Have I done any damage?

[RoninLB]

...I Love my CHT gauge..I mounted it on the console..it's an Aircraft Spruce dual ga./cyl2&5...easy install..............Ron

[cary]

I've read enough. I'm modifying my center console. and putting in a CHT and a volt meter.
I watch my volt meter all the time in my 914. It shows when/if the belt is slipping.

[thrown_hammer]

I read Waynes post and he says to use 6 shims. I was told to use no shims so the belt wouldn't slip? Who is right? Also gonna throw my spare belt in the trunk tonight.

[Jim Sims]

Using no shims could result in overstressed alternator bearings, a damaged alternator shaft and maybe eventually a "trashed" outer pulley and fan. Make sure you understand how the pulley adjustment works. All six shims must be installed either between the outer pulley half and the fan or on the outside of the outer pulley half underneath the dished or domed washer and the alternator shaft nut. Placing more shims between the fan and the outer pulley half (and fewer on the outside) reduces belt tension as the shims reduce the effective diameter of the pulley by opening it up and allowing the belt the ride further down the pulley groove. Fewer shims between the fan and outer pulley half tightens the belt. Just remember that all six shims must be somewhere; either between the fan and outer pulley half or on the outside of the outer pulley half. If you can't reach proper belt tension with a minimum of one or two shims between the fan and outer pulley half you have a stretched or the wrong size belt. Cheers, Jim

[Phoenix]

I'm towing the car tomorrow am. Oil change, leak down, compression test are all on the agenda.

Learnings so far:

1) keep 2 extra belts in the car
2) make sure I have the proper tools to do the job
3) practice changing the belt myself (at first under the watchful eye of a mechanic)
4) explore methods of getting an auditory signal vs. light only when the belt fails

I'll post as this progresses.
(I', starting to think that I'll never be able to just start, drive and enjoy this car without problems. Soooo many problems over sooo little time. )

[Wayne 962]

Don't lose heart - you may be okay...

thrown_hammer - there are a lot of people who give advice on nothing that they know about. The fan belt is one of the more dangerous things to mess with. Check out the tech article:

http://www.pelicanparts.com/techarticles/911_fan_belt/911_fan_belt.htm

for the proper installation procedure.

If you don't have the extra shims on the outside of the shaft, then the nut may bottom-out on the threads. This will result in the nut being "loose." It will eventually fall off, or become loose enough to vibrate, cut-through, and destroy your fan belt.

This is serious stuff - not to be played around with. If you don't have the six shims in there, you shouldn't drive the car until you do. It can also seriously affect your alternator bearings as previously noted...

-Wayne

[thrown_hammer]

Wayne,
They are there, just between the nut and outer pulley half. So the pulley is at its tightest setting. I am going to read the tech article you referenced right now.
Thanks.

[Doug Zielke]

Lots of excellent cautionary info in this thread.
Seeing as you may have mere *seconds* to shut your motor down if the belt breaks, you really need a good warning indicator.

Personally, as effective as it may be, I don't want a big red "tail-light" stuck on my dashboard. And a CHT is great, but not down on the console; imo it would need to be up with the other gauges, right in the normal sight line.

So....I'm scratching out a simple circuit (relay(s), 12v Sonalert, etc.) that will howl when the alternator stops turning. With a bit of additional trickery, I think I can make it do so only *after* the motor is started, so it's not too annoying. (Slow day at the office.)

[Sean Hamilton]

"12v Sonalert"
Hey how about you two blokes get your scones together on this and rig up a "Pelican Parts" accessory?
This thread is giving me the willies!
Consider my order for one placed now.

[Jim Sims]

"12v Sonalert"

How about a voice synthesizer chip with a sexy female voice saying "Master alarm, fan failure; piston seizure in 20 seconds, master alarm, fan failure; piston seizure in 15 seconds, master alarm,......" Jim

[N11Porsche]

I don't want to destroy my 3.0 litre engine, anymore than anyone else but I think this fanbelt issue is freaking some people out. How often have you ever had a fanbelt break? I know they can break and it should be a place for concern. My way of sleeping good at night is to do two things: I carry a spare belt AND I change my fanbelt every year with a quality belt. Works for me.........................

[Doug Zielke]

Originally posted by Sean Hamilton
Consider my order for one placed now.

I'll get in touch with the R&D division of the SCWDP.
We'll make them (exclusively) available to SCWDP members, at cost. Every 3.0 is worth saving from a meltdown.

[Leland Pate]

I replace my fan belt every year... (just did it in April) I keep a spare as well as the old ones in the smugglers trunk along with extra relays, plugs, plug wires, CD box, fuses, roll of 16 ga. wire and asst. connectors, cap, rotor, air box strap, air compressor, two qts of oil, and a gallon of antifreez..... just kidding.

I also installed a CHT gauge along with a voltmeter under the ashtray in my car. I make it a habit to check all of my running gauges about every 3 minutes of highway driving.... it's natural to me now. Passengers even notice me brousing my needles and ask me what I'm doing.
I've been tempted to get one of those huge red "Stop The Car A-Hole!" gauges but I think they look horrible.
Doug you bring up an interesting idea.

I am getting to the point where I shudder at the thought of adding any additional electrical components to my car.... after the trouble i went through this weekend with my blinkers and windows... It just seems that every additional wire you add in there is another chance to cause problems.

In addition to the CHT and voltmeter gauge, I have also installed a stereo and hard wired a radar dectector.

Here's a shot of my gauge setup.

[Jim Sims]

Old or rountine belt replacement results in lot of belts being replaced and a portion of those installation jobs are botched. Hence belts still fail, often taking outer pulley/fan and sometimes alternator and engine with them. It's good to replace belts routinely but only if you do it properly. Cheers, Jim

[Don Haney]

Agreed! Belts don't fail very often at all, UNLESS THEY ARE INSTALLED IMPROPERLY.

The 101 Projects Book actually has a much better write-up on this topic than the tech article I wrote a few years before.

One tip from the book: tighten the belt, then turn the car over with the starter, and then retighten. Lather, rinse, repeat.

The nut will tighten down against the shims. This is very hard to explain, but I'll try. If you tighten down the nut and don't have enough shims on there, then you will pinch the belt. This will feel like: tighter, tighter, tigher, arrgh, I can't tighten any more. This is the way it would feel if you were tightening a retgular nut - it's basically linear.

The correct way is to have the proper shims in there. As you tighten the pulley, you will feel a certain amount of resistance that shouldn't increase too much. Then, all of a sudden, the nut will stop, and you won't be able to tighten it anymore. This will feel wrong, but is actually correct.

What is happening here is that you're compressing the belt slightly, and then the nut hits the shims and stops (while you're tightening it). This is correct.

If you do it incorrectly, you will have the pulley half compress the belt and squeeze it against the fan. This is INCORRECT, and will damage the belt if you run it this way (and possibly alternator bearings). The nut needs to bottom out against the shims.

The unused shims MUST be placed on the outside of the outer pulley half, between the spacer and the outer pulley half. Otherwise the nut may reach the end of the threads of the alternator and will feel like it's tightening down, when it's really not.

Hope this is clear...

-Wayne

[Leland Pate]

The main thing is to ensure that you are using the proper amount of shims... either between the pulley half or on the outside between the pulley and nut, and that the pulley half isn't canted when you tighten it down... I usually tighten it while spinning the motor over by jerking on the pulley nut with a wrench.

The belt slips around the crank but it moves the fan and hence tightens on all sides of the pulley keeping it from being canted.
You will know if it is canted when you fire up the engine and you can see the pulley half wobbling...


Phoenix, I hope for the best with you and your engine.

[Early_S_Man]

This whole issue brings up a few points where experience with air-cooled VW engines is VERY useful, and every new 911 owner should change the fan belt ASAP ... just for the experience and practice, and recheck it over and over again just to be sure there aren't any problems with the installation! A bit of extra time to check fan belt tightness and condition can save a lot of grief and expense later!

1. It also lets you find out whether all of the proper tools are in the tool kit

2. it gives you the experience ... so a broken fan belt can be handled routinely, rather than as a catastrophe!

3. Fan belt(s) should be present in EVERY tool kit, both a brand new one, an an 'experienced' good spare.

4. Change your fan belt every two years, and you will probably never experience a failure!

5. Inspect your fan belt regularly ... if you need to add air to your tires, CHECK THE FAN BELT ... glazing is normal, but any cracks you find signals the need for a new belt!

[pbs911]

This is serious stuff - not to be played around with. If you don't have the six shims in there, you shouldn't drive the car until you do. It can also seriously affect your alternator bearings as previously noted

No kidding. I just had to spend $50 ( 2.5 cases of Sam Adams) on a new outer pulley after reading posts that said install "5 shims". The lack of the 6th shim ended up destroying the outer pully half and probably contributed to the alt bearing going out. Luckily the alt was under warranty and Pelican was able to send me a new shinny new outer pulley half the next day.

[Jim Sims]

Apparently some of the cars came OEM with five shims - this may be a function of the depth of the domed washer as they were different for various years and models; one has to look and see if the domed or dished washer (under the nut) is contacting the "squarish features" on the end of the alternator shaft; if it is and the belt is correct and correctly installed then one needs an additional shim. Cheers, Jim

[TimT]

For those planning on installing CHT and EGT gauges check outhere they make some really cool combo gauges like these they will even make 4 gauge combination gauge with warning lights etc. Appantely this company caters to the aviation field, you can have the gauges certified, but i think thats kinda spendywith a little ingenuity the triple square guage should mount where the clock used to live