A/C Compressor Pulley bolt - fell off!

[SteveS]

Was working on the truck this afternoon with the engine ticking over nicely....after a few minutes I heard a strange noise.....essentially the a/c compressor pulley was working its way off of the spindle and impacting with the plastic fan blades. Luckily I was able to stop the engine before any damage done.

So the question.....of course I can't find the bolt....I've no idea when it fell off. Is there anything special about the bolt (ie shouldered, LH, short/long, special washer etc? What is the torque setting for it?

I looked at a FSM and the a/c unit there is shown in a different place on the engine.....possibly the V8 version. However, it shows a number of shims and circlips which appear to hold (that version) of compressor pulley on. Does anyone know whether the pulley is supposed to easily slide off the spindle when the bolt on the end is removed......I'm wondering when I take the pulley off if there is more wear/damage I should be inspecting for.....ie knackered/broken circlip.

Does the pulley bolt need any thread-lok on reassembly?

All help gratefully received.

 

[Sag]

Glad you spotted it before it came off,now that could of caused a right mess.

 

[frank rabbets]

The bolt is 10mm head with 20mm thread all the way up. It just holds the outer clutch plate with the rubber. It does not hold the pulley on. With the bolt missing you should be able to slide the clutch plate off but don't loose the shim washer inside. In fact put a tray beneath in case it sticks to the compressor then drops off.. In fact I don't know why the clutch plate has not fallen off. With the clutch plate off you should be able to see a circlip holding the pulley on to the nose of the compressor. If the pulley is in fact moving back and forth something is loose, broken or missing.

 

[SteveS]

The bolt is 10mm head with 20mm thread all the way up. It just holds the outer clutch plate with the rubber. It does not hold the pulley on. With the bolt missing you should be able to slide the clutch plate off but don't loose the shim washer inside. In fact put a tray beneath in case it sticks to the compressor then drops off.. In fact I don't know why the clutch plate has not fallen off. With the clutch plate off you should be able to see a circlip holding the pulley on to the nose of the compressor. If the pulley is in fact moving back and forth something is loose, broken or missing.

Thanks Frank - I put an M6/10mm AF x 20mm bolt in (I came to the same conclusion first thing this morning) - so this stops the clutch plate and the pulley spinning off. Ran the engine (without a/c engaged) and it is now OK to move. However, I understand your point about the circlip etc.....I think I will get a kit of bits (circlip, shims etc) from Toyota, disassemble the pulley and reassemble

I'll recheck that the whole pulley was moving out and not just the front face......it may have been that I thought it was the whole pulley not realising that the inner/clutch bit was a separate section to the pulley.....I'll take a look when it stops raining

 

[SteveS]

Thanks Frank - I put an M6/10mm AF x 20mm bolt in (I came to the same conclusion first thing this morning) - so this stops the clutch plate and the pulley spinning off. Ran the engine (without a/c engaged) and it is now OK to move. However, I understand your point about the circlip etc.....I think I will get a kit of bits (circlip, shims etc) from Toyota, disassemble the pulley and reassemble

I'll recheck that the whole pulley was moving out and not just the front face......it may have been that I thought it was the whole pulley not realising that the inner/clutch bit was a separate section to the pulley.....I'll take a look when it stops raining

OK - braved the rain.....loosened the bolt and was able to wiggle the inner section but the pulley did not have any back/forth play on it - I think therefore that the main pulley was OK from the outset and the circlips etc OK too (good!)......just the clutch plate that was working its way off and hitting the fan blades.

Frank - any idea on the torque setting for that bolt? Does it need any thread-lok or a locking washer - I just put a large plain washer on temporarily

 

[frank rabbets]

10 ft lb Steve. You need a clean thread and a smear of Loctite but that is not essential.

If I were you I would take the belt off and take the bolt out and slide the clutch plate off without loosing the shim. Then you can check the condition of the circlip. The circlips are tapered in cross section and in theory keep tightening into the parallel groove in which they run but it's best to check and close the eyes together firmly which wedges the circlip firmly. They ARE a weak point and if come loose ruin the compressor which will run a long time without you realising. Then assemble. Then check the pulley spins freely with the bolt done up. If the pulley is stiff you will need a thicker shim.

The pulley should run on a true axis with the aircon engaged. If the pulley is wobbling sideways with aircon engaged this means the circlip has been running loose for some time and has worn the aluminium front nose of the compressor.

I'm in tonight.

 

[SteveS]

10 ft lb Steve. You need a clean thread and a smear of Loctite but that is not essential.

If I were you I would take the belt off and take the bolt out and slide the clutch plate off without loosing the shim. Then you can check the condition of the circlip. The circlips are tapered in cross section and in theory keep tightening into the parallel groove in which they run but it's best to check and close the eyes together firmly which wedges the circlip firmly. They ARE a weak point and if come loose ruin the compressor which will run a long time without you realising. Then assemble. Then check the pulley spins freely with the bolt done up. If the pulley is stiff you will need a thicker shim.

The pulley should run on a true axis with the aircon engaged. If the pulley is wobbling sideways with aircon engaged this means the circlip has been running loose for some time and has worn the aluminium front nose of the compressor.

I'm in tonight.

Thanks Frank - for the sake of a few quid (although knowing the price of bits from Toyota probably more than I expect) I'll get a few of the minor bits on order- then do the job once and properly. I've read your other post on the a/c refurb you've been going through which is most useful. Thanks for the tip on the circlip. I'll investigate the a/c on/off running to see if it exhibits any of the symptoms you describe

Thanks for your help

Steve

 

[frank rabbets]

The clip must go on the right way round. It is flat one side and concave on the other. The concave side goes out, facing you. So you are looking at the back of a shuttle cock shape.

 

[SteveS]

Checked the pulley today and it is running true and has no play in it. Torqued up the temporary bolt and run the a/c. The clutch locks ok.....so I can now get the right replacement part on order. Thanks for the help Frank