Jatco 3N71B/4N71B (automatic trans) buildup information

Ah… are they hard to do? Ive honestly never even taken the filter or pan off (my dad has though…).

Is there anyone making big power with these tranny mods? Anyone ever break this tranny with mods and at what power? I ask beacause ive got my 84 turbo with rebuilt vg33 and supposedly "built" auto trans it chirps 2nd gear so i know its not stock but im installing a holset hx35 and trying to get at least 450whp out of it and i dont wanna spend money on having jim wolf tune an auto ecu if the trans is just gonna break on the first run

So im getting this done to my auto transmission, am I going to notice any big difference?

mods are, 3 row rad, intercooler, NA2T, and 3in stainless CM all the way through.

am I going to be putting down some good power through the level ten mods on the trans?

Don't forget a good transmission cooler.

[quote]Rick88ss wrote: Will I really need one with the 3 row rad? I will probably get one because anyone knows more than I do about this, but im wondering.

[quote]J18199 wrote: [quote=Rick88ss]Yes.

I had this mod done to the auto 7/87 turbo I had earlier this year. It made a huge difference. Like adding a shift kit to a GM TH350 or TH400. I also used a brand new OEM turbo tourque convertor. I don't know about how it would hold up to additional HP because the car was stock otherwise. The transmission shop did not charge me extra to do the mod while doing the trans rebuild.

So the shop in town doing this for me says that he saw debris on the internals of my trans, upwards to 2400 for complete rebuild…I dont have the money and its 280 for the mod. I of course just said do the mod and put it back together, will I be ok for ahwile so I can save up for a trans from level ten?

Hard to say if an otherwise used auto trans will hold up to a performance mod. I would not bet on it. I've had three auto trans rebuilt and never paid over $1800.

Well its never been terrible for me and has been strong since ive had the car, and if its anything like the engine was (didnt have to be rebuilt at all ha) then I should be ok Im hoping, and even so, if it goes, it will be sometime in KC so I will be closer to some resources.

Im going to quote myself here and say "you F*ing retard!!!" lol…trans took a shit and lost first and second gear, is on its way to level ten to be modified and built.

Was just wondering if anyone knows or has…any experience with their transmission in the Z? Im so excited to get it back in a week that I reaaaallly wanna know! haha

As soon as the weather lets up I can get mine on the road to let ya know.
Tracks here don't open again till end of April even then it is still cold to get real traction.

I did a complete rebuild on mine and all the mods from level ten and keas, except cryo treat, and the upgraded output shaft.
Also have a 3500 stall TQ that is waiting to be tried out.
I got max pressure, all the cushion out of it, set-up with a b&m rachet shifter.

Dmann, do you have pics of the shifter? I am interested to see what and how you did it.
thanks.

Sorry for the thread jack…

What did u guys do about the ecu. Do u need to swap an auto ecu setup into a manual z or can u use the manual ecu. Also with the ugrades can u still use drive or do u have to shift manually from here on out. Its for a customer.

You can use a manual ECU only with a manual trans, and an auto ECU with auto and manual.