I can see that this was built never to be worked on, as the bracket was most likely welded to the bumper with a carriage bolt hanging loosely inside of the bracket. There is NO way to now slide a carriage bolt into this bracket and have it protrude so that it can be fastened to the front of the car.
I am contemplating cutting a slot into the bracket and sliding a new bolt into the correct position and then MIG welding the bolt securely. It prolly would be unwise to remove and re weld the entire bracket as positioning is critical in this area.
I would recommend Kroil or another penetrating oil as these 50 year old bolts did not want to budge. Had to use a cheater bar on some and of course the sawzaw on the front two as the inside bolt head (similar to a carriage bolt, but flat) was just spinning and many words of anger were spoken as it was 20 degrees in the garage. Cold concrete sucks the lifeblood from ones’ soul!
We did try out one of the tubular propane heaters which quickly brought the temperature to t-shirt weather and the beautiful Angela began to get a headache and runny eyes and a sore throat from the fumes. The monoxide meter did not go off, but I will check again with another meter to make sure I wasn’t killing myself slowly…
The top hat bracket that is welded to the front bumper blade in your video was originally fitted with a snap nut (reference McMaster Carr’s web page https://www.mcmaster.com/#clip-on-nuts/=1bg1jfk for an image and details.
This nut snapped into the slotted top hat bracket hole from the blade side toward the rear of the car) such that a regular hex head bolt could be passed through the inner bumper arm and could be threaded into the snap nut. This retained the bumper to the inner mounting arm.
As our car was manufactured earlier than yours, I consulted the Jaguar Parts Manual and confirmed that Jaguar used the same mounting configuration and parts throughout MK2 production.
With respect to your current challenge, it may be possible to simply hit the center of the cut off bolt with a punch and hammer to knock the snap nut out of the slotted top hat bracket hole. When released, the snap nut will slide out from behind the bracket from either the top or bottom. Be judicious when you strike the bolt as you don’t want to dive the snap nut out so hard that it dents the bumper upon impact.
I’ve attached a photo of our MK2 so that you may see the hex head bolt and bumper mounting arm orientation for reference.
This makes sense as I can now avoid MIG welding a new nut into place. I will find all of my broken pieces and figure out the correct sizes.
Should I go with stainless nuts and grade 5 or 8 bolts?
Why is your car so clean underneath?
Another problem I face is the incorrect reassembly of nuts and washers on the side brackets by someone many moons ago. I will logically reassemble as the books don’t show all of the diagrams of washers in proper order or do they?
As it appears you have recently installed the bumper, are there ways to align it fore and aft or it might be the case that my bumper is bent after the small accident in the late 1970’s in Denver, Colorado The right side of the bumper is closer to the body than the left corner. Not noticable until you really look closely.
The Factory Parts Manual does not graphically depict the assembly order of the hardware but it does describe what is used and the order in which they are arranged. Per the Factory Parts Manual, the original fasteners were as follows:
Bumper Blade to inner Bumper Arm
Jaguar part number UFS.137/7R Tanslated…
F=Fine Thread
S= Setscrew (I believe this means that the tip of the bolt has a point to aid with starting the fastener)
1 = Hex Head,
37 = 3/8" Thread Diameter in hundredths of an inch 37/100 ~ 3/8 (Fine thread count per inch for a 3/8" bolt is 24)
7 = 7/8" length in eighths of an inch 7 / 1/8 ~7/8 (The length of this bolt really matters because if it is too long, it will bottom out on the bumper blade and potentially create a dimple in the chrome if tightened too much. If its too short, it will not grip the snap nut).
R = the fastener is “Wrench Driven”
In layman’s terms…You will need Qty (2) 3/8"X24 Hex Head Bolts that are 7/8" long (measured from tip to beneath the bolt head)
(2) Spring Washers
(2) Flat Washer Beneath the Spring Washers
(2) Snap Nuts
Inner Bumper Arm to Body Mounting
(4) UFS.143/8R = 7/16X20 Hex Head Bolts that are 1" long
(4) Spring Washer
(4) Flat Washer Beneath the Spring Washer
Outer Bumper Arm to Body Mounting
(4) UFS.143/8R = 7/16X20 Hex Head Bolts that are 1" long
(4) Spring Washer
(4) Flat Washer Beneath the Spring Washer
Outer Bumper Arm to Angle Bracket Mounting
(2) UFB.143/12R = 7/16"X20 Hex Head Bolts that are 1-1/2" long
(2) Flat Washer Beneath the Bolt Head
(2) Flat Washer Beneath the Spring Washer
(2) Spring Washer
(2) Nut
I took this photo while I was assembling our car. It’s still clean…but not this clean .
Relative to hardware type…That’s a personal choice. I stripped/blasted all of our original hardware and had everything re-plated per the original finish (black oxide in the case of the bumper bolts). According to the head markings on my original bumper hardware, they were a Grade 5 equivalent. As bumpers are a potential safety item, fitting Grade 8 wouldn’t be a bad idea.
Relative to re-assembly, I loosly mounted the inner and outer bumper arms to the car and pulled them away from the body as far as I could so that I would not touch the body when offering the bumper up to the arms. I applied several layers of masking tape on the body and rear edge of the bumper to protect the new paint in the event that the bumper moved unexpectedly. I strongly recommend that you have two additional sets of hands and eyes. I had a person on each side of the blade holding it in position while I was underneath installing the blade to arm mounting hardware. There’s quite a bit of movement available when all of your hardware is loose. You may be able to align you bumper as is. Check your arms and blade for trueness and straighten as necessary before re-re-plating and painting parts. I recommend performing all of this fitting activity BEFORE you paint your car (if that’s what you’re going to do) as you DO NOT want damage freshly applied and polished paint.
I can tell you put a lot of effort into your reply. THANK YOU very much. I will study my parts manual to better understand how Jaguar outlines their parts and assembly order.
We’ll be skiing in Northern Michigan in a couple weeks…It’s not the Colorado Rockies but it beats the mole hills that we ski downstate. If I didn’t have a day job, I’d take you up on it!
What prevents the snap bolt from puling through the top hat bracket once I tighten my grade 8 bolt, cock washer and flat washer? ACE hardware has the snap bolts but not in SS so I will just smear some grease on it as I think the factory did not use stainless steel and it lasted 50 years without grese.
I am also wire wheel cleaning the back of the bumper blade of surface rust.
Seems the fragile arms on the snap nut will collapse?
I will prolly make a short video as I think that my side L brackets are not 90 degrees true and that is causing major misalignment problems with the bumper.
Remember the car did have a small bumper bender back in the early 70’s. I think the second L bracket being measure should either be hammered forward or removed and put in an anvil and made into a perfect 90 degree angle.
Should these be 90 degrees?
Mea Culpa with regard to the shaky ness of the video as things are a bit cluttered and it was chilly out there.
Using a propane rocket heater which works well but makes the beautiful Angela a bit woozy with the fumes.
I have power wire wheel cleaned 50+ years of surface rust off of the bumper and have found a few nicks from low lying bumps in the road, bruises of life!
Brian noted I should use a larger bolt but in my ACE hardware search i used the biggest snap nut they had which was not in SS. I could always order the McMaster/Carr set, just the shipping always irks my frugal inner self!
The bolts and washers are grade 8 but the snap nut is not, I fear that the snap nut will crush/collapse under torque of the bolts and nut being tightened?
All thoughts welcome.
It is 11 degrees F so we prolly wont be going in the garage today!
Thank you all for your patience as I dissect this problematic bumper scenario"
Another short video:
To appease Wiggles and others I have liberally applied anti-seize and Kroil to the thread and they move like smooth butter.
Both of the brackets are 890 degrees and match up when put one on top of the other.
I will check Brian’s list of nuts,washers, and botls but I believe there is an extra huge fender washer that someone added years ago to adjust the blade? Accident in the mid 70’s and or careless painter in 1981.
I just watched your video and I share your concern about the snap nut possibly being pulled through the slot when you tighten up the bolts. The original snap nuts were a snug fit in the slot. In a previous post, I provided a link to McMaster-Carr’s page where they list a variety of snap nuts of varying dimensions. I suggest that you measure the height of the slot in the top hat bracket and see if you can procure a larger snap nut that will reduce/eliminate the amount of clearance/slop. This should help ensure that the nut will not pull through when tightened.
So the snap nut should be snug between the bumper blade and the inside of the top hat bracket?
I could also mig a nut or a bolt ( and work backwards into the brackets with nuts on the drivers side of the assembly). Although that would defeat the design.
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