Sanden SD-507 a/c compressor & belt tension adjustment

Note of attention: SD5Hxx compressors, even though physically compatible externally, are not to be used on Ferrari V8 applications as they aren't designed to rotate backwards. Their noise-reduction helical gears will push in the wrong direction and self-destruct. Same applies to the variety of Chinese knock-offs. The Sankyo/Sanden SD-50x use straight cut gears and are therefore compatible with CW and CCW rotation.

 

What gears? There are no gears inside these compressors.

 

Some Sanden models have gears.

 

Not after they have self destructed...

 

All of them have.

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Interesting so what are those gears driving exactly? The drive for the wobble plate comes from the other side and the plate is supported on the thrust side by a large ball bearing in the center. I have never come across these gears when dismantling an SD507 or 508.

 

The green one is fixed and the red one maintains the wobbling plate in position (stops it from spinning) while it is being wobbled via the big ball bearing (blue), whose other side is turning on an inclined surface (yellow) via the belt drive.

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Ah OK, so there is no rotational movement. I think the older ones may have used some other method of preventing the plate from rotating.

 

Well, the red gear does rotate around the green one at the speed of the compressor.

I haven't heard of any change other than the change to helical gears to reduce compressor noise. The information re the new compressors not being allowed to turn backwards is from Sanden directly. It invalidates the warranty.
The gear drive change happened when R134a was introduced and the designation was changed from SD-5xx to SD5Hxx.
My SD-508 was cleaned and runs with Sanden's SP15 oil compatible with R134a, happily.

 

Hi there,

sorry to warm up this thread... My SD508 in my 3.2 Mondial may need some attention. At his point I am not sure, if the compressor already runs on R134a. The System has a leak and I am willing to overhaul the 508 or get a new one.

Sanden is not the biggest fan of a 508 R134a conversion, as it was originally running on R-12. See here:
https://www.sanden.com/objects/retro.pdf

So is it possible to reseal the 508 and fill it with SP-20 (@afterburner: Sure on the SP-15?) and be happy? Or is it possible to get a 508-Style compressor that is working with R134a?
I understand the the SD-5H14 is prepared for the R134a but can just run in one direction.

 

Good morning sorry for the late reply - busy here. R12 vs R134a: Theoretically you should be able to tell from the recharge connections and sticker on the receiver/driver.
But it doesn't matter if you overhaul the system as you'll be fitting new seals and receiver/drier anyway.

Unless your compressor has mechanically failed, I don't see why not overhaul it. New gaskets and seals are available, and they are solid machines.

I converted mine 35'000km ago and it keeps working flawlessly - knowing that AC is needed permanently here in HK.

Yes, done with success, I am currently using SP-20.

No, they have helical gears and will fail because of the running direction of our cars. Besides being made in China.

Correct.

 

Thanks for the quick reply... I just encountered that the current Delphi dryer shows R134a... So the system may have been converted earlier.
As AC here in Germany is not as critical as in HK I still have some time on my hand to look into the system...

 

Good the conversion was done that should make it easier. Before you order the replacement head gasket measure the OD of the head. There are 2 sizes (older and newer version from what I know). Have a look at my thread (post 387 etc) there is a section when I had to restore my compressor, which had spent 2 years outside on a shelf and it did show. It's been back on the car for over a year/10'000miles and works perfectly despite the "mistreatment" it suffered.

https://www.ferrarichat.com/forum/threads/some-tlc-for-my-qv.482046/page-4