NCT Result - Rear Axle Alignment?

FGR

Hi all.

Have a B5 Passat 130 TDI. It flew through the NCT so am happy with it but I'm hoping you could help me with one part of the results that I don't understand.

The 'Rear Axle Alignment' which has a threshold of +18 to -18. My result was -11. Now I have absolutely no idea what that means even though I'm glad it passed.

Is the Axle Alignment the same as Wheel Alignment/Tracking or is it something completely different altogether? Does it affect the driving/handling of the vehicle and is it worth bringing as close to 0 as possible?

Thanks for your help!

The Nutty M

The rear axle should line up with the front axle and that's where the -11 come's out of,the rear axle is 11mm out of line with the front. When you are tracking the front axle it's the two wheels on that axle that are a lined up perpindicular to each other with a little toe-in. Worn bushes on the back axle is the reason for the -11,no major hassle to get them replaced.Replace them before the next test and you'll be grand.
In so far as would you notice it on the road,you may find the car weaving a small bit on a straight road but that could be put down to the camber of the road just as much as worn bushes.You may be hearing a knocking sound coming from the back axle from time to time also going across humps and bumps.

On a little side note,is that a 97-00 estate?

FGR

The Nutty M wrote: »

The rear axle should line up with the front axle and that's where the -11 come's out of,the rear axle is 11mm out of line with the front. When you are tracking the front axle it's the two wheels on that axle that are a lined up perpindicular to each other with a little toe-in. Worn bushes on the back axle is the reason for the -11,no major hassle to get them replaced.Replace them before the next test and you'll be grand.
In so far as would you notice it on the road,you may find the car weaving a small bit on a straight road but that could be put down to the camber of the road just as much as worn bushes.You may be hearing a knocking sound coming from the back axle from time to time also going across humps and bumps.

On a little side note,is that a 97-00 estate?

Thanks for replying. Always appreciate the help here

The car in question is a 2003 saloon. Great car and fun to drive. I have noticed a knocking sound from the rear when turning left at low speeds - particularly coming off roundabouts. Must mean it's time to get those bushings looked at.

Will I have to get the tracking done on the car again afterwards ? Put four pirellis on last month and got the tracking done but want to make sure I don't unevenly wear the tyres.

The Nutty M

No you won't need to go near the tracking.Tracking the wheels only happens on the front of your car.The bushes are on the back axle.Replace both bushes as they are only I think less then 30 euro each.
The knocking you hear more than likely is the bushes alright.

Are you sure it isn't a B3 you have?

...http://www.micksgarage.com/steering-suspension-parts/suspension-mounting-kit/volkswagen/passat/passat/2000-2005/1.9-tdi/15417/

A little bit pricier than I thought.That's the B3.The B5 as far as I can see is a 97 to 00 estate that only has a TDi engine up to 115bhp but I'm probably miles wrong.

Nissan doctor

The Nutty M wrote: »

The rear axle should line up with the front axle and that's where the -11 come's out of,the rear axle is 11mm out of line with the front.

The -11 in fact means that the rear axle has slipped to one side at total of 11 meters over a simulated 1km on the NCT rollers. I.E the car is crabbing.

The Nutty M wrote: »

No you won't need to go near the tracking.Tracking the wheels only happens on the front of your car.

Tracking is the wheels tracking or pointing straight ahead on the road, this referes to both front and rear axles. The fact that the rear axle on the passat in question doesn't have adjustment for the tracking doesn't mean that its not off. the same is true of all measurements such as camber, castor etc. The axle may be slightly bent or it may be worn bushes as you said. It could also be different tyre threads and tyre pressure too.

Chimaera

The Nutty M wrote: »

No you won't need to go near the tracking.Tracking the wheels only happens on the front of your car.The bushes are on the back axle.Replace both bushes as they are only I think less then 30 euro each.
The knocking you hear more than likely is the bushes alright.

Are you sure it isn't a B3 you have?

...http://www.micksgarage.com/steering-suspension-parts/suspension-mounting-kit/volkswagen/passat/passat/2000-2005/1.9-tdi/15417/

A little bit pricier than I thought.That's the B3.The B5 as far as I can see is a 97 to 00 estate that only has a TDi engine up to 115bhp but I'm probably miles wrong.

The B3 Passat was discontinued in 1993. The B5 platform was used under the Passat Typ 3B from 1996 to 2005, with a facelift in 2000 for MY 2001. This platform also underpinned the Audi A4 Typ 8D from 1995 to 2001, and the Skoda Superb Typ 3U from 2001 to 2008.

The sales type is a 2 character code specific to a model range. A 3rd character is used to specify sub models. Typ 3B3 is a Passat typ 3B saloon manufactured after the facelift (the pre-facelift saloon is typ 3B2; the estates are 3B5 and 3B6).

FGR

Thanks all for your help. I hope the axle isn't bent as it sounds like an expensive fix. I'll pop into my mechanic over the next few days to have a look at it.

goz83

My front axle is off on my FTO by +4. What would be the likely cause here?

Nissan doctor

goz83 wrote: »

My front axle is off on my FTO by +4. What would be the likely cause here?

Any of the issues mentioned above could be the cause, wheel alignment, tyres, worn suspension etc etc.

FGR

Just looking there at my NCT Report and my front axle alignment was bang on.

The rear wheel alignment from a recent tracking I had done shows the rear axle at +0.44 degrees. Would that be enough to drag the car -11m/1km?

Still wondering how on Earth the rear could be so bad.

On a side note my car is pulling to the left..but not slightly. If I let go of the wheel on a straight road I could reach the ditch within seconds. The steering wheel pulls left as well.

Could it still be the bushings or is there something else at play here?

Nissan doctor

FGR wrote: »

Just looking there at my NCT Report and my front axle alignment was bang on.

The rear wheel alignment from a recent tracking I had done shows the rear axle at +0.44 degrees. Would that be enough to drag the car -11m/1km?

Still wondering how on Earth the rear could be so bad.

On a side note my car is pulling to the left..but not slightly. If I let go of the wheel on a straight road I could reach the ditch within seconds. The steering wheel pulls left as well.

Could it still be the bushings or is there something else at play here?

The alignment of the rear axle directly effects the front axle.

If the car was only aligned using basic front wheel gauges then the misalignment of the rear axle will not have been accounted for which is likely why the car is pulling to one side.

MugMugs

Or just the road camber.... Are you sure that knocking is at the rear of the car when turning left?

FGR

I'm pretty sure the noise is coming from the rear left hand side of the vehicle. It only becomes prevalent when accelerating out of a roundabout and the slight turn to the left that comes with it.

I'd like to think I'm used to the camber of the local roads here. My previous car seemed to drive fine with an ever so slight left bias which I put down to said camber. This on the other hand is a little bit mental.

Is it being suggested that I get the tracking re-done on the vehicle?

Again thank you all for your help in relation to this. It's a small matter but frustrating given my 50 mile commute each day.

Nissan doctor

FGR wrote: »

I'm pretty sure the noise is coming from the rear left hand side of the vehicle. It only becomes prevalent when accelerating out of a roundabout and the slight turn to the left that comes with it.

I'd like to think I'm used to the camber of the local roads here. My previous car seemed to drive fine with an ever so slight left bias which I put down to said camber. This on the other hand is a little bit mental.

Is it being suggested that I get the tracking re-done on the vehicle?

Again thank you all for your help in relation to this. It's a small matter but frustrating given my 50 mile commute each day.

I'd be suggesting that you get the 4 wheel alignment properly checked and this will point to where the problem lies.

FGR

Yeah I think it's best just to get a 4 wheel alignment done before taking it any further.

Thanks again for your help.

FGR

I hope the mods don't mind my resurrecting my own thread as it involves the same car and the same issue!

Please find an alignment printout attached from a main dealer in relation to the alignment. I can't understand what's on the sheet but it was explained to me that the rear offside camber is pretty out and they reckon the only way to repair it is to -try- and adjust the subframe which can be difficult if the car's corroded heavily or to replace the torsion beam as it may have been bent over the years.

The car is still pulling heavily to the left - is this the main reason? The dealer wasn't sure. They put it down to the car being 10 years old. It surprised me as I've driven a few B5 Passats and they all drive true.

In the meantime I wasted a fortune on having control arms and tie rod ends changed - all to no effect.

Thanks for reading and hope you can help.

Mech1

Pulling to the left constantly, or only under power / acceleration?

FGR

Hi Mech1! Thanks for getting in touch. It happens while I'm coasting, driving and braking. I have to hold the steering wheel straight otherwise it drifts to the left aggressively.

Mech1

First tyre pressures,
then swap tyres on front from side to side.
report back.

FGR

Sadly already done. Tyres switched left to right and still pull to the left.

Mech1

FGR wrote: »

Sadly already done. Tyres switched left to right and still pull to the left.

I dont see much in your result sheet to give your "bad pulling" symptoms, any chance left brakes are dragging (sticking on a bit)?

FGR

Mech1 wrote: »

I dont see much in your result sheet to give your "bad pulling" symptoms, any chance left brakes are dragging (sticking on a bit)?

I've wondered that myself. I don't hear or feel anything aside from the drift/pull. Is there any way I can check that without having to bring it to a garage?

sean1141

Try feeling each wheel (carefully) to see if one is hotter than the others