Sorry to resurrect this. I was having trouble with the bonnet catching on the back edge. I have to pull the bonnet forward a bit when I open it a bit, to stop this happening.
My bonnet also sits a bit high on the back edge.
I would have though all this was down to adjustment, however, with the bonnet shut from the front, if you walk to the back edge you can gently push it shut all the way, in other word the hinge closes the last little bit.
I was wondering if anyone had fitted helper springs to help the bonnet close that last little bit? Helper springs might also pull the back edge away from the scuttle when the bonnet is just starting to open.
I suppose they would stretch between C and the lowest hinge point below (marked with a red line).
On the other hand, they just could make the whole situation worse.
When faced with the same issue a couple of years back I also contemplated helper springs, concluding the hinge geometry doesn’t lend itself to the approach.
There’s been a fair bit of conversation on this, and no single solution. Some have reported improvements after rebuilding the hinges, eliminating slop in the pivot points. Some others have purchased and installed brand new hinges without improvement.
As you’ll read in the post below, I sat on a stool in the vacant engine bay while my wife repeatedly raised and lowered the bonnet and observed the hinges dipping downward slightly just as they began to actuate. The dip seemed to coincide with the edge of the bonnet striking the scuttle. Soldering a small stop onto a link of each hinge solved the problem. However, at least one other owner - it may have been Rob Reilly - reported that his bonnet hinges did not dip downward as described.
I and my painter spent several (expensive) days trying to find an answer to this. My conclusion is that individual car assembly and parts tolerances dictates whether or not you have a problem. Mine clearly did - I tried new hinges (worse - less rigid, just as much play), rebushing my old ones with oversize bushes which I made up on the lathe (better), even taking a whisker off the rear of the bonnet. I also tried adding metal (small spots of weld dressed back) as in Nick’s solution, but all to no avail.
We ended up spot welding a small rectangular steel plate on to the bulkhead behind each hinge, which physically stopped the hinge moving backwards and taking the rear of the bonnet into the bulkhead. I reasoned that if these were made carefully and painted over with rest of the bulkhead they would not attract attention, and were a far better option than a chipped bulkhead or bonnet trailing edge. With these in place the bonnet cannot physically touch the bulkhead, even if the hinges wear in future.
Jaguar just can’t do hinges. Don’t get me started on the door hinges again…
Peaking through the bonnet gap during the last few inches of travel it became apparent that the bonnet stay was too long when clipped into place on the bonnet. It is non standard, but has been there at least 40 years I would say.
However, it was just catching a lip on the bulkhead pressing, just as the back of the bonnet dropped into place, holding the bonnet up. There was actually a little telltale mark if you looked carefully.
I have just cut and re-welded it so that is now not an issue.
I can see the difficulty in adjusting the bonnet. Those short rear hinge sections really swing down and also back at the same time right at the last couple of inches of bonnet closing movement when you cant see it unless you do a Saltarelli. This arc is greatly affected by how high the hinges are relative to the bulkhead.
What a nause when you are trying to get a decent gap at the back at the same time.
I may have said this before on one of the other times this subject came up.
I’ve been thinking about how it would most logically be done on the production line, and I think the way the factory boys did it at Foleshill was with the bare body on the painting trolley, with one guy under the bonnet and another outside to shift it around. The latch mechanism would not have been installed yet. They set the bonnet in place, with some sort of spacers of cardboard or something, to get the gaps right. Then the guy underneath installed and tightened all the screws a little at a time, the guy outside shifting it around until he was satisfied with the gaps. With these hinges you have both vertical and fore-aft adjustment, and a little side-to-side. Then the underneath guy would tighten them all down. And never touch it again. Paint the body with the bonnet on. Install latch mechanism afterwards. Paint black inside the bonnet area.
After the '52 move to Brown’s Lane the procedure may have been slightly different, as the bodies were painted on rotisseries, and some of you have reported your latches are body color, so they were probably installed before painting to hold the bonnet closed when it was upside down.
I have done it a couple of times on my assembled car. I would set the bonnet with a larger than correct gap at the rear, snug up the bolts, try it again, snug up the bolts a little more, and move the bonnet back a bit or down a bit, snug up the bolts again, maybe go through this in several increments. If your hinges are in good condition this ought to work.
Hi everyone,
Can I resurrect this thread please?
I spent this afternoon re-fitting the bonnet which I thought would be a simple task as I had marked the position of the hinge brackets before strip down and all that has been done is a bodywork re-paint. When it was taken off it fitted perfectly but now I cannot get it to close at the front but it is perfectly aligned at the back. The bonnet will not go down far enough at the front as it contacts the bodywork about 14mm before it has gone down to the locking plate. It looks as though it needs to move forward, so I have moved it forward on the hinge plates to the point where I now have a 5mm gap between the rear edge of the bonnet and the bodywork below the windscreen area at the back. If I move it further forward there will be an even larger gap. It will look awful.
I have a dreadful suspicion that something happened in the body shop and they have applied a lot of filler to the area in front of the locking plate and I am going to have to do some serious metal re-aligning at the front. Any ideas?
Sorry about the standard of the photos, I’ll get the memsahib to take some proper ones with the camera tomorrow. (The photos of the rear of the bonnet are before I moved it forward, the gap is now much larger)
David
As far as I know all steel body bonnets require a movement forward while opening, a straight pivot upwards will always collide the trailing edge to the firewall.
There are few things more frustrating than refitting the bonnet on an XK120, at least that’s been my experience. I had mine fitting nicely before the paint job, then struggled to get it fitting well when I took it off to do the rewiring job. I could still spend a few hours adjusting it a fraction of a mm here and there.
You might ask yourself what might be different from when you had it fitting well, aside from the bodywork, which might seem to be the most likely culprit - bodywork absolutely must be done with the bonnet fitted - was the chin piece between the wings replaced? Did you replace the six rubber bump stops? They have a remarkable effect on fitment, but not as much as the hinges. How well does the bonnet fit loosely sitting on the bump stops, unattached to the hinges? How are your elevations, ie. how does the bonnet align with the wings? The hinges themselves in combination with the bump stops and locking plate can subtly change the shape of the bonnet.
Nick,
Thanks for the reply. I think you are spot on about the chin piece. The bodywork was done with the bonnet off unfortunately. When I re-fitted it I can verify the following:
I checked the hinges over and they are fine, no wear and back in exactly the same place as before.
I put six new, rubber bump stops on
I put the bonnet on in exactly the same place as before on the hinges
The chin piece was not removed or replaced
I did as you suggested and put the bonnet in place but not attached to the hinges. It sits on the wings and bump stops fine but it can’t go down far enough at the front. The bottom, front corner on the left as you look at it from in front, just below the grille, contacts the wing before it can go down completely. It looks as though the chin piece and the where it joins the wing is further forward on the left by about 12 to 15mm, in other words it is not exactly in line across the front (ie left to right), looks bent, as though it has had a bash.
I’ve taken a good look underneath and it looks as though I will either have to fit a new chin piece and align it properly, OR, try and bend the existing chin piece and wing on the left (right side of car) further backwards so that the chin piece is in line L to R, then the bonnet will go down and engage with the locking plate. The wings are being re-fitted this week so I’ll ask the body shop guys what they think, they didn’t do the re-spray but I have a lot of confidence in them rather than the previous lot. (that’s a long story of being fiddled out of rather a lot of money, don’t ask, it’s too annoying to think about!)
I got the memsahib to take more photos but they are not much better than mine before, but you can see that the chin piece is further forward on one side than the other. There’s also a photo of the bonnet on not attached to the hinges and you can see it sits well with the wings but can’t get down at the front.
I’ll let you know what they say next week, I have a sneaking feeling this will be a dockyard job!
David
I’m afraid that does look as if the chin piece has been pulled forward on one side. Maybe it got caught on something whilst the car was being pushed backwards?
I have a slightly wider gap than that at the rear of the bonnet (140), just for peace of mind really.
Yes, the chin piece appears to be a bit wonky. There’s a lot of “structure” in that area so quite rigid. I don’t imagine there’s going to be a whole lot of available slack to move that one side backward but it’s worth a shot. I spent a fair bit of time cutting and rewelding the steel in that area to get it right, then finished it with body solder.
Nick, Roger,
You are both right, after spending ages under the front one can see that the chin piece has been pulled forward and upward on the left which has distorted the wing so that the bonnet cannot go down. The chin piece is noticeably bent forward. It is very obvious when you compare Nick’s photo and the photos below of mine. The chin appears to be quite a flimsy affair and there’s a horizontal crack in the join between the chin and the left wing (right wing on the car), you can just see it in photos 4 and 5 below. It must have happened in the body shop after they had painted it, either towing it around or hitting it with a jack from underneath. Water under the bridge there.
I’ll speak to the guys who are re-fitting the wings next week. It looks as though the chin will need to be cut out, all the bolts in the central bonnet lock frame loosened, the wing pushed back into the correct position, the chin re-welded in place and everything lined up and re-bolted.
Unless anyone has any other advice? Thanks for the help.
David
Only that once the old chin piece is cut out you should work at achieving a “best fit” of the bonnet by playing with the hinges then do fine adjustments with the front of the bonnet locked down on its buffers with good gaps all around. Only then work on dry fitting the new chin piece. Get it perfect and weld it in place.
Nick. Thanks, that’s good advice. I had better order the new chin piece as I think there’s a couple of months delay after order. Funny how time flies when you work on these old cars.
David
The chin piece is a subject area onto itself. The first one I bought was a poor fit. The second one no better. I ended up fabbing one myself, got it real close but it still required a couple of ounces of body solder to get it perfect. This is a good discussion:
Nick, thanks a million for the link to that old post, it says it all and the photos are first class. It’s heartening to know that lots of other owners have been through the same bonnet problems. I’ll pass all of it on to the body guys tomorrow, to paraphrase it - 'Take it slowly, make sure the bonnet fits absolutely right all the way round and then, only then, fit in and weld the chin piece. I might take your route Nick and fabricate my own new one as the photos of the parts on offer look as though they will be short at the sides, like yours were.
Thanks again everyone, what a gem this Forum is, my life saver.
The damage to the front has been repaired, the work being done exactly as you guys suggested, ie cut out the chin piece, then re-align the wings with the bonnet in place and then re-solder/re-weld the chin piece back in place. It went like a dream, the two lads who did it have no experience of old Jags but they are patient and really good craftsmen, a delight to work with.
Thanks for all the info and help.
David
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