Speedometer rolling in reverse

Discussion in 'General IH Tech' started by michigan scout, May 31, 2008.

  1. michigan scout

    michigan scout Binder Driver

    I had purchased a scout that the po said it had over 350,000 miles on it. It was her dads and he lived in New Mexico and drove it back and forth to Alaska. They claim that everything was original, engine, trans, transcase. I did find in the owners manual that the trans had been rebuilt at 210,000 miles. No way could the motor last that long. It runs strong no oil use etc. The speedo did not work when I bought it. I took a cable of a parts rig and my odometer runs backwords, when in reverse the speedo will show miles per hour. My guess is the trans case had been removed and changed. A cable is a cable. My uncle said consider yourself lucky with the odemeter running backwords. But I want the speedo to work. He said you can change the grear in the trans case that drives the cable. Anyone done that before? How do you do it? Thanks!
  2. DavidWTravelallfan

    DavidWTravelallfan High Wheeler

    Yes..the motors can last that long..back and forth to Alaska is all hwy miles..which is good. Mine has over 300k on it with original rings and pistons. keep up the maitenance, they will last.
  3. Dana Strong

    Dana Strong High Wheeler

    On my 800 w/ T-18 and D-20, the transfer case has an adapter into which the speedometer cable runs; this contains the gears for changing the ratio to allow for different axle ratios and tire sizes. I would assume the direction of rotation into the adapter would be the same as out of it, so leaving the adapter off (if possible) wouldn't cause your problem. I would also think the internal gear arrangement in the adapter couldn't be changed to leave out or ad one gear, which would change directions.

    If you can tell us which direction (CW or CCW) of rotation (looking from the transmission end or the speedometer cable) makes the speedometer record properly, maybe we can tell you whether you likely have a nonstandard speedometer, or rather have something different down below.
  4. Bill Worden

    Bill Worden Binder Driver

    Which end of the vehicle has the steering wheel?:confused:
  5. Dana Strong

    Dana Strong High Wheeler

    If he remounted the axles upside down, that would fix the speedometer problem---but then he's have French Drive; one forward and three or four reverse!
  6. Paul "Misterfixit" Schulz

    Paul "Misterfixit" Schulz Super Mod from Downunder Staff Member Moderator

    Hmmm, are you sure your scout isn't named 'Christine'???????????????

    Be careful dude, the scout may end up controlling your life!

  7. deafdrummer

    deafdrummer Banned

    Are you sure the vehicle wasn't involved in an accident? A time travel team (from the movie Millenium) might be responsible.

    Stephanie (why is the clock on the wall going backwards?)
  8. Doc Stewart

    Doc Stewart Content Team Staff Member Moderator

    Neglect the opinions of our humorists! :)

    If you pull the outer fitting of the speedo mount at the transfer case, you will find a short shaft with a gear on the end that engages a worm gear on the output shaft of the tranfer case. That gear can be changed to calibrate the speedo. There are also small gear cases that install between the transfer case and the speedo cable that will also change the speedo reading.

    Never in all my days have I seen one run backwards. Haven't a clue what might be wrong.

    I guess we are back with the humorists...
  9. michigan scout

    michigan scout Binder Driver

    My uncle told me that it has been apart somewhere, maybe a transfer case switch and it didn't match up. When I told him it rolled backwards there for the odemeter runs backwards he said "consider yourself lucky". He thinks it is related in the cruise box. He said years ago they ran into that at the chevy garage when they replaced them and they were not the correct one. He told me to hook directly to the speedo from the t-case. So I did no different. He said it is in the t-case someone has the wrong gear in there...guess it's been changed out at one point. But man, nothing like driving a vehicle and taking the miles off if it.
  10. blybrook

    blybrook Farmall Cub

    After reading this thread, it makes me want to hook up the speedo to see if I can get it to run backwards. Sure would confuse the shops when it does go in. Although they get confused enough with the speedo stuck at 40mph sitting still and the same mileage all the time (broken cable & bad gauge).
  11. IHWILD

    IHWILD High Wheeler

    I am betting it is your cable. It could be binding up going forward and then unwinding when you go in reverse. Unless they have switch something totally different in (I'm guessing you did go directly to the transfer case) I don't think it is possible to have it run in reverse. I'd have to go look at the extra gear I have out but I am pretty sure it is cut in a specific rotation not just a straight cut gear. In other words the gear wouldn't be able to be swapped for another gear that would allow it to be reverse. It wouldn't mesh. As for trying to fix the cable you should be able to pull it out and lube it up (do a search for the right lube) It shouldn't be twisted up at all. I have had problems before with a cable causing weird speedo readings. Don't recall it going in reverse though. The only other possible thing is if someone switched things in the speedometer itself.
  12. Jeff Jamison

    Jeff Jamison Dreams of Cub Cadets

    I know on trucks you can hook the speedometer to the tranny or t-case,to dark to see if you can on a scout,if you can I would try and see those results.That should tell you if the problem is in the tranny or not
  13. Randy Z.

    Randy Z. Binder Driver

    Guessing here, but possibly the wrong drive gear in the t-case - as in teeth cut the opposite direction for counter rotation in a completely different app/vehicle? Dunno.
  14. ihairman

    ihairman Farmall Cub

    maybe the cable is in backwards. lol
  15. Cory Smith

    Cory Smith Farmall Cub

    An incorrect tailhousing from a Jeep or incorrect speedometer gears can make the cable spin the wrong direction.
  16. IHWILD

    IHWILD High Wheeler

    It would have to been rebuilt with the wrong gear because the gear driving the output gear to the cable have to mesh and even if they are both the wrong cut it wouldn't reverse the cable rotation. I've long switched over to a electronic speedometer so I can't remember does the original speedometer showing MPH in reverse? If it never did originally then I am betting that the speedometer head unit or cable is malfunctioning. You might have a broken mechanism in the speedometer itself that allowed it jump a stop or something and it allows it to go backwards but not forwards. I have my old speedometer packed away otherwise I'd take a picture of it apart. It is really easy to do just be careful with the tabs on the front not to break them. I'd check your cable for kinks and bad routing where it could cause binding.

    There is no way you could take just the speedometer gear out and accidently switch it with another makes gear to make it run in reverse. The driving gear is always going to try to make it run one specific direction from inside the transmission or transfer case. That gear would have to match the cut to not strip one or the other. You can not change rotational direction by just switching a gear regardless of cut. You would need more then one gear to do that. (if one gear is rotating clockwise the gear it meshes with will rotate counter clockwise.)

    The wrong tail shaft housing idea could be right if they have a different setup but it would also have a different then original transfer case there or an adapter. I still don't think it would do this but I've never looked at a heep but since they have been Chrysler for how many years and our automatic transmissions are Chrysler and since the manuals use the same speedometer I am confident in highly doubting the gears being the problem.


  17. Doc Stewart

    Doc Stewart Content Team Staff Member Moderator

    The cable loading up could not reverse the speedo consistantly.

    The Driving gear on the output shaft of the trans/transfer case is a worm. It could possibly be cut in reverse direction which would explain the problem. I have not seen or heard of a reverse cut worm and neither has my transmission guy.

    Just plain weird. If you sort it out, please be sure to post on this thread!
  18. IHWILD

    IHWILD High Wheeler

    I was pretty sure they were helical cut gears not worms. But the worm is the only one I can't remember how it would drive it. But I am pretty sure they are not worm gears.


  19. michigan scout

    michigan scout Binder Driver

    I will figure it out, my uncle a service manager at a local chevy garage for 30 years says its the gear drive...his assumption. One day I will look at it. Right now I enjoy taking off the miles on it :) It already has documented 340,000 miles. I only put a couple thousand on it a year if that. Exept this sumer I went to Colorado and back. The original owner drove it back and forth to Alaska from New Mexico. I have about 41/2 inches of slips in a thick folder on the thing of oil changes and repair bills etc.

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