Restoring Type 4 pulley/fan alignment

[furgo]

I've read a few threads where advice was given not to separate the alternator pulley/cooling fan assembly on a Type 4 engine, but fewer explain what to do to restore balance once separated.

I'm not intending to separate them on my bus, but I'd like to restore my rusted pulley at some point. I've seen a few already sandblasted and powder-coated pulley/fan combos at very reasonable prices. The trouble is, many of them showed the two pieces separated already.

So first, fact checks:

• The pulley/fan assembly was balanced at the factory
• If disassembled and reassembled without further adjustment, the balance is lost
• An outbalanced assembly can cause excessive vibration, noise and decrease the life of bearings

Now to the questions:

• Are the statements above correct?
• If I don't have the tools/don't want to restore the balance of a pulley/fan assembly myself, can I take it to any machine shop for them to do it for me? Or is there something particular about the Type 4 fan that would require special ACVW knowledge or tools?
• I understand restoring the balance can be done without the pulley/fan assembly being installed in the motor, correct?
• Once correctly put together and balanced, is the balance of the full assembly when reinstalling it on the engine equally critical? And equally complex?
_________________
'79 Westy, P22 interior, FI 2.0 l Federal, GE engine (hydraulic lifters)

Decode your M-Plate

[raygreenwood]

[pioneer1]

I read that you shouldn't take them apart after I took it apart. At least I had marked the alignment of both pieces before. I had no issues.
_________________
"Always waiting for tomorrow ruined everything"

'85 Porsche 911 Targa

'76 Westfalia project

[SGKent]

I took one apart and put it back exactly how it was. The fan belt hopped all over the place because the fan ran untrue. One member here who had been thru it was kind enough to put it on a lathe, spin it with a dial indicator, and spend several hours truing it up as he tightened it. Another member powder coated it while it was apart. What came back was a beautiful true fan. The problem is that the parts can move off center by quite a bit. We've had this discussion on the Samba before. The conclusion was that VW used some kind of jig to assemble them. Unless you have a lathe or equal and too much time on your hands, don't take them apart or they will NOT run true. You'll drive the small main bearing and alternator bearings nuts with the hop of the fan belt. I repeat - do not allow your curiosity or over confidence to take one apart unless you have the facilities and patience to put it back in true again.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[CarlosZ]

Another problem I’ve experienced, not a PO back this time. I took my fan apart to polish and paint prior to reading the warnings. I reassembled the exact way I took it apart. The fan bolts started to come loose and the ring part that holds the belt started to grind against the shroud. I don’t have a torque wrench and looks like I didn’t align the two parts well enough. Conemac, the builder of my engine reassembled it using a lathe or something. He didn’t want to do. He’s done a few in the past and found it to be time consuming, but did. Something about using a lathe or something. Conemac is a machine shop so I’m assuming you could take it to someone for reassembly. I think balance is important.

[furgo]

Thanks everyone for the replies.

[SGKent]

[raygreenwood]

You can do it without a lathe.

If I can get the pictures up....I will show you what I used. I used three 608ZZ ball bearings (technically an inline skate bearkng or skateboard bearing). Good ones are cheap. Most common bearings in the world.

Well...relatively cheap. Mine were rather pricey becuse they were spares for my inline racing skates.....and ran about $130 for a set of 16....but that is still not bad. You can buy adequate onezfor about $2-3 each at most bearing houses.

I mounted them at 120° apart on a 1.5" thick piece of MDO board. Two were on fixed holes on 5/16" axles. The third I drilled a slotted hole for. I put the crank hub in between the three bearings and tightened the slotted one. There was "0" measureable play.

Loosen the fan bolts and tighten them up a few inch pounds....and mount the dial indicator to a solid arm bolted to a plate on the board....not on a magnet stand.

Truing this fan took about 1 and 3/4 hour......and I will freely admit that I got lucky on a couple of my taps to adjust. I had one side of the fan overhanging the edge of the work bench so once I got it there....you can tighten the bolts enough to move the fan and tighten them all the way.

Ray

[SGKent]

[raygreenwood]

[Busstom]

[raygreenwood]

[SGKent]

my question is does the outer surface that is riding on your jig track true with the center 100%. What is needed also is a piece of greased aluminum or low friction plastic that rides in the V of the pulley, while something insures that the hub is 100% turning concentric on the center of the fan. The runout on your crank could even be a slightly bent crankshaft. The measurements on the runout gauge would follow that vee block. Yes - the outer rim and deep V are really unreliable as measuring surfaces.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Amskeptic]

[raygreenwood]

[haggardrob]

Shit, I just took my fan apart when I was painting engine tin etc. Now I wish that I didnt....

Thanks Amskeptic for the rundown of what I need to do come reassembly time

[74westy]

Here is what I did. I've not had to realign it and never shead a belt. The more solid the construction of the jig the better.

Link:
https://www.thesamba.com/vw/forum/viewtopic.php?t=538837&highlight=

Craig
_________________
1974 Westfalia 1800 AW Stock, Twin 34PDSIT
1970 Type 3 Fastback 1600TL Automatic

[williamM]

[img]

if your completely apart, your staring place is an alignment of he timing mark to the dowel on the fan.

Now follow the advise here.[/img]
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[williamM]

uups
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[Busstom]