lou77777

Hi,
I am a new member and I own 3 Lexus cars. I just bought the 1992 Lexus SC300 at auction. I like the car but going down the freeway it is turning 4700 RPM @ 80 MPH. My 92 LS400 goes 80 MPH at about 3200 RPM.

The SC300 shifts 3 times only and I thought these were 4 speeds with an overdrive. My overdrive works right on this car. It shifts 3 times in low range thats with OD off and then one more time when overdrive is activated. To me that is a 3 speed with overdrive.

Anyone know what this car should be doing as to shifting?

I checked the trans fluid and it is topped right and the fluid looks brand new with no residue it is bright red.

Thanks for any help.

OG Dada

iTrader: (10)

When you put it on Drive, that's already 1st gear. So you wouldn't really feel it shift when you're on the move already. You'll only feel 3 definite shifts when the car is already moving. But that 4700 rpm sounds too high.

lou77777

Thank you for your response. Yes you are right but it acts like a three speed as it only shifts from first to second to third and then if I turn on overdrive once more. Thats two gear changes then one for the overdrive. Could it be a solenoid?

This trans feels right, nice a smooth, crisp shifts just one shy of perfection. I have built up my own modified's for circle track using two speed powerglides and know a little about how they work. Have you ever seen a Nascar Modified with 500 to 700 hp and ten inch wide tires running of banked 3/8 or 1/2 mile oval track. Wow is it crazy fun. Much fun, I wish I could still do that.

ANY suggestions are welcomed about this trans shifting problem.

Clean400

iTrader: (2)

Your trans is working perfectly fine! That's exactly how it's supposed to work.

The A340 has three true gears and an overdrive. Just leave O/D on and you'll get good gas mileage on the highway.

If you want more performance on the highway take O/D off at the expense of gas mileage.

Also the reason your LS400 is at a much lower RPM in 3rd gear is because it has something like 3.27 gears vs the 4.27 gears in your SC300 (don't quote me on this but there is a huge difference in gear rations on each transmission). The LS400 is geared like that to make it really smooth around the town, the higher gears make the SC more sporty from a stand still. If this bothers you, you could always swap different ratios in your SC300 trans but you're going to find it a lot less fun from a dead stop.

lou77777

Thanks Clean400, I am glad to hear that. I will leave it stock. I am a bit disappointed in the off the line power in this car so I guess I will have to find a later SC400. I don't drive that far anymore and gas mileage is not on my list. My last modified would burn close to 50 gallons of Methanol one night or racing running 45 laps on 3/8 mile track. Haha thats gas mileage, and tires were good for two nights. I must have been crazy.