Sparky's winter/spring/summer/autumn work

First problem to solve, is the bracket doesn't fit snuggly on top of the diff, as the corners are too rounded, so I had to cut a section out so it would drop down a little. There's a bit of plywood in there in this picture to allow me to get it all positioned correctly.

Edit - hmmm - second problem seems to be my picture is on its side, and the bottom one is upside down o_O

IMG_4191.jpg

I don't have the facilities to bend 5mm plate at a right angle, so I just chopped a section of the same size out of some spare 50mm x 50mm which had a much sharper angle, and welded that in. Drilled the holes and got it fitted to the diff. I will be using different bolts as these are countersunk, but they'll do for the moment. I've taped the 7/16 bolts into the crossmember because they keep falling out when I'm trying to test fit it. I've also cut a couple of short lengths of 12mm ID tube to fit inside the crossmember for the bolts to go through, just as some support.

IMG_4207.jpg

I have worked out that the main bracket needs to run downhill at 3.6 degrees to a point just in front of the handbrake linkage, then drop 54mm to go underneath the next crossmember of the car. The two pieces are just tacked together at the moment as I have to bolt it into the car at the rear and check all the measurements before final welding. I found a piece of solid steel round bar and cut a piece long enough to fit across the main bracket. This was clamped into the vice to act as a former when I bent the bracket, with hammers, jumping on it, heating it etc. I won't weld the bottom of it until a final test fit to check the angle.

IMG_4227.jpg

The front mounting is sitting where it will go but I'm not sure which way it should fit yet :cool: The rear ones fit from the top, with the larger bit upward, and the front one fitted from underneath with the larger bit downward. I assume this is to counteract the torque twist of the diff.

IMG_4228.jpg

There will be a plate covering this, bolted through the crossmember. I don't want to weld anything onto the car, just in case I ever want to revert to original :rolleyes:

Next job is to fit the diff to the bracket and test fit (Again)

Richard
 
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Was it really March when I last updated this? :eek: I can’t remember what order I did some of this now.

Anyhoo, I did have a test fitting with the bracket and it does fit ok, well up and out of the way. The rear bracket beam is bolted into the original rubber mounts with new, shorter 7/16 high tensile bolts. The front isn’t attached yet so the jack is still under there, so I can find the best angle for it to point.

test fit 1.jpg

Room above so it won’t touch the underside of the car, and some room for brake pipes to be fitted.

test fit 1a.jpg

Piccy from the front.

test fit From front cm.jpg

This picture was taken with the camera held against the front diff pinion. Nice to see a clear path to the gearbox. When I get to making up a prop, I could fit a one piece one – haven’t decided yet though, and may need to take some advice on that :)

test fit from diff.jpg

With it in place, I took some measurements and found it to be 1mm too low, and 14mm too far forward :eek: I was a bit surprised at that, but soon sorted it by removing one of the packing washers on the rear bolts, and cutting the tack welds on the top part of the bracket, and sliding it back 14mm. It’s pretty much spot on now.


I then turned the front mount over and bolted it in, then dropped 4 large high tensile through the cross member to hold it firmly in place. I have trimmed them now to tidy it all up, and to stop them touching the main bracket. There is a 6” length of 20mm box section across the top of the rubber mount which stops the bolt turning so I can do the nut up, although its main use is to stop it all falling out if the mount ever failed :)

Front mount.jpg

The bolts inside the car go through a strengthening plate, also held on by the seatbelt bolts. Re gummed it all with butyl, to stop any moisture ingress.

front inside.jpg

The other two are in front of the petrol tank. Yes the tank had to come out, plus draining the fuel etc. I seem to have half the car apart, and the stripdown isn't finished yet.

front boot.jpg

Then, as I knew how the top and cross member of the main bracket would fit together (after the previous measuring and adjustment), I drilled the front hole to fit onto the front mount.



I did spend a little time considering this, but as the bracket was now a bit of a mess, from my poor welding, my unsuitable welder (130A no gas), and all the experimenting, I decided to remake it and get someone with suitable equipment and skilful to weld it. I had the measurements

bracket diagram.jpg
New one ready for welding


bracket new2.jpg

Got it welded up, the test fit into car. This is the first time it was in place and hanging there on its own bolts without support.

diff in.jpg

Ok, it's got calipers and paint but more of that later. Hopefully I'll finish the catch up later - :cool:

Richard
 
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This was the original bracket

bracket old.jpg

New one fitted in place. This still needs some more welding done to it, but I wanted to make sure that everything fitted ok before getting it all done.

Bracket.jpg

To the calipers – they were in a right state. The discs were fubar, so they went in the bin. Calipers were worth saving though

cal 1.jpg

Handbrake linkage was supposed to be over complicated, don’t really see what they mean by that? Obviously never been inside a Rover one

cal 2.jpg

New pistons, seals etc,

cal4.jpg

With everything then cleaned, painted and refitted including new pads, pins, hand brake pads and everything greased up ready, it is starting to look like a bit of a beast

x rebuilt.jpg

This is actually sitting in the car now, but it's coming out tomorrow so I can make up some brake pipes and get it all connected up. Then, I have to work out how to connect the handbrake, and get the final welding done, quick paint and it will be back in, for hopefully the final time.

Then it's just getting the drive shafts out, having them shortened, lengthening the prop, or adding a centre bearing onto the existing cross member, fitting a brake proportioning valve, and putting it all back together.

What could possibly go wrong :)

Richard

Oh, and not forgetting adding a couple of bracing struts to stop it twisting itself out, probably using the old Rover one somehow connecting to the original pin, and perhaps some turnbuckles or whatever running forward from the underside of the diff.
 
Great job! These jobs take a lot of time if you do it the proper way like you do. I do not own a P6 but read that from riding comfort point of view, these P6 s were ahead in their days. So that would mean its difficult to improve it.

Peter
 
I don't feel bad saying this as you have not yet final welded.
You may wish to check the angles on the faces of the gearbox and diff flanges, they should ( in an ideal world ) be the same, this will give you the best shot at avoiding driveline vibration.
 
Thank you all

Cheers Mark, yes I am aware of the angles needing to be equal. From a few posts ago - "Prior to removing anything, I measured the angle the diff sits at and found it to be 1.2 degrees. I was under the impression that it should be 5 degrees like the engine, so that the propshaft flanges are parallel. This is apparently to avoid vibration. I also measure the angle of the engine, i.e. the gearbox flange and found it to be 3.2 degrees :confused:."

Looks like they will both be sitting at around 3 degrees, although without the diff in the car, the back sits a little higher and the gearbox pinion is at 2.5. When the diff is in for good, I can adjust the front mount up or down a few mm, to match the angles.

If I do fit a centre bearing though does this bearing need to be at 3 degrees as well, or vertical?

Richard
 
Looking good Richard,
You’re making more progress than I’m managing at the moment, keep it up.
Are you planning to drill and lockwire the 4 top bolts or just loctite?
(I still haven’t decided myself)
Jim
 
Thank you all

Cheers Mark, yes I am aware of the angles needing to be equal. From a few posts ago - "Prior to removing anything, I measured the angle the diff sits at and found it to be 1.2 degrees. I was under the impression that it should be 5 degrees like the engine, so that the propshaft flanges are parallel. This is apparently to avoid vibration. I also measure the angle of the engine, i.e. the gearbox flange and found it to be 3.2 degrees :confused:."

Looks like they will both be sitting at around 3 degrees, although without the diff in the car, the back sits a little higher and the gearbox pinion is at 2.5. When the diff is in for good, I can adjust the front mount up or down a few mm, to match the angles.

If I do fit a centre bearing though does this bearing need to be at 3 degrees as well, or vertical?

Richard

Sorry I did not re read the whole thing.
I toyed with a centre bearing set up when researching a possible Jag install and could not pin down the angles. From what I read the primary section from the trans rearward can be level, then the secondary shaft sloping down, ideally at no more than 3 deg. But this might be total hogwash ?

All I know is I had a driveline vibration and by replacing joints, closing up the splines on the slip joint, balancing the prop, equalising the flange angles - it has now gone.
another 'test' at Snetterton in the last few days has revealed vibe free running under load at speed :)
 
Just to catch up to date :)

I've not been comfortable with the idea of the diff hanging from a bracket with no other support, so I thought I would utilise these 7/16 UNC bolt holes to construct a hopefully lightweight cage. I found some 40mm x 20mm box section with 2mm wall to start off with.

y cage upside down.jpg

Bolted one of these on both sides

y cage under.jpg

Leaving a long section going forward, to hold some sort of brace onto the cross member to stop it twisting upward under acceleration. When I did the bolts up tight, the sides bowed in a bit so I have to make up 6 x 16mm bits of pipe to support it.

y cage suppport.jpg

Then a couple of uprights, held onto the box section with a HT studding to complete the cage at the rear. This picture was before I put the support tubes in.

y cage.jpg

Trial fitted to make sure nothing fouls anywhere. All is good :)

z fit.jpg z fit1.jpg

Today, I took the diff out again, and was going to make up brake pipes etc, so the diff could go in next time, for good :) I had bought some 3/8 fittings and some pipe. I test fit the fittings and found they were 10mm ones :mad:. So, half an hour of wire brushing found the old ones all clean, sparkly and ready to go. I did the first one and made a right hash of it :oops:. Tried again but it still came out at an angle and looked mangled. I can't actually remember the last time that I made a brake pipe so went and youtubed it, to check I wasn't doing anything daft. I wasn't, but a third attempt still looked like I had made it with a hammer. I opened up the quality brake flare tool, and found this.

crap tools.jpg

The 3/16 one is the third from the left :rolleyes: it's in the bin now.

Oh well, Dorset Steam Fair next week, they always have loads of tool stalls.

Next jobs, brakes and drive shafts.

Richard
 
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Looking good Richard,
You’re making more progress than I’m managing at the moment, keep it up.
Are you planning to drill and lockwire the 4 top bolts or just loctite?
(I still haven’t decided myself)
Jim

I have a fridge full of threadlock so will use that on the top. I will probably wire the calipers though, if I can find some the right thickness. I'll probably use mig wire :)
 
Sorry I did not re read the whole thing.
I toyed with a centre bearing set up when researching a possible Jag install and could not pin down the angles. From what I read the primary section from the trans rearward can be level, then the secondary shaft sloping down, ideally at no more than 3 deg. But this might be total hogwash ?

All I know is I had a driveline vibration and by replacing joints, closing up the splines on the slip joint, balancing the prop, equalising the flange angles - it has now gone.
another 'test' at Snetterton in the last few days has revealed vibe free running under load at speed :)

I do worry about vibration, but the drive shafts and prop are well beyond my capability so will be made up by a company who specialise in them, so hopefully I won't get any problems (crossing fingers).

Richard
 
Why don't you consider running those tubes all the way forward to the end of the mounting and tying them in to give you a nice triangulated support to prevent twisting?
IIRC the replica Camel racecar uses beams along the bottom of the diff like this, then has 3 lightweight tubes running upward to the floor at the front end of the beams, one in the centre and two angle outward to the sides. I will try and find a pic later.
 
Why don't you consider running those tubes all the way forward to the end of the mounting and tying them in to give you a nice triangulated support to prevent twisting?

The vertical gap between the main bracket and the box section is 10mm and I do have some 10 x 20mm box section to fit. But when I fitted the rest of the cage, I started considering running a brace from the end of the tube to the suspension crossmember, to stop the twisting under acceleration, as per my previous post. It would fit like this, suitably trimmed of course :)

front upright.JPG

I don't think this would help with twisting under acceleration though as it is still all on one side of the rubber mounts. So my thoughts were to take say a couple of turnbuckles from the ends of the tube, to the crossmember, this would steady it better and take a lot of the force from that front rubber mount. I may do both o_O haven't decided yet.

Richard
 
Here ya go.
Looks like this arrangement on both sides of the diff. Tube coming toward the camera is part of tubular lower wishbone and tube running across the car is rear ARB.
DSCF4391 - Copy.JPG
 
Jeez, that looks complimicated :eek:

Interesting, but I may give that a miss :)

I like the idea of the ARB though

Richard
 
Not really. It's just bracing going up to the floor from what you have already.
I am pretty sure that is a one piece propshaft. I remembered it wrong there are two brace tubes each side coming together at the bottom.
Interestingly this car was copied from 808D, which now has a Jag diff, but according to Bill Price who was in charge back then the car had the stock De Dion setup and never was raced with a Jag diff.
Even when it came out of hibernation Bill thinks the stock Rover rear end was still in the car and that the Jag rear was put in recently.
 
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