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Discussion Starter · #1 ·
Hi,
I'm getting new problems with this car I bought all the time


The speedomiter has started to act really strange. When I start it is dead half the time but suddenly starts to jump around, then dies again, jumps around a bit, etc.
But only for 10-20 minutes then it get better and better until it works perfectly.

What causes this??

It actually starter happening after a thin brown wire "fell" off the alternator. There are two terminals to put it on so I'm not sure I picked the right one. How do I find out if this is the problem??

TIA
\Henrik
 

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Discussion Starter · #4 ·
I assume it's electric and that it connects to the transmission but where?? And what could cause this?? A bad connection??
 

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Discussion Starter · #5 ·
Hi,
I just found out where it connects to the tranny (I think). It's a thin cable with a square end, right??

I've noticed the cruise control doesn't work when the speedometer is dead, so I assume the cable isn't turning.
What are the chances that a new cable will fix it?? Or is the problem in the transmission??

Henrik
 

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I think the speedometer cable is the same as the Buick & Oldsmobile. The cable is two pieces. One piece goes from the transmission to the cruise control unit. The other goes from the cruise control unit to the speedometer. Think the cruise control unit is on the left inside fender. You might try disconnecting the speedometer cable at the cruise control unit. The upper cable that goes to the speedometer. Try spinning it by hand and see how the speedometer moves. The cable may be worn where is goes into the speedometer. I don't use my cruise control so I just replaced my cable with a one piece cable that went from the transmission to the speedometer. These are easier to find and are less money.
 

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mine does the same thing sometimes, i remember one day when it was very cold, it did that and made horrid noises, sometimes it will still jump for the first 5 mins.

i dont know why, but it hasnt happened in a while.

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1970 Chevelle Malibu, 400sb, Holley 650, Edelbrock Performer, Headers, HEI, PS/PDB, BMR Rear Control arms, 7/8" rear swaybar, CC501's, 1.25" front swaybar, PST Front End, 3.08 open 10bolt, 275/60/15's out back, Corbeau Buckets.... swiss cheese 1/4's :( ... crappy paint.
 

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Discussion Starter · #8 ·
Thanks for the answers.
It's a bit difficult to see where the cable goes in the engine compartment but I'll have a closer look when the weather gets better.

Thanks.
 

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Discussion Starter · #9 ·
WHen I pull the cable from the tranny (can't get to do it any other places) and turn it by hand, the speedometer moves.
Is there an easy way to fix this?? What if I flatten the end of the cable a bit??
 

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Either the cable is worn or where it fits into the gear is worn. I don't know what parts you can find. The speedometer gear is not hard to take out and look at. There's a clamp with a 10 mm bolt that holds the cover on. If you remove the clamp the speedometer gear should come out. These gears are colored. Yours may be white. Every color is different and has different amount of teeth on it.
See if the area where the cable goes into is worn or cracked. That might be why it is slipping. I change the gear if this has happened. I have not tried to fix them. Perhaps it can be fixed. Clean it very well and use some hard epoxy glue. Form it around the area where the cable goes it. It might work.
 

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Discussion Starter · #12 ·
Ok, what's the trick to get the gear out

It wont come out. I've tried prying it out with a screw driver and beating it up with a hammer and screw driver. It wont move at all. My head turns blue every time I try to get it out.
 

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Don't know any tricks. I've removed a few. Are we talking about the same thing? On the THM 200-4R the speedometer assembly is near the rear of the transmission. It is held into the transmission with a metal clamp and a 10mm bolt. After the clamp is removed, the whole assembly should come out. The only thing the assembly has on it is a rubber o-ring around it to keep it from leaking.
I don't know what else I can add. Yours could be stuck into the transmission because of dirt. Doesn't sound to likly. They are a snug fit. Maybe the o-ring was leaking at one time and some one glued it in there.
 

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Discussion Starter · #14 ·
I'm pretty sure we're talking about the same thing. When I removed the clamp I assumed I could pull the gear out but no way.
I can't see any O-ring though but you mean inside the gear or what??
It's so stuck that I'm beginning to think you're right about the glue thing. It doesn't look dirty in any way.
 

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There is another o-ring between the plastic speedometer shaft and the housing. The one I am talking about goes between the speedometer assembly and the transmission housing. You won't see it until the speedometer assembly is pulled out of the transmission.
Sorry, the best I can describe it.
 
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