linrick1 Posted September 15, 2009 Share Posted September 15, 2009 Hello all, I am currently running a nice old R model with a 350 and a twelve speed that I cannot seem to get to shift nice and smooth....especially splitting fourth and fifth. I've tried everything I can think of, clutch, no clutch, short shifting, winding her right up, jake on, jake off, throwing it into neutral to split,and I still cant consistently shift her as smooth as I'd like. I've run a mess of different engine/trans combinations over the years, including a couple of 350/12s and I have never had this much trouble getting one to shift the way I want. Anyone have any ideas? Thanks, Rick Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/ Share on other sites More sharing options...
Rob Posted September 16, 2009 Share Posted September 16, 2009 Hello all, I am currently running a nice old R model with a 350 and a twelve speed that I cannot seem to get to shift nice and smooth....especially splitting fourth and fifth. I've tried everything I can think of, clutch, no clutch, short shifting, winding her right up, jake on, jake off, throwing it into neutral to split,and I still cant consistently shift her as smooth as I'd like. I've run a mess of different engine/trans combinations over the years, including a couple of 350/12s and I have never had this much trouble getting one to shift the way I want. Anyone have any ideas? Thanks, RickTake the top cover off and look at the sliding clutches and mating gears. Sounds like you may have some wear in hard parts within from either a lot of miles, or someone that wasn't too careful with their equipment.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-40434 Share on other sites More sharing options...
fjh Posted September 16, 2009 Share Posted September 16, 2009 Hello all, I am currently running a nice old R model with a 350 and a twelve speed that I cannot seem to get to shift nice and smooth....especially splitting fourth and fifth. I've tried everything I can think of, clutch, no clutch, short shifting, winding her right up, jake on, jake off, throwing it into neutral to split,and I still cant consistently shift her as smooth as I'd like. I've run a mess of different engine/trans combinations over the years, including a couple of 350/12s and I have never had this much trouble getting one to shift the way I want. Anyone have any ideas? Thanks, RickVery Common complaint!Well Rick if you do master this you will be the third or fouth guy on the planet to do so.I know of only one guy where I'm living that mastered IT!I'm no truck driver but i found the only way to split between 4-5 is to split after you engage the next gear on the stick (5th ) first then split back down and that usually isn't real clean either.But good luck to ya ,let us know when ya getter down and maybe will throw a party somthing! Masteing a twelve speed is an art form.Guess what I'm saying is don't be to proud to grind once and awhile its just the way it is. Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-40437 Share on other sites More sharing options...
Swishy Posted September 16, 2009 Share Posted September 16, 2009 Run the gear lever thru neutral Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-40453 Share on other sites More sharing options...
Warpman89 Posted September 16, 2009 Share Posted September 16, 2009 i drive a 12 speed and it will grind regardless if its cold, however when it warms up, when your in 4H, revv it high and shift lever to 5H, then immediately click it to 5D and tap the accelerator and it will be in 5Dlike any crash box, timing is everything Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-40465 Share on other sites More sharing options...
brutus998 Posted September 22, 2009 Share Posted September 22, 2009 i drive a 12 speed and it will grind regardless if its cold, however when it warms up, when your in 4H, revv it high and shift lever to 5H, then immediately click it to 5D and tap the accelerator and it will be in 5Dlike any crash box, timing is everythingI do the exact same thing. I drive a V8 with a 12 speed...I have to shitf 4H into 5H and split back to 5Direct it is impossible to go 4H to 5D without grinding.I love the 12 speed. Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-40754 Share on other sites More sharing options...
linrick1 Posted June 15, 2010 Author Share Posted June 15, 2010 Well, I think I have this as figured out as I'm going to. My solution has been to split 4L / 4H and 5L / 5H in neutral, pop it into neutral and split up, then slide it back into gear. Not perfect, but better. Thanks Rick Quote Link to comment https://www.bigmacktrucks.com/topic/10674-12-speed-kicking-my-a-wont-shift-smoothly/#findComment-57377 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.