So, I got my truck pretty much all together. Rebuilt the 400 with all new T Meyer stuff, about 400 hp and 500 tq. Rebuilt the C-6 using broader performance rebuild kit for the 500 hp. New locally sourced Torque convertor, billed as a Super stock TC from a respected transmission supplier. Rebuilt the rear end changing gears to 3.55 with a power lock Posi. Took the truck down and got it inspected and licensed, but still had a few things to tweek. Put about 30 miles on it in short runs and it really seemed to me like I wasn't getting the power to the ground. I know that I put taller gears in, as it had 4:11 open diff before, but I more than doubled the horsepower and torque, so I figured it wouldn't really matter. I was feeling that maybe the TC was too loose, but couldn't quite put my finger on what was wrong. Also noticed I got gear whine and OMG the posi clangs and pops a lot more than I would have thought. I don't recall Posi's I've had in the past making that much clatter when turning off the road onto my driveway or turning sharp in a parking lot. Hoping that will change as it loosens up a bit. Anywho. I took it out on a shakedown run yesterday, of about 40 miles with some intermittent stops. Most of the time I was running around 3000 rpm at 60-65mph, so not too bad. I did notice I was close to 4k at 75 at one point when it didn't seem to be running right. Then at one stop at a gas station, when I was leaving, I was on a little incline so I was giving it just a bit of gas to hold the hill until I had an opening to pull out in traffic. When the time came, I gave it gas and it revved but sat there and then all of a sudden took off like a rocket. Literally. Laid some crazy tracks and fishtailed all over the highway. Little later on my way home after it sat and cooled for a couple hours. It seemed ok, but still acted a little sluggish on 1st gear. drove about 10 miles to a stop light and it did the whole sit there revving before engaging. Once it engaged, something popped. Made a bit of a gear grinding sound and then engaged. Pulled into a parking lot and called a buddy to bring a trailer. I'm thinking the first gear clutch pack came apart. So, I'm contemplating my next move. I can probably fix this, but I wanted o/d before I even built this one.... So I can buy an E4OD for almost the same money as a C6, except I have to add the baumann controller and shorten the driveshaft. Ordinarily I would just take this tranny to a shop and let someone who knows what they are doing build it, but, I have another truck I can use these parts for assuming it didn't chew up anything and its an easy fix. So, that being said I have a few questions. I know that the E4OD is 4 inches longer than the C6, but I want to know about the rest of it. I know there is a change to be made to the cross member, but I've got headers, and wondering if the E4OD is a problem with Hedman headers on the 2wd truck? I've got the Dakota Digital gauges, so I don't think integrating the controller will be too difficult and having the lockup TC will be nice as I've also tried to quiet the truck down. Actually almost too quiet. Put on the biggest magnaflow muffler, should have done the 18" one. Anyway, any thoughts on the E4OD swap as far as fitment and difficulties I might encounter, and any suggestions on where to get it? https://www.bestbuytransmission.com/e4od-transmission seems to have a pretty decent deal.... Of course I don't have a core, but I do have a spare 4R70W laying around maybe I can send that to them.

 

Actually, it can matter a lot.
While it sounds like your trans an handle it, and maybe the torque converter needs to be sized/specified to work with a completely different rpm range, the main thing I see is that whenever you change to taller gearing, or a larger tire size, coupled to a more powerful engine, the parts that see the most stress are what's in-between. Namely the transmission and driveshaft.
All that power is now being forced to push against taller gearing and the trans needs to be able to handle it. Sounds like your trans can handle the power, but I wonder what details of the TC might be working against you.
Did you get a stall-speed specification, or other details on your TC?

I hear ya. Not sure I'd be able to tell what was what inside an auto trans either. Especially with all the new stuff.
Larger engines, more power, more torque in different rpm ranges, all effect how a torque converter shows itself on the ground. Did you tell the supplier what all you'd done to your engine and the gear ratio when they sold you the TC?

It very well might. But I would help it along by adding another tube/can of friction-modifier additive. You DID put a can in when you added the gear lube, correct?
Even when the lube says "compatible with limited-slip diffs" it's usually not enough unless it's a really slippery synthetic. Especially if it's a performance oriented limited-slip. My 9" unit from Ford Racing was quite stiff and took two full tubes of friction modifier to settle it down when going around sharp corners. Very noticeable in reverse especially.
The gear whine you describe is not a good thing though I don't think. Is it there all the time?

Ok, agree that's not too bad. Kind of high in fact! But that takes everything I said about using too tall of gearing with your newfound power out the window. That 3000 rpm indicates plenty of gear for the tire size.
In fact, that's crazy high considering you had 4.11's before!
Are you running a 26 inch tall tire? Is your tach accurate? What does your rear tire measure from the center of the hub to the ground with the full weight of the truck on it? Just curious and will use an online calculator to confirm your tach readings.

Ok, something is inconsistent here for sure. Either your tach is off, or your trans is slipping a lot more than it should. Which would certainly explain your "soft" feeling and lack of power to the ground.
I think...

What's the stall-speed range of the converter?

I wonder if the fluid is getting especially hot?
Have you checked the level while cold, warm and hot temps? What type of fluid are you using? Did the trans builder, or clutch supplier specify Type-F or Dextron?

Doesn't sound good...

Interested to hear as well. I know that when putting them in some vehicles the overall bulk is enough to require tunnel modifications. But not sure on your truck.

Was the 4R70 just for the Windsor bolt pattern? Or were they available with the 460 pattern? I've heard the 4R is a better trans than most, and if you need a controller for the E4 anyway, just wondering if the 4R would not be a better choice if it could be made to fit?
I love mine behind a 5.0, because the first gear is really low, the stock TC bites early and hard, and the overdrive is a great boon to mankind!

Good luck with all the new difficulties. Sorry to hear your trans was making rude noises, but maybe it's still saveable.

Paul

 

Hey Paul, Thanks for the replies.... So, the TC is supposed to be around 1400 stall. It didn't consistently run over 4k rpm. It was getting a bit warm, although I don't have a trans temp gauge, the engine temp gauge was showing slightly higher temp than it had been with as much radiator as I have it should be cooler. I did smell some trans fluid just before I had that TC slip so much. I'm running the Dexron merc III per Broader performance. I didn't really spec the TC as I'd read that you don't need a stall convertor with these motors and I'm not racing it. The fluid is clean at least what I've seen of it. The 4R70W is only in the small block bolt pattern. Theres an adapter where you cut off the bell housing but by the time I rebuild the 4R70W I have and buy the kit and the controller and the TC it would be a lot more expensive than buying a built E4OD. I'm a bit tired of having to mod everything, but I guess it's the nature of the beast. I don't see any ready made adapters for the crossmembers so I will have to fab those, but the Hotrod article on this swap shows some pics and they dont look incredibly hard. As for the rear end, I think you may be right. I bought the lube with the friction modifier in it, but I didn't add any. Maybe I'll try that. I don't really know how much whine it has because the truck is kind of loud running highway speeds with wind noise and 3k rpm its perceptible but not screaming either. Then again, given the transmission issues, I don't know if maybe the noise came from the transmission. So, I need to just clear a few things off my punch list and see.

 

The 4R70W was only made for a short time with the Windsor bolt pattern. Most of the millions that were made had the Modular bolt pattern. Not a single one was made with the 460 pattern. That's a good thing, because the 4R70W isn't beefy enough to live for very long behind a 460, especially a built 460. The E4OD was a MUCH stronger transmission.

The gear ratios are not much different. First gear in a 4R70W is 2.84:1. First gear in an E4OD is 2.71:1. Overdrive in the 4R70W is 0.70:1, the E4OD is 0.71:1.

 

Thanks Mark. Yeah I had salvaged the 4R70W for my 67 mustang with a 5.0 roller motor... so I need to source another e4OD to send as a core. A lot of these places want 7-800 for a core. crazy