I recently did a cam swap and also added an ASP underdrive pulley.. i got the partnumber gatorbacks that everyone else on the board is using. The belts seemed to fit perfect when i put them on. After driving 250 miles and getting on it one time i noticed the belt was only halfway on the tensioner, water pump, and power steering but was perfectly fine on the pullies bellow. The tensioner had no slack but i managed to slide it back on. I noticed the tensioner didnt have as much play in it anmore and was very easy to move. I drove slow not taking it above 3000 rpms and checked the pullies and they were fine. I figured there was a glitch and it just happened one time. I took the car to 6000 again and right after i checked the belts and the top 3 were halfway on again. It seemes to me like my tensioner is the problem and has lost its tension in the spring. What do you guys think is the problem?

 

the stock tensioner tends to cause slippage at higher rpms. katech makes a really great aftermarket tensioner pulley but they charge about $130 but it is worth it. if you want to save some money you could buy the larry pulley for around 50 from either ttp or tsp.

 

This is a fairly common problem with the stock tensioner/UD pulley combo. The answer is usually the Katech manual belt tensioner. It is a great piece, and well worth the cash.

 

I had the same problem, except mine would literally throw the belt off. A "Larry pulley" with the raised lip solved my problem and it was only ~$50 from Thunder Racing. The Katech tensioner is also a solution, it is more expensive though.

 

i tried to find the "larry pulley but i couldnt find it

 

I couldn't find it either when I looked...you might have to call to ask for it.

 

ok yea i emailed them about it

 

Thunder Racing use to sell it. Give them a call.

But, like others have said, change to a Katech tensioner and not worry with it anymore.

 

MBA also (used) to make a pulley, which is what I went with. It has a raised lip, and looks very nice. Unfortunately, they are now out of business.

 

Yeah, ASP made them for awhile and a few different shops sold them. I've heard of a few guys ordering them straight from ASP.