Write-Up: Replacing Belt Tensioner Pulley (Series I)

Thanks!

Does my parts list look correct and complete?

Al

al_roethlisberger wrote:

Thanks!

Does my parts list look correct and complete?

Al

can't tell you, I have a '98 -- why not just flip the hood & check?

Albertj

albertj wrote:

al_roethlisberger wrote:

Thanks!

Does my parts list look correct and complete?

Al

can't tell you, I have a '98 -- why not just flip the hood & check?

Albertj

I have been under the hood, but that doesn't verify if I have the right PNs or assortment/number of the same. Just thought I'd verify with those that have done it before, before I put in the order.

Thanks,
Al

If you are ordering from rockauto I would not worry about it.

I am ordering from Rockauto, but they have many choices and don't have a diagram or indicate how many of each I need. I guess I'll call them so I don't order too many or not enough of each pulley.

I thing the "genuine GM parts" site may have an exploded diagram with PNs if I recall, so I'll check there too.

Appreciate all the help.

Thanks,
Al

Called Rockauto and they aren't able to confirm the number and type of idlers needed for the Series 1 SC.

I'm 99% I have the right assortment, but just looking for confirmation before I place the order.

Again, it appears one needs three of the same smooth P/N and one ribbed. Can anyone who has a Service Manual or has done this before confirm?

I've Googled the heck out of this with no luck.

Thanks,
Al

https://rivperformance.editboard.com/t3788-series-1-idler

Old but might help, it was ages ago when I did this.

You only have 2 types of pullies. Idler and tensioner. The tensioner ones attach to your arms that tension the belts. Any part number on rock auto under tensioner pulley should work. You need two.

Idler you need one grooved and one smooth. Again any from rock auto under that section should fit.

If you are still not sure, look at the description on rock auto, it lists if its for supercharged, or on the AC line, etc..

Sorry I can't be more help, it was along time ago I did this.

Thanks, I appreciate it. I think I'm on the right track.

From Rockauto:

Both tensioner pulleys:

DAYCO Part # 89007 More Info {#89007FN} Drive Belt Idler Pulley; 76mm x 17mm Flat Steel, 31mm wide
Tensioner Pulley; Alternator and Power Steering
Tensioner Pulley; Supercharger


Both idler pulleys:

DAYCO Part # 89007 More Info {#89007FN} Drive Belt Idler Pulley; 76mm x 17mm Flat Steel, 31mm wide
Smooth

GATES Part # 38009 More Info DriveAlign Premium OE Pulley; Thermoplastic V-Ribbed 6 Grooved (76mm x 17mm x 25mm)
Grooved Pulley; Supercharger

Looks right to me!

At least you know there are no left hand threads and don't have to be second guessing yourslf like when I did this.

OK, ordered:

DAYCO 89007 Idler Pulley - Qty 3
GATES 38009 Idler Pulley - Qty 1

Didn't see it in this or the Series II write-ups (may have missed it, my apologies if so) but is there a torque spec for reinstalling the pulley bolts? And any loc-tite recommended or not?

Thanks,
Al

This thread doesn't have a belt routing diagram for the 3800 Series 1 supercharged engine.

I believe the following diagram is correct for this engine configuration. Can anyone with the service manual confirm? I actually need to confirm this as I reinstall the belts tomorrow

An update: Apparently you can over tighten the bolts on these idler/tensioner pulley wheels and it will make them drag.

When I installed all four, which is three bolts, I was sure I had tightened them to spec. But it is a bit hard especially on the tensioners to get that just right. And so I think I may have over torqued them just a bit.

I noticed this when I was re-gapping my A/C clutch. What I noticed was that both tensioners were visibly jerking and vibrating for a second when the A/C clutch would engage/disengage. Both tensioners didn't do this constantly but would do it for a second or two when the tension on the belt changed. I'd call this behavior "chattering" although it was visible, not audible.

I backed off both bolts just a small partial turn and they turn completely smooth now with no jerking, and there still is no side/side play in the pulleys (well there is a tiiiny bit of side/side wiggle which was there from day one even when the new pulleys were "overtightened").

Obviously way over tightening anything with a bearing is going to cause them to bind up (if the bolt doesn't give way), but I was surprised these steel Dayco pulleys were so sensitive.

So, lesson learned, but I'll have to reference my newly purchased service manuals next year or so when I replace them again to see the best way to get that torque correct. My plan is to replace them with every belt change, as they are so cheap. I put about 30k miles on a year, so annually might be a good frequency.

Al

al_roethlisberger wrote:

This thread doesn't have a belt routing diagram for the 3800 Series 1 supercharged engine.

I believe the following diagram is correct for this engine configuration.  Can anyone with the service manual confirm?  I actually need to confirm this as I reinstall the belts tomorrow

So, posted in another thread that my power steering/alternator belt broke, and I suspect the bottom tensioner for a variety of reasons.

Looknig at the diagram above, and the service manual, it appears that the tensioners can't be removed and changed individually. Instead it appears that this entire "Accessory Drive Belt Bracket" must be removed, and that the tensioners may be bolted on to this bracket from the rear.

However, the service manual isn't terribly clear on this point.

Has anyone replaced the tensioners on a Series 1 SC engine, and if so can confirm if in fact they can't be simply unbolted individually and this whole bracket must be removed?

Note that this setup is entirely different than the Series II.

Any other tips or experience is much appreciated.

Al

I just changed the #7 tensioner on mine just a couple of days ago. That's the alternator/power steering tensioner. The Goodyear PN should be 49335. The idler pulleys at #5 are pancake stacked with the center bolt #20 going through them. #3 is the A/C and water pump tensioner.

The bracket stays on the engine. Be sure to take the belts off before working on the pulleys and idlers. When reinstalling the alternator/ps belt will slip over the alternator pulley last, if you swing that tensioner all the way back. On the AC/WP belt, slip the belt onto the water pump pulley last, before releasing that tensioner.

Good luck and watch your fingers. New belts don't like to cooperate.

ironclyde wrote:

I just changed the #7 tensioner on mine just a couple of days ago. That's the alternator/power steering tensioner. The Goodyear PN should be 49335. The idler pulleys at #5 are pancake stacked with the center bolt #20 going through them. #3 is the A/C and water pump tensioner.

The bracket stays on the engine. Be sure to take the belts off before working on the pulleys and idlers. When reinstalling the alternator/ps belt will slip over the alternator pulley last, if you swing that tensioner all the way back. On the AC/WP belt, slip the belt onto the water pump pulley last, before releasing that tensioner.

Good luck and watch your fingers. New belts don't like to cooperate.

Thanks, but are you talking about just changing the pulleys or the complete tensioner?

I am asking about changing the complete tensioner.

I have replaced the pulleys before and they are a piece of cake

But the diagram above looks like it requires removing the bracket to get the spring loaded tensioners off. Are you saying the tensioners can be removed without taking that whole bracket off? If so, that would be GREAT. And if so, how do you get to them to get them off? Are they bolted on from the rear, and if are there any tricks to getting to them? Or are they bolted on from the front somehow? I've replaced tensioners that can be removed from the front, but they usually have a bracket. These don't seem to.

Thanks!
Al

BTW, looks like GM has discontinued the two tensioners for the Series I SC engine for the Riviera.
 
Some dealers may have some in stock, but I just had them search all of NC and zilch on one of the tensioners anywhere in the state, and one or two of the other one ... but not local.
 
Rockauto has a few (less than 5) left of each, so I'm ordering the tensioners and Fleetrunner Gates belts from them.  The part numbers are:
 
 
38269 {#89056040} - alternator, power steering belt tensioner
 
38268 {#89056039} - supercharger belt tensioner


For the 1995 Series 1, the two standard Gates belt part numbers are:

K060605
K060860

The Gates Fleetrunner version's part numbers are:

K060605HD
K060860HD

Great...I can't afford to buy them right now but my hypochondria for my cars well-being will force me to anyways now...

We're getting up there in age and rarity. My local pick n pull hasn't had one in a while

Hey Al,

Both tensioners are attached to the bracket with one bolt that goes through the spring assembly on the tensioner. It is a separate bolt from the tensioner pulley bolt.

Cheers.

Thanks. Anyone know the torque value for these bolts that go through the center of the tensioner and bolts it to the bracket? I can't find that value in the Service Manual.

OK, found the following on page 6A8-58 of Book 1 of the 1995 G Platform Service Manual:

Drive Belt Tensioner Bolt N*M 50 Lb*Ft 37

This is the only listing in the "Fastener Tightening Specifications" that begins on this page. So it appears this *may* be the bolt(s) that mounts the tensioner. What do you all think?

Thanks
Al

Steel bolts seating in aluminum don't require much torque at all. I remember seeing a diagram that gave the appropriate torque according to the thread diameter of the bolts by grade.

Thanks, well I'm installing this weekend, so any clarification is appreciated.

As long as it's tight, and you don't reef it down like Hercules, I don't see why it matters what the exact spec is. It's not like you're installing Intake or Head bolts....