Hello all. I am new to the board and bought a 1973 Buick Lesabre 2 door with the 350/350. Frame and interior in great shape. Previous owner painted the car a color shifting red.... original factory color was green. I bought the car when my 2008 Ford Expedition decided to have a fight between the ecm and throttle body. I took the opportunity to go old school with NO computer, etc. so no electrical (read: computer issues) to deal with anymore. I paid $4500 for the car and have put another $8,000 into it. I knew it would take some tlc, but the laundry list of fixes is long but distinguished: rebuilt transmission (twice-shop screwed it up the first time- second rebuild on them), new water pump, new fuel pump, new power steering pump, new brake master cylinder, new exhaust, replaced left exhaust manifold, new fuel send, new shocks/springs front and rear, new tie rods/ball joints/ idler. etc. on front, new calipers/rotors/bearings on front, new rear wheel bearings, new radiator, new egr valve, new tires, new washer pump motor, a little bit of body work for rust behind front left tire and passenger door, new heater control valve, replaced rear window "chrome" (aluminum) surround and found missing piece online, replaced oem bumper jack, and a few more things I am sure that I am forgetting. I do have one question... with all of the work done, there is still a intermittent low rumble with associated vibration that can be felt in the floor board and steering column while driving. It only happens in 3rd at highway speed 50-75 mph and is most pronounced at 55 and 60-65 mph. Also, at times when decelerating with no gas pedal usage (coasting to a stop for a stop light, etc.) there is alot of noise that I am guessing is from the transmission and the car slows down like throwing out an anchor. When it runs smoothly and quiet, it is a DREAM to drive. However, I am getting frustrated with having it run smooth as silk on day (or part of a trip, etc.) and the vibrate, low rumble and no coasting at other times. I am suspecting that the transmission shop where I live screwed it up again... Suggestions?
new u joints as well, but have not checked the balance of the drive shaft. Not sure if anyone does that where I live (Nacogdoches/Lufkin, Texas). Hell, there is only one muffler shop left in Nac and nobody works on carbs. Back to the response.... why would it be out of balance one day/time and then not the next on the same stretch of road? If it were out of balance, would it not rumble/vibrate at the same speed all the time? Sorry for the stupid questions and such, but I did not have a chance to take auto shop where I went to school back in the day and am going by the chassis manual, etc I have bought, the internet (which is pissing off my mechanic), etc... However, I am all ears (or in this case, eyes) to learn more about what is going on.... I would like this thing to run smoothly ALL the time because when it runs, it is silk...smooth enough that I have only ridden my motorcycle a handful of times in the past year I have owned the Lesabre and that is saying something...
Make sure you don't have a brake caliper that is sticking. That will slow down the car, more than normal, when you let up on the gas.
Resonance perhaps. Some Buick’s in the early 70 had a slip joint in the driveshaft itself that can deteriorate and go bad. I am unsure if yours did.
Welcome aboard from NY. Just a guess, but may be drive shaft related. I don't recall if they had a carrierer
It is not that.... That is the original reason I replaced the front brakes/calipers/rotors/bearings, etc...
Welcome. Nice to see a 73 get that much attention/investment. Good luck on finding the culprit. Patrick
also, the vibration/rumble (when it does happen) is noticeable and or increases in noticeability when I drive over a depression in the road and the car settles a little.... Drive shaft movement at this time???
First nice car, that is a very interesting color. I mean that in a good way. You mention you feel this vibration/rumble in the steering wheel? This immediately makes me think it's something in the front suspension. I was going to list things to check but rereading your post I see the front end has been pretty much rebuilt. It's possible something could not have been replaced/repaired correctly. At this point my suggestion would be to put it on a lift and do a thorough inspection of the front suspension including tires. Check for things being assembled correctly or marks that something is touching that is not supposed to be touching. Just my two cents. These kind of things can be hard to figure out in person, never mind over the internet.
X2, Is the exhaust original, new replacement, or older replacement? Mufflers can make some weird noises and strange operating conditions. On the "throwing out the anchor" try putting the trans in neutral when its time to slow to a stop, see if it still throws out the anchor, if it does, you have a brake issue.
Get the vehicle to the speed where it makes that noise as then put the trans in neutral. That will tell you if it’s a driveline vibration or not.
