So I'm in the process of pulling my 327 out of my nova and dropping in a pretty stock lq4 with a fast spooling 72mm turbo in it. I want lightning fast response. I currently have the th400 in my car. It's a 1973 short shaft "STOCK" th400 and converter. I do not know what it came out of. But it drives nice and shifts smooth. I'm only looking to make 500-600 hp. With that being said, this car will never go to the track. It's simply for cruising and boiling tires. What do I need to do to make this transmission not blow up on me.

Oh and I'm a jew who doesn't like to spend money....lol

 

stock will live a while at that level with street tires

you will boil the tires before breaking

lots of cheap upgrades for the t400 starting with a shift kit and moving up from there

racing junk you can buy a decent used tranny and sell the one you have if you want to step up the power (and you will!!)

 

What about when I'm strapped on The dyno making pulls? Is it gonna hold up to 10-15 wot pulls at that power level? Not a bad idea to get another th400 and build it. What is needed to make it hold this kinda power Or say another 100hp on some M&H's on the street? if i end up with 650-700whp what am i looking at for parts?

 

TH400 at 700 HP using a turbo, sub 7000 rpm shifts, just needs a good valve body, 34 element sprag setup, and proper assembly. Some rollerizing is good.

 

Ok good to know. Don't really plan on reving much over 6k. And what valve body do you suggest? And what about stall? What would you suggest?

I mean with what's in there now, (dont know what stall i have now) and my 308 gears that I have I'm pulling 19/20 on the hwy rolling @ 3k and 70mph out of my carbed 327. Granted I have a wideband in and I've tuned the **** out of the carb and timing.

 

Valve body depends on your goals, but if it's going to see any track time, a transbrake will help spool the turbo.

As far as converter, you will want a decent piece. Give us a call we're doing them in house with good pricing.

 

Ok good to know. Dont ever plan on taking this to the track. So trans brake is not needed unless its cheap. I'll probably wait until income tax return time to pick up a converter, but I just wanted to make sure that it would survive in the mean time.

I've help my dad do a couple of transmission rebuilds, but I haven't done anything to in depth. He said he would help me tear it down and rebuild it and do what ever we need to get it to hold power. So im just doing my research now and bookmarking stuff. I did find this posted on your site. http://www.jakesperformance.com/TH400_Rebuild_Tech.html

 

So I've been looking at a few parts, are these worth a ****? http://pages.ebay.com/motors/link/?n...907628&alt=web

 

I had a good manual vb and a trans brake on a basically stock t400.. lasted aprox 5000 miles and 50 runs at around 9.50's at 3400 lbs and a good ptc 3600 stall.. but when it let go it took out all the insides.. went to a billet 6 clutch direct, alum 34 or 36 sprag second gear drum and a good pump and they said they would warrenty it for a year less than 1100hp.. but it was 2k in parts.. just depends on how many times you want to chase parts instead of doing it right the first or second time.. you can or will end up spending more unless you do it right once..

 

The price isn't horrible, but not really a fan of those Red Alto clutches or Kolene steels. See if you can find a 6 count clutch pack using Borg Warner Hi Energy clutches.

The direct drum is the third gear drum that also has the intermediate sprag. Sounds like you bought a billet forward drum with an aluminum direct drum.

2k worth of parts in a TH400 will build a pretty nice transmission. For that price you can have a 300M billet input shaft, forward hub, a full rebuild kit, a transbrake, a 36 element iron drum (or a 34 element aluminum drum), and a few factors depending a 300M billet main shaft. Something like that I would have no problem also warrantying for a year as well @ 1,100 horsepower.

It's definitely overkill for the OP though for 5-600 hp. Stock hard parts will do fine, if you're getting a transbrake, make sure the third gear clutches are dual feed, a bleed hole drilled in the direct drum and if possible some firmer return springs wouldn't hurt. New low band, inspect the reaction carrier and replace if needed, 34 element sprag, rollerize the hub and rear, and you're pretty much all set. Honestly those are all good practices to use with or without transbrake, but with a brake they are essential for optimum performance.

 

Ok so I won't be using a manual vb. It's going to be driven on the street on street tires. Never gonna take it to the track. It's 100% street car. Like tex said. Sounds way over kill for what I'm doing.



I plan on doing the dual feed and some rollerizing out back. Along with the 34 sprag. Why don't you care for the alto reds and Kolene steels? I'll look to see what I can come up for on prices, but I may just end up doing that because the price is good and I would assume they are better than what's in there considering it's been sitting in a garage since 1983..lol

 

There was a LOT of money and time invested in the Borg Warner Hi Energy clutches when they were implemented into the factory late model 4L80Es. More than probably any aftermarket company could hope to put in. I have seen several cases of Altos delaminating, especially the bands, including 2 very recent cases on 4L60Es. BW Hi Energies have supported countless 1,500rwhp+ vehicles without a hitch, why fix what isn't broken? Just because something is aftermarket does not necessarily mean it will be better than OEM. We could increase profit margin substantially by using aftermarket parts in our builds, such as off brand wiring harnesses, solenoids, sprags, etc but there is a drop in quality. GM did their homework and took extra lessons on the side with the 4L80E, for the most part.

Kolene steels are a waste of money as far as I'm concerned. The benefits of the process are for hardening of the steel and for corrosion resistance, primarily. They are nitrided and put into a proprietary salt bath. The entire process is actually called molten salt bath ferritic nitro-carburizing. It sounds fancy, and there are many industrial applications where this process would be excellent to use, but as far as a transmission goes, why would you need to harden the steel further and attempt to prevent corrosion? However, I could see an argument for the benefits of it in a 4L60E 3-4 clutch pack where coning is a very noticeable and ongoing issue and the reinforced steels may help prevent that, but even assuming that was the case, it would not apply to the TH400 or the 4L80E.

The steels are already substantially stronger than the friction, if you're at a point where the steel strength becomes a concern, your entire clutch pack is almost guaranteed to be screwed anyways and in need of replacement. Corrosion should not be a concern because once the steels are installed in the transmission, fluid will prevent it. ATF is not corrosive to anything inside of the transmission, in fact quite the opposite as modern fluids are designed to have rust and corrosion inhibitors along with anti-wear additives and more.

 

I believe that oem parts are great. I haven't really ever dipped I to gm stuff until recently. All my experience has been with oem honda stuff. And the Finish work on all there cast parts makes the small block stuff look like it was made in a cave.....lol now the lsx parts....... that's another story. Like you said gm really stepped up on alot of stuff since the sbc days. Thanks for all the info. I'm like a dry sponge right now trying to absorb everything I can. I'll look up the bw stuff. Do you happen to sell them? ......lol ;-)

 

We do sell them actually

When the the time comes for your rebuild, give me a call at the shop and we can talk transmissions and whatever else. I love helping people out

 

I just picked up a full rebuild kit and a converter from you guys for my procharger/LQ4 build. Kit looks nice. Lots of help over the phone deciding what I needed for my setup and that really sealed the deal for me. Thanks.

 

Thank you James! Just wait until you get the converter