Amazingly well documented Odometer Fix

Post by **Ozark Lee** » 21 Jan 2009, 18:51

The brass nut goes to the turbo boost gauge and if you try to remove the back of the cluster panel it will mess up the boost gauge if you do not remove it. I was able (after much cajoling) to get mine fixed after I failed to remove that nut but you are much better off to remove that nut in the first place before taking the cluster apart.

...Lee

pt850 · Post by **pt850** » 22 Jan 2009, 10:21

Lee, I am doubly indebted to you. I just saw your response to my query on dash speakers.

Now, on the turbo boost gauge nut -- the AWDOF called for removing the turbo vacuum hose to get the cluster out of the car, but you are saying that before dismantling the cluster itself, that this brass nut should have been removed, yes?
And so this is why -- although I did remove and replace the vacuum hose -- my turbo gauge stopped working after I completed the odometer fix procedure. Can you tell me a little more about the "cajoling" you had to do to get the turbo boost gauge to work?
Many thanks.

Post by **Ozark Lee** » 22 Jan 2009, 21:33

Ive been racking my brain trying to come up with a coherent and descriptive answer to your question. I have had to replace the gears on all three of the Volvos I have and my daughter's Porsche as well and things get murky as to what happened on what change.

As I recall, on the turbo, I tired to pry the cluster apart and the turbo needle popped off in the process which was not expected as none of the other needles fell off on my N/A cars. At that point I stopped prying and re-assessed the situation and removed the brass nut. When I got the cluster apart it was obvious that the vacuum gauge that drives the boost gauge had deformed in some way but I can't remember with enough clarity to accurately describe it to you. As I recall it was a brass assembly and I actually had to bend it and pop it back to a centered position internally.

I am normally very good about documenting things with the digital camera but I thought the odometer gears had been discussed to a point where there was nothing more that I could offer the community and I took no pictures. It is a weird mechanism that looks almost like an old furnace thermostat with a spring coil.

All I can say is that my problem was obvious - once I saw it. If you completely separated the panel the boost gauge mechanism may have actually broken in half.

I really wish I could offer you more advise.

...Lee

pt850 · Post by **pt850** » 23 Jan 2009, 14:11

Thanks, Lee. I think I grasp what is involved: Either I fix it myself or call in a furnace repairman.

Post by **MadeInJapan** » 15 Mar 2009, 18:20

Decided to replace the small odometer gear in the '94 850 today. I got my gear from eBay- $10 plus shipping I believe- all total about $12. My speedo worked so I figured that the larger gear was okay...I was right. Anyway, it is important to follow the last part of the instructions and make sure that turning the small gear you just installed also turns the mileage gear inside of the odometer. At first I didn't do this because everything looked lined up. I put everything back together and in the car and it didn't work...ugh...everything back out and apart again. Good news is, once you do it once, it goes really fast the next time. Long story short, I went back to the directions and checked the last part and moved the new gear to make sure the total miles' gear spun too before inserting the pin on the motor- It's also important you don't over-tighten the two screws that hold the motor on. On my first attempt, I may have over-tightened those. I got finished just in the nick of time when the sun was setting...While I was in the cluster, I replaced some dead light bulbs. Now my clock and temperature light up but I have an SRS light on... I believe it was one of the bulbs I replaced, so I'll have to figure that one out. I'm just hoping that it's not anything serious and maybe it will just go away by resetting the code for it. I fear it's the clock spring in the steering wheel- these are not cheap and hard to find at a junk yard. When doing the odo-gear replacement, I also forwarded the miles using Lee's drill and pencil method. It worked great!

rayb · Post by **rayb** » 13 Apr 2009, 17:55

I just replaced the small odometer gear and had a few things to pass on. It went very well but two problems came up. The first one was when lifting the dash up enough to get the unit out for the gear replacement. When I lifted the dash up, the plastic trim near the base of the windshield cracked. (Not a big deal, glue will fix it).

Second, I somehow broke the plastic "mating surfaces" where the latches lock the unit in place...Step #7. I didn't think I was too rough when unlatching them but they snapped off...so be gentle here.

I replaced all bulbs while I had it apart. $2 apiece for the big bulbs in the center and , surprisingly, only $1 each for the "idiot" lights.

Thanks for the great step by step.

Ray

TX 850 · Post by **TX 850** » 26 Apr 2009, 19:33

The instructions and pictures made this job almost painless. Thanks to all who contributed and made the information available.

Because I was concerned about cracking the dashboard by lifting up one end with the other still attached, I decided to remove the dash. Seemed like a good idea until it came to the 12th screw - the one that the service manual seems to show in the center of the glove box opening. Never did find it. Fortunately, no damage to the dash.

charliefoxtrot · Post by **charliefoxtrot** » 06 May 2009, 18:28

I would have never given this a try without the posted instructions!
The only thing I would add is to please not do what I did: I used an electric eraser (they spin a narrow stick of rubber, just ask an architect over 35) to advance the odo to approximate the mileage. That's fine, just don't allow the tiny rubber particles to contaminate the odo head. If you do, you'll have to repeat the entire r and r to clean the dust out of the odo gears. What a dope!

KRUZNBY · Post by **KRUZNBY** » 14 Jun 2009, 09:32

Thanks for the writeup. I just replaced the small gear. I'd like to to say it took me only 2hrs, but it was more like most of a day. Much of the time was spent drilling off 20,000 miles to get the odometer to the correct mileage. I'd suggest reading this entire thread first to get everyone's tips.

-Tip the vents forward and pull/pry out.
-Use a bath towel to protect clear plastic from the cluster hood.
-If turbo disconnect vacuum line behind cluster. The white elbow will come off from the brass fitting. I actually removed the floor/dash plastic under the steering wheel to give more slack to the cluster so I could get it out and then remove the line.
-Remove the 8mm nut behind the boost gauge before lifting off the black face.
-There are three screws behind the odometer the must be removed.
-Be sure to stop a few miles before your target milage when using the drill method as you can not turn it backwards. Turn the last few by hand.

I also put the small gear in upside down I think (gear closest to motor and non-gear part closest to odometer). I'm not sure if it matters or not. I was worried that the motor gear would not make good enough contact the other way. It's satisfying to see it working now. It does pulse/tick rather than smooth operation, but others have said that it is normal.

850newbie · Post by **850newbie** » 26 Sep 2009, 19:30

Today I tackled the odometer on my 95 850T wagon. Wish I'd known about the comments section before I started, but many thanks for the tutorial that made the job easy. Comments and questions.

My odometer stopped at 204k. I opted to set it back to zero since I just bought the car. Fresh start idea. As soon as I pulled the rod out that holds all those little gears, I knew I made a mistake. Oh well, an hour later I had all zero's. Do not attempt if you have high blood pressure and no patience.

My boost gauge no longer works. The needle popped off unexpectedly, did I put it back on wrong? I guessed that it should sit at the low end of the scale. When I came back and shut the car off, the needle dropped even lower.

Does the vacuum hose from the boost gauge go directly to the turbo? When I pulled the cluster up, I took a foot of hose with it as I didn't see it was attached. I now have excess hose in the footwell area. This might relate to my above problem if I pulled the hose off whatever its attached to. My car is one hose, it does not have a connection in the footwell.

Definitely take the whole dash pad off, or not off, but at least to make it easier to prop up. Wish I'd known this was doable. I was worried about the Airbag, so I didn't even look at that side.

Buy a set of bulbs before you start.

Great site. Thanks for any help

Amazingly well documented Odometer Fix

Re: Amazingly well documented Odometer Fix