switching trans to low side when slowing down harmful?

you should never "slam" any gears, low or high side. If you need to slam, your got the wrong rpm or wrong speed for the gear.

 

That is why his dad just spent $5000 on a tranny rebuild, I'd yell at him too, then kick him to the curb!!

 

Use the times when you are empty to practice. Shift all the way up, shift all the way back down. Most of the time, I will just shift through and split the top 3 gears. But if I am empty and not in a hurry, I will go through all 18 (all of them that I can before I get stopped again) at lights, up and down. Downshifting should be just as smooth and effortless as the upshifts. If I am out in the middle of nowhere and come up on a 4 way stop at a crossroads, I will jake shift and downshift.

 

I'm surprised. Several ppl here, besides the OP, have also said put it in neutral then put it in the low side.
Never shift your range selector while in neutral. Always shift your range selector before going thru neutral. Upshifting or downshifting, doesn't matter.
These are basics with a range selector, and can damage the range shift fork if not heeded.

 

Great point PattyJ!

 

Dude... its trucking. Not chemical engineering.

 

He never said he slammed anything into gears plus you quoted my comment which had nothing to do with slamming gears??

 

Oh yes he didddddd...

Just givin ya some harmless grief.

Edit: Oops, you may be right on a technicality... the OP said he slammed it to the low side, not lower gear. Maybe no gear slamming involved, lucky you!

 

The range selector will work the same whether downshifting or up shifting, it just works backwards from one to the other, so say it is a 9 speed, when you downshift all the way down to 6th then flip the range selector to the low low side and start over with 5 and keep down shifting as needed. This is what the range selector is built for and it will not hurt it one bit. But as mentioned above, flip the range selector to the low side before coming out of 6th into neutral Going up or down, never flip the range selector in neutral.

 

Might want to work on your comprehension skills. All the OP said was "My dad yells at me when I "slam it to the low side" during slowing down.
He did just spend 5000$ on a tranny rebuild."

I don't see "gears" mentioned at all