rear camber

[joeb]

i had my alignment checked and it is -1deg fronts and +0.5 for the rears. what is the spec for rear alignment? i called a shop and they were not sure what could be adjusted. toe, camber or even caster. they thought there might be a camber bolt kit for the rear but they were not sure. i changed a front tie rod and i know my toe is slightly out but wonder if a bit more negative camber frt/rear would help the car corner better? i think most shops are only open mon-fri so i might have to wait.

[BodybyFisher]

Joe, do you have a service manual, it should be in there, if not, ill look at mine later for you, Mike

That shop should have known all about your car and they should have had the specs, run from that shop as fast as you can..... The lower control arm and I think the toe arm have adjustments, if I am not mistaken.

[joeb]

i talked to the counter guy and he said the alignment tech will find out the numbers when he gets it on the machine. the "manager" said he does not know the details on every car. they see so many. i saw a mercedes sedan today and the rear wheels had noticeable negative camber. i wonder what the spec is for an IRS mercedes? my front struts are adjustable for camber. the strut has 2 bolts and when you loosen the upper bolt, the knuckle will fold in at least 5 degrees. heck, maybe 10. i have no idea how a tech can adjust the angle to +/-0.1 degrees with no camber bolt since the weight of the car is bearing down on the knuckle. the merc did seem to squat a bit in the rear too. hmm, maybe it had lowered springs? that will affect camber. i went to a merc site and they said thats how they adjust camber. by changing spring height with shims. maybe i can lower the rear of my car to achieve more negative camber?

[BodybyFisher]

Oh ok, now I understand, the manager isn't into the details. Every car is different, and the Mercedes info would not help you. I think the front camber is set by adjusting the two bolts at the bottom of the strut.

I would not mess with the front at all, have them put it to spec. IF they agree to adjust the rear camber for you, make sure you rotate the tires more often.

I replaced the rear springs on my car, the lower control arm can move IN and OUT.

[Cadillac Jim]

The rear suspension of the Cadillac is adjustable for caster, camber and toe-in, just like the front suspension. This is true of nearly all cars with independent rear suspension. Some cars with swing rear axles are more difficult but it's true of all of them. Some cars with solid rear axles are also fully adjustable. Any tire or suspension shop should know how and have the specs for your car. The dealer certainly will have the specs, as will the FSM. On my 1997 ETC, everything is near zero. The caster is not allowed to be positive on either the front or rear; this would lead to "wander." For anything more specific, refer to the FSM or dealer specs for your particular car. Some specs, like camber, depend to some small degree on what you are doing with the car.

[joeb]

i don't know if a deville and seville have the same rear suspension. i was looking at a newer DTS and the rear wheels have a fair amount of negative camber. i also heard that the camber is set based on how much weight the car may carry. more weight causes the rear to sag slightly but i also have level control so it should not ride low. i did not see any adjusting screws to speak of on the rear control arms. just bolts that sit in bushings. the infamous rear knuckle bushings that wear out? i am not loosing any sleep over this, just wondering how i can improve my handling and cornering feel.

[lothos]

I have a factory service manual for 1995. I'm not sure if the specs are the same for 1995 and 1996, but I can check after work for you tonight if you'd like.

[joeb]

specs are good. all the shops i talked to said they probably could adjust it and wanted to get it on the rack before saying too much. i just do not see how it can be adjusted as is. maybe with a camber bolt kit or some other type of piece?

[lothos]

This is from the 1995 Factory Service Manual

Wheel Alignment Specs

REAR

Camber 0.0 plus or minus .5

Cross Camber (L-R) 0.0 plus or minus 1.0

Toe Per Wheel 0.1 plus or minus 0.1

Sum Toe (L+R) 0.2 plus or minus 0.2

Thrust Angle 0.0 plus or minus 0.15

It says you can adjust camber by loosening front and rear inside control arm mounting bolts, adjust control arm to change camber, and set to spec. Tighten mounting bolts to 90 N*m (66 lbs. ft.)

You can adjust the rear toe by loosening the inner toe link bolts, using a pry bar and setting to spec. Tighten to 90 N*m (66 lbs. ft.)

I don't see anything about adjusting caster for the rears.

Wow, that just made me sound smart!

[JimD]

Just a word of caution.

It is risky to compare specifications between Seville and Deville models. And even more so when the models and the years differ.

GM/Cadillac incorporated some major suspension system design changes from year to year and at different break points within the model scheme. Stay within apples to apples.

[lothos]

It's the 1995 Seville Deville Eldorado Concourse FSM. It doesn't break it down by models so I assume it applies to all of them. I'm not sure about the differences between 1995 and 1996 though.

[joeb]

i think a 2005 DTS might have different rear suspension than a 96 STS? maybe they added more adjustability than using a pry bar.

[BodybyFisher]

I still contend that there is a wide range of Camber adjustemnt that is POSSIBLE, the figures above indicate ALLOWABLE ranges, allowing negative camber of negative 5. Having had the lower control arm off, there is much more range than that, my guess is that you could go to -1 easily, and it might be worth a try. I will try to find photos of my lower control arm off. I would be SHOCKED if your SEVILLE did not have as much POSSIBLE adjustment as the DEVILLE.

Think POSSIBLE and ALLOWABLE per spec. And by allowable I mean, allowable given acceptible negative conditions might arise as a result of more negative Camber, like increased tire wear, understeer/oversteer (I forget which added negative camber induces, but I think a PUSH would be created). But from my experience with the rear suspension, it has a wide range, how wide only your alignment guy will be able to determine, there may be other considerations, that come into play such as tracking, with the front wheels etc..