Pulley Nightmare

[tc87suburban]

I'm hoping someone out there can help me figure out why I can't keep belts on my 6.2. I'm using Gates green stripe belts.
I swapped a 6.2 with Banks Sidewinder, supposedly a GM crate motor with 30K miles, from an '83 Suburban into my '87. My old motor had 300K mostly troublefree miles. I kept the '87 accessories (A/C, alternator and powersteering pump) and put them on the '83 motor. I put in DSG timing gears, a new water pump and replaced the harmonic balancer as it had some bulging. After reading the various pro & con posts I decided to use the non-dampened crank pulley from the '83. (I don't know what pulley was on the '87 motor, it's been sold with the '83 Burb.) My problem is that it throws the belts after a 1,000 miles (or less). The stamped steel pulley that was on the water pump had 3 different size sheeves. I replaced it with a cast one that has the 2 inner sheves the same size and a larger outer sheeve (the one for the alternator). This is the same configuration as the crank pulley. The powersteering pump has an outer sheeve (the one that the A/C belt runs in) that is larger than the inner sheeve. This would appear to be a problem since the two belts are driven by pulleys of the same size on the crank.
Frankly, I'm not sure how I got in this mess and what needs to be done to correct the problem. Do I need to replace the pulley on the powersteering pump? If so, with what? If I order the dampened crank pulley what are the correct pulleys to run on the water pump and powersteering pump. Help!

[mhagie]

First thing is to check for pulley alignment they need to be in line,sometimes one has to shim a little here and there.
have used a yardstick to help in checking alignment.
Merle

[tc87suburban]

Thanks for the suggestion about alignment. I've used a straightedge and a laser pulley aligning tool and shimmed them as needed. As near as I can tell, they are in alignment.

[diesel65]

Put that rubber damped crank pulley on and it should solve your problem,
I used to go thru alt belts because of the belt whip at idle, what I did temporarily a long time ago what fabricated a idler pulley to go between the crank and alternator.
Then I had found a service bulletin about the rubber damped pulley for the 6.2's earlier than 1986.

I reread you post,
I would put back the water pump pulley that matched the power steering pulley when you started the job.
I went outside and looked at my truck,
The damped crank pulley has 3 grooves, the two outer grooves are the same diameter, the center groove is smaller in diameter.
The water pump pulley is the same configuration, it has 3 grooves and the two outer grooves are larger than the center groove.
The power steering pump has two different diameter grooves, the larger groove is closer to the pump.
The belts are routed as followed,
When installing the first belt it goes crankshaft to waterpump to a/c compressor to p/s pump then back to crankshaft.
Belt #2 goes from crankshaft to waterpump to p/s pump then back to crankshaft.
Belt #3 goes from crankshaft to waterpump to alternator then back to crankshaft.
When adjusting the belts, you need to tension #2 first then #1 and #3 last.
I have found that after I adjusted #2 belt(p/s) then I finished adjusting #1 (a/c), the #2 belt might be loose again, so just watch your belt tension.

[ 11-14-2005, 01:11 PM: Message edited by: diesel65 ]

[mhagie]

I agree use the damper pulley, during the build process on mineI read the article by MP about the damper pulley and was sold on it. bought mine from GM Parts Direct, belts run straight and true w/out vibration.
Merle

[BobND]

Originally posted by tc87suburban:
This would appear to be a problem since the two belts are driven by pulleys of the same size on the crank.
Frankly, I'm not sure how I got in this mess and what needs to be done to correct the problem. Do I need to replace the pulley on the powersteering pump? If so, with what? If I order the dampened crank pulley what are the correct pulleys to run on the water pump and powersteering pump. Help!

[BobND]

Well, I sure screwed that post up!

My 1984 Sub had the same problem when I got it. P.O. had replaced the engine with a newer one. At some point, GM moved the AC compressor from the left side to the right side, and changed the belt arrangement. If you don't have the correct water pump pulley (and POSSIBLY the correct crank pulley) for the setup you have, the PS pump will be driven by 2 belt drives of different ratios. NOT GOOD for the belts.

What side is your AC compressor mounted on? Knowing that, I could post a picture of the correct pulleys.

[tc87suburban]

Thank you, thank you, thank you!!
My '87 motor must have had the dampened pulley which apparently has a different configuration from the non-dampened pulley on the '83 motor. After reading William's post I checked the water pump pulley (p/n 15592122) I had been running. It had a configuration that matched what William said he had. And, my PS pump pulley matched his configuration. I'm ordering the dampened pulley today from GM direct. I'll put the '87 waterpump pulley back on and all should be OK.
I did a pretty thorough search of the posts and found no previous mention of the mis-match between the dampened and non-dampened pulley configurations. That's definitely a concern when installing a dampened crank pulley with older accessopries or vice-versa.
I really appreciate your help.
Cliff

[tc87suburban]

Bob,
The A/C compressor is mounted on the driver side of my '87 suburban. It was on the same side on the '83 I swapped motors with.
Cliff

[mhagie]

My parts were from a 83 blazer, the dampened pulley matched the stamped steel to a Tee.
Dampened pulley has 3 groves with the front one larger diameter than the other two.
water pump/fan pulley also has 3 groves with the front one larger than the other two aslso.
Front belt = alt, second grove = p/s pump.
Third grove = a/c with p/s pump rear grove acting as an idler for a/c.
Merle

[arveetek]

That's funny, I didn't realize the belt pulleys changed so much over the years.

My pulleys match the description Merle gave. My crank pulley is the older, solid stamped steel, and the front groove is larger than the other two which are then the same size. Same goes for water pump. The power steering pump has two grooves that are the same size. My a/c compressor is the large A6 style on the driver's side.

Front belt-alternator, it rides on the two larger pulleys. Middle belt-power steering. Rear belt-power steering and a/c compressor.

My stuff came from various sources (gasser converted to diesel, so nothing's stock), but it probably matches the older vehicles.

I did have to shim the power steering pump out a bit...otherwise it didn't line up with the other pulleys and had a tendency to throw belts.

I still throw a belt once in a blue moon, not often. It would probably help to install the dampened crank pulley. I've just never gotten around to buying one.

Casey