Hey, I finally got my rear axle shifter working again, so its time I learn how to split shift. I've read as many threads as I can find, namely this one: https://www.arboristsite.com/community/threads/using-a-2-speed-rear-axle.98103/ One of the posters mentions that grinding while changing the axle is normal. I just wanted more opinions on this so I know I'm not doing anything wrong. Driving around slowly, splitting 1L -> 1H it seems to shift easily and I haven't heard any grinding. When I get on the road and try higher speed shifts is when I heard some noises that make my butt clench. I have an eaton fuller fs6206a transmission and a meritor A78 4.3/6.0 rear axle. The sun visor in the cab has shifting instructions, which seem to corroborate most of the information online (namely, be in High if you're split shifting), although it says to depress the clutch when going from Low -> High (everyone else says that Low -> high or High -> low just let off the accelerator and it should shift). Can anyone give more feedback/advice? Don't wanna ruin this diff, as it doesn't seem like there is great parts availability for this medium duty meritor diffs.
It shouldn't be grinding at all, you should hear maybe a clunk from it shifting but not grinding. Just let off the accelerator and it will shift and if it doesn't then try the clutch method.
You don’t have to split all gears. Sometimes high range in one gear is very close to low in the next. I always clutch on the up splits, but not on the downs. Never split on a downhill, not even on a slight decline. You can find yourself out of gear with no way to get back in.
Definitely heard some clunking here and there. Maybe the occasions it wouldn't go in gear today was due to being on an ever so slight decline? And I would downgrade the 'grinding' noise I hear to more of a growl, not nearly as bad as grinding transmission gears. It'll probably just take lots of practice. I live near Asheville NC so lots of hills to climb and descend. So far no scary moments!
Only time you are supposed to be shifting any gears in the rears to low is climbing in that transmission. I have identical transmission with rig weighing in at 30k lbs loaded. Doing all that shifting empty is waste of time unless you got a weak engine which my 35 year old DT466 210 HP can do loaded at 30k lbs up most grades without splitting the rear. Only time I am reaching for a split is around 5 to 6% grades when loaded towards the top.
The really old instructions said on a downhill down split to select low range, then mash the throttle So when it broke torque it would pull out of high gear, engine/drive shaft RPM would increase, then it would catch low range when it matched speed. "Supposed to." I think they took this out of the later books. But it's still possible to do it if you are brave. I can't remember the last time I saw a split rear end anywhere.
1low 1 hight 2low 2 high 3low 3high 4 low 5low 4 high 5 high is the pattern that works best in our f700 that being said first gear is nearly useless other then twisting shafts off its 7something in hi and 9something in low to the best of my knowledge. I never clutch to split the rear. Just got to learn to give it a second to do its thing the moment you get in a hurry you'll miss it. When I first got my dl I started to drive it alot and I've never hurt it. You most likely won't hurt it.
My 1976 C65 had Eaton 5 speed, Eaton 2 speed. Instructions were complex in shifting the transmission & axle simultaneous. Downshifting the axle only, just pop it down, let up on the accelerator. Upshifting, pull the plunger up, lift right foot while pushing the clutch, release the clutch when you hear the faint clunk. I don't use it in winter, I always had to remind myself each spring how to shift both at once. I found split shifting worked well downshifting to climb a hill, or upshifting loaded from a stop. Downshifting for a stop sign it was just too many steps, there wasn't time to do it all, I used only the transmission.
My father in law has a Ford F750, 429 gasser, with a 5+2. He has always shifted it 1L-2L-3L-4L-5L-5H. I borrowed it, and by my 3rd trip, I found it ran way better if you shifted it like the sticker on the visor said: 1L-1H-2L-2H-3L-3H-4L-5L-5H. The process is very similar to floating gears on a bigger truck, just your right hand does the action a little differently.
Yes, I've known guys who were more farmer or [insert occupation] than truck driver and driving the truck was incidental to their duties so they would just shift the axle when absolutely necessary and otherwise were a little intimidated or confused by it. Here in the land of steep hills you have to use everything to your advantage and so high revving, split shifting and slapping the shifter and button around becomes a way of life if you don't want to climb the whole hill in first gear.
Weighing 36000 powered by a 427 Chevy truck engine I considered it a success if I made the hill in first gear low. 427 is a sweet engine when you weigh 2/3 that much, and you aren't in VT (everywhere is uphill then downhill from anywhere).
V 478 Gas IH in a S series Dump Truck and GUARANTEE would be In Low Low Side for many of the hills around here
My 2 speed was a little sticky and just never really use it.