I just had a shift kit installed, now when it's down shifting from 2nt to 1st there's a slight hard shift. My trans. rebuild shop said that's what happens when you install a shift kit, you will now feel it shifting. If this is true then why add a shift kit when rebuilding a trans. Besides this problem the trans runs great.

01 f150 4.2 auto

 

Why did you have the shift kit installed?

 

I put SKs in everything, not just to have better shift quality but to increase fluid flow all over internally...or dumping gross PWM converter lockup. OEMs have missed many things accidentally or they had to for shift quality for the masses...aka soft and flaccid. Old Mercedes shift firm from the factory, just how the 722s shift.

It should not clunk on a downshift. You may notice it, but it should not be aggressive at all. I always have mine setup on the most mild settings available. One can increase fluid volume to balance shift quality as needed, removing or reswapping hard parts is never fun.

I have a Superior Towpower kit in my Screw's 4R70W and billet OD servo. Shifts nice, quick, clean.

Ask what kit was installed or if they did the common J-Mod. As I know Superior and Transgo are only companies that make full kits.

 

They said it was part of the rebuild. I had no reverse and 1,2,3 was starting to shift hard.

 

Shift kits make the trans shift firm, or crisp i
Stage 1 kits are nice on components
Stage 2 you start to get a hard shift
Stage 3 shift kits are down right gnarly hard shifts
All are designed to not "***** foot around" with the shift
They want it "now" with "no delay" as to save the clutches from wear
It is the prolonged shifts that destroy transmissions as far as towing or racing is concerned

 

Could adding a shift kit cause only a slight hard shift from 2nt to 1st. ? All gears shift nice except from 2nt to 1st, you can feel a small jerk.

 

Maybe
Not sure
Precision transmission
Watch a few videos of his
He knows alot about shift kits and all the particulars
There are about 75 shift kits out there
Tons of mods, leaving springs and ***** out etc.
Without knowing exactly which shift kit the rebuilder used, it's hard to say exactly what your trans should be doing
They gave you some sort of warranty, right?

 

There are "shift kits" and there are "rebuild kits". Not clear why you got a shift kit when all you needed was a rebuild. Shift kits are designed to modify the behavior of the transmission as described above. Harder quicker shifting.

Seems like the basic question is whether or not the hard downshift will hurt anything. Probably not, so if it's not annoying maybe you should just live with it. Good luck.

Or take it back and tell the guy it shifts hard. Maybe there's a simple fix.

 

A lot of rebuilders always install their favorite shift kits. They believe that it will help with the longevity of the transmission. Maybe they are right...

 

Still under warranty. Shop owner said they used a JR. shift kit. He said with the new springs it will cause this to happen at lower gears. He said it should take about 20,000 miles before that slight jerking feeling to go away.

 

19,900 mile warranty?

 

Thank goodness you don't have to put in a traditional SK anymore. It's all done electronically now with a custom tune.

 

Probably this kit

https://transgo.com/product-details/sk-aode/

2-1 clunk/harsh is odd as just releasing int clutch on the 70W, if it actually that specific downshift. Have you tried manually downshifting from say 5mph? Or going wide open from second to first after that shift to force the downshift?

Without another party riding in it, cannot say if odd or not.

 

2 year 24,000 miles

 

It only happens at about 21 mph when I'm slowing down. So I'm guessing it's 2 to 1st.