[tmr]

My 2005 Elise has around 7,200 miles and I just had new rear tires (A048's) installed. The front tires had a fair amount of tread left, so I decided not to change them out at this time. The new rear tires were purchased from Tirerack and are the correct size with the "LTS" designation on the sidewall. I used an authorized installer that I've dealt with before that specializes in custom wheels and that has installed new tires on several Elises/Exiges in the recent past.

The installer jacked up one side of the car at a time, using a floor jack with a rubber pad at the lifting point marked by the blue sticker and indicated in the manual for tire changing. He only lifted the car enough to clear the ground, was very careful with the removal/reinstallation of each rear wheel. They did a nice job mounting/balancing each tire, both of which only required minimum wheel weights to balance. The wheels were torqued to the correct specification per the manual. The front tires are inflated to 24 psi cold and the rear tires have 27 psi cold.

This shop does not have an alignment rack, as wheels are their specialty. I had the car aligned last year at the dealer, where it only required a small adjustment to the front and none to the rear if I recall correctly. It was just at the dealer a week ago for other service, but I elected to buy the tires elsewhere. I've driven the car about 20 miles since installing the tires.

A few days ago I noticed that the passenger side of the car seems to be sitting up slightly higher at the rear of the car than the driver's side. I also noticed that the tread, which picks up concrete dust like crazy from the new driveway to my basement, shows no dust on the outside inch or so of the right rear tire. This would indicate to me that I have either a camber or toe problem of some sort, which I didn't remember having before changing tires. I've never curbed a wheel or had any major pothole strikes, but it is a Lotus so anything could go wrong.

I remember that sometimes on my old Elan the rear suspension would be raised after jacked the car up, but after a few miles it would normally settle down after a few miles. I would think that the suspension would have settled down on the Elise after 20 miles, but I've never jacked the car before and don't know if this is commonplace. The front appears to be equal from side to side, but the right rear might be 1/8" or so higher. It went down slightly after a 200 lb. friend sat in the passenger seat a few times.

See photos below to see the tread pattern. I'm not that well versed on the shims used for suspension alignment, but it seems that factory alignment is all over the map from what I've read here. I'm going to take it in for alignment this week, but wondered if anyone had advice. I can't imagine that anything the tire installer did could have damaged the chassis or rear suspension based on what I saw. Thanks in advance for your help.

 

[fpitas]

Check the ball joints, suspension pivot bolts, coilover mounting bolts etc. for tightness. Several people have had them loosen (or, perhaps they were never tight).

 

[jmiesse]

Apperars to be a camber issue. I am no expert but maybe you can use some twine and compare the two rear tires by lining up the twine vertically to see if there is more negative camber on the right wheel.

Compare your tread wear on the old tires and see if it telling the same story.

 

[jmiesse]

Oh... also check to make sure the tire pressures are correct! COLD. 26 front 29 rear

To be honest the right looks over inflated!

 

[Dragon]

Assuming everything is tight as it should be then your camber needs to be checked... Adjusting the camber should not affect your alignment, but will require you to add shims to the right rear.

 

[Aedo]

Just had a new set of A048s as well and they both show similar pattern to your right tyre (following alignment)... looks like you do need a proper check though.

 

[tmr]

Thanks for the quick replies. As for tire pressure, I've seen great debate on this and have used 24 - 24.5 front/27 - 27.5 rear for some time with good results. More than that seems like too much. Current pressures are 24.5 front/27 rear cold.

On another note, the car was just at the dealer a week before and I asked the technician (Roman, who is the guy at LOA that everyone seems to have to most confidence in) to check the rear suspension for correct torque (toe links, etc.) while he had the pan off.

If shims are added to the rear chnage the camber, should this drop the righthand side as well? Judging by the looks of it, there appears to be too much negative camber. Making a positive adjustment might actually raise the rear.

The tire store has the old rear tires, as I had no space to carry them home in my car. I could call them up and have them look them over for a similar wear pattern. They were down below the wear bars when I changed them out.

 

[xtn]

Judging by the looks of it, there appears to be too much negative camber.

May I very humbly suggest that there appears to be to LITTLE negative camber on the driver's side?

xtn

 

[Green Ghost]

From the looks of it to me you need to remove a shim (or two) on the drivers (left) side and maybe put one in on the right side. But check your alignment first. You need to know where you are starting.


xtn beat me to it..

 

[TimMullen]

If one side sits a bit higher, one thing to suspect is that the rear suspension bushings were tightened with the suspension drooped. If the rear bushings are tightened while the rear is jacked up with the wheels off the ground, then the rubber bushings will be twisted when the car is at normal ride height - they will be attempting to "lift" the rear of the car because of their twisting - it's pre-loaded.

If this is in fact the problem, then back up the car onto ramps (or a drive on four post lift), and loosen the suspension bushings. Then "bounce" the rear of the car and even drive it off the ramps, and then back up (roll it back and forth on a lift). THEN, with the suspension at normal ride height, tighten the rear suspension bolts. That will put things with no pre-load in the suspension bushings.

 

[tmr]

If one side sits a bit higher, one thing to suspect is that the rear suspension bushings were tightened with the suspension drooped. If the rear bushings are tightened while the rear is jacked up with the wheels off the ground, then the rubber bushings will be twisted when the car is at normal ride height - they will be attempting to "lift" the rear of the car because of their twisting - it's pre-loaded.

If this is in fact the problem, then back up the car onto ramps (or a drive on four post lift), and loosen the suspension bushings. Then "bounce" the rear of the car and even drive it off the ramps, and then back up (roll it back and forth on a lift). THEN, with the suspension at normal ride height, tighten the rear suspension bolts. That will put things with no pre-load in the suspension bushings.

Tim:

After going through an Elan restoration as you have, I remember having many discussions about the correct pre-load on the suspension bushings before torquing them down. I did this work myself on the Elan, as I had much more confidence in my abilities on the Elan vs. the Elise. I guess I shouldn't let it intimidate me, but there's something to be said about completely disassembling then reassembling a car helping one become more familiar with it.

I would hope that LOA's most experienced Lotus tech would know this, but I guess one shouldn't presume anything these days.

I think that everyone has the right idea that I need to get a proper alignment in order to know exactly where my suspension needs shims added/deleted. I will ask the question this time about pre-loading the suspension before tightening, so thanks again for mentioning this. I'll give them a call in the morning and hopefully get this resolved before LOG next weekend.

Thanks to all for your responses thus far. Chime in if you have any other opinions or suggestions. BTW, the car has nearly a full tank of gasoline as we speak. Is the tank symmetrical about the centerline of the car?

 

[xtn]

BTW, the car has nearly a full tank of gasoline as we speak. Is the tank symmetrical about the centerline of the car?

Nearly enough as makes no difference, yes.

xtn

 

[brgelise]

Maybe a silly observation, but with Slightly underinflated tires especially, wouldn't a say 200lb driver be able to compress the left tire more than the right thus giving the visual impression of a broader wear pattern on the left v the right. You should see the wear pattern of a car with a lot of negative camber added !!!

 

[tmr]

Update:

I took the car to the dealer last week and the suspension was out of slightly out of alignment. They got it pretty much within tolerance and verified that everything was tightened as per proper procedures (not at droop, etc.). The passenger side was still a little higher, but this was less than 1/8". After a few hundred miles of driving this past weekend, the suspension seems to have settled, as the ride height and wear pattern look much better than before. Thanks again to all for their input.

Tom