[msinc]

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.