Firstly, being a 109, your Landy should have a Rover front axle and a Salisbury rear. However, that's not the point here.
Fitting the higher ratio Range Rover differentials do make cruising at about 60 mph practical from the engine noise/stress side of things. However the trade off is in slower acceleration since you are effectivly raising all the gear ratios. A 2.5 diesel only chucks out 68 horsepower, and a Carawagon is quite a heavy machine, so it depends on what you want from the vehicle- if you spend a lot of time making long road journeys, then the RR diffs may be the thing.
An overdrive shouldn't produce any more noise- it should mean that the vehicle is quieter overall as when the O/D is in use the gear ratios go up, so you can hold 50mph (say) at 2500 rpm instead of 3500. Overdrives should be quiet- if they make a loud whining noise they're worn out.
I know RR diffs are straight-swaps in Rover axles, but I don't know about fitting one to a Salisbury axle. I'm sure someone here will know.
Fitting the higher ratio Range Rover differentials do make cruising at about 60 mph practical from the engine noise/stress side of things. However the trade off is in slower acceleration since you are effectivly raising all the gear ratios. A 2.5 diesel only chucks out 68 horsepower, and a Carawagon is quite a heavy machine, so it depends on what you want from the vehicle- if you spend a lot of time making long road journeys, then the RR diffs may be the thing.
An overdrive shouldn't produce any more noise- it should mean that the vehicle is quieter overall as when the O/D is in use the gear ratios go up, so you can hold 50mph (say) at 2500 rpm instead of 3500. Overdrives should be quiet- if they make a loud whining noise they're worn out.
I know RR diffs are straight-swaps in Rover axles, but I don't know about fitting one to a Salisbury axle. I'm sure someone here will know.
