Hi - I’m new to this site, but not to Jags!
I read somewhere that it is possible to replace the rear calipers on a series 1 (1971) without dropping the sub frame, but that practicality depends on the variant of diff casing fitted. Does anyone have any more detail or experience of doing this?
Thanks.
Frankie
See http://krissmotors.com/WP/2017/06/14/differential/
The early differential casings are virtually identical as far as I know; only final ratios differ, and that cannot be determined from the case. The rear calipers are difficult, but not impossible to remove/replace with the IRS frame attached. See also http://krissmotors.com/WP/2017/06/16/rear-inboard-brakes/
Hope that’s helpful.
Do not go that way. It is so easy to take down the sub frame so there is no point in spending time and bad language to do it on the spot. It can even be pitiful to do them with the sub frame on the workbench, for example, to get the locking thread right.
Look at this clip on youtube:
Janne
Hello,
I did this on a series III and it was tricky, but very possible and to me easier than dropping the sub-frame.
It is all here: [xj] rear caliper removal
Go to the end to see where I came in.
My main problems were
(1) Getting the caliper into pieces and out. It was all oxidised together and I did not want to force it apart and could not see what the problem was.
(2) Lining it all up and bolting it together when it is back up in the hole. I put all my tips on this at the end of the tread.
Not sure if this helps on a series 1?, but I hope so…
Neil
Having done this both ways, I sure would not attempt it AGAIN with the IRS in the car. The hardest part is getting exhaust pipe out of the cage…cut it and weld it back when done. This will give you access to the E brakes that probably need rebuilding/or a the minimum - new pads. Plus you can clean up the whole area
with the unit out of the car.
You have to have the car securely up in the air at least 18 inches off the ground and can use a piece of heavy ply wood (piece I used is in the photo) and a floor jack… one person can do the R&R but it is easier with two people. Be sure to block the front wheels both directions…
Be sure to replace the front two brake hoses and the rear one at this time… then bleed it properly.
What Roger said…
I would never have even considered doing that with rear end in situ.
The rear end is a brilliant design. If you require rear brake calipers no doubt you require much more servicing.
The mantra of preventative maintenance over if it ain’t broke don’t fix it has served me well in all my years of Jaguar ownership since I was a kid.
Jack up rear, be smart/safe. Remove rear wheels, place jack beneath diff. Disconnect driveshaft, brake line, and 2 bolts at each corner within wheel arches and you’re done. The entire unit simply drops down.
Now ALL is right there before you. Remove the cage and take care of everything.
It will ALL be DONE for a very long time.
Repack bearings at hubs, replace diff main seal, replace oil, clean out the diff perhaps too, etc…It really won’t take long at all, and you will not have this opportunity again so just do it all and go over everything.
Just lay everything out so you know how things go back together. Especially those thin shims on the brake disks. Just ape them together with masking tape and mark them so you remember. You can see them on above photo.
I’ve done it myself, alone, and replaced it alone, and I’m no whiz.
Took me a couple days as I’m a patient guy, and paint needs to dry.
As a note, for me, POR15 is my dear friend. Paint the undercarriage there and wheel wells.
With cage off those large, heavy lower arms are there free and easy to clean with a wire brush/steel wool and paint with a sponge brush.
Up to you if you wish to paint the “pumpkin” (differential) …but I would at least paint the cage with spray black rustoleum.
This is what I would do.
FWIW
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Diff fitted is immaterial, Frankie…
Dropping the sub frame involves manipulating a heavy and ungainly component - if you have the right tools; it’s good practice for a situation when the sub frame must be removed…
Replacing the rear calipers in situ is fairly straight forward, but access is awkward, particularly if problems with bolts are encountered. The bottom tie plate must be removed and the pads pressed back as a first step. Bear in mind that some operations necessary at the calipers is still be required with sub frame removal. And frame out you still have to remove the calipers…
The rear calipers are really meant to be removed with the cage in the car - prefer ‘fiddly, awkward’ to ‘heavy’. Your choice; assess and proceed…
Frank
xj6 85 Sov Europe (UK/NZ)
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it is possible, and much quicker, IF you are totally familiar with the setup, and have a hoist
I have watched an experienced Jag mechanic do this on XJ,
the handbrake calipers need removal, then the calipers can be unbolted and slid around, he did not split them prior to removal
the problem is to reassemble must be done largely with feel, not sight, thats where you may come undone, he has done it a thousand times.
I do know you need a couple of spanners cranked to exactly the right angle to get at the top caliper bolts and handbrake bolts
Thanks, Guys - what amazingly helpful responses!
I have a pit but not a lift and my working area is tight, so whilst I would remove/dismantle components in situ, I would find sub frame removal tricky. I have other issues as well - leaking differential output shaft oil seal for one, and the rear end could do with a full overhaul. As the advice is not universally positive for caliper removal with the cage in the car I guess it’s time to bite the bullet, do the job properly and spend some serious cash!
Frankie
