tone down shifts

[monte0]

I've got a mildly built short tail turbo 400, exact specs I can't remember. I'm looking to tone down the shift harshness a bit. To give you guys a example how hard it shift's, when I hit 1-2nd gear the car more then chirps (and that's not even full throttle) and 2-3rd the car chirps both rear tires hard at 90mph at the track. Now the reason why I think their too hard is just recently I posted that I had too pull my center section apart because the locker broke some retaining clips. Now that issue's going to be repaired.

Well when I was under their looking around making sure thing's were ok, I stumbled upon a weld ripping apart. It's the top cross bar that the upper rear control arms bolt too, where it welds to the main section of frame. The actual weld is cracked right down the middle. Now I'm pretty much guessing the harsh shifts over the years are the culprit.

 

So what exactly could I do to the valve body to tone it down without getting into pulling the trans out?

[monte0]

ttt

[monte70car]

Maybe do a newer valve body to a mild shift kit in it. Other then that I'm not sure how to change how it hard it shifts.

[Mike 57]

Does it have an adjustable vacuum modulator? Try backing it out a bit, small screw driver in the center.

[monte0]

yea, it does. Already backed it out a good amount. If I changed the separator plate between the valve body/trans. with a stock one, would that remove the current shift kit?

[Ian]

Most "shift kits" also move the check balls around or leave some out.

[Grease]

I havent done a 400 shift kit . Did one T350 and that one was a new spacer plate and balls placement as Ian mentioned . The kits I have used in 700R4s are springs and holes drilled larger in the spacer plates . The springs are changed in the valve body . If your doing a rebuild there are kits that change springs in the clutch paks as well .

 

That said perhaps just putting a stock plate back will help you .

[wallaby]

That's a tricky thing to do; every different trans kit seems different from another....how could you tell what's been changed? I think most kits have you slightly enlarge holes in the spacer plates, and relocate or eliminate check balls. I have always chosen the "heavy-duty" or RV shifts for mine. I don't know how the mods are made for the race shift setup. There might be something done with the acumulator or governor, but I would expect most of the mods are all about increasing line pressures to apply the clutches without slippage. A trans that shifts hard is supposed to be a good thing to keep the trans clutches from slipping and generating heat but as you are finding out, it's hard on everything else. I think if it were me, I'd think about getting a higher stall converter. You still have the hard shifts, but there is some slippage to keep them from feeling so brutal.

[Andy's Auto]

A decent stall convertor will tone down the shifts as well. My 71 would kill the rears on the one two shift. A 3000 stall cured it, and got my 60 foots in the 1.80s.

 

Andy

[monte0]

I've been thinking of replacing the seperator plate with a stocker, but someone mentioned to me that the guy that built it might of modified the front pump assembly too.

 

I'd like to go with a higher stall but with my current gearing it wouldn't be ideal. Right now I've got a 2000 stall but that's rated for a light vehical. The company says with my car being as heavy as it is, I would be more around 2300-2400 stall.