epox4life

iTrader: (4)

I've been having a few problems with my 4L60E stock transmission that also has a 3500stall + B&M cooler installed.

The main problem is when it shifts from 3rd to 4th there's a quick grinding noise just before it locks up.

Connected with that problem is while it's locked in 4th if I hit the gas enough it will make a noise and looks like the rpms go up quick like it's slipping. But the converted does stay locked.

Also at certain rpm's mainly 1400 to 2000 the car shakes, could this be a unbalanced torque converter? It only started happening after the install.

And finally I'm not sure if this is a problem, while in 4th I can completely let off the gas and it stays locked and the car begins engine braking. It will only unlock while I'm pushing on the brakes.

Let me know if you think the transmission can be fixed or just needs to be replaced. Also what you think the problem is; thanks.

performabuilt

iTrader: (25)

If the converter wont unlock when you let off and only goes off when you brake, I would think a tuning or wiring issue, However the noise and vibration at cruising would point t and issue with the converter clutch also

epox4life

iTrader: (4)

Thanks. So do you think that even though the only shift grinding is going into 4th that could be the converter clutch?

performabuilt

iTrader: (25)

well you would have to experement with locking and unlocking in 3rd gear to see if your cars even tuned to lock in 3rd gear.
I cant really think of anything that would be unique to 4th that would cause the trans to grind in 4th gear only ,

epox4life

iTrader: (4)

If I put it in D instead of OD it will lock in 3rd at around 45mph I haven't heard any grinding when it locks in 3rd. Only 4th, which is weird.

performabuilt

iTrader: (25)

Well 4th does put more strain on the converter clutch, If it was a trans issue it should make the noise in 4th locked or unlocked

epox4life

iTrader: (4)

Well that's good news I guess because it doesn't make the noise at all when unlocked in 4th, even full throttle.