Bonnet/hood gas strut supports

XJ-S
1

Has anyone thought ‘what if’ the gas struts would open the bonnet/hood a reasonable amount for better working on the engine and other things up front?

I’m the 2nd owner of my 1983 XJS, and have owned it for 15 years, but what was done during the 1st owners 25 years? I found out one thing, and changed it for the better, and their change was even better than Jaguar’s original production fit.

One of the hood support gas struts sticks about halfway closed/open, then makes a ‘pop’ noise and opens/closes the rest of the way … guess I’d better replace it before it totally goes bad (not that it is bad now, but that noise is disconcerting).

I ordered the Jaguar part number shown in my parts book to replace it. However, the Jaguar part was shorter than what was on the car, indicating that a previous replaced had not used the correct part.

However, the shorter Jaguar part number gas strut, being shorter, did not open the hood even close to what the gas struts on the car opened the hood. No way did I want to make working space even less than it was!

I made measurements and calculations to determine what was the longest gas strut which would fit, and what is the longest gas strut which would open the hood the most without creating any issues (such as the grille hitting the intake air pan, etc).

Then I did internet searches to find gas struts which fit the force I needed (the Jaguar part is rated for 265N, i.e., 60 pounds). I searched for 60-70 pounds force.

The longest center to center of pivot extended length to not create issues was a little under 24" (about 13-1/2" to 23-3/4"), with the maximum center to center compressed length was just under 13-1/2" (about 13-1/4" to 13-3/8").

I found these gas struts:

  • Extended Length 23.30"
  • Stroke Length 9.90" (the stroke was not critical as long as the extended length and compressed length fit)
  • Compressed Length 13.10"
  • Force 65 pounds / 289 N

I received the gas struts this morning and put them on - PERFECT extended length and compressed length fit perfectly into the center to center space on the car.

With the Jaguar part gas struts, the hood opened to 29" measured diagonally from the center trailing edge of the hood to the inside corner of the lip with the VIN/chassis number stamped into it.

With the gas struts which have been on the car for at least the last 15 years, the hood opened to 37" measured the same way.

With the new gas struts installed, the hood opens to 48" measured the same way.

The photos show the difference better than the measurements do. I reviewed the post and noticed an easy was to see the difference is the hood opening - look at the hood in relation to the window behind it.

Bonnet gas strut supports Jaguar BD48027
Bonnet gas strut supports Jaguar BD480271920×2560 614 KB

(Jaguar part gas struts.)

Bonnet gas strut supports which have been on car
Bonnet gas strut supports which have been on car1920×2560 569 KB

(Gas struts which have been on the car.)

Bonnet gas strut supports Lift Support Depot SE233P65
Bonnet gas strut supports Lift Support Depot SE233P651920×2560 492 KB

(New longer gas struts.)

Grille clears intake pan
Grille clears intake pan1920×2560 442 KB

(I have a video showing the paper sliding between the grille and the pan, but I guess videos do not upload?)

Bonnet access with new gas struts
Bonnet access with new gas struts1920×2560 550 KB

(Shows excellent access straight in to this area which was only accessible by reaching over the radiator before.)

3 Likes
2

Kirby mentions this in The Book, search for “LONGER HOOD GAS STRUTS”

Replace with a Honda part for hatchbacks, that’s what I did. They are stronger, cheaper, last longer, and put the hood up a tiny bit higher.

3

You have a part number and source? Sounds like a great find for pre-facelifts.

Jon

4

Nice work and write-up.

5

My gas struts had been replaced with the ball and socket ends. I think that the ones I bought are available with different ends as they have several different types of ends.

Shows how to measure the gas struts and the various ends.

Use the ‘how to measure’ for pre-facelift and facelift to confirm dimensions are correct.

Here is how to measure what is on the car versus what will fit: open hood, tie a twist tie around the shaft at the body, close hood. Then open hood and see where the twist tie was pushed to on the shaft. That will show you if your current struts are fully taking advantage of the compressed spaced that is available. Even if they are fully using the compressed space, there may be gas struts with a longer extended length and that same compressed length.

I put a twist tie around the new gas struts with the hood up, closed the hood, then opened the hood to see how close my measurements were. The twist tie was pushed all the way to the end with only a very small space left. I probably have fit in a compressed length of 1/8" longer (the width of the twist tie) as the twist tie was not ‘crushed’ against the end, there was still a sliver of shaft visible. But that gets to … IF … if I could have found a gas strut which was only 1/8" greater compressed length.

For $4.99, I went with 2-3 day Express shipping, I received them on the 2nd day.

6

I hadn’t seen that in Kirby’s book (I’ve looked through Kirby’s book multiple times, and each time I find something I don’t remember having seen before), however, the ones I used are an inch longer and open the hood even farther, to 48"

How much are the Honda aftermarket lifts? More or less than these? The additional 1" extended length adds an additional 1-1/2" to the hood opening.

7

It’s on page 470.

8

Not sure, but I’d be afraid if the hood opens too far, you risk the grille getting crunched.

9

Not crunched (unless maybe if there were no gas struts restraining the hood from falling forward or to keep the wind from whipping the hood forward), however, the grille could possibly be scratched where the bottom might rub the plastic pan forming the bottom of the air inlet to the radiator if allowed to tip too far, which is why I measured once, twice, thrice, and then a few more times just to be sure.

I took included a photo showing that a sheet of paper slips in between the bottom of the grille and the pan.

I also have a video showing me moving the paper around with no resistance (well, other than it was sticking in so far that it bumped over and above the secondary coil).

There were a few other gas struts which may have fit within the compressed length between the two pivot points and which were lightly longer extended length. However, as I recall, those were also just enough greater length at the compressed length that I was not sure they would fit … and as it turns out, they would have either been a bit too long compressed, of just barely short enough to be forcibly crunched into place when closed.

That is why I say to measure. Need to make sure they will fit correctly,

With both gas struts unhooked, tilt the hood forward until it does not quit touch that pan, then measure center to center between the two pivot points. That is the longest extended length one would want to get.

Shorter extended length also works, but shorter extended length also reduces the distance the hood opens for access and work.

10

This is their matching search results for my inquiry based on the ends I needed, They likely have a similar list with eyelet ends, maybe even the same list, just with different ends, and maybe an minor length adjustment based on the end difference.

The ones with 23.62" extended length might have been a tad too long, and their 13.31" compressed length would have been either a tad too long or a little crunched fully closing.

11

Jerrypeck, do you recall where you got the ball studs to convert the mounting points? I measured the threads on the bolts holding the stock struts, and they are 5/16-24. I did not find that size on the liftsupportsdepot website. I really like the idea of that conversion.

12

Mine had already been replaced to the ball and socket when I took over care of the car (ownership)

From the How to Measure link I posted:

In the event that you do not have a metric measuring device, below are a few of the most popular conversions:

  • 8mm = 5/16" = .32"
  • 10mm = 3/8" = .39"
  • 13mm = 1/2" = .50"

With the 10mm/3/8" ones being the same, quite possibly the 8mm/5/16" are the same. I’d take one of yours to a local hardware store which has a good selection of metric/Imperial/USS (USS is SAE, UNF, UNC, NF, NC) nuts and see what screws on it.

Metric threads are measured differently than American/British threads. USS threads are Fine or Coarse and are measured in threads per inch TPI). Metric threads are measured in pitch (thread to thread distance in mm). Typical metric thread pitches are: .7, .8, 1.0, 1.25, and some are very close to our TPI and will fit together.

Are the nuts the ball studs screw into loose or fixed in place? If loose, can you replace the nuts?

I have on of these as it makes verifying size and thread easy.

metric and USS thread checker
metric and USS thread checker1920×1440 244 KB

13

The nuts on the inner fender are welded on the backside of the inner fender. I’ll have to check the ones on the hood.

I’ve googled ball studs with 5/16-24 thread, and found nothing with a 10mm or 3/8" ball. Lots of studs with 5/16-18 thread. I’ll see if something in metric is close.

I thought about retapping to 5/16-18, but don’t know if there is enough material on the nuts.

14

An 8 mm ball would go with the 5/16 stud, and they have 8 mm ball and sockets.

If the bolt for the eyelet end is 5/16, maybe you can replace with 8 mm (5/16) ball and socket end on the same gas strut as shown. It would likely have a different part number.

Their support people are super helpful in finding what fits within what you are looking for.

I sent them a range of what I was looking for (extended length range, compressed length range, force range, and end type/size) … they sent back a list of gas struts which met what I was looking for, then I picked the one which would fit and work best from the list.

The two main things are: must fit within the compressed length space available; and extended length not too long to push grille into the pan at the bottom of the air intake to the radiator (although I was contemplating having to bow the plastic pan down a tad if needed - but that wasn’t needed).

15

What Honda struts fit the bonnet.

16

From The Book:

… go to your local auto parts store and purchase a pair of aftermarket struts
intended for a 1984-85 Honda Accord 3-door. They are made by Pro Lift, part number 92307, or by Motormite, part
number 95038. The ends of these struts are thinner than the stock Jaguar struts, so you should add some spacers to the
mounts to make sure the body of the strut doesn’t contact the mounting brackets…

17

I did this conversion today on my ‘87, and WOW, what a difference. Accessability is vastly improved. I used the recommended ball end struts. The hard part was finding the correct ball studs, as I couldn’t find an equivalent strut with bolt on fittings per original. The threads are fine thread SAE, and all the aftermarket ball studs i could find were coarse thread. The late XJS’ came with ball studs with proper threads, but Jaguar wants $30 EACH for them. I finally found a private guy parting out a late model, and I got all four for $25. Took about 10 minutes to change everything out once i had the parts. The struts are quite strong, and do a great job holding the hood up.
Thanks for this thread. Well done.

Jon

1 Like
18

I’m glad the ball studs I sent worked out for you.

And thanks for sharing this info,

Rob

19

My 1987 xjs has the eyelet holes. Anybody know where I can source “ball studs” ? Would a 90s-2000s XJ6/8 have them?

20

If you know what size/thread yours are, the link I provided for the gas struts also has ball studs.

They will also replace the ball socket end with an eyelet end if you prefer the ‘original look’.

Center to center length, the ball sockets and eyelets ends are the same.