IRS shock bolts

[Joes66]

Hi all
I am putting my IRS back together and have found an annoying problem with the bolts that hold the shock absorbers to the IRS frame
I have fitted Gaz shocks and I have the original nuts and bolts that I took out of the IRS
When re fitting the bolts they are to short to allow the nylock nut to engage the thread at the end
I have checked the parts book and it shows a flat washer both sides of the bolt in the frame
But if I fit them the bolts are too short once tightened up
Anyone else had this problem?
I will have to find longer bolts to fit them correctly with the 2 washers and it just seems odd that the originals no longer are long enough
Any thoughts?
Joe

[Tom W]

If you’re talking about the top bolts, then the dampers don’t have any influence on the length of the bolt. The damper is sandwiched between the outer face of the cage, and a reinforcing plate, so the length of the bolt is dependent only on the distance between the plates on the frame. Check the part number of the bolt against the fastener decoder, it should tell you what length they should be.

[Joes66]

The bolts BH607171 are from what I can find out 2 1/2 inches long
This is the same as the ones I have
Very odd
I am wondering if the gaz shock is slightly wider across the mounting hole and the frame is not compressing as much
Or the new sleeves I have fitted in them are slightly wider
If I dont use the washers they are ok
Joe

[mgcjag]

Hi Joe...are the nuts extra thick......the SC parts has them listed as 1/2nuts.......SNG list them as thick.....not sure what the originals were...Steve

[abowie]

Obviously they should fit. If they don't, can you buy a longer bolt?

[rswaffie]

Hi,
There are only a couple of factors that would affect the amount of thread available for the nut.
1. The length of the bolt.
2. The thickness of the washer between the head of the bolt and the mounting face of the cage.

As long as 1 & 2 are to spec, and you’re not using more than one washer, there should not be an issue.

Have you got any pics of the fixings in situ?

[Joes66]

The parts book shows 2 washers per bolt
One inside and one outside
Not just one washer
I am fairly sure when I removed the bolts there was only one washer in each bolt but cant remember
I just checked parts book on sng site to make sure I was putting them back right and it showed as I say 2 washers
Is the parts book wrong?
Or if so which side does the one washer go?
Indeed shorter nyloc nuts would help and thinner washers as the ones I have are quite thick,but I have no reason to believe the washers I have are not originals

[Tom W]

The parts book (3.8) shows 4 bolts (UFB.143/16R) and 4 washers (FW.107/T)

[mgcjag]

Hi Joe there are various "parts catalogues/diagrams etc on different supplieres websites..they are not all 100% acurate.....a proper Jaguar parts catalogue for your model will give you full details ( please try to put your model and name in the signature area.....I just looked at the S2 parts catalogue in our knowledge base section it liste 4 plain washers for the shock top mounts...one under each nut....Steve

[Joes66]

Ahh
That explains it
Thx guys, I think that will do the job
Joe

[Robbiee]

What model is your car
My S1 3.8 has one flat washer per Bolt and it sits on the outside of the frame under the nylon nut
I’ve just measured the bolt and it has 2 inches of “shaft”
The nylon nut is normal size (not slim) and is just correct
The jaguar spare parts book shows ONE washer per top fixing of each shocker ..this should indeed sit under the nut.
Just as an aside ..it’s interesting how many photos, including those from “rebuilders” of IRS units show the bolt going fro out to in instead of the correct in to out!
Robbie

[Robbiee]

Photo

[rswaffie]

On the 3.8, SNG shows only one washer for under the top mount bolt and a self locking nut.
Therefore, if you are also placing one under the nut, you will have less thread.

[Joes66]

Hi Richard
That's interesting
If you look at the SNG series 2 2+2 parts it shows 2 washers
Parts 8 and 11
As mentioned it must be a mistake
I've sorted it out now
May let sng know as well that there is a mistake on their site
Thx for all the answers
Joe

[Robbiee]

Interestingly I’ve just looked and I seem to have erroneously placed a flat washer under the bolt head too...this might explain why my Nyloc Nut JUST fits flush and has only a hint of thread appearing.
I guess I’ll just leave it?
Anyway a 2inch shaft on the bolt seems correct

[Joes66]

Easy done Robbie
It's important that the nylock nut is completely engaged with the thread otherwise it could come loose
This was my issue with it
Joe

[rswaffie]

Robbie
There should be a washer between bolt head and mounting, and no washer under the nut, as per sng diag.
Which is what was in place when I removed the irs from my 63 3.8. As you can see, no washers under nuts for top mounts. Maybe Jaguar changed things for later models.

[mgcjag]

Joe...how about adding you model and name to the signature area...makes it much easier for anyone trying to help you.....they dont have to ask what model you have....Steve

[Robbiee]

Richard
Thank you , you are absolutely correct. I’ve just checked my 1962 pre strip down photo and YES the plain washer is under the bolt head inside the frame as on my last photo and there is NO washer under the nyloc nut on the outside
This should make my nyloc nut sit perfectly
Thanks one and all
I hope Joe’s is resolved
Robbie

[Joes66]

Ahh
Ok so no washer on nut side
That will solve the problem
Seems odd though
But I am sure jaguar knew what they were doing
Glad I asked here now as it is confusing
Wonder how many others are incorrectly fitted
Thx all
Joe