If I am correct since you are still away from retiring your disability benefit in SSDI should be higher right now than your proposed retirement benefit. So if approved you would get your disability benefit which will simply become your retirement benefit at age whatever.

I you get LTD typically they will pay your claim while you wait for the verdict from SSDI. say your LTD is 2000.00 they pay you while you apply. SSDI comes along and awards you 1,000 per month. you will still get 2,000 month 1,000 from LTD and 1,000 from SSDI. But not more than 2,000 total. Also typically you will have a period from when you applied and the LTD was paying you until your ss decision, all the while accruing backpay. Now you are responsible for paying the LTD company back the money you recieved in between the decision. You still get a monthly check but you don't get to keep the backpay. If you use a lawyer they also are paid from your back pay. I have found out a lot about this very fact just today we are applying for my wife. Not to be confusing but her LTD company will represent her with a lawyer to get her SSDI!! Think about it, if her claim is valid it's to their advantage to get the govt. to pick up the tab. Hope I've helped ya.