hey, about 50% of the time when i accelerate (and usually during heavy acceleration from complete stop in 1st gear), i hear and feel a heavy knock or thud coming from the rear (differential, maybe?). it feels like as if a heavy object like a bowling ball rolled back due to the momentum and hit the back of the trunk. any ideas? g13
87 740 wagon loud thud/knock when accelerating
Dec 04, 2006
6 Replies
The center support on the drive line is weak, let's the drive line hit the exhaust pipe. At least that's what happened with our 2000 XC 70. Had to replace the drive line, couldn't get the center neoprene mount separately, according to our technician.
Dale
The 740 has a more robust drive train (since it has lasted nearly 20 years in this case), but then all the modern Volvos are made from rubber bands and matchsticks. I don't know what I buy if my 940 becomes uneconomical to repair (hopefully it will last until the oil runs out and I'll convert it to electric).
Anyway, its probably a loose bush at the rear, holds some arm in place, something is colliding under rotation. Support the car on axle stands or ramps and take a pry bar underneath and leaver each bush to check for excess play.
-- Tony
I HAD THIS WTH MY WIFES CAR A GEARBOX MOUNT WAS WORN OUT REPLACE IT MARKING WHICH WAY IT GOES IN .I didnt and had to put it back in right side up oy voy a dumb goy !
Have you checked that there isn't a bowling ball in the trunk?
Please tell us which on it is as I believe its the gear box mount to the frame and I have two 740 turbos .
SORRY THAT DIDN'T MAKE MUCH SENSE CANT BELIEVE I WROTE IT, BUT TRY OUT THE MOUNTS ON THE GEAR BOX ANYWAY !
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required