So went to change my tranny fluid in my 2005 Blazer V-6/4.3 4X4 5spd. manual and it's a little different from my ole '86.........to my surprise it's a couple of 6 point hex heads. It looks to be a hex 17mm. A call to my local Chev dealer proved useless. On to some of the local automotive supply stores. No good news to report here either. So I'm left with doing an order with an online store and would like to confirm the size before ordering. It appears to be a 17mm hex. Anyone???

 

I'm 99% sure it's a 17mm. I just used a bolt with a 17mm head and a couple nuts jammed together to remove/install mine. Way cheaper than buying a special tool.

Later, Doug

 

No one had hex key sets? Heck, my autoparts stores would let you take the metric and standard key sets out to your truck and try it out. Bring your jack with you (if you need one) and give it a go.

 

DriftinBlzr aka Doug....brilliant suggestion. I'll definately be doing this and any other odd hex size in the future that isn't available at my local supply store(s)
swartlkk........one store had a 16mm which they let me try only to discover it was too small........then tried a 5/8" (I believe) with the same results............thanks guys and Blazer forums!!

 

11/16" (0.6875" = 17.45mm) is slightly larger than 17mm (0.6693") and quite possibly could be it.

 

My plugs were pretty rusted so I took a propane torch and heated around the plug since the trans case is aluminum and the plug is steel. Made removal a lot easier!

Later, Doug

 

So I picked up a 10mm bolt (to fit the 17mm hex head of drain/fill plugs)and two nuts=$2.43.........both plugs came out no prob and changed fluid and cleaned up within 30 mins. Thanks again guys for your suggestions..........now on to do a rad flush.....