By M.Pope on Friday, March 16, 2001 - 12:06 am: Edit

When the tread of your tires have one tread section going up and the next going down around the tire, is that "cupping"? I have that going on with the innermost section of tread on all four tires. Is this sign of needing new shocks?

By Cal on Friday, March 16, 2001 - 01:21 am: Edit

Possibly just an allignment problem. Shocks shouldn't cause this since Discos have solid axles. Your local dealer will probably charge $80.00. Otherwise take it to someone who has aligned Landrovers.

Cal

By Jerry Crawford on Sunday, March 18, 2001 - 12:22 pm: Edit

Another suggestion is tire inflation pressure. Here is my sorte into why the manufacturers make such a big deal out of it and why some people get outrageously good mileage out of their tires while others have cupping after a few months in spite of front end alignments and tire balance.

There is an optimum tire pressure necessary for best longevity of tread as well as performance and it isn't necessarily the pressure on the tire or the door post. Those are base line numbers. You have to determine what's best for your tires based on the load you are carrying and average speed you are driving.

You should begin checking the pressure for that base line number at home in the garage before the trip when the tires are cold. After fifteen or twenty miles at normal highway driving speed pull off into a rest stop and check tire pressure again.

(yes, this is tedious but it only takes ten minutes and may give you several thousand more miles of tread wear as well as reduce the number of unnecessary alignments you have to pay for at LR dealer rates)

There will be a difference of pressure in each of the four wheels from what was there when you began the trip. If everything is good the tire pressure should GO UP about 10% of the original (cold) pressure because of the heat expansion of the air in the tire from sidewall flexation. You have to adjust the tire pressure to achieve this 10% rule for best tire wear. This takes some cockied logic; if the percent of change is greater than 10% (say the pressure went from 30# cold to 38# hot, a 24% rise)ADD air because the tire wasn't hard enough to start with and the excessive flex of the sidewall rubber created more heat (ergo higher pressure) - if the percent of pressure rise was less than 10% the tire was too firm to start with and didn't flex enough for good wear and traction properties, therefore you have to let some air out.
Think about it and it will drive you crazy or make perfect sense. As always, the caveat, anyone having reason to believe that my logic is flawed please respond - I'm using information I gathered twenty years ago and it may be different now based on new tire technology. Happy Rovering!