Reconfigure GM R4 compressor to Mercedes (upside down)

rkpatt · #1 07-29-2006, 09:02 AM

I have been given a factory new R4 for a GM car . I will be using it in 1983 Mercedes 300SD . It is my understand that the R4s for that Mercedes is configured differently -

Karl on usenet said - " A word of advice on buying a replacement compressor: Any one you get that does NOT come from Mercedes will have the front bearing cover installed UPSIDE DOWN. Look at the cover on the front behind the clutch. It will have 4 bolts. Between 2 of the bolts will be an embossed X. This is the position of the oil hole to lube the front bearing. The R4
compressor was originally designed for GM cars with the compressor mounted
on top of the engine. The X and the inlet/outlet port is UP. Mercedes used
the compressor but rotated it 180 degrees and mounted it under the engine.
This put the ports DOWN. Then they rotated the front cover so the X is UP.
Oil does NOT flow uphill. If you use an aftermarket compressor with the X
down, you will starve the front bearing of oil. It may last a week, a month,
6 months.... depends on the quality of the bearing they put in "

I want reconfigure this compressor so it will last . Can it be done somewhat easily . How do I get it apart to rotate the front plate 180 deg and back together not damginging anything. I really need some help . - Thanks

jbaj007 · #2 07-29-2006, 02:03 PM

Job # 83-526 on the service manual. Send me your email address and I can email you direct the PDF file for it. Too big for this sites PM or email (2mb). You'll need to borrow Autozone clutch tools. Also, a 2 jaw puller and snap ring pliers.

Edit:
See if this works:http://mb.braingears.com/126_DISC1/program/Climate/83-526.pdf

rkpatt · #3 07-29-2006, 04:13 PM

jbaj007 - The link worked . This is a good start . Do I have to go beyond taking the clutch off to rotate the front plate 180 degress . Could any one who has has an R4 completely apart and back togther please give me the details . - Thanks

jbaj007 · #4 07-29-2006, 08:43 PM

I'm not 100% sure on this next part. Remember that

I think there may be a pulley alignment (with the crank pulley) problem if you use the "lightweight" R4. There are two main divisions of R4's, lightweight and standard, and the pulley doesn't stick out far enough on some R4 clutch/pulley assy's? There are short and long shaft models that correspond to these. I know the lightweight pulley/clutch was a problem for me, so I just used the original standard pulley/clutch on the new GM compressor (whatever it was; light or standard). I'd have to see 'em to know for sure. Do some dry fitting first. One yoke didn't go with the other pulley/clutch, or some such. It's been a while since I did mine and I had all the pieces from two compressors available in my hands.

my123ca · #5 10-05-2012, 12:53 PM

Quote:

Originally Posted by rkpatt

I have been given a factory new R4 for a GM car . I will be using it in 1983 Mercedes 300SD . It is my understand that the R4s for that Mercedes is configured differently -

Karl on usenet said - " A word of advice on buying a replacement compressor: Any one you get that does NOT come from Mercedes will have the front bearing cover installed UPSIDE DOWN. Look at the cover on the front behind the clutch. It will have 4 bolts. Between 2 of the bolts will be an embossed X. This is the position of the oil hole to lube the front bearing. The R4
compressor was originally designed for GM cars with the compressor mounted
on top of the engine. The X and the inlet/outlet port is UP. Mercedes used
the compressor but rotated it 180 degrees and mounted it under the engine.
This put the ports DOWN. Then they rotated the front cover so the X is UP.
Oil does NOT flow uphill. If you use an aftermarket compressor with the X
down, you will starve the front bearing of oil. It may last a week, a month,
6 months.... depends on the quality of the bearing they put in "

I want reconfigure this compressor so it will last . Can it be done somewhat easily . How do I get it apart to rotate the front plate 180 deg and back together not damaging anything. I really need some help . - Thanks

Just want to ask if the OP was able to do the job.

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