Dwayne

Sorry about the confusion, Steve. I believe the source of the scraping is the spring contact on the wiper/cruise/signal cluster is pressing too hard against the horn contact on the steering wheel as Jerry suggests. This was a regular occurance on my '84 until I figured out the cause of the scraping. I would commonly have my cluster out of alignment and it would cause the scraping. Since you have installed a new steering wheel, it seems it would definitely need to be checked. You can either slide the cluster a few mm down the steering column or you can depress the spring contact to relieve some of the pressure agains the horn contact. I've used both methods.

You are correct about the dielectric grease. It is non-conductive and intended to repel moisture and protect against corrosion rather than conduct electricity. However, my horn still works and I only applied a very thin layer. I will update this thread to remove the reference for dielectric grease as I believe most grease types will work or a conductive grease would work as well. THANKS for bringing this to my attention and improving the quality of this thread!! Let us know how your repair goes.

whiteNSXs

Thanks a million Dwayne,
If you ever publish a 928 service book, I will be the first to buy. The factory manuals are as good as junk for DIYers.
I will be taking your and jerry's advice to work on the switch. If I had your skill and dedication, I would take the entire 928 apart and switch out all the problematic components with proven parts. I have already bought a bunch of vacuum lines and actuator diaphragms from Roger just so that I switch out everything for just ONCE before fixing the rest of of the HVAC. Your website
Dwayne's Garage: http://dwaynesgarage.norcal928.org/ is my new bible, not that I had one before. Your incredibly detailed step by step tutorials are invaluable but also very depressing for me. So many projects with so many steps but with so little time. Damn 928 is so gorgeous but so ........ I don't want to get flamed for my love/hate relationship with the 928 again. I am sure Jack Kennedy felt the same way about Marilyn Monroe.
Again, thanks for being a huge part of the 928 community. You made my ownership much easier.
Wait, did you just move to California? Northern??!!! Ridgecrest? That's NOT Northern, is it?
Gratefully,
Steve

Dwayne

THANKS for the feedback, Steve. It's always great to hear that these procedures help others out and I'm always interested in improving them.

I've actually been living in CA for about 20 years - in the Mojave desert - a great place to own/drive a 928!

whiteNSXs

The "dielectric" grease means to be a NON-nconductive grease VS conductive grease. This definition is well established and not what the confusion was.
Steve

stolarzj

Maybe a question Dwayne can answer.. I took it apart again and put in the washer on the odometer shaft as shown. Everything appeared to be working fine until I hit 49.9 miles on the trip odometer and it started to click, click, click, it will not roll to the 50th digit. Do I possibly need a thicker washer on the odometer shaft, or would the trip odometer not be related to that? Perhaps a washer on the trip shaft? Once I got to a stop and hit the reset button everything was working fine again, I'm guessing till I hit the 50 mile mark.

Anyone run into this?

Ducman82

ya that should have said DOES NOT..... opps

Dwayne

Hello stolarz,
If you have already inserted a washer on the odometer shaft and the free play between tumblers has been minimized or is zero (but the tumblers can still rotate freely), I would consider the trip odometer first. Given that resetting the trip odometer cleared the problem, it sounds like the trip odometer may need a 2nd look. IIRC, my trip odometer tumblers did not have significant slack between them so I didn't investigate inserting a washer for the trip odometer. I would monitor it and see if it does it again (hangs up) when the trip odometer attempts to turn the single, the 10's or the 100's tumblers. If there is significant slack or free play between the tumblers, they can get locked. So it may be worthwhile to investigate the trip odometer free play between tumblers and take up the slack, if needed.

Another thing to watch for is the tightness of the tumblers after inserting a washer to take up the free play. If the tumblers on either the odometer or the trip odometer are too snug, it will be difficult for the odometer worm gear motor to turn when advancing the tumblers. Make sure the free play between tumblers is minimum but the tumblers still turn easily. Just some ideas to consider if the problem persists and you open it back up. Let us know how it performs. THANKS for the question.

stolarzj

Thanks.. I'm going to let the trip odometer hit 49 again and see if it will fail to hit 50 again or not. If does I'll have to dig into the gears again.

Andre Hedrick

Dwayne!

Thank you!!! This worked exactly as you described.
When we meet, I own you a beer/soda and a handshake/man-hug.

Cheers,
Andre

Dwayne

THANKS for the Feedback, Andre! It's always good to hear if the procedure is accurate and is helpful.

billtool

So I had intentions of pulling the pod and sending the speedo off for it's badly needed odometer repair. Too - the speedo was working intermittently and the connection in the spare well is fine. After reading Dwayne's write-up, I figured what the hell...it's not like I haven't brought a bunch of parts to a gunsmith asking him to turn it back into a gun again...

Upshot is - my time was well spent. I cleaned everything up nice and pretty and the odometer works like a charm...as does the speedo...and my gas guage came back to life! Bonus! Took 4-1/2 hrs. (pod removal newbie) and was a complete success. I didn't remove the flex stuff though. Only speedo focused.

Dwayne - next time you're in Houston...the beers on me. Thanks bud.

Tommorrow is the flex plate check and Roger's back-up clamp install.

Jim A

What a great write up. I will order a replacement gear today. Regarding the tumbler slack, did you consider adding the thin washer to the left, rather than the right side?
I also plan on using a pencil eraser to burnish areas of electrical contact on the flexible and hard PC boards.
Thanks,
Jim

ksucat90

Jim, be careful with the pencil eraser, I'm not sure what year your car is, but those contacts on the flexible PC boards are fragile, ask me how I know, and some PC boards are no longer available.

Good luck, and yes it is a great write up.

tmpusfugit

Some additional findings on odometer gear replacements. I have completed 3 odometer drive gear replacements in the last few months. One of the 3 worked perfectly when completed and continues to this day. The other 2 both "had issues". Namely, they both worked for a while, one for 40 miles, the other for 120 miles, and then both stopped. On the first one I ended up replacing the entire spedo assembly and it now works fine also. On the last one, I decided to troubleshoot and find what I think is the real problem. I had the old gear, which was for the greater part, intact. It's diameter is .686". The replacement gear measures .707" diameter. Sure enough, the worm gear on the stepper motor was bound up tight in the meshing of the new odometer drive gear. I removed the single screw that mounts the stepper motor and inserted a .015" washer under the mounting point, then reinstalled the motor and screw. This modification allows just the slightest freedom between the worm drive gear and the engagement of the new drive gear.

I now have a few hundred miles on this last modification, and it is working fine. I recommend checking the assembly for this bit of freedom, and shimming it with a thin washer if none is found....

finally!

WOW! I have an 89 with electronic display so no need for this repair but sure enjoyed reading the detail of the write up! Impressive!