Hi all.. I just pute together my first 904 from late 79 with lockup. Also installed a shift improver kit. Nothing drastic. rite from the start I had a small 2-3 shift flare. it kind of feals like the band lets go and the front clutch kicks in late( in my imagination). front clutch is to middle of specs, did a psi test and @1000 I get 65 move throtle lever back just before kickdown line is at 80 lever all the way back 110. front servo follows line psi dead on, and has smooth opreation. The part that has me stumped is when i return the throtle lever slowly back to the forard position I feel a buzzing on the lever and front srevo psi goes to 30 then kicks into 3rd again with 65 psi. this cant be right. in my line of thought the throtle valve is bounsing against the internal valve spring. fluttering or moduelating the end of the valve?? has anyone seen this before? what do you gies think? I should also say that light throtle produces less flare heavy throtle produces longer flare. havent tryed wot yet didnt want to burn anything up. Ah.. also installed a 3spd govenor with smaller weights to rais shift points because of the hi gear rear. 2.45.shifts 1-2 at 25 is perfect 2-3 35 need to work on that yet and lock up at 45 would like to make that later too, but really want eletric lock up. is all this info worthless?
Thanks Hank.

What is the 2 gear band lever's ratio? ( it is a number stamped on the side of the lever)

This will sound backwards but try loosening the 2nd gear band a couple of turns, to see if that changes the "run-away" shift quality.
DD

Thanks Doc. The ratio is 3.2 if my eyes serve me. I forgot to say the front band is a ridgid type. and is backed off 2 turns, but will adjust more tomaro. I should ask what your thoughts are on loosening the band.

TransGo had some info saying to loosen the 2nd band to help correct a 2-3 run-away shift and it seemed to help with one I had years ago.
I think it has something to do with having a enough pressure "bleed-off" from the 2nd gear band circuit, before the 3 gear shift valve will activate.

Like you... this did not sound "right" but doing the 2nd gear band adjustment(s) is easy so it's a fast way to collect more data.
DD

Thanks for this topic and the info. I need to try this on my Project V trans. I may have set that band a bit tight before installation and maybe it's still fixable w/o major disassembly. Pretty solid flare up on recent drag outing.

Cheers,

Lou

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Home of Slant6-powered fun machines since 1988

Ok.. So today I adjuster the front band out 4 turns, and heres what I got. At moderate acceleration (normal road driving) the 2-3 flare is noticeably worse. However at wot the shift is proper. would like to feel a stiffer shift though.
This is by no means a strip car, just a daily driver for now and for fun.
Might I try a different valve body., say a body from a 81-82 904?
I wonder if those have different 1-2 and 2-3 shift valve springs?
Are low ratio and hi ratio tranny valve bodies different?

Good data...
I agree that changing-out to a different VB is a good "next step".
Be careful with using the later valve body, many of those have a different shape around the accumulator and will create a pressure leak if you try to use it in an earlier transmission.
DD

Thanks for the heads up Doc. Ill keep you posted.

Note to others. When in a hurry, dont forget to install the lockup body. It has a tendency to creat a large internal leak. *Clown* Ok. So the valve body did the trick and no more 2-3 run away. I adjusted the kick band back to 2 rounds shifts are firm and snappy. GOAL.. now to address the 2-3 and lockup timming, compared to road speed, they are still early.
But now my question is what is differant between these bodies? Externaly they look the same. Could be spring differances but i didnt dissasemble them and compare.