Wheel Alignment

[NCGermerican]

I guess this could go in any of the 944 groups, but since it has to do with a turbo, I'll post it here.

After replacing the short block on my 87 turbo, I needed to get an alignment since I disconnected the castor blocks from the frame. I took the car to a very reputable, if not THE most reputable non-Porsche dealer service shop, here in Raleigh to get an alignment. I first called and had them confirm they had the correct alignment tools (cone-shaped bolt for the steering rack and the toe adjustment tool for the rear). They said "absolutely, we've done many alignments on 944's but to let you know, it takes a few hours".

After the alignment, the car tracked very straight, while having some tramlining from what probably comes from having 245's on the front (could more toe help with this?). However, the steering wheel was clocked slightly to the left. I didn't think it was a big deal - when I got home, I disconnected the battery, waited 30 mins, pulled the airbag and wheel and tried to shift one spline to the right. Well, that put it TOO far to the right.

Something didn't sit well with me, so I checked the alignment dimple on the steering rack. With the dimple dead center of the viewing hole, the steering wheel was further off and the wheels were not pointing straight?

Am I wrong in thinking that the steps to proper alignment are:
1) Align the camber and toe on the rear
2) Adjust front caster (castor blocks)
3) Insert centering bolt (the one with the cone on the end) into steering shaft
4) (if needed) Center the steering wheel on steering shaft by adjusting steering wheel on the splines
5) With both rack and steering wheel locked in position:
6) Adjust camber (eccentric bolts)
7) Adjust Toe (tie rod ends)

This makes me think they did NOT use the centering bolt in the rack FIRST when doing the front alignment. If they did, shouldn't the dimple be centered AND the wheel be perfectly straight?

[dr bob]

I've grown more than cynical about alignment places and Porsches. That cynicism is documented in many places, and I won't regurgitate all the background. It did convince me to buy and/or build the tools and fixtures to do my own alignments.

Recognizing that this isn't for everybody, I always recommend that you bring any interesting tools needed. Starts with the rack centering bolt, something anyone can easily create with a small grinder after a visit to a decent Ace Hardware store. The pre-visit owner checklist includes getting the car weight correct and specifically do all your ride height and corner-balancing work before you drive to the alignment store. Do your own testing for wear on suspension parts in advance of the visit, and fix any of those. make sure your wheel bearings are adjusted correctly, and that means by the workshop manual method rather than by 'snug until there's zero play felt'. Set your tire pressures where you want them, something you'll do prior to any corner balancing and height setups. I place a couple bags of something in the driver's seat to mimic driver weight as part of that process, and fill the tank to at least 3/4 full.

Take a copy of your actual target alignment settings with you. The better machines have a library of cars and their factory settings. Your preferences are likely different at this point, with modern wider/larger tires, better dampers fitted, different anti-roll settings, different ride height, etc.. A lot will depend on how you use the car, as track-day settings tend to be way different than street settings. And they don't really mix that well.

The 928 alignment is a bit more involved than the 944, and I can do it easily without the fancy machine in under 2 hours all in. A shop suggesting that "the 944 takes a few hours" is trying to bullwink you into either more money or trying to impress you with how much care their operator needs to invest when their machine pretty much does it all. It won't install a rack centering bolt though, and the machine operator won't be used to using that vs. a steering wheel brace on the seat. That bolt is in place for camber and toe, out for caster measurements when the steering needs to move. All three adjustments are interactive so using the centering bolt likely won't be the operator's first choice as the adjustments are made.

The off-center steering wheel and any minor pulling are discovered and solved with an immediate test drive. Can't imagine a car getting out the door without that last step. Be sure you get the printout from the machine from whatever last adjustment step the operator performs. If he/she needs to add a slight camber or caster mismatch to solve for driving on a crowned road, let them explain it to you. Else, insist on both sides of the car matching as perfectly as they can. The tolerance ranges for adjustments are great, but I still need the two sides to match unless there's some really good reason.

A very good alignment will last a long time, and the car will be a joy to drive. A less-than-perfect effort will haunt you until you have it corrected. In my experience.

[walfreyydo]

Sounds to me like they set the front toe without the rack centered. Take it back and have them re-do it, explain that the steering wheel isnt centered while driving and you suspect the rack wasn't properly centered when the last alignment was performed. Also as a side note, when changing the position of the steering wheel as a work around, it can affect things like your blinker automatically turning off when turning, which is based on your steering wheel position.

Based on that, I would be skeptical of whether the rear alignment was done properly. Due to the rear trailing arm/spring plate setup on these cars, changing rear toe also changes rear camber at the same time, and they need to be sort of zeroed in simultaneously. This can be a challenge for techs that dont have experience with this rear suspension geometry configuration, and can add additional complexity requiring additional time. What I have seen with my own car, is they will adjust caster/camber, then adjust toe, but then the camber goes out of spec and they will say "thats the best we could do with camber" not realizing that the adjustment was thrown off when they did the toe setting (not withstanding the "toe and go" mindset of some alignment techs).

Hopefully the shop provided you an alignment sheet showing before/after settings (especially rear camber)? Centering the rack is pretty basic alignment 101 so not sure what to say.

[Evan]

I guess this could go in any of the 944 groups, but since it has to do with a turbo, I'll post it here.

After replacing the short block on my 87 turbo, I needed to get an alignment since I disconnected the castor blocks from the frame. I took the car to a very reputable, if not THE most reputable non-Porsche dealer service shop, here in Raleigh to get an alignment. I first called and had them confirm they had the correct alignment tools (cone-shaped bolt for the steering rack and the toe adjustment tool for the rear). They said "absolutely, we've done many alignments on 944's but to let you know, it takes a few hours".

After the alignment, the car tracked very straight, while having some tramlining from what probably comes from having 245's on the front (could more toe help with this?). However, the steering wheel was clocked slightly to the left. I didn't think it was a big deal - when I got home, I disconnected the battery, waited 30 mins, pulled the airbag and wheel and tried to shift one spline to the right. Well, that put it TOO far to the right.

Something didn't sit well with me, so I checked the alignment dimple on the steering rack. With the dimple dead center of the viewing hole, the steering wheel was further off and the wheels were not pointing straight?

Am I wrong in thinking that the steps to proper alignment are:
1) Align the camber and toe on the rear
2) Adjust front caster (castor blocks)
3) Insert centering bolt (the one with the cone on the end) into steering shaft
4) (if needed) Center the steering wheel on steering shaft by adjusting steering wheel on the splines
5) With both rack and steering wheel locked in position:
6) Adjust camber (eccentric bolts)
7) Adjust Toe (tie rod ends)

This makes me think they did NOT use the centering bolt in the rack FIRST when doing the front alignment. If they did, shouldn't the dimple be centered AND the wheel be perfectly straight?

You are exactly right. Your steps are correct.

It sounds like they did not use the centering pin. They just centered the steering wheel visually and then set the toe, which is the wrong way to do it.

The rack's internal centering is the true starting point. With the pin in, the steering wheel should then be centered on the splines. The fact that your dimple is off confirms they skipped the pin.

Take it back and tell them to do it properly using the Porsche-specific procedure and the centering pin. A reputable shop should own this mistake and fix it.

[Evan]

..

[cda951]

Am I wrong in thinking that the steps to proper alignment are:
1) Align the camber and toe on the rear
2) Adjust front caster (castor blocks)
3) Insert centering bolt (the one with the cone on the end) into steering shaft
4) (if needed) Center the steering wheel on steering shaft by adjusting steering wheel on the splines
5) With both rack and steering wheel locked in position:
6) Adjust camber (eccentric bolts)
7) Adjust Toe (tie rod ends)

This makes me think they did NOT use the centering bolt in the rack FIRST when doing the front alignment. If they did, shouldn't the dimple be centered AND the wheel be perfectly straight?

The centering bolt should only be used to ensure the rack is centered (as in an equal amount of turns lock to lock for both sides) and that the steering wheel is in the correct position relative to this.

The bolt should be removed during the adjustment of the front alignment, with the steering wheel held in the centered position using a spring-loaded holder as pictured below (can additionally use a bubble level if need be). If this is done properly, the steering wheel will be perfectly straight with the front toe being even side to side, and with equal tie rod lengths. In my experience, leaving the bolt in place doesn't guarantee a perfectly straight steering wheel, there is still enough slop possible to make it just a bit off-center, even with a perfect alignment.

I have aligned many torsion bar 911s and 944s at my shop and we know all the tricks, but we still charge more for these cars than for, say, a 986/987 Boxster (which actually has its own challenges in getting the rear toe/camber relationship correct).

https://pmdproducts.com/products/steeri ... VbEALw_wcB

[NCGermerican]

Here is the alignment sheet. I removed the name of the shop via the "clean up" feature on my iphone. Notice they told me I need camber plates….

IMG_6360.jpeg (1.91 MiB) Viewed 460 times

[cda951]

Here is the alignment sheet. I removed the name of the shop via the "clean up" feature on my iphone. Notice they told me I need camber plates….
IMG_6360.jpeg

Ah, this makes it clearer. What the shop should have done or should do is match the front right side camber setting to the left, say -0.5 degrees side to side. We often run into old cars not being able to set within original factory specs side to side, which is the point where we notify the customer and ask what they want to do, and if they don't know, we help to make an informed decision based on the use case of the car.

The front camber off by almost 0.6 degree side to side will cause a pull, though usually not an off-center steering wheel. In any case, the front camber needs to be re-set (which also mean re-setting toe----caster is good).

[walfreyydo]

Is your car lowered? (An otherwise stock ride height car, should not need camber plates as the OEM eccentric bolt on the shock should allow enough adjustment). However, if its lowered, this makes sense (although I would expect the rear camber to also run negative, which is curious to me)

Front caster and toe appears to be the biggest adjustment they made. The rear was already in spec before the alignment. Again, likely the centering pin wasn't installed during front toe adjustment. Basically when you adjust the tie rod, the steering wheel will move to compensate unless its locked down.

[NCGermerican]

Is your car lowered? (An otherwise stock ride height car, should not need camber plates as the OEM eccentric bolt on the shock should allow enough adjustment). However, if its lowered, this makes sense (although I would expect the rear camber to also run negative, which is curious to me)

Front caster and toe appears to be the biggest adjustment they made. The rear was already in spec before the alignment. Again, likely the centering pin wasn't installed during front toe adjustment. Basically when you adjust the tie rod, the steering wheel will move to compensate unless its locked down.

It's funny you asked that. To my knowledge, it's the stock ride height. The previous 2 owners of the car, back to around 2002 (from the records I have) were....at the age where I doubt they lowered the car - and there are no records of it. They look like stock springs to me. The only upgrades are the koni shocks front and rear.

However, the shop told me the car WAS lowered. I told them it wasn't but they kept saying it was. It "looks" lowered because I have a larger diameter wheel/tire combo, plus the offset of the wheels puts them flush with the fenders. So it does "look" lower, but I'm 99.9% positive it's stock springs in the front.