Tranny slams into gear

[dr8082]

Before and after chip installation my tranny slams into gear, mainly 3 and overdrive. Over drive sometimes shifts so hard it feels like i got hit in the rear.
HELP!

[kanuck15]

Your trans has detected an issue and has went into protection mode. it ups the line pressures to prevent slipping. Either take it to be scanned or unhook the batteries for a few hours and let it all reset

[dr8082]

Thx for the feed back. it only happens once and a while. Mainly when it shifts into od.

[kanuck15]

Are you having any kind of OD light flashing? If its an intermittent kind of thing then id play around with having it shift at different throttle positions. It would still seem as something is wrong though. Id have it looked at before you end up like me with 3 burnt trannys and a 5g repair bill

[dr8082]

OD light has never flashed. I have not noticed any slipage. Its really a random thing. Meaning sometimes I can lanch from a stop WOT and its smooth as silk. When I notice it most is interstate driving, when it shifts down going up a steep grade then shifts back into OD when the cruise is on. If I dont have cruise on and I let out of throtle it shifts into OD nice and smooth.

Im thinking I need to change/flush the trans fluid and change filter. Im also thinking about a shift kit/throtle body.

[kanuck15]

Ah cruise will do that, It tries to hurry the shift so it doesnt drop speed. But a professional flush and filter is always good. Shift kits cant hurt so long as its done right. Also our trucks dont have throttle bodies?

[dr8082]

LOL yeah i meant valve body. Multi tasking today. You seem to know right much about the subject whats your opinion on the TC lock up mod? I dont do alot of towing and when I do its light. Not much interstate driving either, maybe 30 hours a year. I do however drive off road right much about half the year either hunting or playing on the beach.

[kanuck15]

Some guys swear by it, And some transmission builders say its horrible. A lot of it is how you use it. Its nice to be able to lock up the TC earlier than the trans wants but it rides on the forward coast clutch as well as the clutch packs. If your trans isnt up to the task already I wouldnt do it. Its not a towing modification really cause you put a ton of strain on things. It wouldnt do you any good off road on on the beach as thats when you need the TC unlocked

[dr8082]

Thanks again for all the info. I'm very much a DIY guy. Poor as hell.

[kanuck15]

Same here, Tell ya what. PM a guy by the name of Jake (thats his user name, can be found lurking around the OBS chat and the Buckeye Powerstroke sections) he has a nifty way of doing the TC lock and a lot more info on it