How To Install a Serpentine Belt System

Offroad VW based vehicles have problems/insights all their own. Not to mention the knowledge gained in VW durability.
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Lotrat
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How To Install a Serpentine Belt System

Post by Lotrat »

The first thing you may ask is, "Why bother?"... I did. Once I started looking into it, I found that the serpentine belt has a few advantages over a V-belt. A serpentine belt has more surface area than a V-belt for better grip, lasts twice as long, is less likely to jump off the pulleys, and puts less drag on your motor which frees up some HP. Today, most car manufacturers use serpentine belts. Serpentine belts were even used on the Beetle in its final years. Check out the alternator stand mount:

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Enough history... I installed the MST serpentine belt system. The same kit works on either generators or alternators as the tensioner will take up all the belt slack on either one. The MST crank pulley has engraved degree marks, so they won't wear off. It even has BDC marked. The Scat brand has their big logo where a BDC mark should be. The MST kit includes an extra long crank pulley bolt where most kits don't. I got the sand seal version which did not include the seal. It only uses a Scat sand seal, so I had to hunt that down. It would have been nice to have it in the kit, but not a big deal to get. MST also offers a press in sand seal adapter, which I also installed.

While I could just cut and paste the MST instructions from the kit, I found that the layman would need more info than what is in the instructions provided.

First step is to remove your pulleys. Here's the tourniquet method I used for getting the crank pulley off:
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Then remove the generator/alternator pulley.
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Make sure you don't lose the shaft keys on the crank and generator/alternator. Mine were on pretty good, so I left them on.

If you are installing a sand seal, the MST press-in adapter is pretty nice. It has provisions to bolt it on so that it won't spin. This kit will only work with the Scat Sand seal even though their web site says otherwise.
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Press the seal into the adapter.
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Many say to coat the seal edge against the adapter with RTV, but mine was really tight. I can't see it spinning.

Next is to "press" the adapter into the case. I used the "piece of wood and rubber mallet" method to get mine on. I also drilled and tapped the retaining screw holes off-center. I didn't think it would be a good idea to have them on the case seam.
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The MST kit includes a tensioner which requires you to remove the front 2 generator stand studs. These studs have no exposed threads above the existing nut, but you may get lucky by using 2 thin nuts torqued against each other. You'll also need a thin wrench to use this method.

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The above worked on one of my studs, the other wouldn't budge.

The provided instructions tell you to remove the alternator stand which will require you to remove the generator/alternator, the wires to it, the wires to your coil if mounted on the shroud, the accelerator cable, the accelerator cable tube, and then lift the fan shroud off. Thank God you have an exposed motor after this.

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I used a stud remover and some heat to get the stubborn one out.
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The MST kit includes long bolts that will be screwed down into the block. These bolts are going to be tough to get to so be patient when you're tightening them down.

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Other kits have captive nuts on their tensioners making installation easier, but the metal will be quite a bit thinner.

After you install the pulleys, the real fun begins. The pulley faces need to be within 1mm so that the belt tracks properly. Here's what mine looked like:

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Way more than 1mm. I later discovered that my fan shroud was bent. You can see on the right side of the level that it's off a bit.

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Once everything is put back together and the pulley faces are in alignment, it's time to make sure the tensioner is positioned so that the belt tracks properly. Those hard to get bolts holding down the tensioner bracket will make you say words you never knew you had in your vocabulary. Using a large wrench on the crank nut, turn the pulley to verify the belt is tracking correctly before starting the engine. This will take a few attempts to get it right.

You will also need to manually set the tension. The MST kit has interlocking teeth to help. This is a great feature.
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Once you think you have it right, fire it up and see if you're as good as you think you are.
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I had to adjust mine more than a few times, so again, be patient.

Time will tell how it holds up and if it's worth $200 bucks for the conversion.

Before:
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After:
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man I need new headers...

The MST system can be purchased at: http://prostores2.carrierzone.com/servl ... etail?no=2

I contacted Ken at MST for help on my alignment issue and he offered up some great advice which led me to finding my issue...

Hope this was helpful.
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Hedrock
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Post by Hedrock »

Awesome write up Lotrat,,, Thank you very much :D
Collecting parts again... No I'm not going to say why!
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Lotrat
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Post by Lotrat »

Hedrock wrote:Awesome write up Lotrat,,, Thank you very much :D
I knew one guy would benefit from it. I hope it helps when you install yours. The two tensioner bolts will enrage you. Have a cold beverage nearby to keep you cool...
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Leatherneck
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Post by Leatherneck »

Nice "How to" thanks for taking the time and effort to post it for us.
tikotiko
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Post by tikotiko »

very nice. now are those just for looks or do they do anything else as far as function
I just wanna drive it that's it.
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Lotrat
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Post by Lotrat »

It's more than just looks. A serpentine belt system has better belt retention properties, longer life, and because of it's higher efficiency, robs less power, and decreases fuel consumption. The two biggest problems have always been thrown belts and broken pulleys on big HP motors. A serpentine solves these two issues. My motor runs smoother and quieter. Maybe I just think it does because it has new parts on it...
tikotiko
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Post by tikotiko »

Good info i hope im not the only that wondered
I just wanna drive it that's it.
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Lotrat
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Post by Lotrat »

Nope, I wondered too. So I looked into it...

Anyone else running one? Any opinions you would like to share?
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Jason C
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Post by Jason C »

It might be a good time to upgrade to a welded fan. The stock belt slips enough the slow the fan down at higher speeds. I have heard of the stock fans detonating with the serp. belts.
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baja5
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Post by baja5 »

I have a serpentine system also,It's a BMD.Top notch quality.I do have to adjust the belt tension every so often.I have had it for 3 years or so now.I don't really know if my fan is stock or not but so far it hasn't grenaded, and I run it pretty hard.

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Jason C
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Post by Jason C »

Sorry for the link to TOS, but it is a good read.
http://www.thesamba.com/vw/forum/viewto ... welded+fan
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Lotrat
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Post by Lotrat »

baja5 wrote:I have a serpentine system also,It's a BMD.Top notch quality.I do have to adjust the belt tension every so often.I have had it for 3 years or so now.I don't really know if my fan is stock or not but so far it hasn't grenaded, and I run it pretty hard.
Baja5, how much deflection do you have on your belt?

Interesting post on TOS. I'm have 1" of belt deflection now so I may just leave it there for the slippage. I don't think my stock 1600dp will be seeing 7000 RPM's anytime soon.
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baja5
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Post by baja5 »

I'd say about 1/2 in.I keep it pretty tight or it will chirp.
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baja5
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Post by baja5 »

Just thought I would throw this in there, as some of you know my serpentine belt tensioner pulley exploded over Thanksgiving weekend.Ih has been on there for a little over 3 years now so not a huge shocker.Anyway I called BMD today to order a new one.The guy asked me for my address and said that he would get it shipped out.I asked him if i needed to give him my CC number to pay for it and He said that he would send it no charge.So, anyway that's my plug for BMD pulleys.
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57baja
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Post by 57baja »

That's really cool. Some companies fail to see the significance of going the extra mile for their customers. When people stand behind their stuff, it builds customer loyalty, and referral business. I would consider buying one of these systems now myself.
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