Need advice on bonnet fitting - was: High profile bonnet hinges

(Manfred Bendisch) #1

Hi gents,

my problem is that my bonnet sits too far back and too low, giving me insufficient gaps at the sills and bulkhead. I have added as many shims as possible, but would still need some additional room. I know there are low profile bonnet hinges available which help in case you cannot remove enough shims. But how about the opposit?
Are there hinges available that move the pivot point further out?
Did anyone ever attempt to cut and reweld a pair of hinges, adding some material?

Thanks, Manfred

(Erica Moss) #2

How can you have too many shims? Worst case you might need longer bolts. I don’t know of anyone that’s made a higher profile hinge and even if they did you’d still need longer bolts to install it.

(Jeff Smith) #3

Classic Jaguar sells a hinge that might work for you… http://classicjaguar.com/cjparts/hinge.php

(Les Halls 1968 S1.5 2+2 Atlanta) #4

I believe Classic Jaguar makes or made hinges for just this kind of problem.

(69 FHC ) #5

If you have too many shims on one plane you won’t be able to get the bolts in on the other plane. The holes in the hinge won’t line up with those captive nuts, even taking their movement in their cages into consideration.

(Erica Moss) #6

that’s a lotta shims

(Mitchell Andrus) #7

They’re $195/pr (machined aluminum) and move the fulcrum 1/2" in each direction in the event you’ve removed all the shims up/down or in/out and still have a gap/sloppy fit. It allows you to start tight and add shims to fit. Nice to think someone is looking out for us.

I’m just tomorrow going to delve into this problem, overlooked by the PO. I’m a stickler for gaps. Have a look at my MGA for proof of that.

I’m thinking that I can do an awful lot of fabricating to save 200 bucks.

(Erica Moss) #8

I have a set on my car and they do exactly what they claim to. I think they were inspired to make them based on someone here experimenting with a standard set, cutting them down and welding them. If you’re super handy maybe you can make them well, and make them secure. I personally didn’t want to go through that hassle. The welders I’ve worked with in the past are more about zapping things together reasonably fast than zapping them together pretty, or zapping them together in spot on perfect orientations. That bolt tube has to be exactly parallel to both planes.

(Jerry Mills) #9

No there is not. I looked for some last year as I have a mismatched bonnet.
The hinges from CJ will only make it worse. In my internet and local search I did gather some interesting info.
With max shims to move it forward you now have to trim the bonnet.
That’s not as hard as adding more metal. If it’s close, it can be done with a belt sander or a grinder / cut off wheel. Touch up paint required.
Maxed out on the up shims is not easy. One guy I met shimmed the trapeze / radiator mount at the bottom attachment and gained about 3/8 inch. Don’t know if that’s a good idea but it worked for him. Second option is to remove and shorten a section of the bonnet where it meets the sill.
Search archives for that one.
Now the really potential bad news.
I’d ask you first how long have you had the car and when did you notice this ? There’s a chance you have broken or damaged frame rails.
If you don’t see any damage, try this procedure.
Start by carefully measure the gaps.
Jack up the front using the picture frame.
Check the gaps.
Set car back on the ground and roll around to settle the suspension.
Jack up the car at the firewall with all that weight hanging out front.
Check the gaps.
If you note sizeable differences start drinking immediately .

(Manfred Bendisch) #10

Thanks for all your replies!

I already knew about the CJ hinges, but as has been mentioned, they move the bonnet in the wrong direction for me. And you can add only so many shims until the threaded plates in the valence hit the captive cage.

I have bought the car two years ago and am restoring it since then. It had been hit at the chin (or probably has hit something with the chin) which damaged the lower bonnet valence and cracked the bonnet support frame. I have had the valence repaired and replaced the bonnet support frame. The engine frames are definitely sound and straight; media blasting didn’t expose any rust or cracks at the joints. The attachment points at the bulkheads measure ok as per the dimensions in the manual and they are not pushed back.

The reason for my request is that I wanted to evaluate my options. If modifying the hinges such that the pivot point moves out in both directions could solve my dilemma, but I must confess, would be a cheat.

The core problem ist probably, that the mounting points for the hinges at the valence are still off. That means I have to dis-assemble the bonnet again and have to have the mounting points at the valence straightened out.

Thanks again for all replies, Manfred

(Geoff Allam) #11

Manfed. Do you have these spacers on the lower attachmnt of the side frames to the picture frame. If they are missing ,and they are in many cars, adding them will raise your bonnet to a degree. These may well be the shims that someone mentioned to you. They are supposed to be there. I see no reason why another set could not be added between the pocture frame and the bonnet mount to give you a bit more height if needed.

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(Manfred Bendisch) #12

Geoff,

thank you for your reply. No, I don’t have that plate between the picture frame and the bonnet support frame. And it was definitely not there when I dis-assembled the car. Looking at your photo, the holes for the bolts have a different pattern. Mine is an S3 from '72. Is your picture from an S2?

Can anyone confirm that the plate/spacer was used on the S3 also?

Thanks a lot, Manfred

(angelw) #13

Hello Manfred,
No spacers.
Try and determine the actual problem and rectify that rather than fudge it, would be my approach. Set the car up on stands with the floor parallel to a relatively flat, level surface. 6 o’clock on the bonnet hinge frame pivot tube should be inline with the bottom surface of the floor; the same distance from the flat level surface as the floor. Check also the distance from the face of the bulkhead to the centre of the pivot tube. It should be 127cm, plus the thickness of the picture frame.

If the above dimensions check out OK, then the issue will be with the mounting faces of the Lower Valance where they interface with the hinges.

Regards,

Bill

(Karl B.) #14

Hi Manfred

I had the same problem with my Ser.1 in the opposite way, so I would needed the hinges of Classicjaguar. I found these too expensive, so I cut the old hinges in two pieces, grinded them down 5mm and went to a bodyshop to weld them together in the correct way.
Why shouldn’t work this with adding some more material? I paid 40 Euros for it :grin:
If you want, send me a private message, then we can call by phone.
Karl

(John Macleod) #15

I read your post with interest, as I am in the reassembly stage of the front end of my S2 OTS following engine frame-off R&R firewall forward. One of the things uncovered in my frame disassembly was six stacks of eight washers each, placed on the six lower bolts between the picture frame and the radiator support (bonnet carrier) frame. I do have the correct oval “packing pieces” on the other side of the picture frame.

The effect of these washers (used with longer -than-original bolts) was to push the bonnet out and up slightly, “sort of” solving essentially the same issue you have. These washers were placed on the frame bolts by a PO, along with a stack of shims on the hinges, which resulted in a proper gap. However, I’m certain they detract from structural strength and have eliminated them in the rebuild, so I may need a set of modified hinges when I get to that point.

In recent discussion with George Camp about this problem, he pointed out that Jaguar Technical bulletins discuss production and use of the “Service Bonnets” which were made to have the scuttle end trimmed to individiual models. So possibly, this is where the problem originated (fwiw). I will not be trimming my bonnet at this point.

(Ray Livingston) #16

Which will move the hinges BOTH forward AND up. This, to me, would be the best way to solve the problem on a bonnet that is already painted. Otherwise, the correct fix is to trim the bonnet, and perhaps re-work the rockers for correct fit with stock hinges and nominal shims.

Regards,
Ray L.

(Manfred Bendisch) #17

After more careful thinking this afternoon I have come to the conclusion that my main problem is not in the hinges. What I didn’t realize is that the top of the fender would end up higher than the bulkhead if I would move the bonnet up by another 3/16th of an inch. As of now, the fender top is exactly the same height as the bulkhead while the lower edge touches the sill extension.

I think that means I will have to shorten the fender height by the necessary gap width!? Can anyone of you share how this is best achieved?

Now, the question is, how can this be? I have bought the car with a damaged lower valence and bent/cracked bonnet support frame. But the damage doesn’t have anything to do with the fender being too tall!? Which means, the fender must have been too tall and touching the sill before the damage. Probably, someone in the past installed that fender and didn’t care about a good fit?

Anyway, I have decided to do it right, although I was hoping to get the car to the painter soon:-( Now it looks there is more cutting, welding and grinding to be done.

One more question: I haven’t glued the internal bonnet panel as of now. Is it better to first tailor the bonnet and, after having achieved a good fit, glue the panels? Or is it better the other way around, first glueing and then continuing with the fitting?

Thanks, Manfred

(Nick Saltarelli) #18

I fully assembled the bonnet, including bonding flanges, before final fitting. In my case the bottom edge of the front wings were almost touching the tops of the new outer sills so required adjustment to achieve the target gap, which iirc was 4 mm.

(Geoff Allam) #19

Manfred. Sorry. Did not realize you had a series 3. Picture is just a stock picture taken from online. Late series 1 or series 2 judging from the horn mounts. I would suggest that before you start cutting and grinding on the bonnet that you spend a bit of time setting the car perfectly level on blocks and then measure carefully to ensure that the frames are dead centre and level side to side. Then mock up the bonnet using temporary shims between the picture frame and bonnet frame and with the rubber landing strip installed on the cowl. Once you have the bonnet in the best possible position you can accurately determine what adjustments need to be done to the sheet metal and mounts taking into consideration the eventual removal of the temporary shims.

(Paul Scott) #20

Manfred,

You mentioned that the lower valence/under panel was damaged.

I spent many happy hours adjusting my bonnet; shortening the wings lengthening the bonnet etc and have now concluded that perhaps the real problem was the bonnet under panel.

I repaired mine but I now think it is entirely possible that the support member where the hinges attach was leaning slightly forward, or the bottom was welded slightly back.

This has the effect of dropping the bonnet at the front and in my case pushing the bonnet forward. It is easy to see that if this panel is not in the correct orientation, it could have a drastic effect.

Even a few degrees off vertical/horizontal could make quite a difference.

I would suggest that you take a closer look at the repair on yours to see if this is could be the problem.

Regards,

Paul