XJ6 & XJ12 Series I, II & III 1968-1992
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Front Sub-frame removal

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  #1  
Old 05-09-2019, 01:08 AM
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Default Front Sub-frame removal

OK!

I'm I the process of assisting a friend fixing a leaky sump on a 1981 series 3 XJ6.

We realise the front subframe has to come out to remove the sump and are well on the way.

After detaching the rack, we've hit a seemingly insurmountable hurdle with the engine mount under the intake manifold.

How in the name of all that's holy does one access the 9/16ths AF nut that attaches the engine to that mount without removing the intake manifold??

I'm no stranger to old car mechanical work, including some very recalcitrant French cars, but this is one challenge that has caused me to go into my house & open a bottle of good red wine & ponder the situation:

1. I can't see the nut to undo it.

2. It so tight that I can't get a long enough spanner on it to loosen it.

3. If I do somehow manage to remove it, how in God's name do I get to restart it on re-assembly?

We look forward to replies from others that have walked this path before us.
 
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Old 05-09-2019, 04:05 AM
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It's a long time since I took out an XJ6 engine, (like late 80s), but but if you take out the radiator, access is fine. Yes, Jaguars are like that !! Just look at a Mark 2 if you want to see restricted access.
 
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Old 05-09-2019, 04:33 AM
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I removed the subframe last spring for suspension work. Can't speak to how tight your bolt is and I concede that it isn't easy but it can be done.

You take your wrench and do it all by feel. You need to move the amplifier and approach from the front under the manifold. Put the wrench on the bolt at 90 degrees to the engine and turn a tiny bit at a time.

Putting it back on is no treat either, but basically is just the reverse. There is a write up in jag-lovers.
 
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Old 05-09-2019, 04:45 AM
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A 9/16ths ratchet spanner is a big help.
Amazon Amazon
 
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Old 05-09-2019, 06:48 AM
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Thanks Greg!

I have a set of metric ratchet spanners and a 14mm just fits a 9/16ths nut.

Its now 2150hrs where I am so I'll try again in the morning.

Getting the nut back on will be a bridge I cross later on.
 
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Old 05-09-2019, 08:49 AM
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You really only need to swing the subframe down. Leave the front mount bolts loose and they will 'hinge' so the pan is accessible.

The car does need to be high (I use a lift).

bob
 
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Old 05-09-2019, 02:31 PM
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Originally Posted by motorcarman
You really only need to swing the subframe down. Leave the front mount bolts loose and they will 'hinge' so the pan is accessible.

The car does need to be high (I use a lift).

bob
Bob, thanks for the tip. That's some impressive Jag history that you have!

We have the car 20 inches off the ground measuring at the wheel hub.

Are you suggesting we can we leave the attached paraphernalia (rad hoses etc) attached and swivel the frame down with the motor still attached so as to access the front mount? Or are you referring to when we take off the sump?

I suspect it's the latter!

Assuming we can remove that swine of a 9/16ths nut with a ratchet spanner, I'm going to put an aggressive taper on the mount's stud so that when I replace the nut it will just drop on the conical bit of the stud & I can twiddle it to start the thread then finish with a spanner
 
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Old 05-09-2019, 09:01 PM
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Success with the engine mounts!

The ratchet spanner worked fine EXCEPT once the nut came up a bit, the spanner would not release until the nut was completely free. And it was a 2 handed job to stop it freewheeling as it got near the end. We will use plain nuts to re-assemble with flat & shakeproof washers. I have thick forearms & man it was tight under the manifold!

NOW! what are the tips to release the front mounts. They are unbelievably tight.

We are thinking a 3/4 drive 1&1/8th socket with the levering arm on the floor then using the cars weight by lowering it onto the lever.

Thoughts??
 
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Old 05-09-2019, 09:10 PM
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The engine needs to have a 'cross-bar' mounted to the wings so the the motor mounts can be disconnected and the entire subframe can be 'hinged' to swing free.

I have not done this in 25 years or so but I used to do this regularly when the front crank seals or the pan gaskets needed replacement.

I think that the steering rack can be left connected to the subframe as long as the column is disconnected and marked for orientation. Been a long time but if I were to stand under the car, it would all come back to me.

I bought my first Jaguar (1966 'E'Type coupe) in the early 1970s. Several MGAs, A 1963 BSA A10 and a Triumph TR4A IRS before I found the Jaguar. Never looked back.

bob
 
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Old 05-10-2019, 07:13 AM
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Jaguar shops used to have the factory tool to support the engine whilst the subframe was out. It rested in the channel where the hood dropped down onto the wings. I made my own up using some Dexion angle pieces, and some wood to rest on the channel so the paint didn't get damaged.

https://www.dexionstore.co.uk/dexion...E&gclsrc=aw.ds

You can probably get similar stuff in the USA
 
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Old 05-10-2019, 03:25 PM
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Available at Harbor Freight, but not displayed on the floor. You have to ask for it.
Engine Support Bar.
Sits as shown, in fender channels. Infinitely adjustable.
Without this little toy we would Never have got the front suspension refurbished.

(';')
 
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  #12  
Old 05-10-2019, 04:39 PM
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Yes!
We have the garage equivalent of a sky hook in place.
We didn't use the sling function as the sump has to come off. By some miracle, I had a length of identical all-thread on hand so I welded on (with extreme prejudice) 2 bits of a D-shackle & engaged the front hook with a block with a block & tackle on the rear hook as insurance.
I am acutely aware that this damn thing weighs nearly as much as 6 (six) Dauphines

OK! Throw me some pearls of wisdom on how to release those big bolts holding the front of the subframe in!
 
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Old 05-11-2019, 12:03 AM
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Originally Posted by geodon



Yes!
We have the garage equivalent of a sky hook in place.
We didn't use the sling function as the sump has to come off. By some miracle, I had a length of identical all-thread on hand so I welded on (with extreme prejudice) 2 bits of a D-shackle & engaged the front hook with a block with a block & tackle on the rear hook as insurance.
I am acutely aware that this damn thing weighs nearly as much as 6 (six) Dauphines

OK! Throw me some pearls of wisdom on how to release those big bolts holding the front of the subframe in!
Get the weight neutral, as in No Stress on those bolts, and simply tap them out.
Keep track of what goes where and in which direction.
Be sure not to lose washers if you have any.
Gather up your courage and Just Do It.

If I've forgotten to mention something important, someone will be sure to jump in and make correction.
(';')
 
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Old 05-13-2019, 03:13 AM
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Default Attacking the big bolts



The bolt heads were held with a 1 & 1/8th socket and a cheater pipe locked on the floor. The nuts were loosened with a ring spanner turned with a garage jack, 1-2 flats at a time until a ratchet could be used. The bolts are soaking in penetrating lubricant prior to being hammered out.
 
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Old 05-13-2019, 09:49 AM
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Yeah! That works!
(';')
 
  #16  
Old 06-06-2019, 10:59 PM
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Default Holy Moley what a journey!




Well it came out nicely allowing us to remove the sump.

The sump gasket was in a dreadful state with evidence of foul play insofar as heaps of silicon sealant; someone had done a shoddy job the last time it was off.

The return journey had its moments especially with the rack mounts and those damn engine mounts. At one stage, on the difficult side to boot, the engine mount nut was tightened down but we could not get the ratchet spanner off! We had to resort to jacking up the engine on one side then the other to get the stud on the mounts equidistant in the slots in the brackets so the spanner went on & off cleanly.

We have some queries:

1. New mounts were fitted & it APPEARS the clearance between the bottom of the sump and the crossmember has narrowed. Can anyone suggest what the clearance should be? Yes there were some big round washers on the old mounts & they were replaced as we found them.

2. Fitting the calipers. Could someone please post a photo of how the various brackets that hold the pipe & the shield are fitted? I should have taken a photo but forgot. The calipers are so damn heavy, it ain't easy to play around with them until the correct juxtaposition is found.

*Don't be alarmed at the rusty disc. The frame was out in the weather for a weeks or so & got wet. It cleaned up fine*
 
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Old 06-07-2019, 01:17 AM
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By the way, when you put those Giant bolts back, if you put a little Anti-Seize on them, they go in a Lot easier.

Tomorrow I'll post pictures of caliper mounting hardware. It's a bit late at my house now and Rhine has set in.
(';')
 
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Old 06-10-2019, 12:57 AM
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Ok

I THINK this is how they attach.

The caliper is held in by one long (lower) & 1 short bolt. These are the two that are staked with wire.

The 2nd short (inboard) bolt attaches to the stub axle independent of the caliper & serves to hold the disc dust shield & the bracket supporting the brake line.

Have I got it right??

I'm mystified why they use such a heavy duty bolt for such light duties as holding a couple of brackets. It also almost seems there should be a spacer between the stub axle & the brackets.
 
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Old 06-10-2019, 05:16 PM
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WOW! Time REALLY flew!
I have relatives visiting so I'll use them as my excuse for leaving this hanging so long.

(';')
 

Last edited by LnrB; 06-11-2019 at 02:18 PM.
  #20  
Old 06-10-2019, 05:25 PM
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Excellent! Thank you! The factory workshop manual was not this helpful.

So No1 & 3 bolt the steering arm and caliper to the stub axle?

No2 attaches just the brackets for the pipe & dust shield?
 


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