I have a drive line vibration when braking. I have new pads and rotors on the front and resurfaced the rear which were pretty new.
The brakes are butter smooth but I get a lot of vibration as it slows down.
It's a five speed.

No vibration in the steering, it's in the seat.

I'm thinking center bearing maybe? The busings in the rear suspension all looked fine.

Any thoughts or experience appreciated.

Hawk

I need to add this vibration is really a shudder. The entire car shakes.

Hawk

Although the "link" below refers to a 940, I've had the same problem source with 240s as well, both front and rear.

I hope the photo of the "rust void" shown in the pad contact area will make it clear.


https://www.brickboard.com/RWD/volvo/1595586/940/960/980/V90/S90/got_brakin_shakin.html



--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Every time I've felt that vibration when braking that comes up through the seat, It's been the rear u-joint.
--
Bruce S. near D.C.

vibration when braking i think narrows it to warped rear rotors rather than anything in th driveline.

a bad driveline will cause vibration as it rotates, faster = more vibration

There has always been a little vibration at higher rpms until it went into 5th gear. This vibration is only when braking and not initially. It shows to at around 30 mph as the vehicle slows down. Rotors are brand new on the front and resurfaced on the rear yesterday and the guy who turned them said they were really straight.
I'll check the ujoints.

Hawk

If you do not feel it in the peddle and it's kind of in the seat of your pants. Jack up one side in the front and check the Tie Rod ends. Grab the tire at 9:00 and 3:00 and push pull and look for movement. Do the same on the other side.My Son had these same symptoms on his Mitsubishi. Oddly there was no vibration in teh steering wheel either. Drivers side Tie rod was loose. New one solved the problem.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/

U joint or driveshaft issues will be felt at certain speeds regardless of braking. Rear U joint failure causes a distinct shudder upon deceleration.

Volvo rotors don't do great with resurfacing. IME, brake shudder is most often caused by improperly bedded pads and/or uneven transfer of pad material to the rotor. I would replace the rear disks with new and your problem will go away.

I have looked at my drive train. I found that the rubber around the center support seems "loose." It would allow the drive shaft to move about 1.5 inches in all directions. I also discovered the spring was missing from the bottom of the support.

I am about to just pull the shaft and see what the u joints look like.

If anyone has a good set of directions to pull the shaft I would sure like to have a copy.

I'll keep you posted and thanks for all the responses!

Hawk

Pull the driveshaft. My bet is that you have a binding rear u-joint. I just had to do this for my '90 240. Common symptoms of a frozen rear u-joint is shuddering when braking/decelerating.

While you have it apart, check the center bearing and the rubber support. If the center bearing freezes up it will spin in the rubber support. If you need to replace the rubber support, try to get the OEM one. I installed an aftermarket one on my daughter's 240 and it lasted about a year.

I have Moog u joints and an OEM center support rubber, spring, washer, and bearing on the way.

I'll report back and thanks to everyone here for the help.

Hawk

My vibration and shimmy has been solved, The rear u joint was bad. One cap was dry and the needles were pulverized. The other three were dry. The front joint was loose but not yet gone. Neither had zerk fittings, the new ones do.
I replaced both and pulling it was easy.

My drive shafts were marked with arrows to use to realign it.

It's smooth as butter now.

Thanks to all for the help,

Hawkeye

Hawkeye,

How many miles on your 1990 Volvo 240, please?

Thank you.

B.
--
Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.

315,000 miles. Generally well maintained by the previous owner and by me.

Hawkeye

Hawkeye,

Thank you.

My 1992 240 GL does the rumble on deceleration without brakes applied.

I'd had the drive shaft out of it with a new center support bushing and bearing. It may have 160,000. Maybe 5k or so ago. Yet it rumbles from 60 MPH on downward to about 30 or so.

The U-joints and giubo appeared fine then.

Maybe not now. Pagdeda's guibo replacement urgencey makes me wanna get the thing up in the air and treat it. (With no garage, on hot asphalt. Yay.)

Thank you,

Buttermilk Boy.
--
Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.

When I got under my 240 wagon to see if the u joint was bad it seemed fine. It did not have any visible or detectable play in it. It was actually the opposite. When I pulled it the u joint was tight, too tight. The grease was dry.

Hawkeye

Pulling the driveshaft is pretty easy. The center bearing support can be removed by only disconnecting and removing the rear section of the shaft. If you're replacing the carrier bearing, you can remove the whole thing. Mark the two halfs of the shaft to maintain alignment. Everything unbolts easily. A spare jack stand makes any nice extra set of hands to support the shaft.