Hard Shift from 1st to 2nd & shuddering
- Thread starter Syclone7114
- Start date
George Blake
DONATING MEMBER
Re: Hard Shift from 1st to 2nd & shuddering
Don't check for TV issues at WOT. At WOT you are getting full TV boost and your 1-2 is gonna be hard. That's how it works.
TV issues usually center around PART THROTTLE driving. Say, 20% throttle, steady. 1-2 shift shouldn't be that hard. Harder than a Astro Van but softer than your own truck at WOT or 50% thottle. More throttle, the harder it shifts. Now, if your cruising along at 20% throttle and the truck is jerking your teeth out, something is wrong. 1-2 shift should occur at 11-16 mph and NOT be hard at about 20% throttle.
Your breaking up and studdering is a detonation or boost control issue. I remember serveral years ago, there was a sleu of MSD boxes causing problems. Completely disconnect the MSD box and disconnect the boost control solenoid (if it's a stock turbo) and you'll get a max of about 8 psi boost. See if you still have the studdering. If it goes away, hook the boost control solenoid back up. If you still don't have the studdering, it's the MSD. You need to run Datamaster or Tunerpro and see what EVERYTHING in the engine is doing.
Don't check for TV issues at WOT. At WOT you are getting full TV boost and your 1-2 is gonna be hard. That's how it works.
TV issues usually center around PART THROTTLE driving. Say, 20% throttle, steady. 1-2 shift shouldn't be that hard. Harder than a Astro Van but softer than your own truck at WOT or 50% thottle. More throttle, the harder it shifts. Now, if your cruising along at 20% throttle and the truck is jerking your teeth out, something is wrong. 1-2 shift should occur at 11-16 mph and NOT be hard at about 20% throttle.
Your breaking up and studdering is a detonation or boost control issue. I remember serveral years ago, there was a sleu of MSD boxes causing problems. Completely disconnect the MSD box and disconnect the boost control solenoid (if it's a stock turbo) and you'll get a max of about 8 psi boost. See if you still have the studdering. If it goes away, hook the boost control solenoid back up. If you still don't have the studdering, it's the MSD. You need to run Datamaster or Tunerpro and see what EVERYTHING in the engine is doing.
Syclone7114
New member
Re: Hard Shift from 1st to 2nd & shuddering
Ok guys... update on this.
After a few more launches and some trouble shooting.. ive came to these facts.
1. If i launch with the shifter in "D" right after the initial launch it will take off hard, and before it reaches 2nd gear it bogs, studders, the motor keeps revving but the truck falls flat on its face. after that it will just take right back off agian and keep going. I did notice the factory boost gauge goes above the "15" mark (but it does this at other times and has no affect on the truck, i am guessing that the factory boost gauge is just way off as usual)
2. If i launch with the shifter in "OD" i can boost as high as i want and it takes off like a bat out of hell.. no bogging, studdering, free revving.. nothing....
Any ideas?
Ok guys... update on this.
After a few more launches and some trouble shooting.. ive came to these facts.
1. If i launch with the shifter in "D" right after the initial launch it will take off hard, and before it reaches 2nd gear it bogs, studders, the motor keeps revving but the truck falls flat on its face. after that it will just take right back off agian and keep going. I did notice the factory boost gauge goes above the "15" mark (but it does this at other times and has no affect on the truck, i am guessing that the factory boost gauge is just way off as usual)
2. If i launch with the shifter in "OD" i can boost as high as i want and it takes off like a bat out of hell.. no bogging, studdering, free revving.. nothing....
Any ideas?
George Blake
DONATING MEMBER
Re: Hard Shift from 1st to 2nd & shuddering
The difference between OD and D is the overrun clutches and piston. It's possible that you are losing pressure through a torn overrun clutch piston seal. That piston only gets pressure behind it in D. In OD, no pressure there. You'll need to hook a pressure gauge up to see if it falls off on the 1-2 shift when in "D". It unfortunately sounds like it may be a trans issue. I wouldn't WOT it anymore and I'd leave it in OD and keep driving it until you can afford to have it pulled and gone through.
I would still get a Datamaster style cable from PPI Typhoon and get Datamaster (free for 20 runs) and monitor what the engine is doing.
The difference between OD and D is the overrun clutches and piston. It's possible that you are losing pressure through a torn overrun clutch piston seal. That piston only gets pressure behind it in D. In OD, no pressure there. You'll need to hook a pressure gauge up to see if it falls off on the 1-2 shift when in "D". It unfortunately sounds like it may be a trans issue. I wouldn't WOT it anymore and I'd leave it in OD and keep driving it until you can afford to have it pulled and gone through.
I would still get a Datamaster style cable from PPI Typhoon and get Datamaster (free for 20 runs) and monitor what the engine is doing.
Syclone7114
New member
Re: Hard Shift from 1st to 2nd & shuddering
Thanks.. I will be getting datamaster for my truck soon enough... so no worries there.
Ill probably just park the truck until i can get it looked at.
George... I sent you a PM.
thanks
Thanks.. I will be getting datamaster for my truck soon enough... so no worries there.
Ill probably just park the truck until i can get it looked at.
George... I sent you a PM.
thanks