I've done some searching and decided to just post this up and see what everyone thinks. The stock 4l60e was rebuilt about 20k miles ago by the previous owner and seems to perform fine except at WOT. Under heavy throttle, right at the 2-3 shift point, RPM climbs and for about a second I'm hitting the rev limiter before it shifts. Once it does shift its fine. 1-2 is fine WOT, part throttle it doesnt act up at all. The car has a 3600 Fuddle and my tuner tried everything he could but no dice. I've read that our trannys are sensitive to fluid levels so I'll have to check that the next time I'm over there but would it act up in other ways if it was the fluid? I'm hoping it may be a simple/cheap fix, the plan was to drop a 4l80e in her for the future build but I'd like to put that off as long as possible. Is my tranny going bye-bye or is there still hope? Thanks, James.

 

It could be fluid im guessing if its really low but I doubt it. My old built trans would shift 2-3 all motor and 125 flywheel shot but then I upped the jetting to more of a rear wheel shot and it would hit the rev limiter no matter what I lowered the shift point to so I just decided to upgrade to a 4l80e. The trans should be fine to drive around with and last quite awhile but it will probably need to be looked at by a trans specialist if you do plan on fixing it. I had a 700r4 in my truck that would flare on 2-3 shift for about 10-20,000 miles then one day it gave up although the truck did shift fine at WOT but it made like 170rw maybe with the 350 tbi.

 

Were you manually shifting or letting the computer do it ?

 

Both.

 

I tuned the car and FWIW even with the 2-3 shift commanded and happening around 5k it still taps the limiter before making the gear change.

 

Yea they could check there fluid lvl maybe they will get lucky and that would be it but it would probably have to be quite a bit under filled its probably just the good old 3-4 clutch pack it will probably last awhile id imagine though im no trans expert either haha im just going based of some experience and hearing a few things here and there.

 

I know you are lowering the RPM but are you also lowering the MPH for the shift they work together .

 

yup set lower, they work together as you said, did it in all tables too. Even tried to force the shift with the scanner lower than 5000 and it still taps the limiter. It only taps it once though then falls into gear.

The trans will also slip right before the gear change as well when set to a normal mph/rpm shift point, about a 400 rpm slip around 5000, then drops back, then to shifts, taps limiter at 6300 briefly, then goes into 3rd gear.

BTW, Hazelton PA sucks, I was there during xmas.

 

You got that right

 

Im not sure if this would help but you could try maybe lowering the wot shift table to maybe 4500rpm and and alittle lower mph or maybe bump line pressure (lower force motor current and mess with shift pressure settings). Im not sure how much power his car makes on the top end but maybe raise the rev limter alittle more.

 

Its just a bolt on car w/3.73s and the Fuddle. Jeremy, when I was at MM on Friday it the limiter for a good second or so, probably bounced off it 4 or 5 times both runs. Felt like an eternity! lol

 

Already tried that and it was a no go. Even commanded 0MA to the force motor with HP tuners, hard shifts at part throttle, but still hit the limiter. 6300 is the highest I will let a car with stock valvesprings go. I only bumped it to 6300 on his car because I was troubleshooting the 2-3shift, I normally keep it stock unless they have springs.

 

my car did this today i hope to god the trans was just cold

 

One thing to be aware of here when chasing an elusive 2/3 upshift using line pressure adjustments is if the 3/4 clutch pack has excessive wear and you take the pressures "too" high, then it is possible to blow the snap ring out of the drum.

Keep in mind though that the ones we have seen were high mileage units with considerable clearance.

Just an FYI. Good Luck with it guys.

g

 

Same question posted last week (and pretty much every week). Here is the link https://ls1tech.com/forums/showthrea...&highlight=2-3
He fixed his by tuning TPS percentage.

 

My car was hitting the limiter 1-4 times on the 2-3 shift every time right before it started to slip in the higher RPMs at WOT :'( I changed the fluid and filter and it didn't do anything.

 

Dammit concept I didnt want to hear that! lol

 

It's already slipping, go take it out and watch the tach in 2nd gear around 5k.

 

I know, I'm just glad its a toy and not my DD. I'll try some new fluid and if that doesnt do anything it's time for a rebuild or the tranny swap.

 

i hate to say it but it is time to make that choice get a FLT trans!