P80 AWD prop shaft balancing

Post by **abscate** » 23 Oct 2020, 20:01

There has been some debate as to balancing prop shafts on P80s

Does Volvo use different screws to balance it?

Answer..see table of balance screws

Post by **jimmy57** » 23 Oct 2020, 20:19

Yes for 97-98 (they had 855 AWD in Canada and other parts of the world) and maybe a portion of 1999 the longer bolts were the balance weights. The driveshafts were then balanced whole and the driveshaft flanges at viscous coupling and angle gear had improvements in radial runout and the flanges added the lip to hold CV joint. The first design was flat flange with a longer shaft with a centering pilot. The centering hole on CV joint was in a stamped steel cap with less reliability of that being a durable true center. There was a procedure in the manuals for balancing and later Volvo had a fixture with sensors and a strobe light to aid inn determining where the weight would go. Personal experience was getting CV joint runout to nearly zero had good results.
The lipped flanges ad balanced shafts fixed the issue. Driveshaft vibraton on AWD from 2000 through today is almost non-existent. The P3s and the P5 platforms use three piece driveshafts that do not run in anything close to a straight line.

Post by **scot850** » 24 Oct 2020, 08:42

I have read what you have found abscate, and also jimmy's always appreciated input. I have pulled 6 or 7 AWD prop-shafts over the years and have yet to find any different bolt lengths on any year. I'm sure there may be some out there but I have not come across any yet. The different designs of the flanges and diameters I have seen. The later ones are possibly a better design but a swine to get apart in areas where you get rust as they are countersunk into the flanges of the V/C unit and angle gear. If you pull the prop-shaft (assuming you have not already undone it) what I used to do was mark the flanges to ensure they went back where they came from, and then mark the bolts and used a piece of cardboard which holes punched in a circle so I knew where each bolt came from.

Neil.

Post by **abscate** » 24 Oct 2020, 12:31

I marked the flanges but was not knowledgeable enough to mark the bolts.

The good news is that there only 6! = 720 comb8nations so I will soon be an expert on driveshaft installation

Post by **abscate** » 24 Oct 2020, 14:35

Hmmmm, I wonder what these mean???

Post by **scot850** » 24 Oct 2020, 16:04

Assuming you didn't do those, it is probably someone replacing the rear seal on the angle gear for the position of the rear flange and possibly if it has a torque + angle tightening for the nut.

Are any of the bolts longer than the others? If not don't worry. If they are then don't worry. If there are say 2 longer I would say as good a guess as any other is to put them as close as opposite as you can.

Neil.