Thread: Speedo's gone wild

It may have got oil feed up the cable into the speedo head this will cause the magnet to get sticky in the needle drive housing causing the needle to flicker , to check this pull the cable off the back of the speedo , if it is oil there from the transfer case then this could be your problem. Could also be drive gear slipping on out put shaft or dry or kinked cable, If the cable is dry , only lube the bottom 2/3 's if the inner cable other wise the oil / grease can get up into the head.

If there is oil in the head it will need to go to instrument repairer to be cleaned out , you will need to wash the cable out & replace the seal on the drive at the transfer case . I would also check the breather on the transfer case 7 gearbox is not blocked.
speedo head.jpgspeedo drive.jpg If you take the cable off the transfer case end & oil runs out the cable the seal (18 ) will need replacing & cable washing out the excessive oil & speedo head cleaning if it has got into the head. Check the drive flange nut (8) is tight on the back of the speedo drive housing on transfer case , if it is loose it will cause the drive gear (2) to spin on the out put shaft. If the cable is kinked it will need replacing if inner cable is dry / rusty * lightly* grease the bottom 2/3's .
Hope this is of some help.

Originally Posted by 1950landy

It may have got oil feed up the cable into the speedo head this will cause the magnet to get sticky in the needle drive housing causing the needle to flicker , to check this pull the cable off the back of the speedo , if it is oil there from the transfer case then this could be your problem. Could also be drive gear slipping on out put shaft or dry or kinked cable, If the cable is dry , only lube the bottom 2/3 's if the inner cable other wise the oil / grease can get up into the head.

If there is oil in the head it will need to go to instrument repairer to be cleaned out , you will need to wash the cable out & replace the seal on the drive at the transfer case . I would also check the breather on the transfer case 7 gearbox is not blocked.
speedo head.jpgspeedo drive.jpg If you take the cable off the transfer case end & oil runs out the cable the seal (18 ) will need replacing & cable washing out the excessive oil & speedo head cleaning if it has got into the head. Check the drive flange nut (8) is tight on the back of the speedo drive housing on transfer case , if it is loose it will cause the drive gear (2) to spin on the out put shaft. If the cable is kinked it will need replacing if inner cable is dry / rusty * lightly* grease the bottom 2/3's .
Hope this is of some help.

Wow the oil makes it all the way to the speedo? Is that common? That's pretty full on. I've got it up on stands and it started raining so waiting on it to dry up

Thanks for the info.

Originally Posted by shwza

Wow the oil makes it all the way to the speedo? Is that common? That's pretty full on.

I had that happen in 1971 on my near new Hillman Hunter except it drove around to full scale deflection - 120mph - when driving around town.

It was repaired under warranty. It was the only warranty claim
made on the Hunter.

As above - the most common cause of this sort of effect is the speedo drive gear on the output shaft of the transfer case slipping. It only spins with the shaft because it is clamped by the nut holding the output flange on.

Note that if the bush in the speedo itself is dry it can increase the load on the cable and result in breakage, but this is very unusual, and take care to avoid excess oil in the speedo. Oil migrating up the cable is likely to reflect a blocked transfer case bleeder.

Originally Posted by JDNSW

As above - the most common cause of this sort of effect is the speedo drive gear on the output shaft of the transfer case slipping. It only spins with the shaft because it is clamped by the nut holding the output flange on.

Note that if the bush in the speedo itself is dry it can increase the load on the cable and result in breakage, but this is very unusual, and take care to avoid excess oil in the speedo. Oil migrating up the cable is likely to reflect a blocked transfer case bleeder.

Awesome info John thanks so much. I'll let you guys know how it goes once I get all my tools and parts!

Cheers

Originally Posted by 1950landy

It may have got oil feed up the cable into the speedo head this will cause the magnet to get sticky in the needle drive housing causing the needle to flicker , to check this pull the cable off the back of the speedo , if it is oil there from the transfer case then this could be your problem. Could also be drive gear slipping on out put shaft or dry or kinked cable, If the cable is dry , only lube the bottom 2/3 's if the inner cable other wise the oil / grease can get up into the head.

If there is oil in the head it will need to go to instrument repairer to be cleaned out , you will need to wash the cable out & replace the seal on the drive at the transfer case . I would also check the breather on the transfer case 7 gearbox is not blocked.
speedo head.jpgspeedo drive.jpg If you take the cable off the transfer case end & oil runs out the cable the seal (18 ) will need replacing & cable washing out the excessive oil & speedo head cleaning if it has got into the head. Check the drive flange nut (8) is tight on the back of the speedo drive housing on transfer case , if it is loose it will cause the drive gear (2) to spin on the out put shaft. If the cable is kinked it will need replacing if inner cable is dry / rusty * lightly* grease the bottom 2/3's .
Hope this is of some help.

I can't find any of that level of detail in my workshop manual. I've got a blue manual for series 3 printed by Leyland part no akm3648. It seems pretty good but I can't find that detail of the output drive shaft in it at all. Is there a better manual to use?

Currently the speedo is showing 10 or more kilometres under. Do you have to remove the prop shaft to get to that nut?

Originally Posted by shwza

I can't find any of that level of detail in my workshop manual. I've got a blue manual for series 3 printed by Leyland part no akm3648. It seems pretty good but I can't find that detail of the output drive shaft in it at all. Is there a better manual to use?

Currently the speedo is showing 10 or more kilometres under. Do you have to remove the prop shaft to get to that nut?

These drawings are out of a S3 military parts catalogue I have . Parts catalogue's are good they show every single part , nut , bolt & washer all in the correct sequence I find them better to work with than workshop manuals .
If you mean the drive flange nut , yes , if there is a sliding joint in the rear tail shaft you should only have to remove the four nuts at the front uni & compress the sliding joint , you will find the nut under the front uni flange.

Originally Posted by 1950landy

These drawings are out of a S3 military parts catalogue I have . Parts catalogue's are good they show every single part , nut , bolt & washer all in the correct sequence I find them better to work with than workshop manuals .
If you mean the drive flange nut , yes , if there is a sliding joint in the rear tail shaft you should only have to remove the four nuts at the front uni & compress the sliding joint , you will find the nut under the front uni flange.

You're a legend cheers. Those drawings you had are much easier to see. I thought this manual seemed pretty good it's pretty comprehensive but obviously not enough. Yep the drive flange nut. I was bashing my head trying to find it in my manual. Like you said it's not in sequence it's in sections. I pulled the cables out and they seemed fine they weren't dry and no excessive oil but couldn't quite make out how much I needed to pull off to get to that nut