wildcamaro

iTrader: (15)

Ok so here's the background...I was at the drag strip last weekend and to make a long story short I blew up my 10 bolt...I replaced the entire rearend and now I have transmission (4l60e, stock converter) issues...

I have to start out in either 2 or 1 in gear selector, BUT I have all 4 gears bc once I start going I can then shift manually into D(3rd) then OD(4th)...but if I try to start out in D or OD it will just rev like I'm in neutral...same thing happens if I start in 2 then shift D to OD and then come to stop sign or red light, I have to put shifter back into 2 or 1 to get going again...

Another part of the equation is I had 3.73 gears before I blew the rearend and had my PCM tuned by PCMforLess to accommodate the gear change as well as turning up the line pressure for firmer shifts and the new rearend has 3.42 gears, but I wouldn't think that small of a gear ratio change would warrant these shifting issues but maybe I'm wrong...

Anyway does anyone out there have any idea what's going on with trans? I can't understand what mangling the rearend has to do with the transmission???? I wanna send the PCM out for a retune but wanna make sure I'm not just throwing that $ out the window when I can be spending it on fixing my transmission...thanks in advance for the help guys, I know if anyone can help me it's someone on LS1tech..

mrvedit

The forward sprag is blown. Sorry.
You are running on just the overrun clutches, which are engaged in D1, D2 and in 3rd gear of D3. Finally the forward sprag is not needed in 4th gear. The overrun clutches are not strong enough to hold under WOT.

If you get the trans rebuilt, be sure that the builder installs the Sonnax HD 2-3 shift valve. By racing in D3, this ensures that the forward sprag and overrun clutches share the load. Also be sure the Borg Warner HD sprag is installed.

Unfortunately it is possible the broken sprag has contaminated your converter and cooler with metal shavings. The converter then needs to be sent out to be opened and cleaned (flushing is not enough). And the cooler cannot be reliably flushed either and needs to be replaced. Otherwise the rebuild trans might die within months.

Sorry to give you this bad news.

wildcamaro

iTrader: (15)

Hey it's bad news but at least it's news you know what I mean...rather than live in disbelief I'm glad to at least know what my issue is...I pretty much know everything bout the entire drivetrain, but the auto trans still has me baffled as you can tell...

So basically I need a complete rebuild is what you're saying? I've researched monster in a box, but rather than tackle it myself or let the hillbilly a at my local trans shop mess with it who do you recommend? I'm not going to even try and salvage the converter as I would rather have an upgraded stall anyway...

I'm happy that the car at least moves bc it sucks when it's out of business totally...I'm currently interviewing with a couple companies (delphi packard for one!) for a mechanical engineering position so I will have the funds very soon and I wanna do it right the first time as I like to drag race a few times a year ..

Bottom line 13 years/85,000 miles with alot of racing on the stock transmission is ok by me, I'm surprised it lasted that long lol...but thanks for the help/opinions

FirstYrLS1Z

iTrader: (4)

I had a similar situation,forward sprag (stock tranny) went at the dragstrip during the 1st-2nd shift. Pulled the pan,no contamination. Drove it manually for 3 years,even a trip from Ohio to Florida. Eventually 4th gear went and the time came to pull the tranny as I was running 4.56 gears and not having 4th (overdrive) with 4.56s' put the RPMs' high. I had 2 used 4L60Es' that Ipicked up in anticipation of the trans swap.

mrvedit

I detailed in another thread that IMO "Monster in a box" is not an up-to-date rebuild kit and that better ones are available. Also, looking at Monster's BBB record and my discovery that they own/control a fake "review site" which has obviously has nothing but the most glowing reviews, I would avoid them.

If you don't have a good local trans shop, I would avoid that too. It seems that many rebuilt 4L60E don't hold up as well as the original stock one.

I would therefore recommend a performance unit from one of the sponsors - FLT, RPM, Jake Performance or PerformaBuilt. PerformaBuilt is in eastern PA. A good "Level 2" with shipping is under $1800.
I'm not an expert on this, but it is likely the trans vendor will insist you get your converter rebuilt or replaced, and the cooler replaced before they will warranty the new one. IIRC PerformaBuilt always supplies a new cooler and it sounds like you will be getting a new converter anyway. A $500 converter from CircleD or RevMax should be fine for your application; they have billet cover ones for $750, which is also the price of the popular Yank SS series.

FirstYrLS1Z: Thanks for the info that a no-sprag trans could be driven manually for that long.

wildcamaro

iTrader: (15)

Yea good info, I wasn't sure if I kept driving it if it would eventually be completely smoked...

About monster, my cousin bought a complete heavy duty trans from them, and they offered him a 5% total rebate if he video himself Doing a burnout and giving a great positive review, so they basically pay for good reviews. His trans works good but he has to shift manually in the 1/4 mile which if you ask me is bullshit on a brand new $1600 transmission..

I plan on getting a yank 3200/3600 billet converter for sure has many people have had great success with them...I will contact performabuilt as I'm located in pa myself...thanks again guys, any other sponsors on here I should look at?

mrvedit

Sounds like you are on the right track.
I mentioned others sponsors FLT (Illinios), RPM (Indiana) and Jake Performance (Texas), all of which have an impeccable reputation.

wildcamaro

iTrader: (15)

Cool thanks for the info...I'm gonna do a price comparison between a new auto/stall combo compared to a 6 speed swap bc I do love bangin gears, but I'm sure something has to be done with the PCM