200-4R QUESTION

[TexasT]

Love to see your input. I've built a grand total of one 2004r so obviously I don't have the 35 yrs experience you have. Keep your input coming.

On the opposite side of that I do have thirty yrs experience as the owner of a Turbo Buick and have experienced just about every failure the 2004r can experience. I spent countless thousands getting them overhaul/rebuilt and even had a 700r4 in the car for a number of years. That said, this unit I have in the car now, that I assembled, is shifting well four years later and it has the seven vane pump, the pump mod you mention to prevent the front seal blow out as well as the gm seal retainer to keep the seal in. I run a 700r4 bottom feed filter and a quart over full on the dipstick to prevent "sucking air" . I think the pump failures in the 2004r can be attributed to the fragile pump rings used early in the production. Once the ring breaks, catastrophic failure is imminent.

I agree GM has done millions in research but max performance isn't their main objective. The buzzing pump noise cure with the offset vanes on the rotor and other upgrades are nice but it doesn't make for max pump volume.

Keep your input coming, I'm always looking to learn.

 

[Rob-Legacy1]

I appreciate your input as well the buzzing noise is resolved by grinding a valve land the vane change to ten was to eliminate cavitation , then again to thirteen to stabilize fluid pressure, My great grand father smoked two packs of smokes a day lived til he was 98 no cancer my grand mother did the same died at 67 from lung cancer just because it worked this time doesn't mean, you should continue to gamble. Have an awesome day !!

 

[melloelky]

I never have, but I wouldn't mind obtaining a copy.

i finally got my hands on this book & man what a book it is.I'm waiting for my friend to finish up a project before he has time to help me with mine(I'm still collecting parts)before he can help me with my upgrades.

 

[olds307 and 403]

The 13 vane rotor is a very questionable upgrade. The strength is a big knock against it, supposedly can break on start up if not properly primed. Most builders agree the 10 vane is the best one to use, more consistent pressure and not as weak as the 13 vane. Of course billet pump rotors are part of the big torque models with near 300 psi line pressure.

 

[Longroof79]

Were these transmissions ever upgraded with a 10-13- vane pump from the factory? Somehow I don't think they were. I'm guessing it was an aftermarket upgrade.

Also, was the hardened sun shell and stator support a factory upgrade? Obviously, you can differentiate between a hardened (spline) stator support and non-hardened unit....but how can you tell between a hardened and non-hardened sun shell?

 

[Longroof79]

i finally got my hands on this book & man what a book it is.I'm waiting for my friend to finish up a project before he has time to help me with mine(I'm still collecting parts)before he can help me with my upgrades.

I think I'm going to have to bite the bullet and spring for a copy.

 

[Rob-Legacy1]

Were these transmissions ever upgraded with a 10-13- vane pump from the factory? Somehow I don't think they were. I'm guessing it was an aftermarket upgrade.

Also, was the hardened sun shell and stator support a factory upgrade? Obviously, you can differentiate between a hardened (spline) stator support and non-hardened unit....but how can you tell between a hardened and non-hardened sun shell?

Gm didn't come out with upgrade until the end of production of the 2004r but it was suggested by Gm that when rebuilt that you make the upgrade.

 

[melloelky]

I think I'm going to have to bite the bullet and spring for a copy.

I haven't forgotten about you Jack but by all means don't let me hold you back on your project.if i get through with my trans/book and you still need it I'll gladly send it your way,it's quite the book.i'm waiting on my friend to give me a hand so i can't complain about the time frame.

 

[Longroof79]

I haven't forgotten about you Jack but by all means don't let me hold you back on your project.if i get through with my trans/book and you still need it I'll gladly send it your way,it's quite the book.i'm waiting on my friend to give me a hand so i can't complain about the time frame.

Thank you, Chris, you're much too kind. I still have to accumulate parts, so there's not a big rush. I appreciate the offer, though.

 

[TexasT]

While not quite 300 psi at idle mine gets to 270psi at full tv according to my notes. Seven vane pump works fine for me and several of my friends that are running mid elevens in the 1/4 mile. Your money, your choice. I've not had failure in the 30 yrs of using the seven vane setup. I guess that makes me like the grandpa.

As far as the factory hardened parts, these are almost thirty yrs old for the newest pieces the factory installed. Probably a good idea to just replace the stator and sun shell. That is money I would spend, along with the hard rings, larger valves and spring and the stiffer slide spring.