My 1996 LS400 with 225k miles seems to have developed a catastrophic problem.

I put the car in drive and push the accelerator and the engine and drivetrain seem partially decoupled. The engine revs but not the car only partially accelerates. The problem developed over a course of 4-5 miles of driving and is getting worse by the mile. In fact, the ratio of "engine revs" to car movement is now so small that I worry that the car may soon not move at all when the gas is pressed. It is like the engine is revving and whatever is spinning the wheels is slipping. There also seems to be a stuttering noise at times in the back of the car.

I am hoping to learn what the possible problems are and the potential cost of repair before towing the car to the shop. It's old and probably only worth $2000 to $2500 when fully healthy, so there is a limit to how much I would spend on it before just selling out.

 

What is reverse like?

 

I went out to test and both forward and reverse were affected. However, during the test the engine became completely decoupled from the drivetrain and now the car does not move at all forward or reverse.

 

Added Info: The car has been whining recently. I thought it was the power steering, but a Google search reveals that a torque converter may whine, too.

 

First thing to do is check the transmission fluid. You are having some sort of transmission problem. And I'm sure Banshee just forgot to mention to check and make sure there is transmission fluid and its on the stick. Check it with engine idling car on level ground, in park. Something happening fast can be a fluid leak.

 

Lol dicer, I was getting there.

Yes, check the fluid when the engine is running. It's best to do it when it's hot. There is a hot range on the dip stick. Quarter turn it, pull it out, wipe it off, reinstall in the dipstick tube fully, remove again and look at where the level is on the stick.

Also check color and smell of the fluid.

I hope that I am wrong but I have a gut feeling you're going to be in need of a transmission overhaul when it's all said and done. Check the fluid first but usually when the fluid is low the transmission will not go into gear at all. Low fluid is usually either it works or it doesn't kind of thing. When you mention the whine, and you've ruled out your power steering pump, that is your transmission fluid pump. They sound very similar to a power steering pump when they are starving for fluid. Usually what happens when you have a whining fluid pump is that your strainer has clogged with debris. The filter on your transmission is a fine metal screen. When a transmission begins to fail it will start to shed clutch material into the fluid. The fluid passes through the strainer and starts to clog it. The pump isn't able to pull enough fluid to provide enough pressure to the unit to operate. What that will do is exactly what you are describing. The clutch packs in the unit will partially engage and slip. This generates an enormous amount of heat and finishes ruining the clutch packs in a hurry. Typically a transmission will not run very long with what you are describing.

You can remove the pan and clean or replace the strainer but that will not buy you much time. If, and I'm not saying this is definitely what is going on with your car, your strainer is clogged the only end solution is an overhaul. I've tried other things multiple times but every single time it's an overhaul that fixes it.

Bottom line, if it were me, if the car is in nice condition it's worth overhauling the transmission. If it's in poor condition then probably not.

 

im saying diff. I bought a used one, popped that in and have had no issues since. Try checking/draining your differential gear oil.

I had an issue where my wheels randomly locked up at low speeds. Transmission would be in drive, but car wouldn't move, engine just revved up but no movement in the wheels whatsoever. I thought my tranny was toast but ended up being the diff and transmission is totally fine. I'd rather have a bad diff than bad tranny any day.

check out my build thread for pics and videos of what i went through

 

just checking, those Rubber bushings on the driveshaft are still intact right? They basically couple the transmission output with the driveshaft and then the driveshaft with the rear diff. I recently replaced mine because there was cracking around all 6 bolts on both the front and rear Guibo couplings

 

Transmission fluid is pinkish brown in color. When cold, it is filled properly to the cold level. After warming up, it went properly to the warm level.

 

Is time for Banshee to fly in and fix it for you.