Write-Up: Replacing Belts and Pulleys

dboydakid wrote:

thanks man...number 3 has 2? or u replaced it twice?

Look closely, there are two #3 pulleys in 2 different locations. They are both tensioner pulleys. One is for the SC belt and the other is for the accessory belt.

i feel dumb lol..ok thanks

dboydakid wrote:

i feel dumb lol..ok thanks

unfamiliar, yeah; dumb, nope.

Albertj

i agree

Anyone have any idea why parts stores only seem to show inventory for one of the two tensioners? I can't seem to find a listing for the 2nd 2 pulley tensioner.

manofmany wrote:

Anyone have any idea why parts stores only seem to show inventory for one of the two tensioners? I can't seem to find a listing for the 2nd 2 pulley tensioner.

www.rockauto.com You can look up both tensioners.

GATES Part # 38351

GATES Part # 38152

Don't you wish it was this easy....

Haha! thats fantastic!

That made my day. Thanks for posting!

Don't know if this ever got posted.

James came along with a little mod to make belt changes a lot less terrible.


There's the engine bracket for the passenger mount.


Grind out that bad boy like this so that the bottom stud can slide out from underneath, granting an exit for the belts.



Also need to angle grind the spacer on both sides so that it is able to swing down out of the bracket without loosening anything else once you take the one nut and stud loose. FYI, you do need an E socket for that stud.

Here's the result.


1 - remove nut and then the stud

2 - swing the spacer sleeve down and out

3 - belt access granted

That is an ingenious mod that wont really affect the performance of the mount. Good work. The end of the stud is broken on mine, so I cannot fully remove the mount, I have to cram it behind the different area's of the mount with what little (and I mean LITTLE) space is provided from sliding it forward.

it would be great if the pics on page 1 were updated

Dude That is awesome! I think I will try this

The bottom tensioner pulley on the supercharger belt is going out, yes the one that you have to take half the car apart to get to....what replacement part number do I use ? I have bought a plastic one that is the same size as the tensioner pulley on top but the top one is metal. Should I use a metal one for the bottom too ? What diameter should it be ? I plan on going to a 3.4" sc pulley soon. Thanks

98RiviSC wrote:

The bottom tensioner pulley on the supercharger belt is going out, yes the one that you have to take half the car apart to get to....what replacement part number do I use ? I have bought a plastic one that is the same size as the tensioner pulley on top but the top one is metal. Should I use a metal one for the bottom too ? What diameter should it be ? I plan on going to a 3.4" sc pulley soon. Thanks

I moved your post to this thread. The first post of this thread has the number that you need.

Do you recommend a metal replacement ?

Dayco 89006

Thanks for your guys help...much appreciated....now to put everything back together lol...

All done and now #8 sounds like its getting worse...since its grooved can I change it to a metal one ? Or leave it plastic ?

Nothing wrong with plastic pulleys, and they are lighter in weight. A plastic pulley will usually not fail until its bearing wears out, which is a pretty long time - just as long as a metal one, imo.

I think im just gonna go all metal...might as well make them look good and match...is there a good website you guys recommend for buying a sc pulley ? Thanks

Glad to see a write-up on this. I am going to change my belts here in the next week or so. The SC belt is starting to show cracks in the grooves. and the accessory belt is starting to get where you get a little black on your fingers when you touch the grooved side.

From Gates Rubber:

Steel Pulleys
• Metal deflects dirt and grit particles in high
contamination environments to protect
belt performance.
• Metal resists abrasion to maintain proper belt alignment.
• The thermal properties of steel dissipate and
distribute heat more evenly and efficiently to
protect bearings longer.
• Bearings do not distort significantly when pressed
into a steel pulley. Bearings that maintain correct
roundness last longer.
Plastic Pulleys
• Dirt and grit embed in the plastic surface and act
like sandpaper on the backside of the belt, leading
to early belt failure.
• Plastic is less abrasion resistant. Abrasion can lead
to belt misalignment and can even cause a belt to
fly off the drive.
• Plastic retains heat longer because it acts as an insulator
rather than a conductor. As heat increases, the bearings
essentially cook and degrade performance further.
• Bearings can distort during the molding process as
the plastic shrinks around the bearing. Out-of-round
bearings have a shorter operating life.

--------------------

so why use plastic? Albertj's opinion:

- less parasitic drag. supposedly metal pullies cost you some (albeit small) HP
- they do last "long enough" to cover new car warranties and then some
- they are probably cheaper by the dozen so to speak

what does Albertj use?

- given a choice, metal. And he checks pullies by listening to them/watching them run from time to time. Because Albertj has had 2 plastic pullies fail catastrophically. That is, the pulley failed before the bearing failed. Compared to steel pullies which although they fail they do so with a **lot** of warning - that is, the bearings wore out.

I'm beginning to understand some of the reasons for going with metal. I get that metal is a better heat sink for the bearing compared to plastic. I can understand that. But...

I've had two OEM metal pulleys fail before 100k miles. One of them (ribbed idler) was replaced with a plastic version. It too eventually wore out, but was replaced before it became a hindrance. I've never had a plastic pulley just frag - but I did have one where the bearing went out first. Usually, it gives a warning (noise) before it goes.

On the parasitic drag issue: I'm not so much worried about losing HP as I am the SC belt slipping. Imo, a much heavier metal pulley stores inertia, so when you let off the gas, it wants to keep that belt moving, and that means a tendency to slip around the blower. A plastic pulley pretty much goes with the flow, offering less resistance to changes in belt velocity.

Bottom line for me: there are 10 pulleys on our engine. Most of them are parts of accessory components, and so are metal. 4 of these are idler/tensioner pulleys, and of those, only 1 is ribbed, giving the option for plastic. That one idler pulley happens to be the most accessible for inspection and replacement. I can change it with a single tool in under 1 minute.

So in opting to use plastic, you are making that decision only for ONE out of 10 pulleys, and it is the easiest one to check, maintain, or replace. It also happens to be on the supercharger belt, so the fact that there's less moving mass is good for limiting slippage.

PS - if there's such a thing as a smooth pulley made out of plastic, I wasn't aware of it. If there are such things, I probably wouldn't use them. The design of these is such that the belt is permitted to walk a slight amount - more so than with the grooved version, which can't walk at all. I'd think this movement could be enough to erode the plastic over time, causing center or edge wear.

AA wrote:

I'm beginning to understand some of the reasons for going with metal. I get that metal is a better heat sink for the bearing compared to plastic. I can understand that. But...

I've had two OEM metal pulleys fail before 100k miles. One of them (ribbed idler) was replaced with a plastic version. It too eventually wore out, but was replaced before it became a hindrance. I've never had a plastic pulley just frag - but I did have one where the bearing went out first. Usually, it gives a warning (noise) before it goes.

On the parasitic drag issue: I'm not so much worried about losing HP as I am the SC belt slipping. Imo, a much heavier metal pulley stores inertia, so when you let off the gas, it wants to keep that belt moving, and that means a tendency to slip around the blower. A plastic pulley pretty much goes with the flow, offering less resistance to changes in belt velocity.

Bottom line for me: there are 10 pulleys on our engine. Most of them are parts of accessory components, and so are metal. 4 of these are idler/tensioner pulleys, and of those, only 1 is ribbed, giving the option for plastic. That one idler pulley happens to be the most accessible for inspection and replacement. I can change it with a single tool in under 1 minute.

So in opting to use plastic, you are making that decision only for ONE out of 10 pulleys, and it is the easiest one to check, maintain, or replace. It also happens to be on the supercharger belt, so the fact that there's less moving mass is good for limiting slippage.

PS - if there's such a thing as a smooth pulley made out of plastic, I wasn't aware of it. If there are such things, I probably wouldn't use them. The design of these is such that the belt is permitted to walk a slight amount - more so than with the grooved version, which can't walk at all. I'd think this movement could be enough to erode the plastic over time, causing center or edge wear.

The OE lower idler on the later Rivs (idle behind the engine mount on the front pass side frame rail) was plastic (Well, was plastic on my car), as were all the original smooth idlers. They worked OK, on mine they failed by grenading into little shards. Not sure how I missed the impending failures.

Albertj