10 vane or not


Well-Known Member
So as my luck goes I always tend to brake things when driving like a grandma on the way to church. Here is what I was told my transmission has installed:
billet drum
fully rollerized gear train
front pump and output shaft
customer servo
trans brake, stage right
555 and 405 boost valves
rev kit
alto wide red band
billet anchor pin
extra clutches throughout
I am now running a PTC convertor, which I dont remeber the specs excatly but I think it was a 3400 stall single lock up disc.

Last week I broke something and today it got disassembled and was told what i broke does not often break.
Vane and rotor assembly with the ring around it.



Active Member
I wonder if the sudden deccel in rpm when locking the converter is hard on the pump assembly? I am guessing that you locked up the 5 disc converter in your signature when you had it installed? If so maybe it weakened the pump and then it finally let go. I don't have any experience with that just speculating.

Definitely recommend Dave also.
I've broken 2 in the past 4 years so the last one I replaced was with a 10 vane kit just to get the new slide but I still went with the 7 vane setup. I too am a Dave supporter as it was Dave that supplied me all my parts and help.


Staff member
If a factory side and rotor are used, the pump isn’t cavitated, and the clearances are adhered to failure is rare. Usually a problem with clearance or some wobble from the pump drive causes failure. Cavitation can cause rapid failure. Iirc there’s a GM bulletin on the 13 vane equipped transmissions about filling properly to minimize risk of cavitation on startup

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Steve V

Steve V's Automotive 757 560 2782
I replied to your post on Facebook, but I will post here for those who do not do social media. 13 vein is week stay away, 10 vein is better and 7 vein is strongest. Most have gone back to 7 vein , the extras just smooth out the pulses they do nothing for volume or performance gain. The aftermarket rotor has 1 part number IIRC GM has 14!!! of different thickness. Pump must be set-up to .0015 the pocket, when aftermarket stator support is installed lots of times it's not square, any more than .002 out and it can cause issues like a broken pump rotor. The fix is to parallel deck the pump in a lathe. The came direct from Bruce and was in the sticky strengthening the 200-4r. It often takes thousands sometimes 10k miles to show up. A little bind the vein catches and all hell breaks loose. I had the EXACT same thing happen to me last year cruising on the highway, pump had been together for 12k miles, .500 boost valve, stock reverse boost so no crazy pressures.


Texas, Where are you from
those are some large size boost valves. Have you put a pressure gauge on the unit when it was working? Making lots of pressure is hard on parts. As Steve points out some stacked tolerance on the pump parts really gets the thing out of kilter and even at a 2k rpm cruise those parts take a lot of abuse. Looks like the slide cracked. This could have been if th slide spring isn't stiff enough and the whole thing gets to vibrating. Sonnax spring with the stock inner is what I use


Texas, Where are you from
sounds like you got your moneys worth. Time for another. X5 or so on the give David H a jingle. He will get you setup.


Well-Known Member
Last week I broke something and today it got disassembled and was told what i broke does not often break.
The 10 vane rotors didn't break 20 years ago. The problem now is garbage metal from china. Dave knows the difference between the good quality 10 vane rotors and the bad and you can purchase billet versions now.
The 10 vane rotor is something that was created for 700R4 transmissions. The 700R4 trans has been used far more in trucks than cars,so the 10 vane rotor was created for trucks with plowing and pulling heavy loads in mind,not high rpm drag racing trucks. For towing and plowing,the minimizing of pressure pulses is desirable at low rpm operation and is counterproductive as the rpm goes up,but it's not counterproductive enough to avoid at all cost. In fact,it will work just fine. I use a 7 vane rotor in my trans because I want one and have a few of them. I have them because I've been doing this for a long time and have bought some transmissions from salvage yards over the years. The factory 2004R transmissions all have 7 vane rotors in them and is the only place to find them now.