I measured, and my pully on heavy is def bigger, about 1 inch in circumference (not diameter, this is key) - there was no way to mount the new compressor with the old belt and get the manifold on straight - even if I adjusted the tension as far as I could. the flange wasn't the problem, I was able to get the belt on the pully - but it pulled the compressor out of square. The question is, does this slightly larger pully throw off my balance in any way? I just don't know if these things are engineered for specific accessories and belt size - or if there is some give in the engine design to accomodate slight variation?

I have a supply of r12 I've sourced from here and there - so I want to use it and go full classic mode (I'm an originalist/stock kind of guy). My observations and research also tell me a working r12 w123 (with refreshed seals, etc) has more value than a converted one.

__________________
Andrew
Montclair, NJ
--------------
1982 300D Turbo
120k
Petrol Blue Green

"def bigger" does not tell me much. Do you have numbers? It does not have to be accurate to 3 decimal places. I used a ruler and eye balled it. I would say my measurement of 5.125 or 5-1/8" is accurate to 1 decimal place.

Did you replace all your hoses?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I measured the circumference of each pully with a soft tape measure, and the heavy R4 was about an inch bigger around. ~16 inch circumference versus ~17 inch circumference is less than .5 inches in diameter difference between them (5ish vs 5.4ish inches diameter). But it was enough to make the old belt too small. And what I mean is, I could get the belt on with the tensioner moved in quite a bit, but at that position the manifold no longer would seat properly. I wish I had taken some photos, but the issue was pretty clear when you looked at the situation. It's important to note that the compressor I removed was also not original to the car - possible it was "smaller" than stock.

Or, is it possible I just installed the wrong compressor? It seems to work well, all bolt holes lined up nicely, and no leaks.

__________________
Andrew
Montclair, NJ
--------------
1982 300D Turbo
120k
Petrol Blue Green

Anything is possible. Where did you buy your R4? What is the part number/ does it match your application? I posted the brand, p/n, and where I bought my heavy R4 in a thread and do not recall having any issues with the belt. I can look for the p/n on the belt if that helps you.

Is there a reason you won't answer my question whether you have replaced all you AC hoses? This is the third time I am asking. I want to know for a data point.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I did not replace hoses. I bought the reman 4 seasons heavy from pep boys - it was part number #57229. thought it doesn't look exactly like the one in the photo for that part. It looks like the one pictured for #57228.

In looking more closely now, I probably (surely?) bought and installed the wrong one - can't even understand how I could be this stupid considering how much preparation I've put into everything.

Belt/clutch size discrepancy aside, it does seem to fit nicely on the car and no leaking. Does anybody think this will be a problem? Optimal AC performance aside - is this going to damage my engine or the bracket, running with this compressor?

Gah, how could I be so stupid with these part numbers? I don't want to hurt the car, I wonder if I should just order another, proper compressor and step back again. Somebody walk me back from this cliff please...ARGH.....

Here's my thread looking into the 4 Seasons reman R4 from Pebboys for my 85 300D

4 Seasons remanufactured R4 compressor

Funny Huskyman is not here bashing you not buying American.

I posted a link to 4 Seasons ecatalog eCatalog

If you plug in the 2 part numbers there is clearly a difference in pulley diameter

5.0" vs 5.5" for 57228 vs 57229

eCatalog

eCatalog

What really matters IMO is the orientation of the compressor, whether the lowest point is where the mini reservoir "sump" is. Everyone says R4's has no sump but that is not entirely true, there is a small reservoir where oil collects that holds some oil. I took apart 2 R4's a few years ago and noted such a reservoir.

Another thing that matters is whether the clocking of the 57229, if different than the clocking of 57228, puts undue stress on the manifold.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

So... what should I do? Rip it out and get another one? According to 4 seasons website compatibility tool, neither heavy r4 is compatible with 82 300d -. Seems to work and aside from clutch diameter, everything else looks identical on the outside. I don’t understand what clocking is though. Damnit I’m so mad at myself.

Damage to any AC components aside - do you think this compressor is going to damage my engine? That’s what I’m stressing about now, and I’ll just cut the belt off until I can get a different one.

Here is pic of the larger compressor (also with different coil clock) in place.

https://photos.app.goo.gl/KtAuVzC5ZhvD5Xxk2

hey all - really sorry to bump this... I want to put this whole thread to rest, trust me!

But I'm at a juncture where I need some advice or consensus. It turns out I installed a compressor (Four Seasons 57229) that has a pulley diameter of 5.5 instead of 5 inches. It also has a 9 coil clock position, rather than a 12. (From what I've determined, this is the position of the clutch wiring connection? either comes out from side or top?) - in my case, it seems to work fine.)

The compressor is currently mounted fine, running smooth, and the AC is functioning. So we've established I have the wrong heavy R4 on there - and the main meaningful difference, from what I can tell, is that the pulley is .5 inches larger than it should be.

What I'm hoping to get consensus on is whether or not this is a factor that will potentially hurt my engine. i.e - are these engines very sensitive to the specific pulley/belt ratios and geometry from factory. I'm aware that with the wrong-sized compressor could likely be suboptimal for my AC performance - but I'm WAY more concerned that I could be exposing myself to future engine damage because that .5 inches of pulley diameter compromises the engineering of the engine in a bad way.

If consensus here is that this compressor could damage my engine and related parts, or significantly reduce my engine power, then I'm going to take it out and source another part. I shed a few tears thinking about doing this again, but I will not expose myself to needless potential damage if I camn avoid it. However, if it's just "not optimal" or it's agreed that any potential problems would be confined to the AC, I will consider my options and risks involved and go from there.

Thanks for all the help, funola, billgrissom, vwnate, diseasle, rollguy - and everybody - I could not have come this far without all your time and help.

__________________
Andrew
Montclair, NJ
--------------
1982 300D Turbo
120k
Petrol Blue Green

Bigger pulley on the compressor = lower compressor rpm = it pumps less refrigerant = your engine is working less hard for a given rpm. There should be no concern to engine damage since it is working less hard. Clutch connector clocking is important only when a belt breaks. Is it in a location where the connector will be easily taken out by the broken belt?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

The diameter of the pulley has no bearing on balancing or damaging the engine. No idea where you got that idea from, but it needs to go away right now.

As Funola said, the larger pulley just means the compressor is going to run slower for a given engine RPM. If the A/C is working fine, I wouldn't give it a second thought. Enjoy the cold air.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

OK - thanks Funola and Diseasel. I didn't get the idea from anywhere or anyone, but since I really don't know anything about how sensitive the engineering requirements / tolerances are for these engines I did not want to make a the foolish mistake of assuming that a bigger pulley was no problem. I've made similar assumptions in the past and they've turned out to be problematic. Don't worry, I'm not going to spread this inocrrect idea beyond this question, promise!

My calculations tell me that I lose about 8-10 percent of RPMs going up about a half inch.

__________________
Andrew
Montclair, NJ
--------------
1982 300D Turbo
120k
Petrol Blue Green

A slower AC compressor could lead to reduced cooling at idle. Other than that, no big deal if the pulley does not rub anything.

COOL.

Also my car is cool! Now I need to attend to this loud aux fan before it craps out. I think a cleaning/lube/greasing of bearing/motor is in order.

If the W123 fan has anything in common with the W126 fan, you have a ball bearing and a bronze sleeve bearing. Don't grease the bronze bearing, you'll ruin it. Oil for electric motors ONLY (such as Zoom Spout oil or 3-in-1 in the blue bottle). The ball bearing is typically not a sealed bearing and is better to be replaced than lubricated.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)