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Old 05-24-2022, 04:58 PM
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Default Toploader eating speedometer gears????

Lets try this one more time, with more info this time......

I have a Superformance Mk III. I just got the car in December. The Smith's speedometer {complete with reverser} worked and read steady, but it was off by 10mph slow. I do the math and figure out that I need a 16 tooth gear on the cable {driven gear}. I get one and install it and it reads dead on perfect but it goes to zero after about 1/4 of a mile. Pull it out and it is destroyed. Get another one and a new drive gear. Pull the tail housing and change them both. This time I get about 1 1/2 miles with the needle bouncing and it goes to zero....gear destroyed again.
At this point I was unaware of the fact that it had a reverser and started googling the issue. Now, I have removed the cable, speedometer and reverser and tested it all on the bench. I checked one at a time and then started putting them together. Whether by hand or by cordless drill everything spins easy and smooth. I can get the cable to give a little wiggle when all three are together, but the needle on the speedometer still reads smooth with no bounce and it spins with very little drag at all.
While I am no scientist or engineer, this aint exactly rocket surgery either...I cannot get, nor do I believe that any of this has enough drag or pressure to destroy both gears in a mile or so.
Checking further, in my paperwork on the car it says this is a David Kee Transmission. I have a little trouble believing that because, although it works good, there is no gasket on the tail housing. It absolutely does have a Kee tail housing though as it has both mount patterns, the big lug thing on the top and the letters DKT on the left side of the tail housing near the rear seal. Maybe it is a Kee transmission that someone removed the tail housing before I got it and failed to replace the gasket. It had silicone and did not leak.

Here are a few facts:

1. I am unable to reproduce what I believe is enough friction/drag/pressure/whatever you want to call it, that would seem to be enough to wipe out these gears while testing on the bench. Even if I wrap two loops in the cable it still spins and reads smooth.
2. It has had two sets of the correct gears and wiped both of them out quickly.
3. The tail housing is a Kee's and the slip yoke bushing is tight. U-joints are perfect and move smoothly.
4. The reverser had plenty of good wet grease inside and spins very smoothly both by hand and with a drill.
5. The dead center of the driven gear becomes "hour glassed" to the point it wont spin.
6. The drive gear, after failure, appears worn more on one side than the other and the surfaces between the teeth appear smeared or galled.
7. Given the condition of the failed appearance of both gears, one would conclude that they suffered some sort of high {for them at least} friction. High enough to cause immediate failure.
8. The tail shaft itself was checked for end play and it had less than .012" which is probably to be considered pretty good given it's mounted in an open ball bearing.
9. Looking through the cable mounting hole the drive gear appears pretty well centered and where it should be.
10. When I installed the first gear I noticed that it had to be held back against the cable drum to get the clip on, as if the inside cable was a tad too long. I cut about 1/8" or less off with a Dremel and the clip went on with no pressure, but very little {.004-.006"} play.
11. I removed the inside cable and looked it over good. There was no evidence of a kink or where it tried to come apart. No evidence of damage to the interior cable was noted at all.
12. The outer jacket appears to be in excellent shape in keeping with this vehicles 3100 miles.
13. There are no leaks on the transmission at all anywhere.
14. There is no Ford tag on the transmission.
15. I cannot ascertain whether or not the lack of a tail housing gasket can cause a misalignment issue enough to be a problem, but the gasket is not very thick, as I recall, and so it is doubtful.

I really hate to pull this tail housing again and throw money at it without some kind of a reasonable "smoking gun". The big question...has anyone out there seen anything like this and what fixed it???? Thanks in advance for reading this and also for any info. It is greatly appreciated!!!! M

Edit: almost forgot...one other question, since this has a replacement tail housing, there is a chance this transmission is one of the Galaxy types that had the left side entry cable. I have to wonder if that could be an issue, and/or if it's okay to just swap the tail housing to make it a right side entry?????

Edit II: one thought just occurred....how, if at all, do these gears get lubed??? Do they not require any sort of lubrication while the transmission is running??? It would seem like, even though there is not a lot of pressure or strain that they might need some.

Last edited by msinc; 05-24-2022 at 05:15 PM..
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Old 05-24-2022, 07:54 PM
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I have some thoughts for your consideration. The lube in the main case should transfer to the output shaft housing. Your lack of a gasket at the output shaft housing to main case and an overly generous application of "silicone" may be restricting the lube. The transmission case could also be low on lube, which would restrict lube to the output shaft housing. A lack of sufficient lube in the output shaft housing would accelerate the wear of the moving components there. I'm thinking new speedometer cable, new drive and driven speedometer gears, new gasket at the output shaft housing to main case, clean all the old silicone off of main case to output shaft housing and only use liquid sealant at the bolts holding the output shaft housing to the main case, you don't want lube leaking past the threads and verify proper lube level. You may also want to check for excessive wear at the output shaft yoke to yoke bushing and yoke seal damage in the output shaft housing. All those items could have been effected by a lack of lube in the output shaft housing. If the output shaft housing is removed all the wear items associated with it are cheap and easily replaced. The preceding advise are the ramblings of a mad man and to be followed at your own peril! lol Hope this helps, good luck finding a solution.
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Old 05-25-2022, 04:28 AM
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Thanks again John, "the ramblings of a mad man" that is almost as mad as me!!!! All good advice that I will absolutely do. Yes, in fact the lube level was low. Now that you brought that up, the destroyed gears appear to have been "dry"......Other than getting thru the output shaft bearing, is there another way that gear oil gets to the output shaft area??? Yoke bushing and seal have not been compromised. Thanks again.
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Old 05-25-2022, 05:01 AM
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I believe the only way for lube to reach the output shaft housing is thru the roller bearing. I suspect the proper speedometer gears, once installed were destroyed by the lack of sufficient lube.
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Old 05-25-2022, 05:13 AM
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i doubt omitting the gasket creates any issues since as you said it’s very thin. I put two gaskets on mine and it was fine. There should be lube getting through the Rear bearing unless somehow a sealed bearing was installed. I would suspect something amiss with the speedometer gear adaptor.
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Old 05-25-2022, 06:04 AM
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Quote:
Originally Posted by DanEC View Post
i doubt omitting the gasket creates any issues since as you said itís very thin. I put two gaskets on mine and it was fine. There should be lube getting through the Rear bearing unless somehow a sealed bearing was installed. I would suspect something amiss with the speedometer gear adaptor.
"speedometer gear adapter"??? Can you clarify what you are calling an adapter please sir??? I am not familiar with what that is. I will definitely inspect that bearing...it would be just like my luck to have had some idiot install a shielded or sealed bearing in place of the correct open one!!!! Thanks for the info!!!! M
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Old 05-26-2022, 09:53 AM
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Quote:
Originally Posted by ERA174 View Post
I believe the only way for lube to reach the output shaft housing is thru the roller bearing. I suspect the proper speedometer gears, once installed were destroyed by the lack of sufficient lube.
After thinking about this "lack of lube" thing, it makes perfect sense and it sure seems like the gears would need some lube. But......the fact is, after I changed the output shaft "drive" gear I did in fact fill the gearbox with 90w gear oil, so while I will buy it for the first set of gears, I know I had plenty this last time and it still wasted them.....nothing is ever simple!!!!! M
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Old 05-26-2022, 06:26 PM
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Just pulled a C7(unable to read all the casting #s) output shaft housing from a C8 main case and I was incorrect about the lube only flowing thru the bearing. The main case I viewed had an approx. 1/4" dia. hole about 1/4" C/L below the bottom of the bearing in the main case. The output shaft housing had an oval hole which would line up with the hole in the main case. These holes should equalize the lube in the main case and output shaft housing assuming proper lube level, not sure if all cases are like this. With the lube properly filled to the bottom of the main case fill hole and assuming the lube in the main case had flowed to the output shaft housing to the proper level without leaving the main case below the optimal level, I don't believe the speedometer gears in the output shaft housing would be submerged in lube when the vehicle was stationary on level ground. It appears the speedometer gears need to be lubed upon installation and then will receive lubrication as the lube transfers back and forth between the output shaft housing and main case. My statements are hypothesis based on the inspection of the previously stated items, all submitted for your consideration.
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Old 05-26-2022, 07:15 PM
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"gears need to be lubed upon installation"......this could be the problem. Admittedly, I just put them in and didn't really consider any need to pre-lube. I am wondering if this equalizer hole {for lack of a better term} is even open on my transmission......I will find out when the new gears get here. I did in fact get a new cable and I found Ford OEM gears. Gears are on the way as well as the tail housing gasket. Thanks again John!!!!! M
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Old 05-27-2022, 04:44 PM
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Quote:
Originally Posted by msinc View Post
"speedometer gear adapter"??? Can you clarify what you are calling an adapter please sir??? I am not familiar with what that is. I will definitely inspect that bearing...it would be just like my luck to have had some idiot install a shielded or sealed bearing in place of the correct open one!!!! Thanks for the info!!!! M
Maybe adaptor is a bad term. The fitting on the transmission end of the cable the driven gear fits into and is inserted into the side of the tail housing over the drive gear.
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Old 05-28-2022, 04:45 AM
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Maybe adaptor is a bad term. The fitting on the transmission end of the cable the driven gear fits into and is inserted into the side of the tail housing over the drive gear.
That's kinda what I thought you meant, but wasn't sure. Thanks for the clarification. I have a new cable and OEM gears on the way. I will find out something when the gears get here. I intend to turn the output shaft with an inch pound torque wrench {beam type} with both cables and without to see what if any differences in drag I get.

Edit: if it appears that the gears are "meshing" too hard or too tight, too close together....the only thing I can do is gently file them for some clearance until the drag eases up. Don't know what else to do at this point.
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Old 05-29-2022, 06:46 PM
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Default Speedo Gears

Toploader speedo driven gears come in right hand and left hand configurations
depending on which side the cable comes in at. Make sure your using the correct gear
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Old 05-30-2022, 05:34 AM
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Toploader speedo driven gears come in right hand and left hand configurations
depending on which side the cable comes in at. Make sure your using the correct gear
Thank you sir, yes, I am aware of this issue and am certain I have the correct gears. New ones should be here tomorrow. I am getting ready to pull her down now and will advise asap when I have anything new to discuss.
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Old 05-30-2022, 06:18 AM
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Hope you can get it figured out.
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Old 06-12-2022, 05:34 PM
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Well, I guess I had better do a follow up to this thread and post what is happening at this time. Got the new gears and a gasket for the tail housing. Pulled everything down and did a few tests before I just change gears again and put it back together. First, I reinstalled the speedometer and got a brand new cable. I pulled the cable wire out and lubed it as well as the cable jacket with GL-4. This was done at the advice of John {ERA174}, who has been very helpful.
I installed the new gears and before I put in the cable with the gear on it I measured the torque, in inch pounds, required to keep the output shaft in motion while the gear box was in neutral. Then I installed the cable and driven gear assembly and measured it again. No discernible difference. Then I sprayed each gear with flat black spray paint and did a roll contact pattern test, similar to checking a new ring and pinion. I was looking for any possible issues with the way the gears meshed. That all looked fine. Unable to find anything that looked like it might be a possible problem, I did the final assembly. This time I soaked each gear with gear oil and took the car for a test drive.
I am happy to report that after a 12 mile test drive the speedometer was still working and read the correct speed. I pulled the driven gear out at this point and inspected it for any issues. None!!! It looked as good as when it was installed. I have since driven the car another 36 miles and the speedometer is working just fine. I believe the problem is solved.
I want to report a few things too...I did in fact search and read every possible thread regarding speedometer gears, looking for any info that might be of some help. What I found was what I believe to be some bad information. Several posts referred to "different" or "top loader specific" gears that were a must to solve this problem. It was repeated several times that "you couldn't just order Ford speedometer gears, you have to get the ones for a top loader"....this proved to be not sound advice and simply not true. Everyone {pretty much} is aware that there were left side entry and right side entry gears with the teeth cut differently, but there are not any other magical mystical "top loader specific" gears in existence.
I hope someone finds this thread useful and I am very gratefull for all the tips, info and help I received!!!!!
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Old 06-13-2022, 04:19 AM
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It sounds like it just needed a liberal dose of lubricant on all the gear parts upon installation. I think I usually coat the driven gear with chassis lube before installing but never thought much about it and may have failed to at times. I’ll certainly do so in the future. Glad it’s solved and didn’t involve a boat load of parts replacement.
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Old 06-13-2022, 04:59 AM
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Originally Posted by DanEC View Post
It sounds like it just needed a liberal dose of lubricant on all the gear parts upon installation. I think I usually coat the driven gear with chassis lube before installing but never thought much about it and may have failed to at times. Iíll certainly do so in the future. Glad itís solved and didnít involve a boat load of parts replacement.
Yes sir and thanks for all your help....I too have installed several speedometer gears over the years and I am pretty sure I never put any lube on any of them. You can best believe I wont do it again though!!!!!!
You know, the parts, in this case pale in comparison to the amount of labor involved. This car is a Superformance, and while I really love just about everything about it, it has a strangely over complicated emergency brake set up that, for as intricate and complicated as it is, really should work better than it does. It only takes about an hour to remove it so you can take the drive shaft off. Thanks again sir!!!!
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Old 06-15-2022, 08:37 AM
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FYI, in your first post with the pictures of your gears you have one left gear and one right gear. If the gear in the transmission is plastic, it may have been damaged by running the wrong driven gear.
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Old 06-15-2022, 10:10 AM
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Quote:
Originally Posted by 6TNCRZY View Post
FYI, in your first post with the pictures of your gears you have one left gear and one right gear. If the gear in the transmission is plastic, it may have been damaged by running the wrong driven gear.
Yes sir, you are correct the original gear, the 21 tooth red gear was in fact a Galaxy or left entry driven gear. When I got the first replacement proper 16 tooth gear, which also was the left entry correct cut, I installed it and it immediately failed. That is why I replaced both drive and driven the next go around. Just like you say, I really thought being run with the wrong gear might have compromised the drive gear. Unfortunately I got the same result...quick failure.
The fact that the gear that was in the car worked fine and was the wrong cut really made it more confusing when the next two sets burned up so quickly......how could the wrong gear work fine {save reading the correct speed} and not burn up but the brand new correct ones wouldn't last 1/4 of a mile???? The answer to this whole dilemma proved to in fact be a lack of sufficient lube upon installation.

Last edited by msinc; 06-15-2022 at 10:13 AM..
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