Wheel torque and dodgy alignment

[logan86]

I recently got a wheel alignment done at a tyre place which is usually very good, so I don't want to drop them in it here. But basically the steering wheel is no longer straight. Weirdly though the car does seem to turn in better and is more stable, but the wheel is maybe 10% right to go straight.

I should mention that I've had done: upper and lower wishbone bushes, anti roll bar bushes, v mounts etc, so I don't think there is anything wrong with the suspension.

But anyway they also did a front wheel balancing, and that worked great, but just to make me even more anxious they couldn't find the correct wheel nut torque. They said they thought it was 102nm, so they did 110nm to be on the safe side. Is this correct, and what about the steering wheel not being straight? Thank you to anyone who can give me some insight on this.

[mike020150]

Assuming you have a steel X100 model, the wheel tightening torque should be 88NM to 102NM. The steering wheel alignment is probably just plain annoying rather than something to be concerned about. These days, most garages start alignment adjustment by straightening the steering wheel and locking it in position before adjusting the tracking. If they get that step slightly wrong but everything else right, the car will behave as intended but the steering wheel will always be 'off centre' on a straight road. Before air bags and locking steering columns, it was easy enough to undo the steering wheel (one nut), remove and reposition it and all was well. Today, you either live with the problem or the car will have to have its wheels re-aligned to straighten the steering wheel. Mike.

[logan86]

Thank you for the info that's much appreciated. I hope 110nm wasn't too tight then, it's not much over so hopefully ok. Regarding the wheel alignment I actually called up and said I wasn't too happy and they're going to check it out again for me for free so I can't complain too much.

[BrianG]

I have had good results for tracking adjustment on various cars over the years at a local National Tyres depot until had two new front tyres fitted and a wheel alignment done on my X350. The steering wheel was left off centre at an angle of some 15 degrees when the car was going in the 'straight'. Despite complaining on the spot and them having another go (it was not much better) and them assuring me it was down to road camber, I was not convinced it was OK, so I took it to the Jaguar main dealer and paid for a full four-wheel alignment on their Hunter's machine. The printout showed that left front wheel was toeing out by 1.2 degrees - yes that's degrees, not minutes. After much argument with National's head office about letting my car go with such a dangerous fault, when I showed them the printout they gave me a full refund for their work and paid for the cost of the Hunter alignment. Fortunately I had not driven very far to cause damage the new tyres before it was put right. It dented my confidence in using any tyre fitting place for this sort of alignment work unless it could be shown to be correct with a printout from the machine.

[wombat]

The track rod ends need to be adjusted to centre the wheel. The alignment could be fine, as you adjust 1 track rod end, you compensate on the other.
Normally the wheel is centred and then held in position till the tracking is finished ensuring it is as you want.

[J44EAG]

I agree with Wombat.

Regrettably, not all technicians are as bright as others and some are not sufficiently well trained!

The V12 XJS I owned for a short period had tracking issues, the worst part being an off centre steering wheel. Not being willing to crawl under the car, I decided to use "The Professionals". I explained the problem which also included the near side tyre hitting the ARB on full right hand lock. The first thing the clown allocated the job did was centre the steering wheel with the usual lock. "No", I said, What was needed was to centre the rack. The fellow looked at me as if I came from The Moon."We don`t do it that way" was the reply. A short lesson from me in sunshine management followed. Aghast, the fellow saw me produce a 3/16 drill bit and a spanner from my pocket. I undid and removed a brass domed headed nut on the outer rack casing amidst cry's of protest. Matey thought oil would pour from the rack. Insisting the wheel clamp was removed, I had the man turn the steering wheel until the drill bit slid into the outer case and into a centering hole in the rack itself. Our hero complained the steering was solid and the wheel off centre. "Watch and learn" was my reply. I insisted the drill bit remained in the rack until all four toe angles were satisfactory.

Dropping the car down to floor level and grabbing a socket and wrench, I removed the central column nut, horn push, sprung conductor, bashed the back of the steering wheel with my fist, popped it off the column and I turned the wheel to get it level by three splines. With the steering column nut re-tightened and the horn push re-installed, I had the car raised again. Out came the drill bit and back in went the domed nut. Job done with the car driving a hundred times better than previously.

My parting shot was to ask the over confident fitter where he went to college. I went on to ask why he didn`t know about rack centering. The reply was that it hadn`t been taught.....that explains a lot about the levels of training given to the latest generation of mechanics. It would appear that rack centering on older cars is not covered. Perhaps they keep that back for the clever guys!

As regards what most wheel alignment companies offer, this is often an unexpected disappointment. Despite expensive Hunter or John Beam benches, few operators offer castor angle checks or adjustments. Castor is a function of wheel base length. Not a lotta people know that! If you know the wheel base length, you can use that to set castor. On an X350 SWB it is from memory, 119.4". Usually I again find myself acting as an instructor when setting one of these cars up. I start with camber at 3/4 of a degree positive. Then I set front wheels parallel. For castor angle, I take a steel tape measure and place the tape hook on the rear edge of the rear wheel pulling the tape tight through the centre of the axle line but reading the dimension as found at the rear edge of the front wheel rim. I read off the measurement. If it is less than 119.4", the car has "set back". More than 119.4" and the car has "set forward. On the X350, castor is set by moving the banana arm bolt along a slot in the sub-frame one way or the other to get that vital 119.4" wheel base length.Toe angle is again adjusted to parallel, then adjusting for 1/32" toe in on both track rod ends. Again, I`m suprized most so called wheel alignment garage mechanics don`t know this little trick to work around equipment that doesn`t have castor angle adjustment facilities. Monkeys or what?!

Definition of an engineer. A person who has more knowledge than is necessary for the class of work in which he is involved. Source of this gem? A standard question asked by a Civil Aviation Authority surveyor when examining a potential aircraft engineer with a view to issuing the candidate with his first licensing privileges. That is the difference between a mechanic and an engineer.

Mike K