View Full Version : Speedo Gear Q's
11-16-2002, 04:31 PM
For the past year, my speedo has been acting up. Going down the road, the speedometer would flucuate very bad. I would look under the truck and the speedometer gear housing that bolts to the tranny would be loose. I would just tighten it up and go on down the road. This always fixed the problem. Well, it started on me again last week and I took the gear housing off, cleaned the connections and re-installed it. This time, it would stay at 0 and sometimes fluctuate. Today, I finally got the chance to disassemble the whole speedo gear housing. The plastic gear tooth looked fine. What seems to be my problem is the 1/8" keystock that runs off of the plastic gear housing has rounded off at the end and is causing the key stock to turn inside the square housing.
Has anyone replaced the whole gear housing assembly? Any part numbers you could pass along? I take it this is a ******* only item? How much did the part set you back?
Thanks in advance.
11-16-2002, 08:05 PM
If you disconnect the tailshaft "U" joint you'll see a large nut holding the output shaft in place. This nut acts like a jamb nut holding the speedo drive gear in place. It needs to be tight like 300 plus ft. lbs. If it's not it will do just what your describing - mine did. I had Dodge do mine under warranty many years ago. I have to give the tech who did the work credit because the TSB was only for 4X4's. He tried it and used blue lock tight - end of problem.
If it's the drive gear theres a number on the drive gear itself - number like 31 - thats the number of teeth on the drive gear and Dodge should be able to replace it for you. Heck just let me know what the number is - I've got a rebuilt Getrash (1000) miles on it in the garage which has everything except the sender - the parts are yours for the cost of shipping.
11-16-2002, 08:08 PM
Yessir...the tranny is the Getrag 360 and I do believe the number on the yellow gear tooth was 31. But, the gear tooth looked great..it was the 1/8" key stock that turned in the square housing.
11-16-2002, 08:21 PM
Monty<br>I missed the 5spd in your sig. See my revised answer above.
11-16-2002, 08:44 PM
Thanks Bob, check your PM box.
11-17-2002, 12:07 PM
In my 89 the speedo gear case rounded the square drive pin off and broke it in half.. After some research I just went down to a speedometer shop that serviced taxis, did calibration etc. and they sold me the pin to go into the gear assembly that hooks to the cable.
There is a small spring clip to hold the pin into the drive.. the part cost me $1..... The gear assembly was around $150.. ;)
Try that first...
11-17-2002, 12:13 PM
<br>In my 89 the speedo gear case rounded the square drive pin off and broke it in half.. After some research I just went down to a speedometer shop that serviced taxis, did calibration etc. and they sold me the pin to go into the gear assembly that hooks to the cable. <br><br>There is a small spring clip to hold the pin into the drive.. the part cost me $1..... The gear assembly was around $150.. ;)<br><br>Try that first...<br><br>J-eh<br><br><br>Thats the same pin im talkin about!! How in the heck did you get the spring clip out of the gear assembly?<br><br>Monty
11-17-2002, 10:48 PM
I PM'd you.. <br><br>But like I say, I will have to pull mine off to see. Its been about 4 years since I did that repair and my memory isn't my strong suit... LOL...<br><br>I'll get back to ya on anything I can find...<br><br>J-eh
11-18-2002, 01:17 AM
See Lil' Dog, that's what happens when you sniff air from old truck tires.... geeezzz, ya try to tell em, but do they listen... nooooooo...;)<br><br>bob.
11-19-2002, 02:21 PM
[laugh] [laugh]<br><br> [eyecrazy]J-eh sssssss :P
11-20-2002, 10:10 AM
sounds like u found the trouble, but I'll just say that usually the housings are made to fit in one of 4 ways, depending on the speedo gear used (to accomadate larger/smaller ones). if you don't put it in with the right index your speedo won't work at all
12-28-2002, 12:35 PM
Well, I finally got around to fixing the speedo problem. Had to make a wrench out of 3/16" plate to get off one of the 5/8'' nuts. After taking the speedo gear housing all apart, I took some silver solder and filled the gaps in the housing where the key stock had rounded out. Put it all back together and is working like a new one. Thanks for the help guys.
02-09-2003, 01:46 PM
Just a little update:<br><br>My speedometer had quit working again last week. I had 2 problems now. ::) The speed sensor head's nut had split and wasnt allowing the keystock to make full contact with the housing it rides in. So, I replaced speed sensor head with the Napa/Echlin head, part number VSS100. I also found that the other keystock that goes straight into the transmission was rounded off very badly. Since I couldnt get to the housing with the keystock still in place to solder it. I had to build the keystock back up with a brazing torch and a piece of wire. After building it up, I grinded down the excess metal and reinstalled it. Well, so far so good. Hopefully this will cure ALL of my problems with the speedo. There was no way that I was gonna pay 95 bucks that the ******* wanted for the L shaped gear ratio adapter.<br><br>
02-09-2003, 05:07 PM
I just fixed my speedometer problem yesterday. Somehow during my NV4500 swap that little drive shaft jumped out and ran off. I made a new one yesterday, and it is working well so far. It's hard to look at the speedo now after I have been driving by the tach for two months. ::) <br><br>Mike<br>
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