All shifts okay except 3-4
 

I think I finally have all the vacuum leaks in the engine compartment fixed. My1-2, 2-3 and 3-4 shifts below 2,000 rpm are very smooth, but a little soft.
1-2, 2-3 are quick and firm, but not too firm, just right, 3-4 flares a little at 2,000 to 2,500 rpm. WOT are all quick and firm with no flaring. The transmission hangs on to 2-3 too long and then thuds into 3rd when creeping along in traffic. I just changed the filter and all the fluid using Valvoline Max Life Dex/Merc fluid. No change in the shifting from the fluid/filter change. I have the VCV set per the manual. If it ever stops snowing I will hook up a vacuum guage for concise readings. I have 10 hg on the modulator line with a Mity Vac, but it leaks down quickly. Will slackening the Bowden cable help with hanging on to 2nd gear too long? And what can I do to eliminate the 3-4 flaring under medium acceleration? I have not touched the Bowden cable or the modulator on the trans.
Thanks.

Which vehicle?


According to Steve Brotherton and others, the early 722.3 trans was notorious for this flare.

Adjusting the modulator and teh bowden cable may remediate the flare, but there is a good chance you will be sacrificing shifting performance on other shifts to get there.

Your best bet is to read up on the Superior Shift kits or the K1 and K2 kits from an MB dealer.