BLOWNBLUEZ06

I have been throwing belts off since I got my maggie charged car. I got the update that bolts the tensioner to the block to keep if from flexing and twisting. That helped some, but it wasn't enough to keep the belt on. When I go wide open and grab a few gears, I will usually find the belt moved over toward the alternator and 1 rib chewed off. Thanks to RJW, I found out that Magnuson has a new fix out that can be gotten through Callaway Cars. Their fix comes with a Dayco idler pulley part number (589.50.9043 is the old part #....I believe the new part# is 89003, which is a 76mm O.D., 17mm I.D. 26mm wide with a flange), a bushing, and a m10 x 110mm bolt. The problem is that they tell you to put it up top and again thanks to RJW, I discovered a different option for the idler pulley that places it lower. With Callaway's fix, the pulley is too high and won't clear my Caravaggio hood and I would be surprised if it cleared anyones hood. I performed RJW's fix, but did it with my own twist. RJW re-located his reservior and ran his 5/8" line under the blower. I did not want to take the time to do that right now but may do it later because it prevents you from having to take the reservior loose to change the belt. What you will see is a 10 gauge steel bracket that I bent at a 90 degree angle and then used a 1" i.d. pvc connector as a sleeve to protect the line and then a hose clamp to hold it to the bracket. The power steering line is under no stress using this method.

TYSON1997

Also check your alternator. I messed w/ belts for about a month. Then figured out the shaft on my alternator was now bent and to make it worse it actually hung up in one spot. I havent had a problem since I replaced the alternator.

BLOWNBLUEZ06

I checked everything. I even had the alignment " professionally " checked. All is good. Driving the car like I do just throws the belt. I was told that when under boost and high rpm, changing gears quickly drops the rpm so quickly that it " unloads " and takes slack from the tensioner and throws the excess belt over the alternator. I was also told about a 2004 automatic C5 alternator that has a clutch in it. I just don't want to buy an alternator if I can cure it with this. Magnuson was familiar enough with this problem to come out with another " fix ". If this doesn't take care of it, I am going to give ECS a call and get their super heavy duty tensioner. I hope I am done with this problem. It really sucks to have these relatively simple problems keep me from enjoying my car as much as I should be able to. It sure beats the alternative of having major problems though!

Chris@East Coast Supercharging

There are two options we have found. We make a heavy duty tensioner and we also make a alternator with higher ridges so the belt cant come off. We are testing it on a customers car with great results so far. Maybe he will chime in here.

lucky131969

Check the temps by the PVC. PVC only has a usable temp of 140 F, and starts to deform at 176 F.

BLOWNBLUEZ06

Thanks for the tip. I will keep an eye on the pvc. I will sleeve it in metal if this doesn't work out.

RED99

I would bet your alternator needs to be adjusted. Mine showed in alignment, and was squealing and making the tenioner clank. Doug at ECS gave me some ideas to look at, then at a HPDE event, I made the belt jump 1 tooth. Then I knew there was an alignment issue. I noticed after that, when I tighten the alternator a certian way, I could see it tilt. So I tighten the 2 bolts in reverse order, and it didn't tilt.
The pulley may be aligned on the top where the belt is leaving the pulley, but it could be out on the bottom where the belt comes on the pulley. So check to see if the alternator is tilted. If the belt is jumping, then the pulley needs to move in the direction of the belt.

BLOWNBLUEZ06

I put a long straight edge against the pulley following the belt to the pwr steering and toward the idler pulley and it's an even gap both ways. I couldn't see anything at all. I took it to a professional for a second opinion and he agreed that everything was properly aligned and suggested that I buy the 2004 alternator for the automatic tranny with the clutch in it. I figured I would try this first. I have driven the the car for about 150 miles so far with no issues.

BLOWNBLUEZ06

Here's a reminder for those of you with Maggies that have problems with the belt jumping off.

navy99vert

auctiondepot

Ive never seen the belt jump on my maggie, I added an additional tensioner to prevent slip. The second tensioner adds about 40% more tension, the length of the lever arm controls the additional tension.

Has anyone ever seen empirical evidence on the claims of additional tension for replacement units?

BLOWNBLUEZ06

Belts jumping off is much more prevalent on manual tranny cars where the driver shifts quickly.
If it walks on an automatic, you must have an alignment issue.

Not sure I understand your "emperical evidence" question. If you're asking if I know for a fact that the ECS tensioner adds tension, the answer is an emphatic "yes". I could easily collapse my Maggie tensioner with my hand. Not so with theirs. It was easily double the tension.