As I was very aggressively accelerating my '02 Harley F150 up the pretty steep freeway onramp (that was curving sharply toward right, if that matters) I heard and felt strong thump (so strong that it scared me) that sounded as coming from transmission during upshift right when I hit the top of the ramp.

Can anyone tell me what might be the cause for it and would there be any damage due to it?

Thanks!

ZoranC

 

I have a Superchip, which amplifies this "thump" significantly. Here is a link to a thread on this site from Mike, the Superchips distributor on this site: https://www.f150online.com/forums/sh...threadid=81350. I don't really like the feel of it either. I am going to ask the dealer about that when I go in next time. Our 2001 Supercrew (5.4L as well, but no SC) did not have that "thump," but from what I understand, this is a new tranny for this year.

Don't like auto trannies myself, and don't know too much about them. This is only our 2nd out of 17 cars with an auto. Even my 530i is a 5-speed. It's not really driving if half of the fun is computer controlled. I like to row my own boat.

 

Zoran...

Do you have a chip? Tranny mods? I had my second gear break in half inside my tranny, but if something that extreme happened you would know due to shifting problems under acceleration in the lower gear range. More exactly, you would see it run to high rpms before shifting from 1st to 2nd.

IF all else fails you might see if you can get ahold of Gregg Evans, Factory Tech, who builds and services the trannies the 02 HDs have and the Lightnings.

Eric

 

supercrew 820,

I don't think the dealer is going to appcreciate a question about hard shifting when your chip is contributing to the problem...

Might want to take that out first.

Just a thought

Ken

 

Im with ken on that one. Theyll trll you your screwed if you dont take out the chip before going in. Make sure you disconnect the battery ground for about 5 min also. It will reset any codes that the chip might have triggered. Who knows that might even be your problem. I had a shift problem between 2nd and 3rd gears where the truck lagged right before shifting. Not good for the tranny. I had a flip chipand fliped it to the street setting and it went away for the most part. I just put in the Fact. Tech Valve body this weekend and im very happen w/ the results so far. Today I just got my chip back from reprogramming for a bunch of other mods that I added and cant wait to install it before leaving for work in the morning.
Just make sure you take the chip out, put the little piece that goes in the hole were the chip goes back so it doesnt look like it has been tampered with, and reset codes. Chip arent suposed to mess w/ warr. but it gives dealers a reason to BS around and take there time on fixing it.

 

No chips or any mods whatsoever (yet) on mine that could have contributed to it.

My wife says she experiences similar thing in her Mustang when by coincidence she takes the foot off the gas pedal right when tranny tries to shift. I dont remember easing off the pedal or letting it go when this happened though. Except for yesterday I dont feel or hear any thumps when shifting. Only thing that ever came even close to this is when I aggressively pushed gas pedal in the curve and truck roared and responded with series of shifts in quick succession. Only similarity between these two I see is attempt to aggressively accelerate when in the curve.

In any case, I tried to reproduce it today but onramp was packed with cars. I will keep trying and also take it up some long steep slopes in the neighborhood.

Thanks!

ZoranC

 

Thanks for the advice guys. I thought of that before - I get my questions answered at one dealer and have repairs done at the other. The repairing dealership is right by my house. The "questions" dealership is where I bought it. They're pretty good about answering ANY question I have, such as effect of Superchip and drop shackles. I paid sticker for the truck...they'd better! My question will not involve dropping the truck off, but only with the question of what the torque converter/tranny is doing during aggressive acceleration.

I have heard that letting of the gas just as the tranny is about to shift is a bad thing to do. I get weird noises when I do this (driving a stick for the past 11 years will do that to you). The chip aids in those successive quick shifts.

BTW, the SuperSCrew_820 is shorthand for "SUPERcharged SuperCREW_#820".

 

I remember a thread explaining the hard shifts as being designed that way to help protect the clutches under hard accellerations. Something about soft shifts actually slipping the clutch discs.

I am not sure what forum it was in. HD or Lightning.

 

That supercharged motor is putting out peak HP at right below your shift point.... (factory shift is 5200) (peak hp is maybe 5 or 5100)...

If you acclerate hard and the let off the throttle right before time to shift, it will SLAM into 2nd. This is BAD on the tranny...

Get a factory tech valve body installed. That little unit is supposed to clean up shifts and keep slam shifts from happening.

I had a slam shift in my wife's honda minivan that was so hard, I thought I had been rear-ended!

https://www.f150online.com/forums/sh...ght=slam+shift

from the L forum...

Ken

 

Ken800,

Your explanation and discussion you pointed me too sounds what might have happened. I don't remember leting go of gas pedal, but there is a chance that as I was on top of that ramp my leg reduced a pressure a little bit.

If that is the case what might be the consenquence to my tranny?

Also, here is a stupid question from an absolute newbie: What is that factory tech valve something something youy mentioned and where do I get it?

Thanks!

ZoranC

 

http://www.powersurgeperformance.net/shift.htm

check it dude. all you ever wanted to know about your tranny and shifts...

Ken

 

Thank you guys!

ZoranC