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420A Belt slipping Off AC pulley

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gmullins2G

Probationary Member
13
6
Mar 21, 2020
Athens, Tennessee
I've been having this problem for about a month and have not been able to drive my eclipse. Womp womp womp. Anyway, I ended up pulling the ac compressor, I replaced the bearing in that compressor, and thought maybe that was it because it was slipping off that pulley. Well, that didnt fix it. So I figured it was maybe the idler pulley considering it was right above it and it looked a little bit more wore out. The bearings in the pulley didnt look that great. So I ended up ordering a new idler pulley. Just about 30 minutes ago I replaced the idler pulley and that belt is still slipping off the AC pulley. Any ideas on what it could be? Just trying to get my Car back in commission. Lol. Much appreciated
 

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There is a way to adjust it with the adjuster bolt. It looks like the one OP has is not the original and maybe he needs a longer one to put more tension on the belt.
 
The ac is driven by the wrist belt, so slipping off is because off alignment, check all the pulleys are align and the idler pulley is the one responsible to keep the belt align.

Note, if the ac compressor is not seating all the way and bolted down correctly it will be off alignment.

Can you take a video while running and get a lot of angles to see if we can figure it out
 
Based on that picture, O.P. is 420a.

@gmullins2G Are you loosening the nut on the pulley before tightening that long tensioner bolt? If not, the tensioner pulley is not moving and you're doing no good. Just be sure you're tightening it up enough, but not too much or else you'll break a belt (which I have experience with).

Any specific questions, ask me. I've dealt with the 420a power steering and the a/c systems WAY TOO MANY TIMES.
 
The ac is driven by the wrist belt, so slipping off is because off alignment, check all the pulleys are align and the idler pulley is the one responsible to keep the belt align.

Note, if the ac compressor is not seating all the way and bolted down correctly it will be off alignment.

Can you take a video while running and get a lot of angles to see if we can figure it out
Here's a video of it running.
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note: whenever you turn the car on, it'll stay in place for a few, I test drove it around the block and it rode off on the side.
 
Based on that picture, O.P. is 420a.

@gmullins2G Are you loosening the nut on the pulley before tightening that long tensioner bolt? If not, the tensioner pulley is not moving and you're doing no good. Just be sure you're tightening it up enough, but not too much or else you'll break a belt (which I have experience with).

Any specific questions, ask me. I've dealt with the 420a power steering and the a/c systems WAY TOO MANY TIMES.
I loosened the pulley before I tightened that bolt up. But boy has this been a problem I've had for awhile. Pulley problems. Other than my pulleys, I have 0 problems. So I hear ya whenever you mentioned "WAY TOO MANY TIMES" Does this look Familiar? This is what it is doing if the quality is good enough.
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How old is that tensioner pulley? The bearing could be shot causing the pulley to lean just enough to slowly walk the belt off.
I actually just replaced it the day I made this post. The tensioner pulley I had before, the bearings in it were wore out pretty bad. I replaced it and my ac compressor clutch bearing. What problems did you run into pulley wise and what did you have to replace? The day I replaced the tensioner pulley, I put the belt on, and when I started the car up, it was riding perfectly fine. Then I started to hear a tiny squeal about 10 seconds later; but it was still staying on there, so I drove it around the block and gave it a little gas and drove back home and the belt ended up slipping off. The same thing happened whenever I replaced the AC Clutch bearing.
 
If you've replaced all that then I guess you're not making it tight enough or you need to check you crank pulley and power steering pulley. Also have you bought a new belt? If it's old it could be a little stretched.
The belt is a new belt, but probably has been stretched and worn down with it riding on the side of that AC pulley. I was gonna check the Crank Pulley and Power steering. The first pulley i checked ended up being the power steering pulley. And by moving it forward and backwards and I ended up getting this as a result. Is this normal?
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I can't see the video for some reason, it says "playback error". Anyway, I assume it sliding back and forth, or wobbling?

First thing you should do is try to tighten that nut on the pulley. If it's tight enough, you may want to invest in a new pump.
 
I can't see the video for some reason, it says "playback error". Anyway, I assume it sliding back and forth, or wobbling?

First thing you should do is try to tighten that nut on the pulley. If it's tight enough, you may want to invest in a new pump.
Yeah, its sliding back and forth. Sliding back and forth pretty good too. Never noticed it til today. I'll try tightening that nut up and see if that resolves it. I appreciate your insight dude. Definitely helps me to get an insight on what's going on. I have an Eclipse RS. It's a year 97.
 
You're welcome man. '98 RS here.

When you're tightening the nut the pump will want to rotate. So I just used an impact to tighten mine. Put you'll have to pull the pump out to do that. I guess you can just put a screwdriver through one of the pulley holes to tighten it by hand. Then you can see if it's shaft play or the nut. Like I said, replace the pump if it's shaft play.
 
You're welcome man. '98 RS here.

When you're tightening the nut the pump will want to rotate. So I just used an impact to tighten mine. Put you'll have to pull the pump out to do that. I guess you can just put a screwdriver through one of the pulley holes to tighten it by hand. Then you can see if it's shaft play or the nut. Like I said, replace the pump if it's shaft play.

Alright, so I tried to tighten that bolt up, and put a little muscle into it and the nut didnt turn at all. The pulley still moves forward and backwards like before. So you think I should invest into a new pump? New pulley also, or just the pump? Now you mention power steering, I remember how I've sometimes had power steering problems. So maybe thats another sign‍♂️
 
Yep. Time for a new power steering pump. Hold off on the pulley. If it's shaft play then it's pump related and not pulley related.

Alright. I'll place an order. I'll let you know when it comes in and how everything turns out. Thanks man, I appreciate it. Step by step just tryna get her back on the road.
 
Yep. Time for a new power steering pump. Hold off on the pulley. If it's shaft play then it's pump related and not pulley related.
Alright dude. I got the new pump on, got the fluid flushed, and got the pulley on and everything, and the belt is staying on! So, she's back on the road. Thanks man, I appreciate you. Now time to replace the wheel bearings :D
 
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