When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just kidding - driving a 25+ year old car on a daily basis, well, it does have it's ups and downs.
Latest quirk is a slight (what I thought was) belt noise which over the last couple of weeks has gone from a slight tinkle at startup to a fairly embarrassing metallic ding-ding-ding-grind-crunch sound.
Fortunately the racket does diminish somewhat under load, but at idle, pedestrians strolling by tend to give you the bewildered raised eyebrow. Quite a change from the usual admiring glances the VDP usually gets.
Investigating, the first thing I noticed was that the compressor belt was way slacker than it should be, and as I'd fitted that new belt about 9 months ago was surprised to see it had slackened off to that extent. Anyone who has adjusted the compressor belt tension on one of these 40's knows that it ain't just one bolt that adjusts these puppies, Jaguar decided to nail these things on with about half a dozen.
Getting a second opinion from my pal, we decided that the clutch bearing on the compressor had given up.
The compressor is a Sanden SD7H15 compressor with a single V-groove clutch. I have a spare BTW.
So here come the questions:
Has anyone done this job (replaced the clutch bearing)?
What size is the bearing?
What size puller will I need?
Can the job be done without removing the refrigerant?
(I understand the compressor can be dismounted to get better access.)
Can I swap the entire clutch assembly with the spare from my parts car easier than replacing the bearing?
What is involved in swapping the clutch? Will I need gaskets/seals etc?
Interestingly, the a/c still works ..but boy, that noise!
Well good old YouTube has answered quite a few of these questions, looks like I can swap the clutch without draining the refrigerant.
The bearing is inside the pulley so I'll check the parts car and see if it's good or not - really, what I'd like to do is replace the bearing with a new one if I can find out the size.
The clutch on the parts car is also going to be pretty good as the mileage is significantly (75,000 miles) less than my daily. Maybe I'll swap that too.
Time for a new set of feeler gauges and a circlip pliers as well!
I replaced the compressor on our '93 and on other XJ40s, but haven't replaced the clutch on any, so I'm looking forward to your successful completion of the job and the photos.
Well Don, today has been an accelerated Sanden SD7H15 a/c compressor learning day - with mostly positive results.
After lunch, I dropped by the parts horde and located the other compressor. Tested the clutch and pulley for play and all seemed OK. Came back home and cleaned the parts compressor off and removed the locknut on the clutch. However, my clutch did not "pull off" like the chap in the video's did, but apparently needs a clutch removal (and more importantly) installation tool to do the job properly. The Sanden service manual .pdf was a big help in not messing up at this early stage by using the BFH.
Apart from the circlip pliers and feeler gauges I'll need, conveniently, a Canadian eBay seller has the (Made in China) service tool kit for rebuilding the clutch, bearing etc for a whole $30 Canadian (including express shipping) so it should be here next week.
Access is apparently a bit tight doing the re and re of the clutch and bearing with the compressor in place, but removing the mounting bolts (with the hoses still attached) and supporting the unit on a block of wood or whatever, apparently there is enough room to turn the compressor to a convenient angle for the rebuild.
All seems pretty straightforward but we'll see what happens when I jack up the car next week!
I'm not going to install a new bearing, just swap the assembly from parts car unit to my own. Might then rebuild the replaced unit with a new bearing at a later stage. Maybe!
Apart from the circlip pliers and feeler gauges I'll need, conveniently, a Canadian eBay seller has the (Made in China) service tool kit for rebuilding the clutch, bearing etc for a whole $30 Canadian (including express shipping) so it should be here next week.
Well, there's fast shipping and there's fast shipping!
Kit was bought Friday on eBay, arrived at 7pm tonight (Sunday!!) - WOW!
Now I just have to figure out what those two bearings are for (upper right) ....
Here's the parts unit and the toolkit, dry run coming up soon!
Sanden SD7H15 R134A compressor as fitted to 94MY cars
Clutch and V-belt pulley
Universal A/C Clutch removal/installation toolkit - suits Sanden and Harrison compressors
Larry
PS I just hope the noise is my compressor clutch and not the upper chain tensioner ..
PS I just hope the noise is my compressor clutch and not the upper chain tensioner ..
An inexpensive mechanic's stethoscope might help you confirm the clutch as the source of the noise. I assume you've tried turning the A/C on and off to see if the noise changes?
Don, the bearing is in the pulley not the compressor so even if the A/C is off (clutch disengaged) the V pulley (and thereby the bearing) is still active/turning.
Taking off the belt (pain in the ***) is probably the only way to stop the bearing moving ..I know I should do that and have many excuses as to why I haven't so far, but with nowhere convenient to work on the car any longer I have to plan where and when I can get her up on axle stands. Certainly not on the road outside my apartment!
Picking up a stethoscope tomorrow, thanks for the idea, Don.
Larry
Last edited by Lawrence; 07-28-2019 at 11:34 PM.
Reason: addl info
Taking off the belt (pain in the ***) is probably the only way to stop the bearing moving ..I know I should do that and have many excuses as to why I haven't so far, but with nowhere convenient to work on the car any longer I have to plan where and when I can get her up on axle stands. Certainly not on the road outside my apartment!
A new belt isn't expensive so why not just cut the old one?
Well I didn't cut the belt (yet!) but did pick up a stethoscope and gave it a shot.
Results were not what I expected - I probed several areas of the engine, timing chain tensioner, water pump, air pump, alternator and compressor and was no wiser after the tests than before - all seemed normal - in fact, once I put the scope to my ears I couldn't hear the metallic ringing any more ....
I should add that the sound is most noticeable at idle at first start from cold and gets progressively quieter as the engine warms up. If the engine is under load or revved, the noise eases up. Starting a warm engine, I still get the noise but much less than from cold.
BTW, the a/c clutch seems to be permanently engaged and I don't hear it cycle at all. If that is the case, (I'll check again) I'm going to swap out the stator as well as the clutch/bearing assembly.
I removed the clutch from the parts compressor and even with the toolkit, it is no picnic! That outermost clutch plate was pretty tight on the shaft and took quite a bit of elbow grease to get it to pull off. Add to that the fact that the circumference of the puller centre was way larger than the shaft aperture, there came a point where the puller bottomed out and I had to disassemble the puller and add a makeshift spacer (spare short philips head bolt; small enough to enter the shaft aperture and with a head that self-centres the puller...very finicky).
All the parts were a very snug fit and nothing came apart easily except the stator, which just pulled off with hand pressure once the spring clip was removed. The pulley and bearing however required several good taps with the dead blow mallet to get it moving and off. The bearing seems fine so I'm not going to replace it,
some pix:
drawing the clutch along the woodruff-keyed shaft with the specialist puller tool
The seven components of the Sanden a/c compressor clutch - clockwise from top - stator, pulley w/bearing, clutch face plate, 2 snap rings, shim and locknut.
2 suggestions you probably thought of and did already- Try running the car without the compressor and also check the compressor shaft for play. I had a compressor implode on me although I dont remember if there was any noticeable noise with it. Apparently the vanes in it came apart. This just occurred to me too- Maybe its your Air injection pump? Good luck.
Jerry, that'll be the first thing I do when I get her up on stands - take off the belt and see how she sounds. Pretty sure at this point it's the pulley bearing in the compressor clutch - the a/c still works fine so I think the compressor itself is ok.
Latest theory (guess!) is that the noise is from a shot bearing and a slipping clutch. Judging by the contact surfaces in the clutch, I can see how slipping could cause the metallic noise I'm hearing.
I guess if I pull the a/c relay and the clutch plate still spins, that'd kinda confirm my suspicions - especially as I've never (in quite some time anyway) heard the clutch engage/disengage. There used to be a momentary idle sound adjustment when the clutch engaged but it's been ages since I heard anything like that ...always thought it was weird, but as the vents pumped out plenty of cold I just thought "if it works, don't bother it"
Maybe tomorrow I'll be able to get the car somewhere to raise her up. Losing your workshop with a vintage daily driver can be a real hassle. I even have to get my shiny racing jack out of storage and into the back seat before I plan any work. Oh well, that's city life today I suppose ..now if I only had an bicycle I'd be on the good side of the city council instead of the enemy.
Reassembled the parts car compressor.. clutch not the problem after all.
Got the car up on stands today, took off a/c belt, noise still there. Took off air pump belt. Noise persists ...kind of an initial cold start scraping sound, then a metallic ding ding ding - only seems to be at idle, and disappears after car warms up, even at idle.
Tried mechanic's stethoscope, noise is definitely external to the engine, no component I probed relayed the noise -could only hear noise with the stereoscope OUT of my ears !
Only a few things left to check - alternator, water pump, harmonic balancer and maybe the belt itself? ...any ideas?
Maybe I'll start a new thread as the A/C clutch was a red herring -
Not radiator fan.... Could be loose water pump pulley.. Maybe something is laying on the alternator pulley/ in its guts?
Gets quieter when warm.... Not maybe an exhaust heat shield? Mine are rusty and loose, but i wouldnt describe it as a Ding noise....
Sounds like maybe a loose wire end flapping against a pulley? Or... imagining what could make a dinging noise on a stopped car..... Could either the exhausts be loose and hitting the rear suspension? or could the top shield things on the shocks be hitting something?
Very intriguing...... The world awaits in stunned silence....
The noise is definitely in time with the rpm's and again definitely in the front of the motor - On the 94, only electric fans so not the fans for sure but the other components have a 33-1/3% chance of being the culprit. Ill advised as it was with the engine turning over, I took the flat back side of my prybar and pressed on the belt and the sound disappeared.
Maybe something is laying on the alternator pulley/ in its guts?
Good suggestion, could also be the alternator bearing I suppose? I'll try to find out - might be next week though as car is back from "place where can do work"
I called Jim (manwich66) tonight and described the issue, he advised me to take off all the belts and see if any of those pulleys, WP, ALT or HB have any play.
You can often detect a failing alternator or water pump bearing by placing your stethoscope probe on the bodies of those components with the engine running, taking care to avoid touching the rotating pulleys.
For the harmonic damper, the standard trick is to paint a line across the pulleys and rubber section, run the engine, and check to see if the alignment of the paint mark has changed. My experience with separated dampers is that they tend to sound more like a loud loose belt screech at cold starts, which gradually subsides and goes away as the rubber heats up, which doesn't seem to conform to what you are hearing, but worth testing anyway.
Aligned or not (maybe It realigned the first time, kinda like winning at roulette?) now there is no doubt, the harmonic balancer is slipping.
We were revving the car this morning and I could see the pulley stop dead then re-spin. Oh well, at least I now know what the problem is …
07-26-2019, 10:08 AM
A/C Compressor clutch issue
