I have a 67' 420 and I assume front end is the same as the cars in this forum so i posted here.

It looks like the bottom outside of the caliper is rubbing against the rotor. I have tried tightening all the bolts but I still cant get a sufficient gap inbetween the caliper and rotor.

Its unfortunate because I got new rotors and pads 6 months ago, then I started getting the scraping a few weeks ago, which has now scored the rotor pretty bad.

It appears the caliper is held in place by two bolts. Maybe I should loosen the top one, tighten the bottom some more, then retighten the top?





Anyone have any clues? Bad hub, bearing?

 

Hi 2000CAXK8

It's a long time since I worked on a '67 car, (I rebuiilt my '67 Mark 2 from a bare shell 1981-88), but one thing I do remember, is there were instructions on centralising the caliper on the hub carrier to make sure the gap between disc and caliper is equal both sides. Jaguar supplied shims to allow mechanics to set up the calipers when new discs had been put on.

Essentially this process was needed as production techniques for producing the discs were not as precise as they are today, Can you imagine a modern production line having to set up the caliper fitment on the line ? Doing it takes at least 15 minutes per caliper if not more !!

 

Well gentlemen, this is no longer a DIY job. I took it to a brake shop today and they looked it over. They quoted me 2 rotors, 4pads and all new bearings. The guys told me the bearings were wobbly. I had driven in with a slight scraping noise, and figured "oh ill order the parts this week and do it myself"

Unfortunately as I was leaving I got about 1/2 mile from the shop when I noticed an extreme drag on that tire. (keeping it under 20mph of course) The tire is now kicked outwards at about 25 degrees. I'm afraid the shop I took it to did not tighten the castle nut on the spindle enough and the hub walked its way outwards. I have no idea how much damage was done by driving the car an 1/8 mile with the wheel crooked, but it sounded awful. I left the car at a foreign shop that was within crawling distance.

Sadly, im pretty sure I have no financial recourse against the shop that did the initial dis-assembly and estimate.

Cliff notes:
I own 2 jaguars, now I get alot of exercise walking.

 

Well I reckon you do have recourse because they seem to have reassembled the job incorrectly.

The 'castle' nut is not supposed to be done up tight, it should be tightened up to a point when there is no play in the bearings then backed off until there is 1 or 2 thou play in the bearings. Nut is then secured in position by a split pin. Seems the shop failed to put a new split pin in, so the nut just unturned as you drove home. Did they put in new discs, pads and wheel bearings ? The bearings will no doubt now be shot due to this mechanics error, so you are probably now looking at needing : -

- new stub axle - I think the XJ6 1968 stub axle is the same
- new bearings - two of these, one large, one small - see above
- new grease seal - see above
- replacement (used) hub - there won't be any new ones around now for a '67 car. This might be the same as the XJ6

plus of course, the discs and pads you already needed. The worn bearing would seem to have caused the original trouble.

 

I guess I should Update... For those that already read the above posts, The initial shop did NO disassembly. They claim they only shook the tire to know the bearings were bad.

I ended up going to an independant foreign mechanic who put in 2 new bearings, 1 used pad and buffed the rotor grooves back to semi-smooth. The hub and spindle were not destroyed. He didn't jerry-rig it because I was cheaping out; He believes these fixes to be safe.

I've put maybe another 500 miles on the car since the bearings had failed and its driving fine. Initial shop wanted 800$ foreign guy did the work for 200$

p.s. he quoted me 2,000 to replace rear IRS rotors and pads, and to rehab the differential while the basket is out. I still might tackle that project with a friend.

 

If you have a shop with little or no Jaguar experience tackle the rear calipers and discs on a 420, be sure to provide them with a shop manual as the calipers need to be centred on the discs by means of shims either in front of or behind the brake disc. These shims can also affect the rear camber, so the job must be done with some expertise and caution.

In addition to securing the castellated nut on the front spindle(s), did the shop also renew the safety-wire on the front caliper bolts if the caliper was removed? The front calipers also have shims between the caliper housing and the spindle to obtain the correct angles for the calipers to reduce brake pad wear.

NBCat

 

My front psgr side rotor split yesterday tire was held on only by castle nut, very lucky that I made it to the garage. Spindle was not damaged but I need new
rotor,and all attached pieces and of course new pads and bearings, also new brake
fluid line as it melted due to the heat. I am doing both front brakes but want to try
to understand how a rotor can split like that. I do a lot of highway driving and usually
have my family in the car, so I am concerned. THis time I was lucky, the guy told
me to buy a lottery ticket thats how close the tire was to falling off and I had driven about 40 miles. So my question is WHAT happened to cause this, I don't remember
hitting a pothole or otherwise banging the front end. Thanks to all.
Maria

 

First, I would not go back to the guy who told you to "buy a lottery ticket", you don't need smart-aleck baloney when you are trying to repair your car. Find a professional mechanic, not a clown. Had it been me, I would have left the shop and told him, "I'll let you know if I win the lottery".

maybe the rotor split because it overheated and the metal was fatigued due to extreme expansion/contraction. I think you should replace rotors and wheel bearings in Pairs, any part that you replace in the drive-train including tires, pads, brake fluid lines, tie rods, etc. should be replaced in pairs. that's how I do it when something fails in my Jags.

if one wheel bearing or rotor failed, the opposite side might not be far from failing. It's a balancing act, literally. Yes sometimes it's a matter of economics, but Brakes are not an item to save money on, your life is dependent on them. Do it right.

for good quality Jaguar parts and decent prices check with SNG Barrat USA store:

SNG Barratt - Home

 

The fact that a mechanic tried to inject a little humour into a serious situation does not make him incompetent. It may have been his way of highlighting the seriousness of the event, or calming the customer.

His proposed scope of repair seems well within the the scope of the preceding posts.