vac pump out of line and alternator droop?!!

[chrisc17cjs]

Its the vac pump thats out of line i have worked out, and the alternator has dropped
Has anyone got ay isometrics 3D drawings of the brakets that support this and any ideas that i can do to sort this out.
I can space/ washer the vac pump but how do i raise the front of the alternator
thanks all

chris:confused:

[chrisc17cjs]

Dear All
The diesel page booklets say that the original GM belts have taken account of 6.2 belt problems, does this mean that the gm belts are different than dayco and gates
i live in the UK and am having real difficulties in obtaining a GM belt
Any suggestions or anyone prepared to get me a couple in the us and send me them i can paypal you the money
thanks very much

chri sheerin

[More Power]

The problem you're having is very rare, and that's why we haven't discussed it all that much - as evidenced by how often it is discussed here in the board and in our writings.

As mentioned in a previous email message, most 6.2L diesel owners know that belts don't last as long as the newer serpentine belts. However, you should get at least somewhere in the 30-50K mile range for belt life. If not, it's because of an alignment problem, improper tension, bad belt-driven accessory or cheap belts.

I owned a 1982 6.2L GMC and drove that truck 200,000 miles over 12 years. It had V-belts. During this 12 year time period, I only replaced the belts a couple of times. Generally, if you buy a well-known and quality brand of belt you'll be OK - if everything else is OK.

Solve the alignment problem, and you'll solve your belt problems. You'll have to use a little common sense and put a little thought into how to make the brackets work for you. I do not know of any engineering drawings that show the 6.2L belt-driven accessory brackets.

If all else fails, send me another email message, and I can forward that message to other TDP members in the UK. One of them may be able to point out whatever is wrong with your brackets.

Jim

[Yukon6.2]

Hi chrisc
I'v found that Goodyear belts are the longest lasting belt in the enviroment that i live in.Extreem cold dosn't bother them.I'm going on 7-8 yrs on the v belts on my truck,close to 50kmiles and they havn't been retighteened.I checked them when i installed new batterys this fall and they didn't have any cracks. On my wifes car it's a surpentine and get great life from them as well.It gets started every day,-40C here the last couple of days.The first one i put on hers lasted 8 yrs over 100k KMS,only changed it because i was doing some work that required removing the belt.It is now in the trunk as a spare,very few cracks consiering milage and temps that it operates.
Good Luck
Thomas

[NH2112]

I'm thinking a spacer between the block and the pivot bolt tube, or a sleeve to tighten up the fit between the pivot bolt and mounting ear on the alternator. Maybe both will be necessary.

[chrisc17cjs]

dear all
nh2112 - thanks one of the most constructive answers yet
i dont want to push the alternator pulley further forward if i can help it.
sorry can you try to explain in a different way the sleeve on the alternator ear fixing i dont unnderstand that

could my vacuum pulley be pressed onto far from reading other stuff, how can i easily pull this off, do i need to remove it ?

does yukon6.2 have the goodyear belt codes and is it a basic one or a premuim with a lifetime guarntee as i have read you cant get these anymore?

thanks again to all

cheers

chris

[NH2112]

I was thinking maybe there's too much slop between the long alternator pivot bolt and the portion of the housing it goes through. "Sleeve" might have been the wrong word, shimming it would probably be a better idea. I'd try different widths of 0.010" shim stock, until the pivot bolt just needs a bit of help to go through the housing.

A tapered shim between the tube spacer and block might be what's needed to bring the alternator centerline parallel to the CLs of the rest of the accessories. Or, maybe you could weld & redrill the 3 mounting holes in the upper alternator bracket a little bit toward the front of the engine, which would have the effect of pulling the alternator upward and backward.

I'd definitely check for gaps between the block and spacer tube with the alternator in place and the belt properly tensioned.

[Motorhome]

Here is a pic. of my pump. I have the same setup as you in my Winnebago.
1880

This is my pump and the bracket. You should easily be able to spin the pulley by hand with some resistance once every turn.

If you have 2 belts the shorter shall go over crank, water pump and servo pump. Goodyear #15450. The longer crank - water pump - vaccum pump - alternator. Goodyear #15501.
If you haven't replaced the alternator with the wrong type they should be in line, I think. I suppose you have the same problem as I have - no space to work, just a stupid little "hood" between the driver an passanger seat.

I struggled a year with belts that burnt, squeek'd and ripped off because my belts had the right length but was not wide enough. Here i Europe we normally use not so wide belts, the ones specified above works perfect for me.
/Nils

[arveetek]

Thanks for posting that picture! I have never seen a V-belt driven vacuum pump before!

Yes, the width of the belts is important, too. Getting a wider belt will help tremendously.

Casey