Speedometer not working after transmission oil change

[drzrma]

First thing, I'd like to thank you all for the invaluable treasure trove of smarts and information that this forum seems to be. I've only owned my Jetta for a bit over two weeks now but what I've learned just from lurking has been an immense help.

Car is a 1986 Jetta with the 1.6 turbodiesel, I had though the transmission was an AGS but it appears I may have misread the trans code. I drained the old gear oil, filled to edge of the fill hole, then located and removed the speedometer cable drive end and added the required half liter of additional oil. The problem then became how to reinstall the speedometer drive, since nowhere that I have found has any detail on how that is properly done.

I know there are no stupid questions, only stupid people, so here we go:

When I removed the speedo drive from the transmission, the end was a small square drive like you see on a dremel flex extension. Is this correct, or is the actual speedometer drive gear now lost and homeless in my transmission?

If that was correct, how on earth are you supposed to get everything to mate back up?

I'm feeling pretty stupid at this point, it seemed like such a simple task. The car has been driven a couple miles since last night when I did it, with no apparent adverse effects or noises. Shifts much nicer than before as well, it definitely needed the fluid change, but it would be nice to also have a speedo. I've tried Google, and searched here. I even tried searching the Vortex, also with no results. Any suggestions on where to go from here?

[Dakotakid]

First off, go to this same "troubleshooting" section and look down this first page and see:
"How do I get the speedometer gear out...." posted by "theman53."

Start going through the posts and you will see a picture of what your speedometer gear looks like. It sounds like your nylon gear is still in the transmission. I would not drive the car any further until you get it out.

Please read through the above mentioned topic as there is a lot of ideas in it for this problem. You did the right thing by changing the oil in your transmission (pat on the back here) but, for one reason or the other, your gear did not come out. Read through this and see if you have any more questions.

[drzrma]

Bah, can't believe I missed that thread, thank you for pointing it out.

Read through it and my drive gear definitely stayed in the transmission, and since there doesn't seem to be anything other than the speedo cable that holds the gear in position it is probably either destroyed or someplace inconvenient to recover. Car is at work with me now, so I'll pick up some more gear oil on my way home then drain it and look for either gear debris or see if the gear is within reach of the speedo hole.

If I'm unable to recover the gear, it looks like I'll need to pull the transmission out and apart to clean everything up, preferably sooner rather than later. I also need to identify what color the existing gear was to make sure I order the correct replacement, since my car came with a swapped cluster from some kind of canadian diesel and may have had a different gear than stock, along with a possibly swapped transmission.

Any other ideas or opinions would be appreciated.

[rabbitman]

I bet the PO had the cable out and lost the little clip that holds the gear on the cable, so when you pulled it out the gear stayed in there. I just checked and the gear does sit down into a hole so it could be just sitting in there where it's supposed to just spinning away. Probably when you put the cable back down the hole it missed the hole in the gear.

[Dakotakid]

Maybe you will be able to get it out without doing a trans. drain again. Maybe all you will need is some fine needle-nosed pliers.
I personally hate the attachment/cover site set-up of these trans./speedo gear hook-up. It always seems a little "if-y" to me. The rectangular grommet (made out of somewhat pliable plastic) can and should be replaced if it is cracking or is distorted in shape. It sits atop the transmission case under the flat rectangular "holder/securing" plate which keeps the speedo cable in. This grommet works to seal out the dirt and keep the fluid (gearlube) in the trans. (along with the o-ring). I opt to fit a new grommet to pretty much every trans. I mess with. Ask if you need help finding a place to buy these.

What I call "if-y" is the little 11 mm.-headed bolt which holds all of this in place. It is super easy to crossthread or over-tighten (strip out) this bolt upon replacement. Of course, one can tap new threads into the hole....but, then you sort of tend to worry about where the alum. shavings are going!!!!!!

[drzrma]

So I picked up some more gear oil and got the car home during my lunch.

I popped the speedo cable out again hoping for an easy fix that I might have missed as the light went away last night, with no luck. Decided it could use a flush anyway, so I pulled the drain plug and watched anxiously for shavings of any kind. Not only were there no shavings, but once I'd drained the oil I found the drive gear lying on its side somehow still right under the hole for the cable. Against my better judgment I decided to go fishing for it, despite the fact that every skinny grabbing tool I own seems to have disappeared after I allowed a family member to use my garage.

We'll skip past a great deal of profanity and frustration here and move to the predictable end result. The slippery little guy escaped, and is now residing somewhere in the bowels of my transmission, tantalizingly close while just out of sight and reach. Needless to say, the car is now parked for the near future as I decide how to tackle this. From my browsing of BrokeVW's site, it looks like I might be able to fish the thing out by only removing 5th gear, which seems like it might be doable without removing anything major from the car. I'm guessing with my luck though it's probably better to just plan on pulling the transmission and opening it up.

As fun as that sounds, I'd rather not do it if I don't have to. Aside from finding and seducing some surgical nurse and borrowing an endoscope or something, which I did consider but ultimately rejected due to a distressing lack of suitable local candidates, I'm out of ideas. I think some drinking is in order, along with building a time machine so I can strangle the VW engineer and/or bean counter that decided removing the speedo drive gear to fill the transmission was an acceptable solution to a stupid problem.

[rabbitman]

That stinks man, it's a pain to have to pull stuff apart for such a dumb reason.

Can you see it at all?

[theman53]

I die a little every time I think of a speedo...I die even more when I think of a VW speedo gear.

[drzrma]

That stinks man, it's a pain to have to pull stuff apart for such a dumb reason.

Can you see it at all?

Nope, can't see it at all. I lost it under the input shaft, which I think means it probably fell down into the bottom of the transmission. Even if it fit out the drain hole, I can't think of any way to convince it to move uphill towards the final drive.

I think at this point I'm going to start hunting for gaskets and a case splitter. Housemates probably won't be happy about transmission on the kitchen table, but they can put up with it.

[drzrma]

Apologies for double posting, but I was rereading speedometer drive gear related posts and thinking.

Someone, I believe burn_your_money, said in the aforementioned "How do I get the speedometer gear out" thread that some people that have lost the gear choose to just let it get ingested and change the gear oil after a short period of time. Can someone confirm, anonymously even, that the speedo drive gear is made completely of nylon, without even a hint of metal?

Before you ask, I'm aware all the usual disclaimers apply and everything I do is entirely my responsibility. I'm a big boy now and I learned long ago that everything I do has consequences, and things that I know to be maybe not the best choices often have very irritating and/or expensive consequences. Seriously, I looked on ebay for borescopes and endoscopes. Turns out those suckers are expensive, and most don't come with grabby appendages. Magnets yes, but sadly VW had not yet developed special magnetic plastics for this application as of the manufacture date of my Jetta.

I know it's a stupid idea, and it's not that I'm lazy or not mechanically inclined. I just really don't want to pull an engine and transmission that, thus far, have functioned quite well considering their age. Best case is I'm out the $20 I already spent for replacement gear oil, worst case that I see is an already weak tooth in some gear gives up and partially grenades the transmission. I already elected to pay for towing on my insurance, and a rebuilt AGS is ~$1000, which would be irritating but probably not that much more than the cost of parts and my time to split it and fish out the stupid gear. According to my nearest VW dealership's parts department a neutral(hopefully white) speedometer drive gear is ~$24 plus whatever it costs to get it from them to me on this stupid island.

Any feedback at all would be great. Tell me I'm a drunken idiot, it's probably true. Question my mechanical aptitude and sense, it'll be amusing and I love talking to people that know more and are smarter than me. Best of all, tell me there isn't any metal in that gear and I can just order a new one and change the gear oil in a bit. Or not.

[rabbitman]

I know the gear is held to the cable by a little metal circlip, but I don't know if the circlip stayed with the gear or cable........or if it was never there in the first place.

Maybe you can get at it through the fill hole.

[drzrma]

Circlip is my only real worry, beyond the concerns inherent with stupidly allowing things to be lost in my transmission. It certainly wasn't on the speedo cable end and I didn't see it at the bottom of my drain pan either time I drained the transmission. Reading BrokeVW's transmission teardown guide, he mentions something about a magnet somewhere inside the case, I'm hoping if it has come free of the gear that it will end up there. I ordered a new one when I ordered my new speedo gear, I'll take a look at it when it gets here and go from there, if it's ferrous I may try and poke around with my magnet through the various orifices available. Either way it's a very small piece, and hopefully softer than whatever it might encounter in its travels.

[rallydiesel]

I was able to fish the gear out after an hour of wriggling a piece of wire in there and using that three-pronged grabber tool. It sucked but it is possible. When you can't see the gear, use a stiff wire bent into hockey stick shape to slide it back into view. I used a hooking motion to blindly slide it to where I could see it. Then I used some needle nosed pliers and the grabber thing to snag it. I dropped it many times. Inebriation dampens the frustration a little   .

If you just cannot get it, I don't think grinding it up would be that harmful to the synchros, although it is a last or second-last, resort. I really didn't feel like splitting the case at that time.

[rallydiesel]

Here's a poster I made after my speedo gear ordeal:

[drzrma]

Rallydiesel that's the best thing I've seen all day, it means I've got some chance of fishing the little bugger out. Poster is good too, that stupid gear has already caused me far more frustration than should be possible given its mass and cost.

Supposedly a friend may have access to some kind of inspection camera that is small enough to fit through the speedo hole. Hopefully that combined with as many grabbing implements as I can find and as much beer as can be carried will be a recipe for success. If not, my new speedo gear should be here sometime mid next week and it will be an interesting experiment. If it goes badly, I plan to take up rocketry and put my meagre talents to work building some sort of intercontinental ballistic delivery vehicle so that I may give this wonderful piece of engineering a fitting burial near it's ancestral home.
(Just kidding. Please don't homeland security me...)