Air-con compressor magnetic clutch change (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

wildsmith

SILVER Star
Joined
Jun 8, 2005
Threads
14
Messages
773
Location
Hampshire, England
The air-con compressor magnetic clutch pully had got very noisy on my truck and I changed it today so I thought I'd share, sorry if it's already been covered but I couldn't find it.

With the front under tray removed (can't really call it a bash plate can you!) access to the compressor pulley and drive belt tensioner is not too bad. These pictures are taken looking up from under the radiator.

The drive belt tensioner has a 14mm head bolt, turn it anti-clockwise to release tension and it's spring loaded so it returns to the tensioned position as you release the pressure, very easy:

IMG_0699.JPG


The outer part of the compressor clutch, what I'm going to call the drive plate, is held onto the splined drive shaft of the compressor with an M6 bolt through the nose. Remove the bolt, you'll need to hold the drive plate to stop it turning, I used a screwdriver. The hole in the end of drive plate has an M8 thread so instead of buying the SST just turn an M8 bolt into the hole and it will push the drive plate off the shaft, very easily in this case, leaving the pully assembly exposed:

IMG_0705.JPG


The red arrow is pointing to where there's a circlip. Unfortunately you can't get a very good view of it but with the help of a mirror on a stick and a bit of patience I managed to get it off undamaged. The clutch 'assembly' I'd bought from Toyota didn't include a new clip even though it's supposed to be replaced so it was important not to distort the old one. Once that clip is off the pully assembly can be persuaded off with careful prying with a screwdriver or a really short puller if you have one. With the pulley off the magnet is exposed:

IMG_0700.JPG


The red arrow is showing the groove the clip sat in. The magnet is also held on with a circlip but as that's working fine I left that alone rather than struggle with another clip. These are the old bits at the back, new at the front:

IMG_0703.JPG


The red arrows are showing the circlip and where it goes, the green arrow is showing a small shim and where it goes. According to the EPC there are different sizes of shim but it wouldn't give me part numbers. I checked the clearance of new to old parts and it looked like the existing shim would be fine so I just put that back in. The bearing in the old pulley was very rough and wouldn't have lasted much longer BTW.

I put the new pulley on, installed the clip using my mirror on a stick to make sure it was properly seated, and re-installed the drive belt so I could start the engine and check everything seemed ok so far which it did. Then just push the drive plate back onto the drive shaft and re-fit the bolt that holds it on, job done and it's nice and quiet again.

I used part no. 88410-60440 and my truck is an 2001 UZJ100 with single aircon. The dealer had to order 3 different assemblies to find the right one because the EPC wouldn't tell them which part to order, just kept saying 'not applicable" !
 
You have no idea how happy I was when I read this.

I was going to replace compressor because i thought it might be going out although AC runs strong. Now it makes much more sense.

I'll do this when I do 90k maintenance very soon. Curious. How much was the total cost for this?
 
I'm in the UK so I'm not sure how much my costs will help you but the clutch assembly was £340 from a local dealer. If there hadn't been doubts about which part number I needed I would have shopped around but when the dealer gets 3 parts in for me to see which I need it only seems fair I buy one of them :D

I could have just bought the pully, that's all that needed changing and it would have cost a lot less but I'd never done one of these before to know what to expect so I got the whole thing. My symptoms were no noise with the compressor running and lots of noise when the magnetic clutch turned off.
 
Nice write up!

I was going to replace compressor because i thought it might be going out although AC runs strong. Now it makes much more sense.

What are the signs that the compressor is bad if the AC is running strong?
 
Nice write up!

What are the signs that the compressor is bad if the AC is running strong?

So it may not be my case. The belt whines when turning corners when I run A/C. When I turn off A/C, the belt does not whine. That how I got to my conclusion it is A/C compressor that causing strain on my belt system.

Wrong?
 
Only one thing, especially with a new clutch, to get it to last for the longest time and function the most reliably you need to set the gap correctly between the pressure plate and the rotor with the shim washers.
Standard clearance:
0.5 ± 0.15 mm (0.020 ± 0.0059 in.)
Shims come in .1, .3, and .5mm
You may be able to use feeler gauges on yours, not sure, I set mine up on the bench with a dial gauge.
 
So it may not be my case. The belt whines when turning corners when I run A/C. When I turn off A/C, the belt does not whine. That how I got to my conclusion it is A/C compressor that causing strain on my belt system.

Wrong?

Those symptoms could probably point at a few things loading up the belt - something wrong with air-con compressor, something wrong with PS pump, something wrong with belt tensioner. I'd check the belt tension first if it was me.

Only one thing, especially with a new clutch, to get it to last for the longest time and function the most reliably you need to set the gap correctly between the pressure plate and the rotor with the shim washers.
Standard clearance:
0.5 ± 0.15 mm (0.020 ± 0.0059 in.)
Shims come in .1, .3, and .5mm
You may be able to use feeler gauges on yours, not sure, I set mine up on the bench with a dial gauge.

I'll have to track down some part numbers for those shims but at least only the drive plate has to come off to adjust that, not the circlip :)
 
The 3 shims come in a packet together 88335-14020 don't remember the price though
 
So it may not be my case. The belt whines when turning corners when I run A/C. When I turn off A/C, the belt does not whine. That how I got to my conclusion it is A/C compressor that causing strain on my belt system.

Wrong?
As noted in previous post, many possibilities, if your tensioner is OK, check your belt first for signs of glazing, wear, cracking.............if any, put a new belt on, but first get a tooth brush and a tin of spray carby cleaner and scrub the grooves on each and every pulley before putting your new belt on. See how you go then. (Check PS fluid as well)
 
I replaced new belt not long ago. Only thing causing it to whine was when I turn on the A/C. When off... everything nice and quiet. Now you're saying it may not be A/C but something else as well?

Nice write up!



What are the signs that the compressor is bad if the AC is running strong?

Those symptoms could probably point at a few things loading up the belt - something wrong with air-con compressor, something wrong with PS pump, something wrong with belt tensioner. I'd check the belt tension first if it was me.



I'll have to track down some part numbers for those shims but at least only the drive plate has to come off to adjust that, not the circlip :)
 
The belt whines when "turning corners" when I run A/C.

This is why all the other things are mentioned. This loads up the PS pump, so it could be faulty, or your compressor could be faulty or your tensioner could be faulty.
 
This is why all the other things are mentioned. This loads up the PS pump, so it could be faulty, or your compressor could be faulty or your tensioner could be faulty.

All right. I'll figure this out when I do 90k. Sorry to have hijacked the thread. I didn't mean to.
 
Oh and I can comment on how not to do this job. Be very careful removing the clip. I wasn't and the part that holds the clip cracked and so I needed to buy a whole new compressor.
 
Thanks for the writeup! I'm not positive if I will need to do this, but the reasons why I think I might: noise from the engine that sounds like a bad pulley, and when I have the AC on cold with the compressor and blowers on it simply blows hot air. Does this sound like the clutch or clutch and compressor?
 
Thanks for the writeup! I'm not positive if I will need to do this, but the reasons why I think I might: noise from the engine that sounds like a bad pulley, and when I have the AC on cold with the compressor and blowers on it simply blows hot air. Does this sound like the clutch or clutch and compressor?
Blowing hot air doesn't sound like a simple bearing problem but it could be a clutch problem, the compressor, not enough gas or a combination ...
 
I think this pulley may be the source of a noise that started on my 100 today. It's a loud grinding/rumbling sort of noise. When driving it comes on under acceleration, going quiet again as I ease up on the throttle. Turning the aircon off brings the noise on. Revving the engine quite hard with the gearbox in neutral or park brings it on. I hear it for a second or so as the engine stops after turning the key off.
What do you think guys, is it the aircon compressor pulley bearing, or is something else possible?
 
IMG_1906.JPG
In daylight the problem was fairly obvious. The rubber part of the coupling has failed and part of the coupling is loose.
I'm thinking that maybe the compressor has siezed because I can't turn the shaft. I put a socket on the M6 bolt in the end of the shaft and tried to turn it, but it wouldn't budge with as much force as I dare put on the M6 bolt. But I don't know how hard it should be to turn when still plumbed in with the system charged up?
Image shows the coupling and the loose part which I've removed.
There is no noise now. Will it be OK to run the car like this until I get it fixed? Or could what's left of the coupling fall apart?
 

Users who are viewing this thread

Back
Top Bottom