Author Topic: Adjust SG AC Clutch (intermittent AC problem)  (Read 581 times)

April 22, 2017, 11:49:13 AM
Read 581 times


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Ever since owning my 2004 XS, I have had intermittent AC.  It would work fine initially and then after around 20mins would no longer blow cold air.  Although irritating, I never really delved into the problem and left it as is.  After a recent 3000km+ road trip, where there were some hot days, this became an issue.  I noticed that although the AC compressor pulley was turning, the clutch seemed to slip at times.  Having decided to try and correct this before digging deeper, I searched the web and found a thread on where the clutch was adjusted without any special tools.  I decided to write a tutorial for this forum in the hope that it might help someone with similar issues. 

Some notes.  When referring to left and right I use my position standing in front of the car looking towards the car as reference.  Although the task is relatively simple, you do this at your own risk. 

Difficulty: Easy
Duration: 45mins

Tools required:
8mm spanner
10mm spanner
10mm socket
Ratchet for socket
Feeler gauge (may not be required if you want to wing it)
Old screwdriver
3x M5x35 bolts 1mm thread pitch (I used 40mm, 35 would be better)
1x M6x40 bolt (again 35 would be better, but you take up any additional length using washers)
~13x washers to fit the M6 bolt
Magnetic dish for bolts and nuts (not crucial, just makes it easier)
Beer or preferred beverage.

First we start off with the SG XS engine bay.  The AC compressor is located bottom right on the photo, with a plastic cover over it.

The plastic cover over the pulley must be removed.  Use 10mm socket on the bolt on the left and 10mm spanner on nut on the right.  The cover then simply slides forwards and up.

As mentioned, I use a magnetic tray to keep all the bolts and nuts together, but really not necessary.

You now have access to the clutch and pulley.  What we will be doing is to first loosen the nut keeping the clutch in position, and then using the clutch plate as a type of strong back to pull itself off the shaft.

The bolts that we will be using.  The three M5 bolts will be used to pull the clutch off, while the M6 bolt will be used together with a stack of washers to pull it back into position.

First insert only two of the M5 bolts, using the inner pitch circle of holes.  See below.  Only let the bolts enter the threaded area and not extend beyond the clutch.  I tightened mine in all the way, and with the rotations during removal of the M6 bolt scratched the pulley.  Its not serious but rather prevent it by inserting the M5 bolts only until they are fully threaded.   

Insert a screw driver between these two bolts to prevent the clutch from turning and then loosen the bolt that keeps the clutch in place with a 10mm socket.  The photo only for illustration to indicate the method to be followed.

Bolt removed and the M6 that will be used to pull it back in next to it.

Insert the third M5 bolt and screw all of them in until they press against the pulley body.  They should all be threaded in equally.

This is the initial gap between the pulley and clutch.

By tightening these three bolts alternately, we will pull the clutch of straight.  This is the critical part of this task.  My suggestion is that less than one turn per bolt, then move onto next one, continuing to tighten each one in turn.  It is critical that you do not get hasty and try to tighten each one too much, as you risk pulling the clutch skew and then you are on your own.  Slowly but surely the clutch will move away.

At this stage I realized that by removing the radiator overflow bottle I gain some space to work.  Just remove the two top bolts with a 10mm socket, pull out the overflow pipe and put the overflow bottle somewhere safe.

Eventually the clutch will be out.  Be careful when pulling it from the shaft, the shims will fall out.  Make sure you grab both of them.  The whole idea of this task is to remove one of these shims, effectively moving the clutch and pulley closer together, compensating for the wear on the clutch.

The pulley face exposed.  I used this opportunity to remove some of the dirt accumulated over 13 years (photo taken pre cleaning).  Note the scratches as mentioned earlier. 

One shim removed. 

Now its time to refit the clutch.  Slide it into position and press it in.  It has splines so should align easily.  The X marks one of the threaded holes that I spoiled when pulling using the M5 bolts.  Watch out for this.  I will rethread it at a later stage.  Remember the shim goes onto the shaft before you fit the clutch!

Use the M6 bolt and stack it with washers, then fit it into the threaded hole where the holding bolt originally fits.  Play around with the amount of washers until you have enough to allow the thread to engage, but not have such a large gap that you end up having to turn the bolt in significantly before it starts pulling the clutch.  Too little washers and you also risk bottoming out the bolt before the clutch is fully in position.

Tighten until the gap between the clutch and pulley is roughly 2mm, then remove the bolt and washers.  You can now refit the original bolt.  Also fit the two M5 bolts again, we will be using these again to keep the clutch stationary while tightening the bolt as we did when removing it.

The workshop manual does not provide a tightening torque for this bolt, but does provide clutch gap limits of 0.3mm to 0.6mm, so I just went for a gap of 0.4mm.  Measure around the pulley using your feeler gauges.  Unfortunately I did not measure the gap before starting this task.

Refit the plastic cover and the overflow tank.  And you're done, now go test it.  After testing mine I found it to be working perfectly.  Very happy with the results of such a quick and cheap task.

I hope this is of assistance to someone else as well.

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