's only in the 60-70mph.

I'm waiting for my hub centering ring to come in for my front wheels. Once they are on it should give me a better idea.

I got 4 new tires, wheel alignment, all 4 wheels and tires balanced, and flushed the tranny and reset the ECU and the o2 sensor is still good.

Nomis

I have an appt. witht he dealer for next Wednesday...

Nomis

Okay, had the dealer "power flush" the trans using a BG machine - $198.00. Problem is still there, but seems to be a bit less. I'll have to wait and see if the effects are psychological.

VSsc400

iTrader: (1)

it may actually be that the TC needs to be replaced. I know it sounds weird but have you checked your Transmission mount? I've checked mine out and it seems worn... I'll be replacing this to hopefully get rid of my 65-75mph shudder.

Nomis

I've replaced the trans mount and the engine mounts. I'll drive it over the course of a few days and report back with my findings.