I have searched the forum and discovered I am not the only 6.2L owner with a slipping alternator belt!!!:eek:

I would like to locate (or build) a kit to convert my 82 to a serpentine belt.... is there one out there already???:o:

PS.... BooBoo my 82 will get a name change soon.... dropped her off at the body shop today for some body work and a new paint job..... anyone have a spare front bumper??

You have to buy brackets and accessories from a junkyard off of the later 6.5L motor. The brackets will bolt up perfectly. I did this conversion, but due to other things I also did to the motor and things that happened in life, I haven't been able to start the motor since I did that. Keep in mind that there are two setups for the accessories on the 6.5L.

I believe the 93 setup has the alt and ac swapped? Looks like a bit of PITA to swap everything over....im still debating on putting the 93 setup on my 86 and i have all the parts.....still dont think its worth it yet.....especially if i have to do the ac as well....

FYI if you buy the heavy duty diesel alt belt it stops the slippage....i had that problem on my 82, new belt thats wider and stronger fixes it. If the parts guy isnt sure its HD one.....it ISNT!!! go somewhere else.

I believe that when you swap everything over, the water pump spins in the opposite direction. That might be something you want to take into consideration.

Ive got a 93 6.5 and alt is on the drivers side. Also the water pump does rotate the opposite direction so the water pump will also need replacing, which isnt really a bad thing if it hasnt been done in a while anyway.

I had trouble with alternator belt on my 6.2 motor home it's kind of a bummer its just a single belt, had to replace it every year and then tighten it twice a year, then I put on what is called a "Gator belt" the thing lasted for several years and was still on it when I sold it

The late 6.2s had a surpintine belt.Not shure what year it started but my 91 had it.If you're doing it get a water pump for a 97 6.5.They flow 130 gpm compared to 80 gpm of earlier pumps.

I've done a couple of serpentine conversions, if you can find a '91-up 6.2 or 6.5 at the junkyard it's easy because you can grab all the correct bolts, all the small parts, brackets, pulleys, and even the accessories. The CS130 alt. that the new setups use is worth the swap by itself, and the wiring mod. is really easy. Grab the water pump backing plate as well, it's different for the reverse rotation pump. Like bk95td said, it also enables you to run the later model high flow water pumps. Well worth it just for block longevity.

Thanks for all the info!! I'm looking for parts now....

I have searched the forum and discovered I am not the only 6.2L owner with a slipping alternator belt!!!:eek:

I would like to locate (or build) a kit to convert my 82 to a serpentine belt.... is there one out there already???:o:

PS.... BooBoo my 82 will get a name change soon.... dropped her off at the body shop today for some body work and a new paint job..... anyone have a spare front bumper??
not to sound like a smart aleck but mine was hard to fix from squeeling like a stuck pig. I had to get a big long board to keep the belt tight but it stopped squeeling.

It can help to use a belt as short as you can. The more distance between the crankshaft pulley and the alternator pulley, the more the belt can flop around which makes it more likely to squeek. They also need to be pretty tight. If you have the 78amp alternator, it shouldn't be a problem unless the belt you have is the wrong size.

A front bumper, you can find on a junkyard.

My 93 serp setup is for sale, my 86 ac works so no need to swap it over.

PM me for details. I have the brackets and the alt, ac comp, and power steering pump, as well as the fan and idler pullys.

my alternator belt has never slipped ever its a 1985 it has 2 belts the one for the alternator and the powersteering pump both go over the water pump i changed both belts with them gator ones and never had a problem my powersteering pump belt used to slip when i hit the brakes it starting to do that again so ill tighten my ps pump belt but i see no reason to switch it over to serpentine its just somethin else to do and go wrong

Try to run a 94amp alternator ... And the PS pump is pretty much impossible to tighten. My A/C has leaked out again and I could take off the compressor belt, but it helps driving the PS pump. If the A/C would work, I could turn it on and the alternator belt would squeek ...

yea i dont got A/C but my belts dont queak when theyre tight

The alternator belt is being eaten up when it's tight ... I currently have a belt that at least seems to work when the A/C isn't turned on. But it's getting warmer and warmer here ...

thats strange why they run the A/C and the powersteering off a small belt but like i said my ps belt only squaks when im in the deep mud and i try to turn the wheel thats it but i dont have A/C and its starting to sound better that i dont

thats strange why they run the A/C and the powersteering off a small belt but like i said my ps belt only squaks when im in the deep mud and i try to turn the wheel thats it but i dont have A/C and its starting to sound better that i dont

Are you sure is the belt squaking?? I think thats the pump or steering box itself when theres not enought power to turn or your at full lock.

My ps pump has two belts on it, the main one, then the ac belt also is wrapped around it. Should be plently of friction there.

its the pump stopping cause when you hammer the brakes the pump slows down the engine and if your belts are wet it almost stops the pump but the blet squals around it

I have searched the forum and discovered I am not the only 6.2L owner with a slipping alternator belt!!!:eek:



You probably have the wrong belt. Most part stores like Advance and NAPA only stock the incorrect, but "good enough" belt for the 6.2 diesels, and have to special order the correct one. So, they usually just hand you the wrong belt and don't tell you (or even notice) it's not the proper thickness. They sell you a 3/8" belt, when your supposed to have a 7/16" belt.

A V-belt 6.2 with the correct and thicker belt, along with the rubber-cushioned crank pulley, has no problems with the V-belts.

If you want to spend money anyway, look for a 1/2 ton 1988 or newer. They had the first sepentine setup on the 6.2s.

JD's right, the original belts spec for the 6.2 has been superseceded to the narrow belt in most parts books. Not good!

The other issue with belt slippage is pulley wear. The more they slip, the worse it gets, especially the alternator pulley. I've searched through dozens of cores to find good pulleys that aren't worn, belled, grooved, etc. Once I found good ones, I used the wider belts, through trial and error, and finally have two 6.2's that don't slip and/or require abnormal belt replacement. I went through this with all of my 5.7D cars in the 80's too!

New 7/16" belts, on good, flat pulleys, need to be re-tensioned after running a few minutes. After the initial retightening, they should last the life of the belt.

New 7/16" belts, on good, flat pulleys, need to be re-tensioned after running a few minutes. After the initial retightening, they should last the life of the belt.

If you change over from the plain steel crank-pulley to the rubber-isolated pulley, the belt adjustments hold much better. It's a huge improvement. GM put them on all 6.2s and 6.5s after 1985.

Also, on some older problem 6.2s with all steel pulleys, I installed a larger alternator pulley and that also made a big improvement. Original pulley is 2 3/4" diameter. Putting a 3" pulley is all it takes in many cases. Only slight problem is, if you have a alternator powered tachometer, it will need to be recalibrated via the little trimmer screw in the tach.