727 Accumulator removed, no spring, no stop

[JG71B]

So, when I got this thing I removed the VB just to replace the shifter rods seals and band adjustment nothing else. Someone took it out prior to my getting it obviously. It worked fine other than it would slip going from 2nd to 3rd when at oper temp. Shifts normal only when cold, like the first maybe mile. It slips in D and if manually shifted at oper temp. If I use the passing gear, it would downshift and upshift as normal. It ONLY slips 2nd to 3rd when coming from dead stop, in D. It makes ZERO _ucking sense! Would the missing spring and/or no rod cause the slipping? I'm about to tear it down and do seals, fractions and steels even though it already looks nice inside, fluid looks good after 3 or 4 summers. Thoughts?

 

[pnora]

Sounds like its shifting to quick. If it shifts two quick you will get an overlap with and engine rpm flare. Try extending the kick down rod and see how it reacts.

 

[dvw]

Not all 727's have accumulator springs. So no spring or blocker rod would not cause a 2/3 slip. Does it have a restrictor in the high/rev clutch feed port in the case? Did you pressure check the KD band servo for pressure in 3rd gear?
Doug

 

[Dave6T4]

I quite often left the accumulator spring out on my rebuilds. I tried putting the blocker rod under the accumulator on a couple of rebuilds, but did not like the results, so quit doing that. The flash between 2nd and 3rd could be a band adjustment. Try a 1/2 turn tighter, to quicken band application. Also, check the kickdown lever ratio stamped on it. If it is a 2.9 or 3.2, try changing it for 3.8 or 4.2. The higher #'s will apply the band quicker, hopefully reducing the flash.

 

[DanielSlocum]

Kickdown band only applies going into 2nd gear;releases when high gear clutch pack applies.
Sorry to say you likely have a pressure loss causing high gear clutch to slip.
That is often the result of worn surfaces in reaction shaft support where sealing rings ride and/or bore of high gear clutch drum where reaction shaft support sealing rings ride.
aformentioned sealing surfaces must be in excellent condition to maintain propper pressure. Hot [thin] fluid reduces pressure some making said problem rear its ugly head.
Good luck.

 

[dvw]

Haven't had any issues with rings sealing on the drum surface dur to drum wear, even at higher than normal pressure. Very few drums get wear. My aluminum drum has over 900 runs at 130psi with no concernable wear. The steel ring tends to rotate with the drum. Teflon are the opposite. Have seen the grooves in the reaction shaft wear at a taper wearing one side of the steel rings. Most often the clutch piston seals are worn, occasionally torn. Never seen a band adjustment cure a 3rd gear slip either. If the band was too tight the only thing that I could see happening is it woud have a slightly later release. It could possible have shift overlap with the band and clutch applied at the same time. If the KD servo rings leaks, the band will come off slow. Even seen the 2nd and 3rd gear circuits bleed across the servo cause issues.
Doug

 

[JG71B]

Well then! Seems I'm in for more of an education on this than I planned......no turning back now! Appreciate the input