I used to get the vibration at around that speed with the original tires and then the michelins I had on after that. Finally I switched to the BFG all terrain and it went away. I think the culprit is that on discos the tires wear on the inside portion of the tread while the outside begins to cup. This is what happens on my truck and I believe it is the cause of the vibrations.

So far so good with the BFGs though

 

Suzuki SV650. 65 mpg @ 65 mph and it seats two. Regular is recommended and that's what it gets.

 

my d1 had a horrible shake from about 60 to 63... when i say horrible i mean it was bad i almost lost control a couple times... sometimes it would start and i would have to slow wayyy down, to like 35 to get it to stop.... put all new suspension on and it no longer shakes... coils and shocks fixed what i though was a severely unbalanced tire...

 

been through 2 sets of diff tires and both when brand new did the same thing.

 

Find a company that manufactures driveshafts for agricultural equipment (primarily irrigation pumps and the like) pay them to build you new drive shafts and U-joints. This will cost less than 500 bucks and they will manufacture you from scratch a bigger and more heavy duty front and rear drive shaft that is perfectly balanced. Thsi will fix the problem as well as giving you a heavier duty drive shaft for both front and rear. Do not waste your money on landrover parts, they cost waaaaaay more than this just for front drive shaft and U-joints, which are not nearly as nice.

Common problem on land rovers is drive shaft vibrations, i was told its from a rubber "flex coupling".

This trick worked for me and saved me around 1k in money over land rover parts.

 

hate to say ,all thats been done as well. not new shafts but shafts that i knowwere neutral balanced.ive even tried bolting the shafts up *** backwards several times, same deal. locked the cdl took it out same deal.

 

Whilst you have the drive shaft removed grab your pinion and see how much slop there is between it and the ring gear. If there is a lot of movement change your diff fluids however the primary purpose for doing this is to see if there are any metal chunks in the oil = your ring and pinion "might" need replaced. If all you have is a magnetic plug that looks a little fuzzy = you "may" need to re-torque the pinion. Just a couple of thoughts. Like they say, if I can't see it from my house, it ain't broken.

Robert