| Author | Message | ||
     Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 339 Registered: 9-2004 |
Checking SS2 the prop shaft was not central within the tunnel. The prop rear end was out of alignmentit had been rubbing on the torque tube front mount. Is it to much power to the rear end causing the diff crossmember to twist,there is a small vertical crease mark on the o/s crossmember near the lower diff fixing. Could the cause be something else. I have checked the engine mounts and all is as it should be. Pix of the prop.  | ||
| John Dare Grand Master Username: jgdare Post Number: 224 Registered: 12-2004 |
I have seen this on several occasions and in one case it was the strange noise that caused the agitated owner to bring the car to me. A cursory inspection revealed the results of overall poor maintenence and these were duly noted. It had a most unhappy outcome, for when the noise disappeared (by clearancing the prop. shaft) he could THEN hear the rear axle hum  . Having refused to pay the bill, he then had the temerity to ask what he should do about the rear axle noise now clearly audible. I told him to turn on the radio; if it works! | ||
| Gordon Norris Experienced User Username: crewes_missile Post Number: 39 Registered: 2-2005 |
Patrick, I don't have direct experience with a SS11 prop shaft, and am assuming it is a two piece unit, but I do note RR curiously say to line up the centre bearing in the tunnel. On the XJ6 Jags, They tell you NOT to (!):to avoid noise and fouling it is actually offset at rest to one side(can't remember the exact figure, but can look it up if nessessary) to compensate for the torque reaction under load. (ie/ under load it all comes straight with flexing of the diff and engine/gearbox mounts.) Consequently, the offset was slightly greater for the V12's greater torque compared with the 6cylinder. Jag even specified a service tool/jig, which I made myself: a sraight bar about a metre long with 3 fingers welded on protruding at the correct offset: slacken centre bearing nuts, offer up the jig till the side of the 3 fingers all make contact with the shafts, re-tighten centre nuts..and voila..you're done. If you don't do this with an XJ you'll get whines, sometimes clunks, alot more vibration, and distortion of mounting points. With your car having a bit more power than usual, this Jaguar solution may have some merit/application. Just a thought... GN. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 341 Registered: 9-2004 |
Gordon, the prop is a one piece type with no centre bearing. The rubbing only takes place powering out of a left hand bend,don't like the slight crease in the lower diff fixing position on the rear crossmember. Another removal job of a crossmember maybe. Thanks for your interesting set up on the Jags though. | ||
| Gordon Norris Experienced User Username: crewes_missile Post Number: 42 Registered: 2-2005 |
Pat, sounds like it's all flexing a bit with the torque reaction under power. I think you're in for a job as you say, but at least you can do a bit of strengthening/reinforcement while you're at it. Engineering challenges can be a pain, but are very satisfying if solved well, and looking at pics you've posted, you're a master. Owner's of Lotus elans and +2's know what I mean, especially if they've been tweaked for more power...comprehensive re-engineering needed on suspension mounts for our roads, diff mountings to handle power in the long run, rear halfshaft rubber joint replacement with U/J's or CV joints, chassis reinforcements, a following car to pick up pieces as they fall off  ...the list goes on.. Good luck! GN. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 598 Registered: 4-2003 |
Pat, I assume it's the same car, and that the final drive crossmember is correctly located with new mounts as you stated. Also, the torque arm is presumably secure. Given that you have had all this kit out recently, surely you can eliminate them as the cause anyhow. No, we had no propshaft issue or any damage on our car when the final drive crossmember ripped out. The engine mounts would have to be completely loose before anything like this could occur. Even then I doubt that it would cause propshaft fouling. It would appear to be nothing to do with all those possibilities. I would start at the rear suspension subframe lateral mounts. The subframe is where the propshaft is fouling in any case. Using a jemmy, see if you can lever the subframe to the left as it would in a left hand bend, and whether the propshaft fouls. I put my money on a faulty or missing Brillo lateral bush, allowing excessive lateral movement of the suspension subframe. It's not a big job to correct that. Also check the subframe-to-carbody Panhard rods and mounts. RT. | ||
| Bill Coburn Grand Master Username: bill_coburn Post Number: 350 Registered: 4-2003 |
I am curious Pat to know if the Panhard rods are bent? This seems to happen on a lot of cars and can't surely be attributed to jacking or stump jumping. I believe it occurs with very worn subframe mounts which somehow allow so much movement it twists the rods out of shape. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 344 Registered: 9-2004 |
To All but one,this is not the car that i did the crossmember and floor mounts,that was the SS1, This is a SS2 with more power to the road! Thanks for your suggestions and will get back to you as soon as i carry out the above suggested checks. I will put a posting up on another find for saftey | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 599 Registered: 4-2003 |
Judging by the off-centred propshaft in the picture, the subframe is probably loose as Bill points out. One rough guide is to measure the tyre clearances to the mudguards on both sides. That may indicate that the suspension subframe is offset to the left in this shot. There could even be some signs of tyres scrubbing the guards. Bill, none of this would have happened in the bad old days of stringent annual ACT vehicle testing, eh ??? | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 346 Registered: 9-2004 |
Time this afternoon and all the checks made,wheels to wheel arch ok,panhard rods not bent,resillient [brillo]mounts like new. Rear suspension crossmember soild as a rock. Torque arm ok. Rear diff crossmember some lateral movment on the mountings,don't like that. Another look at the prop in relation to the tunnel looking along it to the rear it is close to the o/s. Another look at the crossmember crease could this really be the cause,cleaned off the underseal and the crease is more visible,this must be the prob but have no idea how this could happen. To much torque prehaps. Pix one.  pix two shows the amount of out of alignment of prop.  A new crossmember is needed here but hang on it might happen again. Out with the porto power and with controled force at different pressures to the diff housing the crease is plenished out and the stress relieved on the crossmember. Pix three is jacking the diff housing across.  The prop is now central and in the correct position. Bill, Richard, Gordon, Robert and all but one is there any record of this problem happening through some other cause. If not i will proceed to remove the crossmember and fabricate a more stronger unit out off thicker metal and of course fit new mounts with the floor plates etc. | ||
| Gordon Norris Experienced User Username: crewes_missile Post Number: 47 Registered: 2-2005 |
Pat, You certainly didn't waste any time. Sounds like a case of Gruntis Excessivus (too much torque) has flexed and distorted it as suspected. As mentioned it looks like it will need strengthening. Be interested to see the final result. GN. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 601 Registered: 4-2003 |
Do you mean that yet another final drive crossmember etc has shown up dodgy ? If so, it seems that you are dealing with the second in as many weeks !! Cripes. You say that the suspension subframe and Panhards are sound, so you must be in new territory I'm afraid. Maybe not, and the boot floor or crossmember are about to give way. I'm not trying to alarm you, but maybe this is yet another of the same final drive crossmember failures waiting to happen. Regards, and keep us informed please, Richard. | ||
| John Dare Grand Master Username: jgdare Post Number: 226 Registered: 12-2004 |
I find it difficult to understand how excessive torque (however quantified) could cause a definite CREASE in the diff. cross member support, thereby leading to differential offset and misalignment of the prop. shaft as depicted. If excess torque, however generated (?) was present, I would expect to see similar evidence of that excess in other Shadows, anticipating that (over time) it might induce some degree of deformation in the form of a twist, possibly not readily apparent to the naked eye. However, a specific crease is perhaps suggestive of a deliberate singular action such as the result of severe accident damage. I recall instances whereby Shadows have suffered rear or side impact damage (proximal to rear door/wheel arch area) requiring the replacement or precision repair, of most of the susp./rear driveline components previously mentioned. For that reason I have access to a dedicated jig for the diff. cross member support and indeed use that reference tool to check used diff. supports prior to sale and installation. | ||
| Gordon Norris Experienced User Username: crewes_missile Post Number: 50 Registered: 2-2005 |
John, What you say is all valid, but why Patrick's car may be affected over other Shadows is that his car is highly modified I believe, and produces more than "sufficient" power. Wider, stickier tyres, which I think he also has, that don't slip so easily can also contribute to increased loadings on aforementioned bits. Really, I must admit all my comments and others are all conjecture until he pulls it all apart for the full post-mortem, but looking at the pics of Pat's car and how much he has obviously worked on it, not to mention how clean it is underneath, any pre-existing accident damage I think would have been noticed by him before. GN. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 353 Registered: 9-2004 |
Gordon Richard and all but one Hehe!!! today i hope to get to the removal of the crossmember. After the ligning up i thought i would put the car through its paces and see if the diff does out of lign again on track off course,i was able to get to some truly remarkable speeds and powering out of the bends was quite something else,i would like to have taken some pixs but felt i should have both hands in full control incase it all went wrong. Of course in true RR/B fashion nothing did, dam. So back to the garage and inspect the diff alignment,can you believe it not any movment,still in the same place dead central! I am still not happy with it as it is,so today with luck i shall take the crossmember out and check all points with the strengthening of the crossmember and set up. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 354 Registered: 9-2004 |
Out with the crossmember, air tools its quicker. Thought i would put the first pix of the findings. As i had stated early on i was not happy with the lateral movement of the crossmember. I had checked the mounts from under the wing and they appeared ok,they are not! Undoing the n/s bolt nut as it came off with the locating plate down came the rust dust. These mountings should be replaced every 6/8 years to be on the safe side if left unatended maybe the torque arms will fail? Pix of the shot mounting. More to follow on the crossmember and the mods Maybe we need another posting on "mods better or worse"!as all these modifications we do not know if they all work until hard testing after completion!  | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 55 Registered: 2-2005 |
Patrick, Yikes! That mounting looks like the steel is about to turn to dust and the rubber crumble. While you're at it, go to a local engineering mount/"metalastic" type stockist and browse their industrial mountings catalogues. These mounts are of a generic design and usually to standardised dimensions, and I've seen them on all sorts of machinery. The good thing is you can upgrade to better/harder rubber and thicker steel, usually with rolled edges to resist cracking. A track tuned Lotus I had used these on the diff mounting and they'd crack across the bolt holes and fatigue the rubber as well. Upgraded mounts as mentioned solved all problems, and bolted straight in (and from memory I bought a handful for less than the cost of one "factory" item) Await pics of other mods with anticipation. GN. PS: You may also be interested in a post I made in the Technical Forum>Spirit/Spur section under "Rack leaks" thread on 8 Mar 05 at about 1:02 pm. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 611 Registered: 4-2003 |
Gordon, I would err on the side of caution with these mounts. R-R put huge efforts into tuning the numerous rubber mounts, and even changed a few along the way when they were not quite right. Notable was the similar-looking front suspension compliant mount among others. For that one, Metalastic declined to provide a special mount when Crewe requested it, so they switched to Avon who offered what was required. Genuine new ones only cost eg £12 each at Flying Spares anyhow. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 355 Registered: 9-2004 |
Phew what a day, first i checked the shot n/s mount,a great amount of movement. This is the side that runs in the kerb and collects the most dirt and water also it should take most of the torque load. Then removed the o/s mount just like new, could the shot mounting allowing the crossmember to whip under the diff directional torque loading and then give up as stated, the crossmember is very lightwieght. The pix shows the crease horisontal above the triangle being worse due to the straitening to the correct position,this must be done first so the fixings are in the correct place for the diff alignment etc when the new pieces are made. Next job to get the steamer up and running and get the underseal off the crossmember this is stationed at my home. The wife was out yipeee. Well things do not go according to plan, as i was useing the damp steamer it seamed to much for the trips and most of the house appliances with time memmorys all shut down panic. I finished the job and back to the garage to mark out the 14g sheet metal useing the crossmember as a pattern. Once done the cutting to shape with the power hack saw,i gave up with that. next the nibbler cripes i have lost count of the replacement cutters but the first part is completed with holes for the diff. I will be strengthening the front and top and bottom of the existing crossmember if all goes to plan. Gordon,those metalastic mounts are defenitly made for some other use as the holes on the new and old are elongated for the RR wider diameter. The only number that does not mean a lot is the patent no,the memmory has lost it, will look it up tomorrow. Richard those mount bolts still don't have nylocks on them.  | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 615 Registered: 4-2003 |
Phew. And I was proud of exchanging the coolant, hoses and V-Belts after dusk. Your pace leaves us all for dead !! RT. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 56 Registered: 2-2005 |
Richard, I agree completely with your rationale re the mounts, but with Patrick's extra power, etc I thought he might want to look at something stronger, and there are now a multitude of variants of this type of compliant mount to choose from. It depends on whether he needs to trade some refinement for durability I suppose. I'm also just keeping in mind he did mention further mods like twin turbo's somewhere along the way...VAROOOOOM...!! And Pat, I said above you sure don't waste any time, but like Richard, I'm gobsmacked at your furious pace! And your quality of work is still brilliant....have you several clones of yourself helping??? GN. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 357 Registered: 9-2004 |
Gordon,just father and son,just myself working on the Shadow. Funny you said clone as every one said the milkman was not around when seeing my son with me! I can get a free bus pass due to my age but of course with all the cars and M/c's that i have collected i never will. Progress to-day has been with no problems so the plates were completed,the crossmember and plate i painted with cold galvanise. The painted sides are then faced to-gether for welding. The welding is not the easiest due to the thin galvanise metal with the foam sanwitch between. After makeing the top and bottom plates,i have decided not to use them as the 14g is more than adequate. I will underseal before refitting the dampers. This when completed should take the torque and will last for years hopefully. Them next part is the boot floor renforceing plates. So will not deal with them as i already have.   |
