2008 XC70 3.2 AWD -- Drive Belt Replacement

[jimmyodonnell]

Hi guys, first time here . . .

I have a 2008 XC70 3.2, approaching 150,000 miles.
I'm using a new dealer shop for maintenance, and it's been recommended that I replace the DRIVE BELT, TENSIONER, IDLER and CLUTCH because "drive belt clutch and pulley are locked" . . . The dealer's estimate for this repair is $1830.00

To learn more about this suggested repair, I've tried to research other threads but I cannot find any mention of the DRIVE BELT.
I see plenty of discussion for SERPENTINE BELT and AUXILIARY DRIVE BELT but nothing on just DRIVE BELT.
This car uses the timing CHAIN rather than timing belt, and this estimate is much higher than the timing belt replacements I did on my 2 previous Volvos.

Is anyone here familiar with this repair? Maybe it's one of the engine's other belts and just being referred to as the DRIVE belt?
And can anyone give insight on whether this estimate is high, or just the going rate for this maintenance?
It seems to me that it must be labor heavy because the belts and parts typically run no more than a few hundred or so on FCP and other markets.

Thanks in advance for any comments.

[ssicarman]

Drive belt should refer to the serpentine belt for the accessory drive, alternator, power steering pump, A/C compressor on the back of the engine.

Did you take the car in for any specific reason/problem?

I think that you need to question the shop as to what they mean by drive belt clutch to clarify in your mind and ours what the actual issue is. Tensioner would be the serpentine belt tensioner. The only clutch on the serpentine belt system should be the A/C compressor.

[jimmyodonnell]

Thanks so much for weighing in on this . . . I'll get more details from the service writer and report back with what I learn.

[jimmyodonnell]

Did you take the car in for any specific reason/problem?





I took it in for 145K service and asked for an inspection of the AC system because it was no longer blowing cold air, and I've never serviced AC in the 4 years I've owned the car. So I'd wondered if it just needed freon service, or if it was maybe the compressor or another serious issue with the AC unit. And the AC is now BETTER just with the freon serviced but it's still not great . . . I wonder if your mention of the clutch on the serpentine belt may be affecting the AC performance.

Anyway I'll get some answers and update . . . thanks

[CVOLVO]

Here's my interpretation of your issues, based on my own experience. Firstly, I'd ask if when you turn off the AC, does the compressor pulley freewheel; ie not turn the compresser? If not, then the AC compressor's clutch is likely "locked". This implies the AC is always on and would possibly contribute to eventually compressor failure and would affect your gas mileage as well. Was it the same shop that did your other diagnosis?

The modern AC systems use R-134a and not R-12 a.k.a. Freon. A few years ago my AC stopped working and the culprit was the front radiator condenser. In colder climates where they use road salt in the winter, apparently the plug at the bottom of the condenser corroded, releasing my R-134a. If you car's AC works, then this is not likely the issue. Possibly the AC was not serviced properly or the compressor may be not functioning properly?

As an aside, I was told by a Volvo dealership's mechanic that the engine's timing chain should last 200,000 km and that's 125,000 miles according to my conversion, so you might be overdue as well?

I'm about to replace my serpentine (drive) belt at 125,000 km and will inspect my tensioner/idler. I heard what sounded like bearing noises last winter, that I initially thought might be this, the water pump or now recently the power steering pump - see my other posting. If the idler was "locked" it would chew up your serpentine belt immediately. The symptoms of any of these components failing is a bearing noise, especially at startup.

Good luck and please do keep us informed of the final problem(s).

[hoonk]

"drive belt clutch and pulley are locked"
And can anyone give insight on whether this estimate is high,

The "drive belt clutch" is the one way clutch that drives the power steering pump/water pump and ac compressor (with a tensioner and idler on the belt also) with the serpentine belt. There is also a one way clutch built into the alternator pulley. Here is a "drive belt clutch" on Amazon https://www.amazon.com/Volvo-3131680.../dp/B00L2ND9MK

Have had a couple cars come in recently with drive belt clutches seized or locked up. Both had serious other problems with items driven by that clutch - one the compressor was locked up, fried the belt, tensioner bearing was noisy - replaced compressor, clutch, tensioner and idler bearings, belt - total was about $2000! The other has a seized water pump, destroyed the "water pump clutch" (the spring that goes between the water pump and the power steering pump) and the drive belt clutch is seized also. Total bill should be about $1700. Hopefully the engine was not damaged when it was over heated (lost all coolant from water pump, damaged ENGINE BLOCK where water pump impeller rides!)

The Drive belt clutch is a $360 part, tensioners and belt about $275, to get all that stuff replaced - you have to remove the ac compressor, mounting bracket (have to take cooling system apart to get that off), power steering pump. It's not an easy job.

Checking for a working drive belt clutch - with the engine off you should be able to push on the ac compressor pulley (with your fingers) and rotate the compressor/p/s pump, easily one direction.

Don't know what happens if you don't replace the clutch when you know it's bad - but I've seen two cars with serious problems in that system with bad clutches -
The question is what happened first - clutch goes bad and makes water pump or ac compressor lock up? Or the other way around. Either way if your "drive belt clutch" is locked up/does not freewheel in one direction I would not take the chance of damaging anything else. Same goes for the alternator clutch, I've seen a seized alternator clutch destroy the pulley and shaft that drive the alternator.

The engine does have a timing chain, First a set of three gears transfer power from the crank to the drive belt clutch one one side , chain in the middle and alternator drive pulley on the other. Then the chain drives the cams. Chain housing is between engine and transmission so you don't want anything to ever go wrong with it!

To learn more about those clutches google "overrunning alternator decoupler"

[CVOLVO]

Hoonk: Thank you for the very informative and insightful posting. I have one simple question. On the Litens web site they state that an OAD has about a 100,000 mile life. Is that your experience with the Volvo 3.2 L engine? Should I proactively replace some or all now (120,000 km ~ 75,000 miles) or wait until I start to hear a bearing noise?

PS: This short video helped me understand the advantages of OAD https://youtu.be/4wlTtIWOgfU

[jimmyodonnell]

Thanks guys for all constructive insight.
It seems the repairs Hoonk has seen recently are similar in scale and estimated cost to what's been diagnosed on my car.
I appreciate the clarity and the detail in which you've explained this.