SF 1HOTLS1

iTrader: (24)

Just put in a new freshly rebuilt 4l60e. new everything. it shifts all gears nice and firm at normal driving but at WOT it just bounces off the rev limiter and wont shift unless i ease of the gas. any thoughts on what this could be?

Strange thing is when it was on the dyno it didnt do this. shifted fine on the dyno. but next day I took it out for some TNT and noticed it doing this.

no engine lights on or codes showing. no MAF sensor and tuned in speed density.

jakemussman

iTrader: (1)

Your saying when you attempt WOT it neutrals out no matter what gear your in correct? As in attempts to up shift but then bounces off of the rev limiter until you reduce speed and it down shifts? Does it tend to do this with the 2-3 shift or with all shifts? How long ago was the trans rebuilt? Do you have an aftermarket shifter or adjustable shift cable?

mrvedit

This sounds more like a tune issue. Especially if you put in a higher stall converter, the WOT-mph shift points needs to be reduces by a few mph.

bernarlitt

iTrader: (11)

I just had the EXACT problem! Lowered the rpm, decreased the mph by 3 and it still didnt help. The solution to the problem was so simple!! I added a half quart of fluid and wouldnt you know, its been shifting perfect every since

02streetwarrior

I had the same problem when i rebuilt my tranny. I havent raced so i don't know if it got fixed. But I changed alot of thing on the tranny the pan, superserver, shift kit, steel braded lines, and a transmission cooler.

mrvedit

The "extra half quart" has been mentioned as the solution many times here. The deeper truck-style pan which holds one more quart is a related solution.
(Even deeper pans risk road damage, especially on low cars.)

SF 1HOTLS1

iTrader: (24)

I have my tuner coming by next week. i will bring up the lower rpm and mph to him. hopefully that works. its got the right amount of atf fluid in it. hopefully its a tune issue.

SF 1HOTLS1

iTrader: (24)

just rebuilt like 2 weeks ago. ya at WOT it wont shift unless i ease of the gas and get back into it. this is for all gears.

SF 1HOTLS1

iTrader: (24)

if the trans is over filled will that cause this problem?

SF 1HOTLS1

iTrader: (24)

thanks man ima bring that up to him.

prokilllsx

If it's all gears I doubt it's a pan depth issue. Sounds like the mph is set too high for each gear. Maybe a last minute FAILED tune adjustment. When mine got dyno'd there were no full throttle shifts involved.

locospl

iTrader: (3)

Was this issue solved?

Charles Yarber

Sorry to bring back up but im having the same issue just got back from tuner and he cant figure out why it wont shift at wot and talked to multiple trans guys with no luck on responce. It commands to shift but will just hit off rev limiter unless i let out and roll back into it after it shifts

bbond105

Try over filling it a half to one quart of fluid.

Charles Yarber

No luck with overfilling

bbond105

I assume we are talking about the 1st to 2nd gear shift. Have you checked the 2-4 servo pin travel? It should be around .075"-.125”.

bbond105

Instructions on how to check the 2-4 servo pin travel.

RevGTO

iTrader: (12)

Was any tuning done on the car for the rebuilt transmission? IIRC, the WOT shift command at VS has to be lower than the WOT shift at RPM or it will not upshift. Or vice versa - I can't remember because it's been 12-13 years since I've done any transmission tuning. But we got it wrong once tuning my buddy's car and it wouldn't upshift at WOT.

bbond105

He says that it commands the shift, so I wouldn't think that the problem would be with the tune.

vorteciroc

You need to take a look at the line pressure now.
Take all the normal line pressure readings, and...

Tell us what the line pressure shows as 2nd gear gets commanded.