I am trying to order replacement drive belts for my LG4 on RockAuto and I can't make heads or tails of what I need. My car is a stock LG4 with A/C and has three belts as follows:
1. (v-belt): A/C compressor, Power Steering Pump, Fan
2. (v-belt): Power Steering pump
3. (serp belt): Alt, Fan

Does anyone have part numbers or specs (length, width) for these three belts?

 

I'm assuming the car is currently driveable and you just want new belts?

Go to NAPA or AZ or Oreillys, that way you can fit them right there or check their length on the car in the parking lot.

This is why I went to a serpentine set up on my 84. I got tired of dealing with these belts.

 

Best to take your old ones in, or pull the numbers off of them. I've found some belt differences between years.

I'm not sure what you mean be 'serp' belt for your alternator/fan? or what year LG4.

 

I Thought The A/C Cars Had 4 Belts.

 

They do have 4.

Looks like OP's car lacks a smog pump though.

I second the single serpentine belt conversion as a good way to go.

But, look at yours for part numbers. Most are in centimeters. Or, you could measure.

 

the change of the alternator/ fan-WP belt from v-belt to multigroove"serpentine"style was a mid-1985 change,85s could have either style-depending on early or later 85 build.

 

Thanks guys, that helps.
And yes, my car doesn't have an air pump, so I've only got 3 belts on mine.

Swap to single serp would be nice, but right now I just need to get it on the road

 

A serpentine belt winds around the pulleys, a description that remarkably matches the dictionary definition of 'serpentine', yes you can look it up.

The flat, ribbed belt installed on the 85-87 alternators is not a serpentine belt.

Swapping to serpentine system, while cool and all, is not a quick and easy task. Especially considering the OP appears to have working AC? (he's asking for the compressor belt anyway). The serpentine swap would involve relocating the AC compressor, requiring new refrigerant lines, refrigerant recovery, etc.

 

Fair point. I do have working A/C, not that I get to use it much here
There are plenty of things I would like to get to before a serpentine swap, hence the reason I am just looking to replace the existing belts. Which BTW I think are original! They've got GM #'s on then and they are by far the worst most deteriorated belts I've ever seen,

 

My 85 Trans Am has the following belts installed: AC compressor is a GM9433766, the Power Steering is a GM9433734, and the alternator is stamped 15455 (not a GM part number). My belt setup is just as depicted in post #4 since it is an emissions car. The two belts with GM numbers are Goodyear brand belts. I have no idea what the manufacturer is on the alternator belt. I can understand needing this kind of information if you don't live in a metropolitan area that has auto parts stores nearby.
Alright, to add a little more to this, here are the lengths I found: the PS, water pump, fan belt is 440x4100. The AC, PS, and fan is 440x5700. Going to the O'Reilly website I see that all the belts are 0.41" wide. The 4100 belt is right around 41" inches long and the AC belt is around 57 inches long give or take maybe 1/2 inch. Not sure what to tell you for the alternator belt but I believe it is around 45 inches.

 

Excellent info, thanks!