Tensioning the alternator belt

[bigfoot72]

Does anyone know how to slide the alternator further up on this lower arm so the belt will be fully tensioned? I’ve tried loosening the bolt and using a makeshift pry bar to push it up. My shop manual says use belt tension tool T63L-8620-A, which I don’t have and don’t really want to buy on EBay. Is there any easier way that someone knows of? Any help would be much appreciated!

 

[Don C]

I've always been able to get them tight enough just by pulling up on them with one hand and tightening the bolt with the other. You can wrap a rope or strap around it so you can get a better grip. I don't like prying on the alternator or power steering pump, to easy the damage something. You can make a tool with all-thread rod and a couple of the all-thread couplers.

 

[bigfoot72]

I've always been able to get them tight enough just by pulling up on them with one hand and tightening the bolt with the other. You can wrap a rope or strap around it so you can get a better grip. I don't like prying on the alternator or power steering pump, to easy the damage something. You can make a tool with all-thread rod and a couple of the all-thread couplers.

Yeah i initially tried by hand to tighten it but it doesn’t look like I pulled it up far enough because I believe it was originally all the way up to the top of that arm.

 

[Don C]

I can see the bolt mark on the arm. With the correct belt it shouldn't be that far, that's at the end of the adjustment. Where the bolt is now is about right. Push in on the belt about half way between the pulleys, if it doesn't move more than a half inch it should be good.

 

[kcmash]

Any good suggestions on how to repair a stripped out housing where the tensioning bolt?

kcmash

 

[Don C]

Heli-Coil inserts are how I've always repaired them.

 

[Fabrice]

Pitty you're not around, I'd replate the arm for you. these are easy part to polish and plate...

For the tension, as Donc C suggests, one hand from underneath is enough. Plus the tightening direction helps on the last bits.

One thing you could do too before is to check if when loose (no tension bolt on the arm) if it rotates easy up and down. I recall, there is some aluminium insert, at least on my 351 there is one. Sometimes they corrode in the inside and you need more force at the ideal tension position and that's exactly when your arm starts to get tired

cleaning + grease should allow you to set it the right tension with not much efforts.

 

[Hemikiller]

Loosen the upper pivot bolt a bit so the alternator moves easily, then tension the belt, tighten the adjuster bolt and then the upper pivot bolt.

Any good suggestions on how to repair a stripped out housing where the tensioning bolt?

kcmash

Heli-coil like Don said, or replace the alternator. I've seen a couple rigged with a longer bolt and a nut on the back, but that would take three hands to tighten.

 

[Carolina_Mountain_Mustangs]

If you have a set of crows foot wrenches with one large enough to fit over the square lug where the bracket attaches you can use that to get really tight. Or a short open end wrench or adjustable. You might mark the casting but a pipe wrench with rag over the teeth also. 

PO of my car put different alternator that I have just left has place for second belt but no way on the drive.

 If I wind the engine pretty tight it likes to roll the alternator belt on it's back no matter how tight. It is aligned good never throws the belt just rolls it over. 

If you over tighten it will make bearing go out fast. As long as it is not squealing should be ok. 

Like stated Heli coil only want to fix without lot of trouble.

 

[kcmash]

Heli-Coil inserts are how I've always repaired them.

Understood.  Its just the thought of the 30 cent helicoil and a $20 tap to make it work as Helicoil has custom taps.

Mine is THE alternator that came on this car.  The 65 amp model for extras, so I  trying to keep it.

kcmash

 

[Carolina_Mountain_Mustangs]

Check at your local auto supply some rent them for free to customers. Or see if a local shop will just do it for you for less. Some people actually install Heli Coils from the start in aluminum components that will be serviced a lot. There are also some pressed in inserts but you would probably have to put a stepped hole to prevent pulling out. If you know good welder you can weld it up and drill and tap again.

 

[Hemikiller]

Heli-Coil inserts are how I've always repaired them.

Understood.  Its just the thought of the 30 cent helicoil and a $20 tap to make it work as Helicoil has custom taps.

Mine is THE alternator that came on this car.  The 65 amp model for extras, so I  trying to keep it.

kcmash

IIRC, the adjustment bolt is 3/8"-16, so it's a pretty common thread size and a good chance there will be uses down the road. Less than $20 for the entire kit. 

https://www.amazon.com/Helicoil-5521-6-Coarse-Thread-Repair/dp/B0002SRDVE/ref=asc_df_B0002SRDVE/?tag=hyprod-20&linkCode=df0&hvadid=312356819466&hvpos=1o2&hvnetw=g&hvrand=17056940463374985663&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1014739&hvtargid=pla-433883463582&psc=1

 

[Don C]

IIRC, the adjustment bolt is 3/8"-16, so it's a pretty common thread size and a good chance there will be uses down the road.

+1, I have 4 or 5 different sizes, nice to have on hand for those "oh crap" moments when a bolt doesn't tighten. A lot faster to grab one off the pegboard than drive to the store.

 

[kcmash]

WOW  a lot better price on Amazon.  At Ace Hardware the tap alone costs $32.   I bought a complete new alternator off of eBay for $78 with free shipping.  So I will return the Ace stuff to say the least, and keep my original on the shelf.

kcmash