Well, servo is good. Only 5 codes came back. They all point to the band. Gotta do a teardown and will most likely be replacing the 2-4 band. Gonna upgrade to the Kevlar style from the carbon style.

 

Hope it works out for you. Just be sure to check the flatness of the reverse input.
Kevlar is finicky about uneven surfaces. Good luck.

 

Plus P0717 Input speed sensor circuit low voltage.

 

Does this upshift from first on its own and when it goes to second will it just rev and freewheel or can you get it to go to third? Band would also give you problem in fourth.

 

It will upshift to second, but I usually have to let off the gas for it to go.

According to Chuck at FLT, "In Manual 2nd it’s using just the band so it still could be bad, even though 4th still works. In 4th the 3-4 clutch is on also which explains why you still have 4th"

I still have 3rd too. Being there is a fluid pressure liss and input speed issues, it appears to be slipping.

 

That is true. Can you make it slip in 4th? You wont have a pressure loss from a worn band.

 

No. Pulls pretty good in 4th.

 

First and second have always "blended" together rather than a firm 1-2 shift since I got it.

 

I understand what you are describing just hard to diagnose over a keyboard. Wish I could pin point your problem. Not much help. Good luck and keep us informed.

 

no 2nd gear

Have you had any luck with your transmission? I have the exact same problem lol. Ironically my truck came from West Virginia also. But I'm in Mi.now lol.

 

No. Waiting on getting my truck into the trans shop. No room til next Monday....if we're slow this week, I might see if we can yank it out at our shop.

 

Well, Truck got into trans shop today....we will see what they find upon teardown.

 

Well, they found basically a stock rebuild with some extra clutches. Stock clutches and steels were burnt to shit. Input drum was wasted. Carbon band smoked.

If this is supposed to be a built tranmission (level 5) then my rebuild.should be about level 9.

Needless to say, I will have my local guy build me it correctly.

Red clutches, Kolene steels, HD input drum, Kevlar band.

 

Really. So he put the thin steels in to get the extra fiber in there?

 

What is the response from FLT?


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I see a few possibilities. Don't take offense to any of this. 1 your local trans guy doesn't know what he's talking about. 2 he's full of shit and wants money out of you. 3 FLT built a legit trans and sometimes things still break but your local guy still is full of it. Or 4 FLT pulled something shady. Which I doubt considering the amount of business they do. At this point what do you expect FLT to do? Now it's been opened up and messed with by someone else.

 

I can see all of those options being possible. But I guess I'd be more curious of what failed and why...on a truck that was not making a ton of power...and did not have a lot of miles on the build.


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I can't speak for FLT as I have an RPM 6. As far as temps go, those are completely normal in warmer weather tho. But I'd agree that the stock radiator leaves room for improvement. I think most of us here could be accused of beating on these trucks...but isn't that the fun part? It sux when they break, but it's an opportunity to build it back stronger and faster. My original plans were a CAI and a handheld tune, lol. Best of luck with the repair and future mods.


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I guess my question is:

Why are upgraded kevlar clutches and kolene steels and Kevlar bands NOT part of most performance oriented builds? From my background, it just seems logical.

 

The stock BW High Energy frictions, for the 3/4 clutch are the best, IMO. You just need to use more than the stock 6...8 is usually enough and allows you to keep the stock thickness steels. The Blue Plates and Red Eagles simply aren't as durable. A lot of people like using them, but I switched back to OEM a while back. Pretty sure RPM and FLT both still use the BW OEM style clutches. That should tell you something.

I also wouldn't use the Kevlar band...there are better options, including the stock High Energy one. I do like the Alto Carbonite one too, but it increases shift firmness a decent amount, and find it unnecessary on mild builds.

It doesn't matter what is done to the 4L70...You ride it hard, and put it away wet, it WILL eventually fail. I put over 30k miles on my home built 4L70 with ZERO TM, and it NEVER gave me an ounce of trouble, including lots of time with a ProCharger. I WOT shifted it DAILY, but I was fair. You can't do repeated WOT upshifts and downshifts, without giving the clutches time to cool. They absorb a TON of heat on a WOT 2-3 shift. The reverse input drum absorbs a ton of heat on a WOT 1-2 shift as well. That drum is super thin, and can't carry much heat, before it warps. Once it warps and burns, failure is imminent.

If you find the fluid quickly getting dark, that is a sign that you are getting the clutches too hot, and they are burning.

FLT and RPM know what they are doing. Follow their lead, if you want to be successful with your trans.

 

The stock BW High Energy frictions, for the 3/4 clutch are the best, IMO. You just need to use more than the stock 6...8 is usually enough and allows you to keep the stock thickness steels.

The stock 4L70 has the additional frictions already...You woul dbe correct if it were a 4L60.

 

Well, I am going to agree to disagree. Kevlar takes heat way more than stock clutches can.

Example: I talked.to my trans guy today about my build. He had a dodge ram truck he built the trans in a couple years ago. Customer blew a cooler line and lost all the fluid. Towed it in, pulled it apart and the red clutches still looked new. Kevlar in my opinion is very durable.

To each their own. I go with what I know. Every trans I installed for a customers hot rod or muscle car that they provided, burned up. I will not say any names, I just am going with what works for me and my experience. Yours may be different.

 

Kevlar isn't a great friction material for an automatic transmission, plain and simple. It doesn't hold oil like the high energy material does, and glazes easily. That held oil is what absorbs heat on the shift. Once Kevlar gets glazed, it won't hold any oil at all, and it is all downhill from there. I know a lot of people like it, because it is what they always used...but it is old technology. It used to be the only "performance" band available. A Kevlar band would NOT have prevented this failure of your transmission. I've seen plenty of toasted Kevlar bands.

The Red Eagle clutches are good. I've had success with them in several builds, but they just don't hold oil like the Borg Warner HE ones do, and they also require "thin" steels. You need steel mass in the 3/4 clutch pack, to use as a heat sink.

If you rebuild it with your suggested parts, you should be just fine...just don't abuse it. Abuse will kill any 4L70.

 

Well, I will disagree again. We'll see how it goes. Kevlar take heat very well that why it's used in manual transmission clutches too.

I'll keep everyone updated. Thanks.

 

Disagree or agree, no matter what u put in a 4l70 tranny it can easily blow the fuck up even when ur at stock levels. Our trucks are heavy and humans and parts are not perfect

 

Actually the bands and clutches are Redline.

 

Thanks for the updates. Good luck man!

 

Good luck to ya man. You've got your mind made up, so I'm not gonna bother even trying to change it.

 

Well got the tbss back! Shifts like a normal trans now! Handles high rpm shifts well too.

Funny thing is, at about 70-80 mph, I am at a lower rpm than before the rebuild.
Before at 75 mph, it would be about 3300-3500 rpm.
After it's now about 2600-2800 rpm. Not sure, but it sure seems more right.