Serpentine belt selection

[Slyclone]

I ended up going with the billet pulley under drive kit which probably was not the best thing to do. Yes I agree it looks good but there is obviously some baggage with the setup.

I have the instructions right here in front of me and there is 2 belt numbers provided. One is #5060930 and the other is #4060930. I ended up going with the #4060930 belt and for some reason it is just way off by a lot. I cross referenced the number and got 6PK2360- It is actually on the pack of the belt I got as well.

I am just wondering why the instructions say 2 belts which are probably not right. There are also 2 kits for the pulleys I purchase and this is the larger pulley kit. 5 or 6 pieces The belt is going to be smaller. where did I go wrong?

Do I have to get the string out and measure that way?

I just read a post on this from 2009. I thought I had my bases covered with my new belt. After getting my hardware for the waterpump pulley and being able to have it be bolted down I learned the hard way again. I got such a good deal on the belt too.

 

[Quickstop [UK]]

Re: Serpentine belt selection

So is the belt too long or too wide? Have you got A/C or delete on there? Which kit - the March setup?

 

[Slyclone]

Re: Serpentine belt selection

yes march pulleys. Belt is the 6 rib it is just too long. Thought the 40 # would be smaller?

I have AC and all.

Looks like pic

 

[Quickstop [UK]]

Re: Serpentine belt selection

You had the same problem as me. The 4060930 p/n is broken down like this:

40-60 -930 = 40 - 6 ribs - 93.0 inches
which is for a 93" belt.

I went to a 90" and that worked for me. I think you found the thread (search for March pulley setup) where I mentioned the length. So try looking for 4060905, 4060900 or even a 4060895 ( 90.5, 90.0 and 89.5")

Have you put the pulley on the alternator yet? I think that changed it slightly as well...

 

[Slyclone]

Re: Serpentine belt selection

I am not using the ALT pulley I have 2 of them I opted to use the fan blade. For some reason you can not use the fan blade and ALT pulley together.You can use the STOCK metal blade with the machine pulley. There is just not enough threads to bite with the lock washer. The machine face depth on the pulley is not deep enough to acomidate for both. I am already skeptical of the fan blade spinning off. It requires a large lock washer and Lock-tite as well as being impacted on.

I am going to try the part number you provided thanks- Makes sense its appears to be about 3-4 inches too long .

Thanks Mark

 

[Slyclone]

Re: Serpentine belt selection

I got a chance to measure the length. I used some string.

Is there any gain or loss with the tension adjuster?

Like was I supposed to pre-load it a bit or do anything special to get a more accurate measurement.

 

[RealFastV6]

Rewrite;

I just had to re-measure mine last fall.

I used a track and field measuring tape to measure it, routed correctly, and then took the measurement with the tensioner limp (untouched). So in that case my measurement would have been outside the groove, not inside the groove as if I has used a string. Also you might find that a string is going to stretch a bit as you're trying to route it and measure it.

Then I went to the parts store and grabbed 3 belts; one was the exact length I measured, one was a half inch shorter, and one more was an inch shorter. The one that was a half inch shorter was dead-on.

The most important piece of advice here is to grab extras and return what you don't end up using. Marks post above about the breakdown of the PN is correct.

The direction and length of deflection for the LS1 tensioner (that I'm using with my AC delete) and the stock tensioner are quite a bit different, so possible you need more or less, but an inch for tensioner deflection would surprise me as that sounds like a lot.

 

[DaveP]

Re: Serpentine belt selection

I've never done this with a serpentine belt, but have with v-belts dozens of time on the boat engines. It works pretty well for getting an acceptable length belt on the first trip to the tienda.

Cut your old belt. Snake it around the pulleys with the ends overlapping. Mark the belt with a sharpie. Measure the non-ribbed side with a tape measure. You then would have to guesstimate the subtraction for the tensioner. You could have a helper hold the tensioner in the mid-travel position while you pull the belt tight and make the mark. A 1" subtraction for the tensioner seems about right.

 

[Slyclone]

Re: Serpentine belt selection

I have 4 pulleys being used, so I am guessing about a +1/2 around pulleys for total measure. Than you mention a 1 inch slack for tensioner.

I measured 81 inches (outside of string)

Do you think a 40608250 is too big?

Thats a great idea to cut the old one and figure it out that way- Funny thing is I was hoping to hold on to it just in case I do not like the way things turn out

Maby I will just cut it and make it easy-

 

[0966Sy]

Your going to have voltage problems if you do not use the smaller alternator pulley. You are effecting the drive ratio of the alternator by decreasing the size of the crank pulley. I had the same issue with the alternator pulley depth, I used a small diameter flat washer behind the pulley and it's works great. Do not over tighten the nut for the pulley. Use the spec included in the pulley instructions.

 

[Slyclone]

Re: Serpentine belt selection

Stock pulley = smaller? I did not use the billet alum. alternator pulley because I did not like how when using it with the billet fan blade it barely grabbed a few threads, even with a washer I cant imagine it biting very hard.

I dug through pictures, Here is what I was seeing I really did not like how it all fit with everything they provide. I had either use the stock steel fan blade with the Billet pulley, Or just use the Billet fan blade with OE pulley. Either way when I was working on this- Something seemed very off and potentially a hazard if not done correctly.

Alternator "fan blade" with OEM alternator pulley
Alternator "fan blade" with March Billet alternator pulley

This kit is all provided in 1 box and is supposed to work. Alternator is a original or OE looking unit ( when I mention OE I am not sure if the arbor or the threaded snout coming out is the correct dimension) Not sure... I have paper work on it from a dealership it was replaced about 4 or 5 years ago. Previous owner had told me it was replaced, and that he had a issue with a puff of smoke from the hood or from the interior I forget I do have paper work in it all some where to verify the alternator make and model

 

[Captain Morgan]

Re: Serpentine belt selection

the alternator pulley should actually be BIGGER, not smaller. You are under driving the crank, over driving the alternator to make up for it, otherwise yes you will have charging problems.

You can't just mix and match the pulleys to what you want to use, thats why you are probably having belt issues.

As for the belts you originally listed, they are both the same belt, same length (93.585") and they both cross reference to the same belts, maybe one is just "heavy duty" or something like that.

our stock belt is 96.081" just for reference.

 

[RealFastV6]

Re: Serpentine belt selection

the alternator pulley should actually be BIGGER, not smaller. You are under driving the crank, over driving the alternator to make up for it, otherwise yes you will have charging problems.

Overdrive alternator pulleys are smaller, not bigger.

 

[Captain Morgan]

Re: Serpentine belt selection

Overdrive alternator pulleys are smaller, not bigger.

sorry you're right, I was confused by the picture, because the billet pulley looks larger than the steel pulley he put up but I guess you really dont want to overdrive the alternator by much otherwise it would just increase brush wear.

Its still probably the reason for why the belt doesn't work.

 

[Slyclone]

Re: Serpentine belt selection

The after market alternator pulley yes is bigger and does not work with other parts provided in kit- See the picture. Its all a out of the box and is "supposed to work"

I have the smaller pulley on that is original steel part.

The instructions they provide suck. Very misleading as far as belt numbers- The first few numbers I provided in the first post were the numbers the provide for the 4.3 s10 s15 truck. I called them and they told me that is the correct belt it is what ever is on the truck stock or factory components and I was under the impression my 4.3 has the same bracketry and components as any other s10 s15 4.3 1988-1994 .A/C,PS,Crank,water pump,alternator

The belt they provide number for is what 93 inches long? I measure 81inches and than gave my self a additional 1-1/2 inches.

There is no way that the 9 or 10 inches is in the alternator pulley.

 

[0966Sy]

You should be somewhere around an 895 belt with a underdrive crank pulley with correct smaller alternator pulley. Remember when decreasing drive pulley diameter, driven needs to decreased as well to maintain correct drive ratio. Alternators are effected by this as the voltage regulator is set for a certain rpm range.

 

[Slyclone]

Re: Serpentine belt selection

I ended up cutting my old belt like DaveP said to simplify things. I measure end to end and came up with 84.5 inches.

At this point its pretty cut and dry, 84.5 inches around... source a belt that length and I should be good.

 

[Slyclone]

Re: Serpentine belt selection

Finally got a chance to pop the hood on syclone. I ended UP buying a new belt and it was wrong!! After measuring it like mention in last post I fugged up somewhere. Just went to my tool box and grabbed the old 4pk60930 and my old fan shroud and the new old belt went right on.

Now I have another spare belt that is smaller:banghead: