My 1971 521

[d.p]

Why would my new alt + belt squeal upon startup? Belt is tight and  looks ok. 

 

Old one didn’t at all.  

[Stoffregen Motorsports]

As an old timer, maybe I can shed some light on this.

 

Back in the old days... We used to use "belt dressing" to get belts to grip better. I think it was basically some kind of wax stick that you would rub on the belt as it was turning.

 

It's kind of like windshield wipers, they transfer some of their material to the glass over time and when you replace them, the new wipers need time to break in. Cleaning the windshield with a specific cleaner helps speed this up.

[john510]

Try a different brand of belt.My wifes Toyota with only 30,000 miles had a squealing belt issue.It was under warranty and the dealer replaced the belt twice.Same problem.I went ahead and bought a Gates belt instead of what Toyota uses and it hasn't squealed yet after another 40,000 miles.Go figure.

Edited September 8, 2019 by john510

[d.p]

It’s brand new gates XL belt.  Annoying as all hell too.  Also just know on the freeway it started squeaking really loud and the ignition light came on. Got off the freeway and slowed down a bit the noise went away and the ignition light went off. 

 

May just go back to my original alt if this keeps up.  

 

 

[Stoffregen Motorsports]

If your alternator or water pump are going bad, they can cause a belt to squeal.

[Crashtd420]

He just put that old altenator on....

 

Yes I would go back to your other one if your belt is tight, maybe tighten a little more and see if it still happens....

 

Sometimes it needs just a little more tension.. did you ever spin the alternator by hand before you installed it?

Did it feel ok?

[thisismatt]

What pulley are you using on the alt? 

[datzenmike]

2 hours ago, d.p said:

Why would my new alt + belt squeal upon startup? Belt is tight and  looks ok. 

 

Old one didn’t at all.  

 

It's replacing what was used by the starter and will have a much higher initial charge rate. The alternator resists being turned by the engine. Loose belt or poor grip and it will slip.

 

 

 

The closer to the engine block the less belt is wrapped around the alternator pulley. If you have room above the idler arm to adjust, lengthen the belt. Put a tire iron between alternator and block and pry the alternator away from the block to tighten. Put thumb on the belt midway to the fan pulley and push hard. The belt should deflect no more than a centimeter.

 

Rain will lube the belt and cause temporary slippage.

 

When alternators start making 80+ amps they resist turning more than a V belt can handle and the main reason the serpentine flat wide belts were introduced.

[d.p]

Gates 7350 XL IIRC.

 

Ill check to see if I cane move it away from the block.  

[d.p]

I tightened it up and it stopped squealing but it’s making some weird whirring noises.  So I think it’s a dud.  

 

Will give it a couple days to see if it gives up the ghost then go back to mine or get something else. 

[d.p]

 

[thisismatt]

Great looking truck mang

 

[banzai510(hainz)]

alternator maybe the issue

[mrbigtanker]

Looks really good.

[d.p]

thanks all.  Belt stopped squealing but the alt does make a noise that reminds of an intake/turbo.  Its a whirring sound, really weird but whatever, will run it till it breaks I guess.  And is anyone else bothered how high my truck sits without much in the back?  

 

 

All I really want is to lower it with 0 wheel gap and still use it as a truck, is that too much to ask?  

Edited September 10, 2019 by d.p

[wayno]

Start with leafs off a 4wd 720, but your going to have issues with the axle resting on the bump stops with them and the lowering blocks you already have in there.

[mainer311]

A whirring alternator (especially at low RPM) usually means that the bearings are toast. Hell, I’ve even bought remanufactured alts that sound like rock tumblers. 

 

Your truck sits almost exactly like mine. It bothers me too, until I go to Home Depot and load it up with shit, and then I don’t care anymore.

Edited September 10, 2019 by mainer311

[d.p]

Wayno I have 720 4x4 leafs but the bolts are seized and I’ve been too lazy to try and get them out.  But even if I did swap them I’d still have issues?  

 

Mainer I agree when it’s loaded it looks great. It just all the other time it doesn’t.  And I know I am just being obsessive but I know what like and this wheel gap isn’t it. 

 

 

[wayno]

Between the lowering blocks(looks like around 3 inch drop blocks) and 4wd 720 leafs you will likely be resting on your bump stops(the figure 8 type), that is around a 4.5 inch drop, I did a 7" drop and had to notch my frame as the frame would have been resting on the axle but that is on a 720 frame/chassis.

You may be able to cut the bottom half off of the lower circle of the figure 8, you may have to cut off more.

How much room you have now between the axle and bump stop?

[thisismatt]

I don't mind the stance, but I like using trucks as trucks.  You could drop it more and add helper bags when you want to carry more weight.

[Charlie69]

I agree thisismatt, a truck is a truck!

 

Sure does make it easy to follow your questions and truck progress!  Thank you for your truck thread.

[mainer311]

We use Timbren bumpstops on the back of our Xterras after lifting. They're basically a big mushy bumpstop. Something to consider if you go lower. https://timbren.com/blog/products-page/absnxf/

[banzai510(hainz)]

with the type of wheel  I think your fine. Its harder to get the look you want with 15 inch rims and 50 series tires w/o lowering it too much. That's why I like the stock rims and tire set up as 3 inch in rear and front droped much as you can look like your lower than you really are plus still have movment and no severe angle issues( notching  bump stops ect,spacer for the driveline.…)

[d.p]

I already cut my rear bump stops in half sometime ago.  I think there maybe an 1-2" of travel between them and the axle IIRC.  Helper bags?  And the wheel/tires aren't going to change, if anything I will just get another set of 15's with the same 50 series tires.  I couldn't run stock 14's because I have disc brakes but I do agree lowered 521s on stock wheels do look good.  Just not the look I am going for.  

[datzenmike]

11 hours ago, wayno said:

Between the lowering blocks(looks like around 3 inch drop blocks) and 4wd 720 leafs you will likely be resting on your bump stops(the figure 8 type), that is around a 4.5 inch drop, I did a 7" drop and had to notch my frame as the frame would have been resting on the axle but that is on a 720 frame/chassis.

You may be able to cut the bottom half off of the lower circle of the figure 8, you may have to cut off more.

How much room you have now between the axle and bump stop?

 

Figure 8 bump stops. I have these on my 710 goon, didn't know what to call them but this is better. I'm lower and never noticed till this spring that the axle is only 1/4" above the 8 This would explain the stiff ride better than the extra leaf and truck shocks I added. I usually lift the body when under the back so never noticed how close it is. It rides just fine but on high speed dips you can feel the firmness when the 8 is crushed. I've been close to airborne (accidentally) but even lowered, it has never bottomed out.