help!-1978 ski-doo blizzard 5500 chaincase-i cant put it on! help!?

[musiklover01]

hey everybody, i have a 1978 ski-doo blizzard 5500 snowmobile and the chaincase blew. I have all the parts but when i go to put the back casing on, the bottom axle is real tight and i can't line up the axles OR the holes for the screws! i know its the right part, because i have the blown one and it matches. do i have to loosen the track before putting on the casing? how excatly should i go about this? thanks for you help

[loaslostnfound]

at the back of the sled there a tensioners to keep the track tight lossen them and make sure you take the jam nut lose first then losen the bolt as far as you can then it should allow you to move it enought to get it back to gather and over tightenning it will cause it to happen again im me if you need any further help okay