My '95 LeSabre with 60k miles seems to be kicking in and out of the converter lock-up. It only happens after it kicks in and the symptoms are little to no acceleration when throttled hard and vibration.

How can I confirm it is the lockup? Can it be fixed externally? Any idea on what it takes to fix?

TIA

Welcome to Bonneville Club!

It'* easier to detect in a Bonneville because most have tachometers. When it slips out of lockup, the engine will turn around 2900 at highway speed, when it would be around 2100 in lockup. You could install a cheap tach, even temporarily, to get a better idea of what is happening. Even better is to hook it up to a scan tool and have a buddy ride along to observe the pertinent parameters as the problem occurs.

Here are some of the things I know about.

The problem can be brake switch adjustment, throttle position sensor, TCC circuit wiring, PCM. There may be other exterior fixes, too?

Otherwise, it could be TCC solenoid (side case) valve body, (inside) worn clutches in trans (very much inside) or worn torque converter.

Hopefully, smarter trans guys will chime in for you.

Well, I'm not a Transmission Xpert but I wonder if what inthedirt is describing might be normal...sometimes. The converter locks up at speeds over 45 mph. It will unlock when you let off the accelerator and then lock back up when you depress the accelerator again, especially on the highway. What isn't normal is when it does NOT unlock when you "kick it" and it should downshift to a lower gear. Has the xmission oil been changed recently? Ever??? Have you checked the level of the trans fluid when it was hot(the fluid that is) and what color is the trans fluid?
And Welcome to the BC.

I have checked the fluid and it is quite clean and the level is fine. However, it is believed to be original and I plan on changing it. The tranny will kick down if the acclerater is depressed enough. I had it up to 85mph yesterday by flooring it. The converter did not lock-up and the shake was not present. More proof that it is the lock-up. I think I have to change the filter and fluid and go from there. Maybe if I get real lucky, it will be a cable adjustment but I doubt it. I also want to balance the tires again and see if that helps but I doubt it.

BTW, I did own a '93 Bonne before we bought out '01 Aurora 4.0. Now Buick is running a Northstar too.

Thanks for the responses, any more???????

It'* possible, that the shake/vibration that you feel might be nothing more than a misfire and could be resolved by replacing the ignition wires. And if you do decide to replace the ignition wires, you might as well replace the spark plugs since you're going thru that much trouble. The spark plugs are relatively cheap (inexpensive?) to replace. Oh, and stick with the AC-Delco brand of plugs.

i believe thats normal for these cars mine has done it since brand new from the factor. it locks up at between 40 and 55 until you floor it or let off the gas

I guess to be fair, I might need to provide more info.

I bought the car a few weeks ago as a commuter car. It was traded in at my brother-in-law'* dealership and I got it for $2500. 58k miles.

The car had a few issues, it was breaking up ( I replaced the plugs and wires that appeared to be original and that cleared up 90% of it), it needed four struts (done) plus I changed the fuel filter and replaced the power steering pump. What the heck, it'* going to the garage in Manhattan. I'm not bringing one of my two Auroras to the city (one of which is an ultra low mileage Final 500).

The only remaining issue is the shuddering while the torque converter is locked-up. I have thought about replacing coils but that would be another $100. I'll also check the tire balance but once again, it only happens in lock-up. I run the car to heck and back at 85mph in 3rd gear and there are no issues. It just has to be the converter. Sometimes it is more noticable than others. If I'm cruising on flat ground with no strain, it seems pretty decent. As soon as I want to accelerate or go up a hill, it gets rough.

I don't think the fluid has been changed and that is on the list too. It appears to be clean and full.