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I have the dynaflow in my 63, only reason I put a 18 tooth in was because that is what was in there originally. Is there something else that could cause the Speedo to move too fast? Maybe the Speedo lost tension? I will try looking into the hole next time i have it on the lift. 

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12 hours ago, RivNut said:

Have you been able to identify what kind of "fluid" it is?  That would help.  

 

8 hours ago, steelman said:

Here is another one that is easier to use, but you must know the number of teeth on the driven gear inside the transmission. Again, these are colored, so remove the drive gear and look in the hole with a flashlight to see the color of the driven gear. Once you know the color, you can determine how many teeth are on that gear and use this formula.

http://www.moveras.com/Support/Tools/SpeedometerDriveGearCalculator.aspx

 

23 hours ago, telriv said:

Any idea where it may be coming from Bob???

Sorry gents: you all are good, but not mind readers. My apologies. The black fluid drips from under the dash on the driver’s side. The fluid hits my left foot while seated on the driver’s seat on the flat part of rubber floor mat.

thank you

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Have you stuck your finger in it and smelled it or felt it?  Any way to identify it other than "black fluid?"

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11 hours ago, retiredmechanic74 said:

There are only two fluids I know of that can leak from the dash. (1) Oil Gage pipe leaking from a mechanical Gage. and (2) The speedo cable and I think that is where it is coming from. The gear in the transmission is allowing the fluid to travel up the cable. If you look at the cable you can see that the cable is made by twisting the metal. This is done to pull some fluid up from the trans to keep the cable lubed ( the idea wasn't a very good one) I would suggest to change the cable and case and the seal in the gear housing. You can get a new cable and case (that way you get the correct length) . Buying just the cable can give you problems with getting it right because the tip that goes into the speedo head has to be crimped and all to often doesn't hold. If you want to just change the cable it has to come out from the speedo head not from the trans.

I believe I know the spiral wrapped speedometer cable you are writing about. Seems to me the best thing to do is replace the speedo cable with casing all in one. This assuming the fluid that is leaking is from the Speedo cable. Maybe I erred I’m not mentioning the fluid that is leaking is black as India ink.

thank you

Red Riviera Bob

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10 minutes ago, RivNut said:

Have you stuck your finger in it and smelled it or felt it?  Any way to identify it other than "black fluid?"

I knew that was coming when I looked at I said smell it, but I did not. The car is in the shop getting some other stuff fixed. When I get it back I’ll crawl under and do a better investigation of what the fluid might be.

thanks again

Red Riviera Bob

 

 

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22 minutes ago, Red Riviera Bob said:

I believe I know the spiral wrapped speedometer cable you are writing about. Seems to me the best thing to do is replace the speedo cable with casing all in one. This assuming the fluid that is leaking is from the Speedo cable. Maybe I erred I’m not mentioning the fluid that is leaking is black as India ink.

thank you

Red Riviera Bob

The black fluid is probably dirty cable grease or trans fluid. 

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22 hours ago, retiredmechanic74 said:

The black fluid is probably dirty cable grease or trans fluid. 

 

22 hours ago, retiredmechanic74 said:

The black fluid is probably dirty cable grease or trans fluid. 

I have a choice between a used original speedo cable or buy an after market cable from CARS LLC.

The cost is small. I believe a used cable with good appearance and solid connections is a safe choice. Also, I know the seller of the part.

thank you for your helP Red Riviera Bob

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On 2/20/2018 at 9:08 PM, retiredmechanic74 said:

The black fluid is probably dirty cable grease or trans fluid. 

Mr. RetiredMechanic74, you are right the speedo cable casing is leaking. I loosened the knurl knob on the back the speedo. I pulled on the casing, but the casing would not budge. The crimped piece at the end of the speedo casing does that loosen? If it is crimped it is not suppose to loosen. How do you get the complete cable and casing disconnected from the speedometer? I just hate braking stuff and making matters worse when a dumb question could solve the mystery.

thank youRed Riviera Bob

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On 2/20/2018 at 8:04 AM, RivNut said:

Have you been able to identify what kind of "fluid" it is?  That would help.  

Ed, the liquid is quite runny. The liquid is coming from the casing. I wonder what would make the casing leak fluid? Obviously, a leaky casing. So, I’ll find a cable and casing the right length and install the whole thing. Are there any gaskets or seals that are needed to replace the old ones? Might as well get the whole kit at one time.

Red Riviera Bob

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2 hours ago, Red Riviera Bob said:

Ed, the liquid is quite runny. The liquid is coming from the casing. I wonder what would make the casing leak fluid? Obviously, a leaky casing. So, I’ll find a cable and casing the right length and install the whole thing. Are there any gaskets or seals that are needed to replace the old ones? Might as well get the whole kit at one time.

Red Riviera Bob

I bought a new cable and the box contained only the cable assembly. No lubricants or gaskets.  Go back an re-read this thread and decide if you want to lube a new cable and if so, what the best lubricant is.  I'm still a fan of powered graphite (it's not liquid and therefore can't leak.😊)

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14 hours ago, Red Riviera Bob said:

Mr. RetiredMechanic74, you are right the speedo cable casing is leaking. I loosened the knurl knob on the back the speedo. I pulled on the casing, but the casing would not budge. The crimped piece at the end of the speedo casing does that loosen? If it is crimped it is not suppose to loosen. How do you get the complete cable and casing disconnected from the speedometer? I just hate braking stuff and making matters worse when a dumb question could solve the mystery.

thank youRed Riviera Bob

+Bob I would suggest that you disconnect the cable and case from the trans first and any reference points holding the cable and case (this will allow you to pull the cable and case out)  then work on removing the speedometer at least enough to gain access to were the cable and case is held to the speedometer this way you can gently twist the case back and forth to remove it. Feed the new cable and case in and hook it to the trans last. Also remove the drive assembly from the trans, remove the plastic gear and replace the O ring and the housing O ring.

Edited by retiredmechanic74
More information. (see edit history)

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On 4/18/2018 at 11:30 PM, RivNut said:

I bought a new cable and the box contained only the cable assembly. No lubricants or gaskets.  Go back an re-read this thread and decide if you want to lube a new cable and if so, what the best lubricant is.  I'm still a fan of powered graphite (it's not liquid and therefore can't leak.😊)

Ed, I use powdered graphite in the guitar nut slots so the strings don’t bind. If, I do not have graphite in a tube I use pencil lead on the nut slots.

RRB

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On 4/19/2018 at 8:57 AM, retiredmechanic74 said:

+Bob I would suggest that you disconnect the cable and case from the trans first and any reference points holding the cable and case (this will allow you to pull the cable and case out)  then work on removing the speedometer at least enough to gain access to were the cable and case is held to the speedometer this way you can gently twist the case back and forth to remove it. Feed the new cable and case in and hook it to the trans last. Also remove the drive assembly from the trans, remove the plastic gear and replace the O ring and the housing O ring.

Sir, I got lucky and purchased an AC. Delco NOS speedometer cable by part number. I will receive the cable in another day or two. In the meantime, I put the car on a lift and removed the speedo cable for seal inspection. ( the cross member under the transmission r e a l l y does support the transmission.! ) The seal looks good to me. Also, I’m trying to find the vent on the transmission. I have been told and I read a clogged vent can cause the casing to leak. The speedometer does not make noise and keeps fairly reasonable speed. What is causing the cable to leak on the speedometer end? I have not taken the transmission down to inspect gears and O rings and whatever inside the transmission. It seems to replace the cable without finding out what could cause the leak might be not the solution we need.

My guess is I have to take the transmission down?

RRB

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5 hours ago, Red Riviera Bob said:

Sir, I got lucky and purchased an AC. Delco NOS speedometer cable by part number. I will receive the cable in another day or two. In the meantime, I put the car on a lift and removed the speedo cable for seal inspection. ( the cross member under the transmission r e a l l y does support the transmission.! ) The seal looks good to me. Also, I’m trying to find the vent on the transmission. I have been told and I read a clogged vent can cause the casing to leak. The speedometer does not make noise and keeps fairly reasonable speed. What is causing the cable to leak on the speedometer end? I have not taken the transmission down to inspect gears and O rings and whatever inside the transmission. It seems to replace the cable without finding out what could cause the leak might be not the solution we need.

My guess is I have to take the transmission down?

RRB

Digging into my memory (which is vastly fading) The vent should be locaded on top of the passenger side of the trans and could very well cause fluid to clime up the cable but other problems would also be present such as other external leaks and over filling. I think pulling the trans for this problem would only be a waist of your time. What I would suggest is to drill a 1/8th hole in the filler tube just below the seal on the dipstick ( it will help the trans to breathe). Back in those years GM thought it wise to counterclockwise the winding of the cable to draw fluid up the cable to keep it lubed (wasn't a good idea) an aftermarket cable and case might be a better way to go.  Hope this helps.   A friend Dave.    

Edited by retiredmechanic74 (see edit history)

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2 hours ago, retiredmechanic74 said:

Digging into my memory (which is vastly fading) The vent should be locaded on top of the passenger side of the trans and could very well cause fluid to clime up the cable but other problems would also be present such as other external leaks and over filling. I think pulling the trans for this problem would only be a waist of your time. What I would suggest is to drill a 1/8th hole in the filler tube just below the seal on the dipstick ( it will help the trans to breathe). Back in those years GM thought it wise to counterclockwise the winding of the cable to draw fluid up the cable to keep it lubed (wasn't a good idea) an aftermarket cable and case might be a better way to go.  Hope this helps.   A friend Dave.    

Dave, again thank you. Over filling just may be the problem and worth checking out. In an early attempt to change the transmission fluid I may very well over filled. ( my earlier maintenance effort could be the problem) I’ll see if I can find the vent with the service and parts manuals zi have for the Riviera to point out the vent. It is close quarters in that tunnel and dirty. The 1/8” hole below the transmission fluid dip stick seal makes plenty of sense. Replacing the casing and cable does make sense since I bought a NOS replacement. ( Is NOS OEM parts? I thought aftermarket was a part that will fit, but not OEM specifications). Dave, I’ll keep you updated.

Bob

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I both agree & dis-agree with Dave's statement about drilling a hole.  This could both be a savior or a cause for disaster. You most be ABSOLUTELY SURE the trans. is vented PROPERLY 1st. Hot oil climbing up the tube & out the hole could cause a FIRE. Hot  trans. fluid hitting a HOT exhaust manifold gets pretty explosive, so USE CAUTION!!! 

Remember the old KISS principal, KEEP IT SIMPLE STUPID. It's amazing how many things can be fixed fairly easily BEFORE taking the big plunge!!

 

Again, just my dimes worth.

 

 

Tom T.

 

 

 

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On 4/21/2018 at 1:37 PM, telriv said:

I both agree & dis-agree with Dave's statement about drilling a hole.  This could both be a savior or a cause for disaster. You most be ABSOLUTELY SURE the trans. is vented PROPERLY 1st. Hot oil climbing up the tube & out the hole could cause a FIRE. Hot  trans. fluid hitting a HOT exhaust manifold gets pretty explosive, so USE CAUTION!!! 

Remember the old KISS principal, KEEP IT SIMPLE STUPID. It's amazing how many things can be fixed fairly easily BEFORE taking the big plunge!!

 

Again, just my dimes worth.

 

 

Tom T.

 

 

 

Tom I have to disagree (in a friendly way) that there would be no danger of the fluid rising that far up the tube unless the trans was grossly overfilled and if the trans vent was completely plugged it would more then likely pop the dipstick out of the tube and spill fluid anyway, by drilling a hole in the tube below the seal of the dipstick insures pressure will not build up and properly filled will keep the fluid from rising that far up. I've done this procedure many times and have never had any adverse effect.

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When a DynaFlow starts to go bad it DOES push fluid up & out the tube pushing up the dipstick in the process. AND, the vent is clear.

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On 2/20/2018 at 8:43 AM, retiredmechanic74 said:

There are only two fluids I know of that can leak from the dash. (1) Oil Gage pipe leaking from a mechanical Gage. and (2) The speedo cable and I think that is where it is coming from. The gear in the transmission is allowing the fluid to travel up the cable. If you look at the cable you can see that the cable is made by twisting the metal. This is done to pull some fluid up from the trans to keep the cable lubed ( the idea wasn't a very good one) I would suggest to change the cable and case and the seal in the gear housing. You can get a new cable and case (that way you get the correct length) . Buying just the cable can give you problems with getting it right because the tip that goes into the speedo head has to be crimped and all to often doesn't hold. If you want to just change the cable it has to come out from the speedo head not from the trans.

Dave, I was able to determine the PO put the gray seal on the wrong side of the speedo gear shaft. Having the seal not where it is suppose to be could have been the problem. The cogs on the gear totaled 19. Five (5) of the cogs were worn badly. I found the 19 cog speedo gear shaft with the seals, washer, and O ring included. The speedometer itself I believe to be just fine. I bought a new cable and casing as a precaution. 

Im going to clean the inside of the casing with Berkible Gum Cutter then grease the cable. I guess, while I have the thing out I might as well put in the new one. Here is what I learned:

1. Put the transmission in reverse somcan reach stuff.

2. The support under the transmission really holds the transmission! No need to remove.

3. The vent is a little pipe that trails on the back of the transmission. If you blow compressed air through vent you’ll push a whole lot of fluid up through auto trans dip stick. No need to do that

4.Recognized after investigation the PO did not have the retainer in the groove that holds part of the speedo assembly in the transmission in the right place.

5. If you can assess the PROPER tool to use to reach Hard to reach nots, bolts, and screws life is easier.

your help along the way made me realize somethings are not so hard once you experience the work. Still, my mechanical skills in down right simple fix it jobs always can improve.

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Speedometer field test after new speedo gear drive with proper seals, etc. worked great. Speedometer is much more accurate now.

R3d Riviera Bob

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5 hours ago, Red Riviera Bob said:

Speedometer field test after new speedo gear drive with proper seals, etc. worked great. Speedometer is much more accurate now.

R3d Riviera Bob

What was your "field test."

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I was wondering if he was using a stop watch, being followed, or what to tell him his speedo was "much more accurate."

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Gents, my field test regarding my speedometer was a result of driving the car in 30 mph residential areas and interstate high way speed. I determined the speedo was fine because I did not get any black fluid on my shoe while I drove the car. The speedometer was steady and s e e m e d accurate based on comparison with other vehicles in traffic AND I’ve driven many types of vehicles on public roads for the last 53 years. Now, I’m happy to be wrong, but at this point I’m satisfied with the speed showing on the speedometer. I’ll check with a scientific method in another few days. Thank you for your help.

Red Riviera Bob

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3600 ÷ # seconds it takes you to drive a measured mile (DO NOT use your odometer) like the mile markers on an interstate highway will give you mph.

 

e.g.  3600 ÷ 60 = 60

         3600 ÷ 60 seconds = 60 mph.

 

3600 ÷ 48 seconds = 75 mph 

 

3600  ÷ 80 seconds = 45 mph

 

etc, etc.

 

Or, if you have one, you have one you can compare your speedo to the speedo on your GPS unit.

 

I can't trust the other drivers on the highway to observe the speed limit.  Too many soccer moms either texting while driving 40 in a 70, or driving 80 and talking on their cell phones.  I'm always tickled at the number of them who think their Honda Passport is a 1/4 mile terror.

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