Installing a fixed belt tensioner

**pajeff02** · 06-13-2011, 06:06 PM

Although I have not experienced any problems, it is my understanding that under high r.p.m. the stock tensioner can allow the belt to launch off the pulleys and cause all sorts of havoc. Since our car has been slowly being built into a street and strip machine I have considered switching over to a solid tensioner. I stumbled upon ls1camino's garage sale thread a few weeks ago and he just happened to have a Katech tensioner for sale that had been on his car for just a short time.

The new tensioner is a solid piece of hardware that easily bolts in place of the stock unit. The only caveat with running this style tensioner is that it will require periodic adjustment, however, as it takes all of two minutes to properly tension the belt it is not a great concern. I would note that a newly installed belt will stretch more than a seasoned belt, so it is best to check a new belt a couple of times during the first month after installation. I do highly recommend Goodyear's Gatorback belts for anyone that is changing theirs out.

The stock tensioner and Katech unit are both pictured for comparison:

To remove the stock unit, begin by using a 15 mm socket on a longer ratchet to rotate the pulley in a clockwise direction. This will pivot the tensioner and allow the belt to be slipped off the pulley.

Again, using a 15 mm socket, remove the two bolts that secure the tensioner to the water pump housing. Once the bolts are removed the tensioner can be removed from the car and the new unit installed in its place. I applied just a touch of anti-sieze to the threads on the bolts before threading them in place hand tight. Starting with the bottom bolt they are both torqued to 37 ft.-lbs.

After the new tensioner is tightened in place, make sure the lock bolt on the back is loose so that the tensioner can pivot. To re-install the belt, you need to first slip it off the fixed idler pulley that rides between and below the water pump and power steering pulleys. The belt can then be slipped over top of the tensioner and then easily slid back onto the fixed idler as it does not have a shoulder:

Once the belt is back on the tensioner and idler be sure to look at each pulley to ensure that the belt has not slipped out of place. I removed the lock bolt from the tensioner and applied a drop of medium thread compound before re-installing it. Using a torque wrench with a short 3/8" extension, 25 ft.-lbs. of force is applied to the tensioner to pull the belt tight. The lock bolt is then tightened with the belt tensioned and is final torqued to 40 ft.lbs.:

The difference in the pulley on the new tensioner is readily apparent. It has a deeper groove for the belt to ride in. This, in combination with the fact that it is fixed in place, means that it is far less likely to throw a belt under both transient and high r.p.m. loads.

**JayTA98** · 06-13-2011, 07:15 PM

nice work Jeff. Does this belt thrown off issue happens even with stock engines?

**pajeff02** · 06-13-2011, 07:19 PM

Originally Posted by JayTA98

nice work Jeff. Does this belt thrown off issue happens even with stock engines?

I suppose it could. I know it has been mentioned both here and in GMHTP before.

**JayTA98** · 06-13-2011, 07:22 PM

Originally Posted by pajeff02

I suppose it could. I know it has been mentioned both here and in GMHTP before.

I see i personally havent experience any issues but i heard about it. The only thing about this tensioner will be that you have to recheck adjustment. How often you think you need to check it?

**pajeff02** · 06-13-2011, 07:24 PM

Originally Posted by JayTA98

I see i personally havent experience any issues but i heard about it. The only thing about this tensioner will be that you have to recheck adjustment. How often you think you need to check it?

I will put 50-100 miles on the car and then check it just to be safe. As my belt is not new, I doubt that it will stretch at all.

**JayTA98** · 06-13-2011, 07:30 PM

ah i see. It looks like it should solve your issue and it looks cool too.

**cammed goat** · 06-14-2011, 06:09 AM

Nice write-up, Jeff.

**ntimid8r** · 06-14-2011, 06:59 AM

Good write up Jeff! This solid tensioner is a new thought for me. I need to look into the pro's and con's of it. I'm wondering if the belt is more likely to snap under torque from accessories (a/c) kicking in with this solid tensioner. I haven't had any issue with my stock tensioner. Please let us know how it goes after some use.

**pajeff02** · 06-14-2011, 08:09 AM

Hopefully, I can get the car back to the track in a few weeks and see how it works. I have just a few more things to do yet.

**cammed goat** · 06-14-2011, 08:42 AM

Stickied!!

**derekbuckner1** · 01-17-2012, 10:18 AM

Katech tensioner fixed my issues. Good write up

**ls1camino** · 01-17-2012, 10:35 AM

I bought this tensioner the day I threw a belt on my Heads/Cam/Intake LS1 while doing a 0-120mph pull...I barely heard the belt leave the car over the sound of the exhaust.

I'm glad it's working out for you, Jeff.

**Smittro** · 01-17-2012, 10:39 AM

Nice set up Jeff!

In opinion though the problem may be the factory LS1 tensioner setup and the way it tensions the belt.

I've been over 7000 sustained rpm on many 60* v6's and never once had an issue with the spring loaded tensioners or belts flying off.

Unless of course the tensioner was shot to begin with.

Just my .02

**zech912** · 07-18-2014, 06:44 PM

bringing back an old thread to ask ls1camino or anyone who knows why would one sell a Katech belt tensioner? I am thinking of purchasing one and am wondering the downside, if any. Thank you in advance for insights.

**pajeff02** · 07-19-2014, 04:41 PM

If I recall, Jeremy's car was in an accident and he was parting it out. No downfall to the Katech tensioner. I have been running it since I started this thread and have had no issues.

**zech912** · 07-19-2014, 06:28 PM

thank you very much Jeff.

**pajeff02** · 07-20-2014, 02:54 AM

You will need a torque wrench to properly tension the belt upon installation. If I recall, I believe the spec is something like 20 lb.ft. of torque on the tensioner and then you lock it down.

BTW: Welcome to the site!

**sjgreen6** · 07-20-2014, 07:06 AM

Originally Posted by zech912

bringing back an old thread to ask ls1camino or anyone who knows why would one sell a Katech belt tensioner?

Quick google search for "Katech belt tensioner" turned up the web site for Katech Performance. Price for the belt tensioner is $135 in several colors.

**Whamhammer** · 07-26-2014, 03:33 PM

Silly question, how fast are your engines revving at, and would the deeper grooves along with the taller ends fix most of those problems?

**ls1camino** · 09-04-2014, 07:05 PM

Originally Posted by pajeff02

If I recall, Jeremy's car was in an accident and he was parting it out. No downfall to the Katech tensioner. I have been running it since I started this thread and have had no issues.

Actually, I ditched the Power Steering and got an Electric Water Pump. The only thing driven by the crank pulley is my alternator. Basically, I had no need for a tensioner.