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Discussion Starter #1 (Edited)
Dear Friends,

I'm happy to share the attached pdf, a tutorial for stepper replacement/repair (for both temperature and distribution steppers) done without dash removal. LHD cars only.

If you intend on doing steppers using this procedure it's important that you download the latest version!!! (6/7/16)
 

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Thank You!

I want to thank you for sharing this great information with us. I have to wonder why so many people on this forum go through the trouble that they do to help out each other. One reason is that the people that do these great things are very nice, kind and intelligent. The other reason is that the Alfa Romeo 164 is a fantastic car with a very unique soul.

Thanks Pinino :thumbup:
 

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Thanks Pinino! I've been waiting for you to publish this:) My red car has both steppers bad. The black one only has a bad distribution drum stepper as I did the repair to the temp stepper on that one.
 

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I posted this link to it in my sticky, too Thanks for writing it up.
 

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Discussion Starter #6
Further reflections

Great to hear some feedback on this.

I’d let to comment on two possible variations to the procedure provided in post #1 :

when remounting the stepper frame, you can do it with the ADS already in place, alla Ries and Del (to do this you will need to “file open” the hole for screw #3 in the frame and have screw #3 already started so the frame can slide into place). Then simply tighten screw #3 with the Morton. (Ries’ modification of the other holes—see photo below—is quite unnecessary with the Morton at hand)

or

you might not even want to bother with screw #3, just leave it out. If you choose this route you might want make a wedge out of styrofoam or tough closed-cell rubber to place between the ADS motor and upper air tube to prevent any lateral movement.


Obviously taking either of these two approaches makes it unnecessary to modify the frame where the “foot” of the ADS sits (page 11) or file off 50% of the plastic pins on the ADS transmission (page 12).

There is a caveat to this however: it can be difficult to “slide the frame into screw #3", even with the cutout, and the plastic bracket that provides the anchor for screw #3 is easy to accidentally unseat; should it fall, it will be very difficult to retrieve.

(These comments have been add to the original pdf)
 

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Discussion Starter #7
I've just uploaded a new version of this document with some expanded sections and more and better photos. Too bad this is not a burning topic any longer due to the fact that most of you have "been there, done that".
 

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Sure would have been a big help when I did my 91S stepper gears. Yes, that stupid third screw was the big bugaboo. Don't know why Alfa did that in such an unserviceable way, when other options could have been much easier to accomplish, such as just a "stick it in the firewall hole" peg at the front of the stepper motor framework.

Thanks, though, for the "Stepper Gear Service Manual".
 

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Very good. I'd like to hear from the first guy to use this procedure. The great thing about this is that it doesn't "down" the car like using the Alfa factory pull-back procedure.

I've done the dash pull-back twice now and didn't find it that difficult, just a time consuming. However, if I were to do it again, I'd modify the bracket per Steven's recommendation just to make it possible to do the surgery "endoscope-style" should the need arise in the future.

I'm not quite convinced that a broken drum pivot can be repaired without pulling the dash back. Putting the reinforcing ring on yes, but positioning the broken piece/fabricated piece?
 

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Discussion Starter #11 (Edited)
I agree with your last point (that repair in situ of the drum key could be challenging). Luckily neither car I worked on, one with 89k and the other with 62k miles, needed the key repaired. But Ries van Kersbergen did accomplish this in place. Also he did not use the standard 3/4" brass ferrule as enforcement, but his own bushing with 18mm OD. Here's his description:

Now it is time to inspect the air valve damage. Use the dentist mirror to precisely observe the condition of the aire valve. When it is cracked or broken and parts are missing (in my case it was) you have to fix this problem first. When it is cracked use the Alfa Pro re enforcement ring. To bring the ring in position one has to manoeuver a lot with extension tools made of 3 mm iron wire or wood . A thin wooden stick with double sided tape on top to stick the ring on, makes also an easy positioning tool. In my case half of the air valve connection was disappeared (Fig 6) and to my opinion it had no use to use the Alfa Pro re-enforcement ring, so I made a ring my self. (fig 5) I used a piece of brass pipe (outside diameter of 18 mm ) wall tickles [thickness] about 0,5 mm. The extra construction on the ring was made to replace the disappeared air valve parts. This was in my case the very special part of the job and costed me several weekends experimenting. Now I have find out how to do it, it will cost me 1/2 hour. My special ring doesn’t have to be glued or something. Just bring it in position and that’s it. (To make sure to recover the ring when it falls in the dash I constantly had a thin wire on the ring. Afther the ring is in position one can tear the wire loose at a suitable moment.)

Adding to Del's lament, it is so sad that Alfa was so poorly equipped to deal with this fiasco. It would have been so easy, they could have even designed a special "Alfa" 90° screwdriver that they could peddle to the Alfa dealerships. Most troubling is that they didn't immediately offer a resistor fix to stop that needless hammering, and didn't modify the stepper frame so the steppers could be easily twisted in and out.
 

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Alas, that is one of the crosses we must bear in owning Alfas, as with some of the engineering involved in making the car so much and satisfying to drive, they sometimes sure put in some lousy body/systems designs here and there (stepper mounts, door handles inside and out, etc). It tended to one the impression that there were two separate groups designing the car, ie, the "lets make this car really fun to drive" group, and the "lets just throw into the body and systems whatever it takes to get the car out the door" lackeys.
 

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"Alfas are alone in this regard"

Actually, not so much, as for sure, they must have learned from the masters, the British Car Industry. Been there, done that, as they say. They were fun to drive, but oh, so unreliable, at least in the years I drove them (the Brits).

I've always stayed with Alfas because of all the different cars I've driven through the years, they were one of the more satisfying to drive marques that I could afford at the time; and, I found the cars to be much more reliable in general than the Brits I drove, as well as my father's GM cars. He had a tough time accepting my buying my first Alfa, saying, "what is this eyetalian stuff, will wear out in 20k miles for sure (I ended up putting 260k miles on that car)". Meanwhile his Caddies, Buicks, and Olds spent most of their time in the shop for one failure or another.
 

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Discussion Starter #15
Reinserting screws just got easier

The original #8-18-3/4” phillips-head screws can be a nuisance to start—they easily fall from the phillips bit. Square-drive screws are the answer as they are held firmly in place in a #2 square bit, makes quick work for reinsertion. The standard #2 bit however does need to be shorted ca.1/4" for screw #3.

Special thanks to Spitfire for identifying a source: McMaster & Carr, part. no. 90395A197 (pitch is not specified in M&C specs but screws are indeed 18 tpi).

If anyone wants a set of 3, gratis, I have lots of them, just send me a pm.
 

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Got your PM. I'm glad this worked out. I hope McMaster doesn't leave off this info on too much stuff. Although the cad drawing was correct, and it sounds like their staff was right on.

I didn't read in depth with the whole process yet, but thought I would throw this alternate tool idea out there. Skewdriver Pro. It looks like it could be lengthened more if necessary, but would be floppy compared to the motion pro angle screwdriver in the write up. Let me know if it looks like it wouldn't cut it. The various joints would want to be taped. Also, the head is on a slight angle, so the handle will be angled out of the service hole. Possible clearance issue?
 

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I need do the resister mod in the LS, as I don't know if those gears in the LS are stronger, or what. Don't want to do the above removal job if I don't have to, of course, although it does make things so much easier. Also don't know about the distribution drum, and if that was updated with something stronger.
 

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Discussion Starter #18
Interesting, this Skewdriver Pro. It probably could service screws #1 - #2 no sweat, but unlikely #3 because the articulated "head/joint" would have to be hand held/guided and there's no room for that. The screwing shaft of the Morton is totally enclosed in a cylinder which gives the tool a unique one-piece design allowing the user to put pressure on the screw by firmly holding the handle even at 11" to 16". (On a side note, according to the manufacturer the tool has a capacity of 65 foot pounds!). I know the Morton is expensive—I'll be happy to loan it to any Alfisti with a good credit score (ha).
 

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Discussion Starter #19
Del, I think you might have missed a note I have quoted before about the modified HVAC design on the later cars, it goes...

Just for the record, I include here a communication of an HVAC engineer who worked on the new programming of the HVAC for the 164 face-lift, i.e. 1994 models and up.

"While the motors remained the same, there was a change starting in '94 with the AC controller (LCD display). While stationary, the stepper motors receive a periodic pulse from the controller to maintain their relative position. This pulse caused "hammering" on the stepper motor gears and is what ultimately causes the "wear & tear" leading to failure. In '94 the controller was reprogrammed to reduce the pulse frequency by 50% to help improve life expectancy of the gears in the stepper motor. I left employment with Alfa in '96, so I don't know if this change produced the desired improvement."​
 

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Thanks, I evidently missed that. Puts my mind at ease...I guess. I may still might put in the resistors, as he wasn't sure his redesign cured the problem.

Any word about the distribution drum failures?
 
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