neblackshirts

Try to make a long story short but just bought an 01 SS w/408, FLT 4L60E stg4, 3600 stall Yank, 12-bolt, 3.73, Moser axles from a person on ls1tech and didn't drive the car till I could get it looked at to check everything out. Well put 10 miles on the car including the drive from my house to tuners shop in Lincoln, NE. Never had the car over 55mph no redlines nothing. Well we strap it to the dyno and right away clank bang drivetrain seemed like it was going to grenade. While on dyno pull only made one pull I noticed passenger axle wobbled a small bit and tech said he felt a bad vibration on upper pull. Came down from pull seemed just OK then pulled car off dyno but didn't seem like it wanted to move almost as if brakes were on. Applied brakes and put a bit of pressure in converter then BANG!!! didn't move. Dropped driveshaft and pushed car into an empty stall in the shop and at a lose for what happened.


Car made 470hp and 465ftlbs at the wheels nice flat smooth powerband but **** I'm speechless. Tuner said everything was turned off in transmission tune?? and said pressure was highest it could go?? if that makes any sense to anyone with experience with a built higher stalled LS car.


Could turning it back to stock 4l60e tune help?


Not sure where to go with this, either have a local transmission shop go through it or let Finish Line Transmission or PerformaBuilt Transmission handle it. Local guy carries all the Sonax brand supplies but not sure what could have happened. If it makes any difference trans fluid was full and didn't seemed burned up.


Also car drove fine shifted leaving lights fine clanked a couple times lightly but seemed buttery smooth. Previous owner stated steel driveshaft was weak link in car but hell I never attempted anything till I could have the tune and car looked at. Also it's on a SD tune if that matters.


Thanks Guys!!

performabuilt

iTrader: (25)

We would be happy to sell you a unit of course, And its possible we may even be able to look at the one you have, However if that is the case I would probably talk to FLT first
As for what happened no way to know short of tearing it down Pressures being maxed in tune is troublesome but not likely the source Of the issue unless its been driven and beat on for some time prior to your getting it not knowing how old unit is or how much driving / beating has been done

I would contact FLT about the unit and see what deal they may work if that does not pan out give us a call and speak to Alan explain the situation and he can tell you what we can do for you.

I do not know what their warranty transfers if any policy is nor do I know what their refresh terms are.
In any case if we can be of any help either way give us a yell .

neblackshirts

Previous owner said install was done in Feb of 2015 and when I questioned a few things he did tell me he did "get on it a few times" the morning a transporter was showing up to make delivery to me. But the shop it's currently at dropped the driveshaft and said the clips and yokes had been tack welded. But as bad as an *** whooping I got paying good $ for car and only driving it a very short distance I do want to make the car right so I can share the fun cruising with my family soon!!


Not much of a better feeling than to share something your passionate for than with your family!!!

neblackshirts

To The Top

mrvedit

From what I'm reading it sounds like a non-professional installation job. Wow, no idea what you could even tack weld in the drivetrain. I won't write what I think.
Sometimes an amateurish installation is compounded by mistakes installing the converter (damaging the pump) and even the "simple" step of double checking the fluid level. The tack welded yoke makes me wonder if a bad drivetrain imbalance damaged the trans.

I'm confident that FLT will give you good service, but won't warranty it if the damage was due to faulty installation. Obviously their Stage-4 can easily handle 470HP with proper installation.

tug686spd

iTrader: (11)

Could the car be pushed with drive shaft in or not? Or was the drive shaft removed before trying? Ive actually had rear end cause these exact symptoms. Except mine would roll with drive shaft in without making a noise. Put it in gear while running all audible noise seemed to be coming from transmition and only when shifting from foward to reverse gear or vise versa. This being done in a pit under car so i was sure it was tranny. Pulled tranny, a quick look through and nothing wrong. Pulled punkin cover on rear and the center section falls to the folor in about a thousand pieces.

neblackshirts

No car wouldn't move till we dropped the driveshaft then it would roll freely. But the previous owner did tell me the driveshaft was the weak link in the build. I was hoping to put a Carbon Fiber shaft in but with spending lots of extra money potentially on other ends I wasn't anticipating on right away it might just be an Aluminum Driveshaft. It has a KTRE 12-Bolt with Moser 31 splines and actually needing to replace axles as found out on Dyno passenger axle had a notable wobble. Was asked if I had noticed a vibration and I never did due to the fact I never went over 50-55 mph till I could get a clean check with the car.

neblackshirts

mrvedit, I should post the previous owners receipts from lots of multiple "race shops" the man put a lot of shop techs kids through college. Unfortunately after I purchased the car and reached out to the owner he said maybe the transporter bent the axle tying down the car and he also said the car drove great the morning it was getting loaded and said he did "get on it" once or twice but certainly did not abuse it one last time. Ouch an email from a previous owner no new buyer wants to read.

Bowtiedford

iTrader: (9)

when it was on the dyno, after the pull how did they let off? shift into neutral? I run 4l60e with a Circle D 4000 stall , I use Jeramy Formato for my tune and never has he turned off my tune on the dyno and I know he doesn't like to use full line pressure on the tune. mine has been abused now for over 2 seasons of drag racing and street driving.

EDS01SS

iTrader: (30)

The pressure being turned up all the way would worry the crap out of me and is probably what killed it. Thinking maybe somebody was bandaiding another issue or just flat out didn't have a clue. Im really surprised your tuner even dynoed it like this. Im pretty sure the FLT transmissions have a shift kit in them already and from what Ive always read and heard you don't ever raise the pressures while running a shift kit. Its one or the other

neblackshirts

Bowtiedford, after the run left in gear but came down quickly because of the driveshaft and transmission sounding as if it was about to split apart. To be honest things were a blur lol all I was thinking was oh **** not even 10-15 miles since bought from a member on here. Tuner checked the tranny tune after all this happened and found the issues with the pressures being set at max allowed. After we dropped the driveshaft so the car would roll the driveshaft was hacked in.

neblackshirts

EDS01SS, kinda what the tuner said is they most likely maxed out the pressures to Band-Aid an issue. Hell for all I know this could have been a salvaged 4l60e and not the advertised FLT stg 4 as was told was in the car. But it did have a higher stall converter that was for sure due to the cam in the car. It's at a local transmission shop right now and they are excited to see what makes a stage 4 FLT Transmission and also excited to take my money. They are a carrier of all the same brand Sonnax as most of the big named tranny shops use. Car was towed to the shop and right away they checked the transmission fluid and was clean in color (red) but he did smell something was defiantly burning. Usually they can get cars in and out within about three days but with this one they said could be 2-3 weeks. They are also going to fix the driveshaft issues and use the correct u-joints and yokes as they were correct before and someone just tack welded it in and used miss matched bolts no joke. Also on the dyno seen the passenger axle was wobbling and it's a 12-bolt with moser axles and uses sealed bearings instead of the c-clips but the transmission shop is going to look into that also and will probably end up ordering new axles. I bought the car on here and am definitely feeling the burn in my *** from the seller!! I have been around older built cars and have owned a few newer f-bodies and contacted seller to express my disappointment but as we all know some just are not honest unfortunately I'm just praying no more issues for awhile at least. I know the nature of the beast in our hobbies but I also know when I've been taken for a ride. Oh well I decided I wanted to enjoy the car with my family so will do what it takes to make the car more than better.

neblackshirts

ttt!@#!

Rick01SS

FLT has a refresh service for their transmissions. $250 labor + parts.

Chuck will tear it down and see what's broke, then call you with what it'll cost to fix.

Got mine up there now.

NJmooch

First, sorry to hear about all this, and everyone on the forum can feel you pain and frustration. Nobody wants to buy a car and listen to it fall apart on a dyno pull.

So you mentioned a few things that really bugged me:

1. Didn't go over 55 mph.
2. Welded parts on drivetrain.
3. Wobbly axle.
4. Most importantly, you paid for it before you got it checked out.

If it is a FLT trans it should be able to hold that power like another member posted. FLT and PerformaBuilt make great products. Hopefully your local shop will figure out what happened.

I will say that I have an upgraded Level VI 4L60E from RPM Transmissions, and have had zero issues with it. All of these shops are great, so I hope things work out for you. Good luck.

neblackshirts

NJmooch, yeah crappy luck so far but I decided to do whatever to make the car better than right. Seller sent me a few videos of the car of which I thought were current videos but defiantly weren't one of the dead giveaways was when it arrived it had hood pins and in the pics he sent and videos they were never hood pins. But it's turning out to be a very expensive lesson but when I called the seller out on the issues and how it didn't even want to run after transporter unloaded car he blamed the transporter on the bent axle and told me the car ran great that morning it was getting picked up even telling me in an email he "got on it a few times but never abused it" wow when I read that I felt kinda cheated. But I knew the risk buying a car over 1200 miles away so that's on me.


Have a really **** local tuner/shop that has a great reputation for anything LS so after I got the car I made an appointment for him to go through everything to make sure things are good before I had any fun. I had to wait about 4 days before he could get to me and that's why it never even went over 55 mph by my choice I never even pushed the car over half throttle.


I'm shocked about the outcome I figured and told the seller based on what he told me the drivetrain should have been bullet proof. But the transmission shop its in sells Sonax parts as what the Big Named Shops do and should have it together soon. It's been in the shop for two weeks now as they said between going through the transmission, new correct driveshaft and u-joints, and doing axles it's going to be a slower process they don't want to rush it which I respect and completely understand.


Yeah tuner was pretty shocked by what happened but after it's out of the tranny shop it's going back to him so can work on the tune. Killing me to have it not mobile for over 4-5 weeks now. Bought it to cruise and enjoy with the family as I had pretty built Camaros (carbureted) back in the day and this is my first built LS car and was looking to enjoy the benefits of modern tech. With 3.73s and no roll cage hopefully when it's back I can cruise it down the highways with no problems.

neblackshirts

First to start off Vendors on this site are amazing for offering advise thanks to PerformaBuilt for never hesitating on sound words for us gearheads and thanks to FLT for the help and advise.




Well in my original post "FLT Stg4 built 4L60E failed?? Need advise vendors welcomed!!" The shop after 6 headed into 7th week has FINALLY gotten to the transmission!!! Well we contacted Finish Line Transmission who updated the transmission in April of 2015 to get the scoop on what has been done because we found an FLT STG 5 engraved in the transmission. Well FLT found the original invoice and it was upgraded to a Stage 5 so should be built to the nuts. But it looks like a Sprag was what stopped the transmission. But the shop doing the work is kind of at a loss as to why this would have failed. But after ordering new parts for the transmission, hopefully my Mark Williams Aluminum driveshaft and yokes, and Moser axles get in this week finger crossed I will need to address the transmission tune.


The car is tuned with HP Tuners Pro only owned the car like 4 days when it gave but was told by a local dyno shop that the line pressures were adjusted super high or as high as HP Tuners software could go. FLT said I need to adjust the transmission setting back to factory, but will this screw with the higher stall Yank converter (3600)?? Was told to especially set the transmission line pressures to factory as upping them is not good. I'm pretty nervous and want to actually enjoy the car for awhile even though fall is here. In all I haven't sat in my car in almost 9-10 weeks and the transmission shop is really tired of my calls and stop ins but **** I'm sure most of anyone else would be the same way lol.


Thanks for any advice guys!!

coryforsenate

iTrader: (1)

That surprises me that the sprag died. An FLT stage/level 5 has a top of the line Borg Warner sprag in it.

I wonder if something else caused the sprag to fail and the sprag itself is not at fault.

rpturbo

iTrader: (47)

With a FLT 5 in it, I would have sent it back to them IMO. I hope your local shop, does better work than most, and if they can't figure it out, it wouldn't leave me with a very good feeling.

Really sucks, and I feel your pain, but mine was just basically stock junk.

neblackshirts

Here's the pictures of the transmission damage that the shop sent me.