Speedo Cable ?'s

[bumpy]

ive had this MJ for over a year and it has never had a working speedo... I'm about to swap the motor and wondering what it'll take to have a speedometer besides my GPS when its all said and done? i was told by the PO that it was a cable from the speedo to the tcase that was what's bad??

 

its a 4.0/5spd/np231 i believe...

 

any insights on what it could be? could the little gear tooth in the tcase be broken or is it more complex than that?? is there actually a cable that could be bad? ...i doubt it could be that simple!!

[jimoshel]

Take them out and inspect them.Unhook the cable from the T case. Is the end of the cable OK, or is it messed up? Remove the gear from the T case. Are all the teeth there and not chipped? Is the end of the cable attached to the speed head? Usually when the speedometer doesn't work it's because the cable came unhooked from the head.

[Eagle]

any insights on what it could be? could the little gear tooth in the tcase be broken or is it more complex than that?? is there actually a cable that could be bad? ...i doubt it could be that simple!!

 

Of course there's a cable. Not a "wire" -- a rotating spring cable inside a non-rotating sleeve. How else do you think the speed information gets from the drive gear in the transfer case to the speedometer in the dashboard?

[Keyav8r]

If your speedometer gear is okay and the end of the cable is engaged in the gear, then you need to check the cable to make sure it is not broken, and then check to make sure the cable is engaged at the speedometer.

 

To check both of these, you'll have to pull the gauge cluster. Before you try to remove the cluster, there is a clip on the engine side of the firewall that you should remove to get some slack in the cab. As you pull the cluster from the dash, push the cable into the cab until you have enough space to get your hand to the cable connection at the back of the cluster.

 

If your 87 is like my 88 it has a plastic connector at the speedometer end of the cable (somebody correct this if I'm wrong about the connector). The plastic is 26 years old and it IS BRITTLE. Use a mirror to see how it is retained and then remove it. Now you can check the cable by turning one end and having another person observe whether the other end turns. If it doesn't turn, replace it. If it does, check the speedometer by inserting a square shank into the speedometer (file a nail down to fit if you don't have a square shank of the right size). Spin the shank and see if the needle moves. I can't remember which it should turn, so try both ways. If the needle moves, the speedometer is probably okay and your problem may be that the cable was not engaged at the speedometer. If it doesn't move, you may have a bad speedometer.

 

Reconnect the cable, making sure the square end of the cable is inserted into the speedometer and the connector is secure on the speedometer hub. After the cluster is installed back in the dash, refasten the cable clip on the firewall but push the cable towards the cluster a little to help keep it connected. Then reconnect the cable at the transmission/transfer case, again making sure the end of the cable is engaging into the gear.