Iffy reverse

Why wont my Chevy Silverado Z71 shift into reverse until it warms up when the temp outside is below freezing?

Have you checked the transmission fluid level? Last time it was changed? Correct type of fluid?

You haven’t give a vehicle year or mileage of any information at all on its service history. Heck, you didn’t even say whether the transmission is automatic or manual, or what it means to say it won’t “shift into reverse” - the gear selector won’t go there? Or you put it in that gear and it won’t go?

If its an automatic that goes into the “R” position but won’t move, check out this recent thread on a similar problem: http://community.cartalk.com/posts/list/2165489.page
The suggested “fix” is not really a fix - just something to get along on for a while. The real fix probably means tearing down the transmission.

If its a manual check the shift linkage - and when’s the last time the gear oil got any attention?

If the fluid level is normal, you probably have a leaky internal seal in the transmission. I had an old Chrysler with a 727 tranny that did the same thing. It had sat for a year before I bought it, and I think the seal dried out. After owning it for a year, the seal revived enough that there was only a slight lag going into reverse. Does the truck set for long periods when it isn’t driven?

You might try one of the products advertised to rejuvenate seals, but a teardown may be in your future.

it has about 130k on an automatic trans and when you put it in reverse it wont go into gear initially when cold but will after it warms up. I dont know when fluid was last changed and dad(was his truck) said this has been going on for about 3 years.