Hi all,

Some quick questions:

1. Would anyone know what size bolt was used to attach (1) the generator mounting bracket to the block and (2) to the generator?

My PV sometimes makes a very loud high pitched squeal at low idle, but goes away instantly with some rpm or driving.

Looking into it I noticed that the gen bracket was not attached to the motor block for some reason (just loose - wedged in place) and is it possible that my generator is out of line (or crooked to) my main pully? To my eye it looks to be off by a mm or two, but hard to tell, or is that normal?

Thanks,
C

Thanks to all the replies.

Would it be worth it to get a new adjustable top slide bracket - mine is SLIGHTLY out of shape, but oh so slightly, one the bolt hole on one side is quite large, so I need a bit washer to make it work.

Regards,
C

The slotted adjuster bar isn't normally a problem. That also has a rubber mount at the engine end. If you just need a thin washer that's fine. If it will flatten with a hammer that's fine too. There are some with a distinct dog leg in them which I think are actually for alternators but could mount to the other side of the top generator mount. The usual problem is the elongation of the two lower holes. Being alloy means they wear easily. The cause is not doing the bottom bolts up tight enough after doing the belt adjustment. Using a lever to set the adjustment will tend to push the dynamo out of line and you need to nip up the adjuster nut before diving underneath to get at the lower bolts. These are a pain as there is little room to hold two spanners and turn one end at the same time. OK if you have a lift but not when grovelling on the ground. Means that "it'll do" comes into play before they are really tight. If the holes in the plate are badly worn it's usually the front one that is worse so the dynamo then takes a twist. The belt can cope with a small amount of misalignment but comes the time when, although it is working fine, it triggers your OCD!
I guess that it would be possible to drill out and rebush the end plates if the hole isn't badly damaged. Has anyone done that?
Bottom line, just convert to an alternator!

SG;

Fanbelt squeal is caused by electrical load, or looseness, or glazing, or misalighnment (which certainly is happening if hardware is missing or loose), or some combination of those...you should be OK once you resecure the Bracket to engine, and Gen to Bracket, and retighten Fanbelt...use nylock nuts on Gen to Bracket, or even double-nut to prevent loosening and [further] ovaling of mounting holes Eric writes of.

Cheers

This squeal, especially if it happens as you start up can be down to a slightly loose belt. You can also end up with the belt and pullies glazed which makes the problem worse. I had this problem when I used a notched type belt, used because I had it, but back to normal with a correctly tensioned standard belt.
All other comments so far are good. The bracket must have the rubber isolation grommets to stop poor brush contact due to dynamo vibration. Not needed for alternators.

It is not uncommon for both the generator end plates and the generator engine mounting bracket to get damaged over time. The holes get elongated by the 3/8" bolts especially if they aren't tightened properly.

If either the end plates or the mounting bracket holes are badly damaged, the generator pulley will not be inline with the crankshaft and water pump pulleys and that can cause belt noise as well as premature generator bearing wear.

The generators that were rebuilt by Bosch would come with new end plates, but since Bosch discontinued rebuilding them, it's hard to find decent replacements.

New mounting brackets are still available, and so are the mounting bracket rubber grommets.

--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

The bracket is mounted to the block with three 5/16ths bolts--course thread and cushioned with a rubber grommet and two metal washers for each of the three bolts. I think the generator to bracket bolts are 5/16ths as well (but may be 3/8ths). The adjusting bracket uses the same cushion/washer combo and 5/16th bolt where it attaches to the head.--Dave