Slipping reverse Chevy Venture

Hi I had a new transmission installed in my 2000 chevy Venture. I have only done about 1500 miles and I am having problems with reverse gear slipping. I cannot take back to the installers under waranty as I exported the car to the UK. Can the reverse band be adgusted without removing the trans? Or is there a simpler way of resolvng the problem. All forward gears work fine.
Thanks in anticipation.

Hi I had a new transmission installed in my 2000 chevy Venture. I have only done about 1500 miles and I am having problems with reverse gear slipping. I cannot take back to the installers under waranty as I exported the car to the UK. Can the reverse band be adgusted without removing the trans? Or is there a simpler way of resolvng the problem. All forward gears work fine.
Thanks in anticipation.
I do not think these transmissions use a band to engage reverse, so no relevant adjustment is possible

I think possibly some debris is lodged in the hydraulic circuit for reverse, which is preventing full hydraulic pressure from being applied.

If you just drive it (going forward) you may get lucky and the debris may work its way out. (it's happened to me in the past)

IMO, check the fluid level first and make sure it is at the full level, without being over filled. Then avoid using reverse. If you must use it, back up with as little throttle as possible to keep slippage to an absolute minimum.

If slippage continues, the relevant hydraulic circuits can be flushed without removing the transmission from the van (I think) which may fix the problem.

Thanks for your quick responce, I haven't chainged the oil since having the new trany installed so will do that first and then go on from there. Can you give advice on how to flush the relavant circut if I need to? Or can I get a user manual from anywhere?
Thanks again.
Gus.