1998 gtv rear camber

[agent86]

Hi Folks,
           Can anyone help with a rear camber problem on my GTV V6 rear end. The driver side rear tyre has scrubbed out on the inner surface after only 12k. This has happened once before shortly after I purchased the vehicle in 2007 at 60k. I took it to my local "no bull" people who aligned the four wheels or so I thought but now with 73k's both tyres have scrubbed the inners again. The camber is nearly 3 degrees which is great for handling but not for tyre wear. As you can see it is only a weekend car but I would be grateful for any clues. There are no noises or rattles from the suspension and it handles and brakes as it should. I suspect something bent but I am in Wodonga Vic so specialists up here are very hard to find. Apart from a very few it is Commodore/Ford country.
Cheers
Mark (AKA Agent 86)

[Jekyll and Hyde]

The camber is not an issue on these cars, providing the rear toe is set correctly.  Often wheel alignment places will not actually see the adjusting rods which set the toe in the rear end, but they are there.  Just put new tyres on my girlfriends '98 GTV V6 after 50,000kms, and they were worn dead even across the tread all round, and like yours it also has about 3 degrees of negative camber in the rear end.  If you were in Melbourne, I'd say take it to Craig at Trackside Race and Rally in Kilsyth, as he does the wheel alignments on my cars, and is very good at getting even tyre wear out of any late model Alfas - he doesn't necessarily use the figures out of a book, but tweaks them based on years of experience.  Perhaps a road trip?

[colcol]

Check all the bushes in the rear arms, they are are problem area in these cars, almost as bad as the top front control arms, rather than hold the wheel 'sqaure' to the road the bushes sag, and the top of the tyre tilts in and the bottom tilts out, you can get replacement bushes for these, or get the complete arm for a little bit more, have a look on EBAY in the UK, there are a few selling them, or try EB Spares or the Alfa Workshop in the UK, Colin.

[Neil Choi]

Often wheel alignment places will not actually see the adjusting rods which set the toe in the rear end, but they are there.  

Interesting discussion and excuse my ignorance, but is this the rod depicted here, plain as day to me, but unless the alignment guy knows the alignment characteristics of an Alfa is about.

[Jekyll and Hyde]

Interesting discussion and excuse my ignorance, but is this the rod depicted here, plain as day to me, but unless the alignment guy knows the alignment characteristics of an Alfa is about.

That's the one.  Not nearly as easy to see from underneath with the wheel on when they have it on a 4 post hoist, I will admit.

[colcol]

In my experience, it is always toe that scrubs tyres out, unless you are running high amounts of negative camber, you need to take your car to someone who understands these cars, i have had some bad alignments in the past by taking it to franchised tyre and service centres, that don't know these cars, such as towing them IN, instead of towing them OUT, you always toe out 33's, Suds, 147's and 156's, adjustable toe on the back suspension eh?, didn't know that one, the next time the alignment is done on the 156, i will check that, see how valuable this forum is, you learn all the time, Colin.

[agent86]

Thanks Jekyll, Neil and Colcol,
   the fact that there is room for adjustment gives me some hope as I was trying to avoid a trip to Melbourne on badly worn tyres. I shall point out the adjusting rods to the offending "no bull" establishment and hopefully get a better run out of a new set of rear tyres. I currently run Michelin pilots on the front so they will go on the rear and hope to match them up if still available, if not I am open to suggestions.
Thanks again for you input we Alpine Chapter members appreciate your vast knowledge.
Cheer 86                                     

[Jekyll and Hyde]

adjustable toe on the back suspension eh?, didn't know that one, the next time the alignment is done on the 156, i will check that, see how valuable this forum is, you learn all the time, Colin.

GTV/Spider has a completely different rear suspension setup to 156/147, 156 and 147 use eccentric bolts on the inner ends of the control arms for rear toe adjustment.  Much easier to spot (and wheel aligners should be more used to seeing them, as it's common to many late model cars, not just Alfa).

[colcol]

The rod with the adjustment thread is used to adjust the toe in toe out, like the steering arms on the front suspension and the rods with the eccentric bolts are used to adjust the camber, is that correct?,  never been under mine to have a good look, Colin.

[Jekyll and Hyde]

The rod with the adjustment thread is used to adjust the toe in toe out, like the steering arms on the front suspension and the rods with the eccentric bolts are used to adjust the camber, is that correct?,  never been under mine to have a good look, Colin.

No threaded rod at all on a 156/147, and only the rear of the two lower arms has an eccentric bolt, which is used to set toe (and would probably slightly affect camber too).  Remember 156/147 have struts in the rear with two spindly little lower control arms, GTV/Spider are multi-link rear ends, with spring sitting on a beefy lower control arm (as you can see in Neil's photo), and a seperate shock acting on another lower control arm.

[agent86]

Thanks again for all the input. To put in simple terms for dills like me the adjustment rods set the toe in/out which in turn affects the camber, but the wear on the inner edge of the tyres is most likely caused by the toe angle and not the 3.00 degrees of camber. The figures for the last alignment are rear axle
camber left 2.53  camber right 1.55
toe left .6   toe right .1
total .7           gen driving axis 0.01
all very technical but I am still confused. I will speak to a couple of alignment specialist to see if they can solve the problem or else it may be that trip to the big smoke.
Cheers 86

[colcol]

According to my 156 workshop manual, rear wheel alignment, rear camber negative 1 degree 27 minutes + or - 20 minutes, toe in, 3.14 mm, + or - 1 mm, or one eight of an inch, + or - .040", this is for 156 sedan, i checked mine and it was about right, but didn't know you could adjust it, camber and toe adjustments affect each other, Colin.