Serpentine Belt Adj...?

[fogducker III]

I am having a little grief with the serpentine belt on the Scorpion. I put a new one on, correct one, numbers match old one. At first when I fire it up everything is fine, once the engine/belt get warm, when I turn it off and fire it again the belt is slipping.............:garfield:

Question is, how much "deflection" is correct? I obviously do not want to run it overly tight...? At present there is approx. 1/2" deflection....

I do not have, or have access to a tension gauge.........:frown:

[DonziJon]

Can't tell you how tight to adjust a serpentine belt. I CAN tell you how I adjust a V belt. I don't measure deflection or tension. I put my fingers in the alternator fan and see if I can slip it inside the belt. (Engine of course is not running.) If I can just barely..or not at all move/slip the pulley..it's about right. If you are able to slip the pulley easily..it's too loose. I don't see any reason why a serpentine belt would be any different. John

[fogducker III]

Can't tell you how tight to adjust a serpentine belt. I CAN tell you how I adjust a V belt. I don't measure deflection or tension. I put my fingers in the alternator fan and see if I can slip it inside the belt. (Engine of course is not running.) If I can just barely..or not at all move/slip the pulley..it's about right. If you are able to slip the pulley easily..it's too loose. I don't see any reason why a serpentine belt would be any different. John

Thanks for the reply, that is one DIFFERENT way of adjustment.........:yes:

I beleive with V belts, usually you are running two if not three on some set ups? The serpentine is one belt driving all the appliances......not sure if that makes a difference?

I understand the concept of not having any slip, but at what point is there no slip...........?:frown:

[BigGrizzly]

Thoes belts get loose i n a hurry at first, Then the problem goes away about the second adjustment. The main reason that auto serp belts hav self adjusters id for that reason and the fact people tighten them too much befor they stretched and seated in.

[fogducker III]

Thoes belts get loose i n a hurry at first, Then the problem goes away about the second adjustment. The main reason that auto serp belts hav self adjusters id for that reason and the fact people tighten them too much befor they stretched and seated in.

Thanks Randy, so you figure after a couple of runs with another adjustment she should be good.......? I checked all the appliances just in case I had a tight or worn bearing and they are all good, water pump, sea water pump, power steering pump and alt. :)

[Lenny]

Jeremy, isn't there a big Serpentine roller spring "self tensioner" on it??? Like all 350's in newer vehicles ???

[fogducker III]

That is what I thought Lenny, it looks like a self tensioning pulley but in fact it has to be set via a "cog" set-up......took me a while to figure out why it was loose, especially when it got warm after running it.......

[Ghost]

FWIW, if anyone's been having issues with a dialing in the tension on a belt, I'd keep my eyes on that belt itself over its lifetime. I had a serpentine belt replaced this year in my car that nearly failed outright and would have damaged the engine. (In a Boxster, it's a little harder than normal to peek at the belt.) It was cracked all to hell with a lot of it just missing.

I suspect the problem dates back about 4 or 5 years to a bad water pump bearing, which started making noise and was quickly replaced. But I think they left the belt--it may have looked fine at the time--but I am betting that brief spell with a wobbly bearing damaged it enough that when it did start to show it became a wreck.

[Donziweasel]

Jeremy, be careful to not over tighten. If you do, good by alternator bearing or power steering pump bearing.

[BigGrizzly]

Ghost, you would be correct in your assumption. That is a common problem even with V belts. In the Boxer's cased the belt first caused the pump issue. There is a certain person I know, who changes all the belts if there is a water pump idler pulley or alternator issue. My blower has a spring tensioner, that after it sets you lock it down. DW is correct too tight and by by wp. Except on some applications loose is better. On the lock down belt situation it usually onlu needs to be re tightened once .