Lexus SC auto trans. support group, lets help each other
06-07-16, 03:23 PM
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Lexus SC auto trans. support group, lets help each other
So I figure if enough of us talk about our auto trans problems, maybe we can help each other.... I have owned this 93 sc400 for 5 yrs and the trans was perfect until 3 months ago. Thats when I had a local mechanic shop pull my engine with trans. and do a gasket reseal because of leaking gaskets. When I picked the car up the tech. asked if it had always went into park so hard. No, it did not. So I left it with him to check all connections and line pressure at the trans. He used a meter and said he lowered the line pressure slightly but didnt want to lower any more. Ive been working with it for 3 months trying to figure out whats wrong. When I first got the car I pulled the trans. pan and cleaned the pan and filter and refilled with Toyota4 trans. fluid. Ive since drained and refilled twice with atf., and new o.e. trans. mount. I recently installed a new o.e. tps and adj. with no help. Idle is at 800 rpm. It has recently started holding first gear until 19 mph when first driven then shifts normal after warm. All the trans. plugs on the outside of the trans. appear to be good. The first time it down shifts into first cold or hot it bangs pretty hard. The trans. detent cable has barely any pressure on it at idl. Im wondering if one of the solenoids on the valve body could be going bad? Trans. has no slipping and the fluid looks and smells like new. Love this car, but im afraid the rear end is going to go out as hard as it goes into drive every time. Also a new aftermarket radiator was installed by the garage.
Last edited by bigwhite; 06-07-16 at 03:31 PM.
06-07-16, 06:57 PM
#2
My experience with every automatic transmission I have worked on or even touched is that fluid is the biggest thing.
I don't recall if I posted in your thread ever, but make absolutely sure you are filling the transmission with the engine in park and idling on level ground. Fluid is everything in an auto.
As to the hard hit into drive issue, maybe it has nothing to do with the transmission. Have you touched your engine mounts? How about your driveshaft coupler? More importantly, have you ever changed your carrier bearing. Just throwing some things out there for grins.
I don't recall if I posted in your thread ever, but make absolutely sure you are filling the transmission with the engine in park and idling on level ground. Fluid is everything in an auto.
As to the hard hit into drive issue, maybe it has nothing to do with the transmission. Have you touched your engine mounts? How about your driveshaft coupler? More importantly, have you ever changed your carrier bearing. Just throwing some things out there for grins.
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