I don't know why thread got deleted but i'll start it over.

So I replaced my stock converter, with a "low stall" single disk converter from a well know tranny builder. Other than the new converter, my trans, and engine are BONE stock. Stock size tires, and 3.73 gears. Truck is a 2007 5.9/48re, and has 27000 miles on it.

NEVER any issues with the trans. NO slippage, it works perfect, and other than the loose sloppy stock converter which is how it is suppose to work from the factory, there are no problems with it either. Once in lock up, it never slipped once. I am very familiar with how my trans works and acts while driving. And that is the ONLY reason I replace the, perfectly fine, stock converter. It stalled to high. I always felt like I was way out of the power band. It just seemed way to inefficient.

So. I got under my truck Friday night, dropped the trans, and by Sat, had the new converter in, trans bolted back up, and topped off the ATF.

I checked the ATF probably 10 times before I even drove the truck. Had it up on jack stands, let it get warm, manually put it in every gear. The ATF is dialed. It's NOT low.

I backed it out of my driveway, put it in drive, and within 10 seconds I new this was the wrong stall. It is higher than the stall in the stock converter. Not by allot. But just my normal driving style, (old man) it took about 200rpm MORE, to get it moving. Drove it 800 feet to the end of my street, and check the fluid again. It's fine.

Got out on the main road and nailed it from a dead stop. Like all stock trucks its a little laggy out of the hole, truck rolled out 10 feet, turbo spooled up and the truck took off. The tach jump up to 2700 rpms shifted at about 3100 into second, where the tach came back down to 2700, then back up to about 3100, shifted into 3rd, and again back down to 2700. So on and so forth. That's where it stalls at now. 2700rpms. About 200 rpms higher than the stock converter. There is a pretty steep hill that I use to let the truck sit at idle, with my foot off the brake, in drive. The truck would just sit there in one spot, and not move. Now with this converter, the truck rolls backwards on that same hill. To me the fluid coupling is not as good. I don't know if i'm using the right terminology, i'm no trans guy.

Now for the second problem. Clutch lockup

Everything works as normal (except the high stall speed) until it goes into lockup. It locks up very soft. I can feel it lock, but it is very soft. Then when it locks, and I get into it a little bit, it doesn't feel like it's holding. It stay's in lock up, but I can see the tack jump up faster than the speedo. 3rd gear where the engine and trans are operating 1:1. I would think the tach and speedo would move together the same amount. That's how the stock converter worked. With the new converter, the tach goes up about 400 rpms then holds back. I think the clutch is slipping a little bit? Its just doesn't seem right. So I parked the truck, I put about 5 miles on the new converter.

Again I am absolutely confident there is NOTHING wrong with the trans. Or maybe now I should say, "WAS" nothing wrong. All I did was take off a converter, and put on a different one. All withing 24 hours. I didn't even take the pan off as there is no reason to do so while replace a converter.

I just don't understand the inner working of a converter as I have never seen one apart. One guy said the builder might have put in a stater for a gas v10 engine trans, as those have a higher stall. But that wouldn't explain the TCC not holding. I am wondering if somehow there is a clearance inside the converter is not right, making everything inside just a little loose?

And yes it was installed right. Seated all the way.

I called the builder last Monday, and he agreed there is something wrong with the fluid coupling. But now I can't get a hold of him. He's not answering his phone, and not retuning my calls. I'm hoping he's out of town or something, as he is a VERY reputable shop. I can't imagine he's going to leave me hanging.

But I guess my question is to people who know the working of these converters. If I take out a properly working converter, and put one in with these issues, what could the problems be?

 

Something in the converter has failed or is not exactly right. It happens.

Lockup firmness is going to be a function of pressure and clutch area, but, from your description it is worse than stock.

Hope you get it fixed.

 

Sounds like the new converter has and internal problem(s). Since the builder admits this, I'd ask him for a replacement along with half the going labor cost for R&R of transmission...........again! Also, I'd pull the pan and take 2 fluid samples. Over night one to Blackstone with a note explaining the problem and see if they will expedite the analysis for you. Keep the other as a back-up. If the TC has caused xmsn problems then you will know it before you reinstall the TC and cause additional problems for yourself. This may sound like overkill but blowing up your tranny and the new TC will hurt a lot more!

 

If that new convertor is bad DO NOT run it... sending clutch material thru your trans will destroy it. Ask me how I know...

 

Ok, thanks for the reply's. Good call on doing a oil analysis. I just hope to hear back from the builder soon. If I don't hear back early this week. I am going to call my credit card company and explain to them what's going on. They should refund me my money, and they will get it back from the builder. But I will still be out a core converter if I have to go this route. What pain in the butt this is turning out to be.

 

al---don`t let us just hang here--WHAT is the latest?
If the builder gives you a hosing, we need to know so as not to deal with them............
Good luck, hope it all works out.