Replacement Front Bonnet Strut

[DrieStone]

I know most Esprits don't have them, but my '83 Turbo has a bonnet strut that was rather weak. Today I replaced my strut, but there's not a direct replacement, luckily it's not that hard to do what I did.

I measured up the existing strut open/closed and figured out that the 110N is a 25lb strut. I placed an order from McMaster-Carr (I think they may be US only though). What I bought was item 9416K136 which is a strut with threaded ends (M8x1.25) 18.18" open and 7.87" stroke. I removed the ends from the stock strut. Here's the photo of the two side-by-side (new on the left, OEM on the right):

The threaded ends are different, so I drilled and tapped the plastic ends of the stock strut to accept the new strut:

Then reinstalled. I didn't have the metric tap, so I had to purchase that in addition to the strut. My total cost? About US$30.

Now my bonnet actually stays open on its own!

Just FYI. The OEM strut (as mentioned) is a 110N/25lb strut. I think you could probably put a 30lb strut in there if you didn't have any other choice. I doubt a 20lb strut would keep the bonnet open though.

[Guest]

My (early) car has an aluminium rail contraption - was your gas strut OEM fit or was it an enhancement by a PO?

The aluminium item was used on a number of cars from the BL factory and even found its way under the bonnet of the Reliant Scimitar GTE.

Does the gas strut cause any issues with stressing the bonnet and causeing cracking/crazing? Does you car have any evidence of this around the bonnet mounting point? Just wondering...

Other than that it is a good article and the pictures are great. Thanks for sharing!!

[DrieStone]

It's OEM. I looked it up in the parts guide and noticed that it may have only been fitted to the USA versions (lazy Americans!)

I don't see any evidence of stress.The bonnet doesn't "pop open" from the pressure of the strut, you still need to open it by hand. The strut doesn't provide any lifting action until the last 25% of the motion, then it keeps the bonnet open.

#50 : Gas Strut, Bonnet Support : C075U6032F

Edited August 5, 2012 by DrieStone

[Lex Templar]

Rob, mine too has the aluminium rail, Domestic spec.

[PhilW]

Ive only ever seen aan aluminim rail. Never seen a gas strut on a bonnet.

[Lex Templar]

Nice work..interesting also that the bonnet hinges are very different to the Domestic cars.

[robington]

Thanks for posting.

Mine has the gas strut (unusually for a U.K car), and that has also failed. I got an aluminium rail to replace it, but the fixings are completely different and have not yet worked out a way to get it fitted in properly, so I may follow your instructions and get hold of a replacement gas strut.

Rob.

[mikec2126]

Just for info guys - my (UK) 1982 S3 NA also has a bonnet gas strut as was when I purchased it in 1985.

[The Veg]

I have a Federal '86 and it has the gas-strut, but it doesn't have the threaded ends like Jonathan's car. It has a ball-joint on either end, and when I bought the car the strut was knackered and would not hold the bonnet open. I took it to the auto-parts shop and compared to what was in stock and found one the right length with the right ball-joint sockets on either end. The thing works really well, and while I have to lift the bonnet initially, at about half-way up the strut takes over.

The only problem I had around the mounting points was that the jacknuts in the bonnet were loose in their holes, making it impossible to tighten the screws. A few drops of cyano-acrylate cement cured that.

Now one of today's projects is to re-mount a rear hatch strut that has popped loose from the bottom end...LOTS of pressure in the thing and it wants to be longer than the distance it must span. Gonna be fun.

[DrieStone]

I have a Federal '86 and it has the gas-strut, but it doesn't have the threaded ends like Jonathan's car. It has a ball-joint on either end, and when I bought the car the strut was knackered and would not hold the bonnet open. I took it to the auto-parts shop and compared to what was in stock and found one the right length with the right ball-joint sockets on either end. The thing works really well, and while I have to lift the bonnet initially, at about half-way up the strut takes over.

Just as a note, the ball-joints are threaded onto the strut. The stock strut is something odd, a really corse thread like an M6x0.5 (just a guess). The ends do come off the stock strut.

[Mesprit87]

Hi Ben,

Try removing the other one and install the longer one first, on mine, for a reason or another, one strut bottoms before the other.

Installing the longer one first gives you some leverage to compress it and align the second one.

Every car is different but it worked on mine.

Luc

[The Veg]

Jonathan- no, mine aren't threaded on like that.

Luc- it wound up not being as bad a job as I'd expected. I popped loose the end that attaches to the hatch, and managed to hold the hatch higher than it usually opens with one hand and re-assemble the strut with the other hand. That said, the brackets to which the struts attach on the firewall are looking a bit tired and have bent a bit from years of stress. Might have to make up something fresher at some point, but it's not urgent.

[Mesprit87]

Same here, mine are kind of loose in the bulkhead but I'll let them be for now.

[medida]

The VEG

For the gas strut that you purchased, what was the vehicle that it was listed under? What this the 1993 Honda Civic with 3 dr hatchback?

[The Veg]

I don't think that there was any particular vehicle. The auto-parts store simple had a display of lots and lots of struts, arranged by size/type. There may have been a book to determine what goes on what vehicle but I don't remember. I just brought my old strut in and compared until I found a close-enough match. I do remember that it was at an Advance Auto Parts store though.

If I remember to, I can look and see if there's any identifying marks on the strut itself that will help you.

[ChrisJ]

I've just replaced the bonnet gas strut on my 1982 Esprit - was original equipment, and the same make as the tailgate struts (also replaced).

 

Bought both items from SJS. The bonnet strut came with end pieces, but without the ball thingy in them. Tried screwing the old ones off, to put on the new strut, but different sized threads.

 

Had a real puzzle how to get the ball out of the old end - didn't have a small enough screwdriver to fit in the slot, once that was sorted, very straight forward, and I've now got a bonnet and tailgate that stay up of their own accord.

 

Chris

[MPx]

I've just replaced my front bonnet strut....twice. 

I bought one from Steve at SJ Sportscars as listed for the TE on their website.  It fitted - as in the ends were correct and a straight forward unbolt the old, bolt on the new.  The issues were:  The force of the strut was way too much so I had to push hard on the bonnet right behind the bracket to get it to close and it seemed very likely to break the bracket off the bonnet if not treated very carefully.  It was also too short a throw so the open bonnet was at an angle rather than vertical when fully open.   

I was at the SWLC open day a week or so back  and telling Phil about it.  I had the old one with me and he offered to get one made to the correct (oem) spec based on my old one.  I've just received and fitted that and its fantastic.  Again straight swap and quality fittings with just the right pressure and throw length.  And SWLC now have a few in stock.

So very happy...or I was until I got the invoice which made my eyes water a bit.  SJs was £41:05 delivered.  SWLC was £**.** delivered.  I understand SGS do one for the TE for £21:53 delivered, but no idea how close to oem spec that is.

[MPx]

Further to my post above...which I can't now edit...after a recount, SWLC price was £55.74 delivered.  It looks a quality component of exactly the right spec, but clearly not cheap. 

[SilverEsprit]

Cleaning up my new 83 Turbo US spec as well and my front gas strut has also failed.  It is labeled STABILUS 6309IQ  0105N 027/03 A 4 G314012.  I see your 110N and wonder if my 0105N correlates to the number you were looking at, and if mine is weaker (23.6lb vs your 24.7lb), and which or if both were originally installed.  I'll have to find one soon too, but broom handle in the mean time...

Edited April 22 by SilverEsprit

[ChrisJ]

Here you go: SJ075U0012 GAS STRUT Lotus Esprit Turbo (Prior 1988) (sjsportscars.com)

I have one in my UK Esprit.

[DrieStone]

On 22/04/2022 at 14:44, SilverEsprit said:

Cleaning up my new 83 Turbo US spec as well and my front gas strut has also failed.  It is labeled STABILUS 6309IQ  0105N 027/03 A 4 G314012.  I see your 110N and wonder if my 0105N correlates to the number you were looking at, and if mine is weaker (23.6lb vs your 24.7lb), and which or if both were originally installed.  I'll have to find one soon too, but broom handle in the mean time...

So weird to see an old post and realize I was the thread starter! I had totally forgotten about this. I wouldn't be surprised if Lotus used whatever was available to them.

I've heard of stories of both MG and even Jeep switching parts but using all the old parts first so you'll end up with cars of the same model year and trim, but with different parts.