Speedometer gear?

[David's Plus]

I am having a problem with my speedometer. It is not working at all. I replaced the upper cable and checked the lower one and it all seems fine, but when you connect it to the tranny it doesn't do anything. If it is the gear in the tranny how do you get it out? I took the screw out and it won't come out? Can anyone help?
thanks

 

[PROPHET]

Welcome to the forum David.

Ive moved this thread to maintenance and troubleshooting section of the forum.

 

[Bizzy]

First, clean the area well with your favorite method. You have to remove the screw which you've done. Then the VSS drive gear needs to be gently pried from the transmission housing. Some will come easy and other will be very difficult if not impossible to remove from the outside. Just depends on how crudded up it is. I've run across a few that I had to pound on the VSS from the inside of the tranny to get them out. You obviously are not going to be doing this since the tranny is still in the car.

I will note that rarely does anything actually happen to this internal gear even though it is made of plastic. Unless of course there is more damage to the internals of the transmission.

Your best bet is to recheck the cable where it enters the VSS, double check that the VSS sensor and stalk is installed properly on the transmission.

If you do remove the VSS driven gear from the transmission be very careful with the rubber o-rings, they are obsolete. If you damage them you could be looking at a more serious problem with loosing tranny fluid. Once removed clean it well as well as the housing around where the driven gear is inserted. Be careful to avoid getting dirt in the tranny, though with the trans installed in the car, some dirt is inevitable.

In the diagram below, gently pry in the hollowed out area with a flat head screwdriver or a chisel. Those will be your best bets in its removal.

This illustration gives you an idea of orientation.

You can see where to pry with the screwdriver in this illustration.

<small>[ March 24, 2004, 05:19 PM: Message edited by: Bizzy ]</small>

 

[DHMag]

on the same note, are the speedo gears replaceable like speedo gears of RWD Fords ? when i changed tire sizes on my Ranger, i was able to change the speedo gear so the speedometer would read actual speed. the gears have different number of teeth, thus slowing or increasing the speedometer frequency. anyone follow me ?

 

[Bizzy]

I follow you Dale, but I don't think that there would be an easy way to do it. I'm sure there are parts out there that would fit...it's just finding them.

 

[David's Plus]

Is the gear in the tranny suppost to spin freely? I had it in gear and out of gear and it spun freely the whole time.. So the best way to get the gear out is to pull it straight out. Should i screw the VSS on the gear, and try to pull it out that way? I have been trying to pull this gear out for about a month now. When i bough the car the kid i got it off of said " the speedometer cable is bad" I looked at it and the housing around the upper cable was gone. And alot of dirt got down and into the cable. So i replaced it. now the gear still wont come out. hmmm.
thanks for you help

 

[DHMag]

Bizzy:
I follow you Dale, but I don't think that there would be an easy way to do it. I'm sure there are parts out there that would fit...it's just finding them.

well, if they are just any old speedo gear, i have several in my garage. i never had a part number though. just walked into the Parts Department, told em i need a speedo gear with X number of teeth.

Beth, do you have any pics of the gear that mates up with the diff ? (not the green one on the diff)

 

[Bizzy]

Is the gear in the tranny suppost to spin freely? I had it in gear and out of gear and it spun freely the whole time..

I've never spun one with the diff installed, but I don't think it should spin easily unless the diff is turning in the tranny. If it turns with ease I'd say that one of the two plastic gears in the tranny are broken.

So the best way to get the gear out is to pull it straight out. Should i screw the VSS on the gear, and try to pull it out that way?

Yes it should be pulled straight out. No don't use the VSS sensor stalk to pull with. Pry in the slotted areas on the VSS (in the first pic) with a screwdriver. You may not be able to remove it. Remember...if you get it out that leaves a huge area where dirt and debris can enter the tranny. Treat it just as you would an open motor and drape a clean rag over the open hole so that dirt doesn't get in there.

Dale, the speedo driven gear may not be that easy to replace. It's got to slide down inside the tranny housing so if you get one that is larger in diameter you won't be able to get it in there. I would also assume that if changing this gear you'd have to replace the speedo gear on the diff as well. (?) I suppose it's worth a try though. Pics per your request.

One is of the speedo gear that goes on the diff (green) just so people can see what it looks like. The other one is of the final drive gear (cream/beige color) that runs the speedometer.

<small>[ March 25, 2004, 07:52 PM: Message edited by: Bizzy ]</small>

 

[DHMag]

Beth, the speedo gear remains the same diameter, just the number of teeth change. changing of the speedo gear on the diff is not needed.

on the above pic, am i wrong in saying the speedo gear is tan in color ? if i recall correctly, that a 23 tooth gear.

gimme a day or two to dig mine out of the garage and get a pic of them for you.

btw, does the gear itself actually removed from that assembly ?

<small>[ March 25, 2004, 09:38 PM: Message edited by: DHMag ]</small>

 

[Bizzy]

What about the green speedo gear though, wouldn't it have to be swapped out as well to match the tooth pattern on the new driven gear? This will be interesting to see.

 

[DHMag]

Bizzy:
What about the green speedo gear though, wouldn't it have to be swapped out as well to match the tooth pattern on the new driven gear? This will be interesting to see.

no swapping necessary. will email you later with more information. right now, have rod bearings to do and work on my own car to finish.

 

[masho95]

DHMag:
btw, does the gear itself actually removed from that assembly ?

Yes the tan/beige gear comes off the speedo gear assembly. You just need to remove the small O-ring at the bottom of it.

 

[Devin]

Kind of off topic, but since this is the VSS, is that where I need to run a wire to for the digital cluster? I don't really see how that works...

 

[David's Plus]

Is the vss and the tranny gear only made for the SHO or is it on other cars? I don't think i can pull this gear out i am going to have to take it to a shop. Does anyone know how much it's going to cost? Labor and gear.

 

[Bizzy]

Devin - Yes, on the VSS sensor stalk there is a place for the connector. However, I don't know how the wiring for the digital cluster differs from the ones we have. Jelloslug would be the man to answer those questions. I believe he had a short writeup about it so search him out.

David, I'll address your question below the pics.

Here's the complete assembly.

On the left is the top of the driven gear that would be in the tranny housing. You'd only see this portion of it. On the right is the VSS sensor stalk. The square metal probe goes into the square driven gear and it spins. The sensor section of it picks up how fast and then transmits that info to the computer I assume so that the computer knows how fast the car is going. The speedo is cable driven however.

The two pieces as they would go together.

And attached. Again, the top of the driven gear is the only part you'll see when it's installed in the trans.

This is what it will look like on your trans. On the VSS sensor. On the left you'll notice the blue connector for the wiring harness to connect in there. On the right is where the speedo cable connects to the VSS sensor. That is what drives your speedo as it is mechanical in nature rather than electronic.

David, the cost of replacing the driven (beige) gear will not be cheap. First off you'll have to pay for removal of the trans. Figure at least $300 for that. Then the tranny case has to be opened. Finding a good VSS driven gear (if that is what the problem is) will not be the easiest task either as the case without it is useless. A lot of times the driven gear is destroyed when a trans blows, but not always.

As for whether those gears are SHO specific, the answer is no, they're not. MTX-III used the same ones however they were discontinued before the MTX-IV. So catch 22 for you my friend.

If you need the green gear I have some NIB. The VSS driven gear I may be able to help you with as well. I'll have to figure out the costs. But the parts costs will be nominal compared to the removal of the trans and installation of the gears. Do keep in mind also that one bearing on the diff will have to be replaced also as the only way to remove the green speedo gear from it is to take that bearing off.

As I sit here and think about this. You may want to check the plastic end where the VSS connects onto the driven gear on the trans. It is also plastic and I suppose it could be possible that the square shaped molded section could have gotten rounded which would allow the VSS to just spin around the metal probe section. If that is the case you might be able to put a drop of thread locker into that hole, then insert the probe and replace the VSS stalk onto the trans. I'd allow at least a day for it to dry. No promises, but it could fix your problem by holding the probe in place. I don't know if thread locker would even set up on plastic, but I suppose it might be worth a try. A small piece of paper towel put into the hole may accomplish the same thing. Epoxy maybe as a last jab.

Where there's a will there's a way?

 

[Devin]

Strange... I swear I didn't see anything like that on my Tranny. Is that VSS on all years?

 

[Bizzy]

They are the same on all 89-95 MTX SHO's.

This is about all you'll see if you peek down inside your engine bay.

<small>[ March 26, 2004, 01:08 PM: Message edited by: Bizzy ]</small>

 

[aleksander j]

David, the cost of replacing the driven (beige) gear will not be cheap. First off you'll have to pay for removal of the trans. Figure at least $300 for that. -------------------------
----------------------
i secound that one.
i had mine removed without taking down the tranny, the only thing, the mechkanic used about 30 min to remove the little screw. after that he just pulled it out.
BTW, mine is bendt. so the gear is totalty worn out..

 

[Devin]

Beth, my tranny is sitting on the floor, so it's pretty easy to look at it now. I just have to take a nice long look at it, especially since I wanna do a refresh.

 

[Bizzy]

Devin:
Beth, my tranny is sitting on the floor, so it's pretty easy to look at it now. I just have to take a nice long look at it, especially since I wanna do a refresh.

Or you could send it to me to do.