Exactly what happened to me if you remember, we discussed the Jaguar part numbers? I ordered the full set of nuts with the bolts and washers, I ended up with M8 instead of M12, the part number is completely wrong even at Jaguar!

Interesting on the vibration tester, I wouldn't know how that works and would be interested to learn how it does work as I worked with Noise & Vibration measurement in industry? I'm also a keen musician playing a brass instrument, so I know all about frequency (vibration is just a low frequency noise anyway, surprising how few people actually realise that). I do remember that our hearing, as humans, is around 20hz to 20khz when we're very young, but our perception of higher pitch tends to come down a lot faster than our perception of the low pitch going up, as we get older (I know why if you're ever interested?). Bearing that in mind the tester you're looking at should cover the frequency spectrum you need? I also remember that to 'simulate' the human limits in hearing noise and vibration, the measurements were electronically weighted at each end of the scale, this was called 'A' weighting, so noise levels that affect humans are measured in 'DbA' (decibels, 'A' weighted). I doubt the meter you're looking at will measure the noise/vibration Linear (DbL), as we wouldn't detect anything outside the 20-20k hz ranges anyway. However, it is generally understood in the industry that we can 'feel' a low frequency noise (vibration) but we can't 'hear' it?

So right now I'm heading out to remove the plugs and put a little oil down the bores of the left bank, see if I can get the engine running after the disaster yesterday (simply have no idea why it lost a cylinder then cut out after 20 or so seconds?). I started a new thread yesterday asking which way the front muffler went on as mine was really tight to get on to the front down pipe, had to use some strategically placed wood and a big hammer, after buttoning the rest up I tried to start it, then it did the cut out scenario. Now I'm convinced, after only running a few seconds, I've got bore wash as there's no compression. I heard from my very good friend ericjansen, we haven't been in touch for some time. Eric was the guy who helped me enormously when I first got the car and I knew nothing about Nikasil engines and bore wash, it seems more than a coincidence that he should 'pop-up' when the disaster struck yesterday, don't you think? I believe I should look at this swapping out for a 4.0 with steel liners, and learn where exactly the VVT oil holes are that need to be plugged, and try and get a breakdown of the procedures.

I guess it may be a while until you're all back together, I realise that you are likely to follow the same processes with the prop as I did, and will be very interested to hear how it goes. If mine works well, and yours too, we should see about writing a 'sticky' for it, there's hundreds of mentions about 50-70 rumbles and no definitive answer to the problem, I've read loads of pages and threads, but only 2 people mentioned the potential problem using wrong/different fasteners, and only you mentioned the correct orientation of the Jurid Couplings!

Let's keep in touch and hopefully we will both end up with rumble free motoring?
Paul.

 

I had no vibration at 50-70 mph but I had a buzz, starting as fairly mild at about 90 and progressively getting a bit stronger as I reach 100 mph and go above. Not too bad actually but a bit annoying for me as I often go at speeds of around 100 mph on highways. I am almost sure it was caused by the extra 10 grams on one bolt at each guibo.

The vibration tester has a probe with a very strong magnet which is attached to points near the propshaft ends. The picture below (a different model vibration tester) shows how it is attached to the diff nose. The diff nose on the Jaguar is not accessible so I will attach it to the diff mounting bracket, the trapezoidal shape cross plate to which the nose of the diff is bolted. At the transmission side, I think the suitable points are either the exhaust mount (the transmission side of it) or the rear of the sump.

Let us know how you progress. Perhaps your trouble with starting the engine was caused by the weak battery. As we know, low battery/alternator voltage screws up all the modules. With a freshly charged battery, I believe that your engine will start and run fine.

 

I've just realised I don't know your name? lol.

Can such a device be connected up, then send a signal to the driver while you're driving to give you the information? When reading data, how is the data laid out, is it a graph or text, such as a low decibel reading? Very interested to know, I believe these cars were designed with the desire to reproduce the Rolls Royce 'waft you along' scenario as near as possible, anything we can do with these classic cars to help that desire has to be a positive?
Paul
BTW, still nothing today with an (almost) fully charged battery, sure it's bore wash, I've started yet another Thread about the whole story that led me to this position. https://www.jaguarforums.com/forum/x...n-help-208434/

 

 

Hi Robman25, yeah I did, caused a massive bang from the top of the TB. I started a new thread https://www.jaguarforums.com/forum/x...n-help-208434/ and did a compression test, see what you think?
Paul

 

Paul and others,

Thank you for contributing to this great thread! I have added a link to the X308 'HOW TO' quick links on the home page of this forum, right next to the link to Highhorse's thread on the driveshaft/propshaft center bearing to help future readers find this very helpful information. I've also added (Driveshaft / Propshaft) to the title of the thread to help the search engines find this thread.

One comment to add: the TSB that M. Stojanovic referenced in Post #6 is an excellent and informative document, but it does not entirely apply to the X308 (it was dated April 1996). For example, the center bearing mounting plate of the XJ40 and X300 allow for horizontal adjustment, but the mount on the X308 does not, so the only available adjustment is vertical, via the shims.

Cheers,

Don