Hi all,

Have a 1988 740 turbo wagon with m46 and type 3 driveshaft.

I recently changed the center bearing and carrier along with 2 u-joints on my driveshaft. After taking it down the freeway at around 75mph I can hear what sounds like the center bearing is whining at a somewhat high pitch.

The carrier bolts to the crossmember and can be moved front to back an inch or so. I installed the new one towards the front of the crossmember and pretty sure the old was was installed towards the back.

My question: can this probably incorrect installation cause the whining I hear?

Thank you for any suggestions.

If you have the carrier slid too far forward it may be putting a load against the bearing. Is the the slip joint at the tranny pushed all the way into the tail stock? If so, I'd pull the carrier back a smidgen.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Hi and thank you for the response.

I will pull the carrier back and see how it goes.

Not sure if I follow about the slip joint at trans however. Maybe we are talking about different drive shafts. I have a type 3 driveshaft that connects to a flex disc/plate at the tranny with 3 bolts.

Thanks again.

Hi,

Just wanted to post back with what has happened with the center bearing noise.

So I slid the carrier for the bearing back to where I believe it was on the cross member when I dropped the driveshaft to replace the bearing, carrier, and 2 u-joints. At first the "whining" sound was still there but after a 80 mile trip into the mountains and back the sound is no more.

Not sure if this is due to the carrier being put back to (what I imagine is) the correct position or not but I am thinking so.

Thanks for the follow-up. Glad to hear it's better - whatever the reason is.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Chris--just so you know--the Volvo version of a slip-joint takes place at the end of the front shaft with the splined front of the rear shaft. Typical American RWD cars with a one piece driveshaft have the slip-joint at the tranny. -- Dave

Owned some BMW's years ago. They have the same setup on their driveshafts as I recall. Two shafts with a slip joint on the front of the rear shaft. Guibo hard rubber joint on the front at the tranny. Must be a European thing...:)

Before the rubber coupling at the tranny in the later RWD cars Volvo always had a solid flange to mount a U-joint--544, 122, P1800, 140, 160, 240, 260, 740, 940. -- Dave

Senior moment. I was thinking back when I replaced the tail shaft bushing in our old 740 that it was a slip joint at the tail shaft. (That's pretty lame when you think about it.) Too many years between then and now......