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MG TD TF 1500 - day 3 of new TF ownership

Gentlemen...I now know why you all love these little T series cars so! My 54 TF finally hit the road for the first time since 1967 on Monday. What a treat to drive. I can't recall having so much fun in a vehicle since...well....that was before I was married. It sure was a handful sticking my 6 foot 2 inch body in there, and most exciting when I came to my first stop sign, and realized that my steel toed work boots were not to be worn when piloting this little green gem. Right boot hit brake pedal, accelerator, and steering column all at the same time!!!! I think my finger prints are permamently imbedded into the steering wheel. There are quite a few things to work yet, which will get corrected as time allows, but one comes to the forefront as it has me puzzled. At a constant speed, the speedometer swings through about 12 miles on the guage, up and down. I'm assuming that it should read somewhere in the middle of its wanderings. I pulled the inner cable at both ends and the cable is well lubricated with no dry spots that are visible. Any suggestions as to what to do next?
Gene Burgess

Gene - Congratulations on getting your car on the road. Do be careful (read the thread about TF collision), there are some real idiots out there on the roads, and you might want to consider a set of driving shoes in exchange for the safety boots. Regarding your speedometer, only a 12 mph swing? That's practically rock steady. You may have a stretched inner cable. Remove the entier cable and lay it out flat and check that the ends of the cable don't proturde excessively from either end of the outer housing. You could also have a kink or a broken strand on the inner cable. Good luck - Dave
David DuBois

I had almost bought a speedo cable, before i noticed that the needle was not moving 'till i got to about 5 mph. Then the needle would jump & waver up & down. It was sticking on the peg at zero. With nothing to dampen the internal spring it would go on for ever! I removed the speedo, took it apart, cleaned & lubed the peg. Len
Len Fanelli

I had the same problem. I took the cable out and if you twisted one end while holding the other you could turn it about 1/2 turn before it would move the other end. Went to our repair guy and he built a new cable for mine for about 50 bucks and it now works fine. I would suggest a new cable.
Tom

David, I pulled the cable last night as I said, and it did appear to be too long for the outer sheath, at least I remember thinking so when I went to reinstall it. I'll pull it again this evening and see if it is too long, and I'll attempt to shorten it. It makes sense that being too long it would bind up and release, bind up and release, and cause the fluctuations in the speedo that I'm experiencing. And yes, I now drive the car exclusively with the smallest pair of shoes that I own. I also think that I'll investigate shortening the throw on the brake pedal, in order to keep my foot further away from the steering column. I'll hold off on that one until I get some input from those more knowlegeable on that particular subject than I. I sure don't want any surprises when it comes to stopping.
Gene Burgess

The strange speedo behaviour continues. I pulled the inner speedometer cable and discovered several sections where the inner cable had spun strands out almost twice its diameter, some sections for as long as 10 inches. I purchased a new inner cable, soldered the original ends on, lubricated the cable and reinstalled it. NO CHANGE! The needle still wavered through 12 miles per hour, going from 50 to 62 and back again, this at 3200 rpms? I then disconnected the cable from the speedometer and using a spare length of cable with a squared off end, placed the squared off end in the speedometer and the other end in my speed drill. The speedometer recorded rock steady mph at all speeds that I put the drill to. I then left the entire cable off of the speedometer, hanging from the dash where I could see it as I drove the car. I could see no variation in its movement as it turned, regardless of the speed I went. Has anyone any other ideas? I'm about to scream.
Gene Burgess

I have had this sort of behavior on late Bs which do not have a key for the speed drive gear on the 3rd motion shaft. The TD does not appear to have a key, by the shop manual. (Note: I see that from gbx TW396 it does have a key, if someone hasn't left it out!) On the B, the nut retaining the driveshaft flange comes loose, letting the drive gear slip. You have to disconnect the driveshaft and tighten the nut, not withstanding the fact that it is a castellated nut and should have a split pin.
OR, there could be something wrong with the speedo drive that comes out the side of the gearbox.
FRM
http://www.usachoice.net/gofanu
FR Millmore

FR,...I'll disconnect the speedo cable from the side of the transmission and spin the end of it with my speed drill and see what happens. If the speedo stays rock steady at whatever speed the drill is at, that would have to support your theory about the drive gear slipping. By the way, my TF has a key built into the end of the speedo cable that attaches to the drive gear. Thanks for the input!
Gene Burgess

GB,
I cogitated on this, and now believe that you have a speedo head problem, possibly in addition to others. You said that you had 50 - 62 mph at 3200 rpms with the drill, correct? [Where did you find a 3200rpm drill?] The speedo should have a small, usually 4 digit number, on the face somewhere. Usually near the part number. That is the calibration number of turns per minute at mid-scale. It is usually around 1000 or a little more. So with your drill, it should read about 150MPH!![that was a hell of a tune-up!] Somewhere on one of these boards I saw that some speedos also have the number marked on the back of the speedo someplace. I have never seen a speedo outside roughly 975 to 1250 tpm, and almost all speedos have this number - it is what a speedo shop would use to check & calibrate.
FRM
http://www.usachoice.net/gofanu
FR Millmore

FR...sorry to misslead you, but I believe I said that at 3200 rpms on the Tachometer the speedometer needle bounces between 50 to 62 mph or so. Spinning the speedometer with my speed drill produced steady readings without the bouncing needle. That was 2 nights ago and i'm guessing now that the speedometer might have read 40 mph or so at most. The point was that the bounce/erratic needle behaviour was gone using the speed drill and just a section of the inner speedo cable. I'm wondering now if part of my problem, or the entire problem, is the result of the cable not being supported properly. At present the drive cable exits the tranny, makes a somewhat sharp turn at the frame, and then hangs down below the frame and the clutch before it rises up the firewall to enter the cabin through a hole alongside of the wiper motor. This cable is not supported at all until it bends over the front of the firewall up towards the wiper motor. Could this bouncing speedometer needle be the result of the entire cable bouncing and flexing up and down as the car goes over irregularities in the road and bounces and jars?
Gene Burgess

OK, the rpm thing was confusing. A "somewhat sharp turn" is best made less sharp if possible, and I doubt that the cable should hang below the frame. But, I don't know where it does go. See if you can route it along the frame flange or even above the frame and anchor it somehow. Be sure the cable is lubricated. Any binding in the cable can cause "bounce".
FRM
http://www.usachoice.net/gofanu
FR Millmore

I finally got time to spend on the TOY tonight. First I spun the inner speedo cable with my speed drill from the tranny end of the cable. At whatever speed I chose, the speedometer needle stayed perfectly steady, with minor variations. I then reattached the cable to the tranny and tied the cable to the fuel line that is attached to the right frame rail, in three locations. A short test drive now gives me a usable speedometer. The needle still wanders somewhat, but it does so less erratically, and only over about 4 mph rather than 12. Thank you so much for your thoughts and input. It is most appreciated.
Gene Burgess

This thread was discussed between 10/06/2004 and 17/06/2004

MG TD TF 1500 index

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