Jimmy_d

iTrader: (3)

So first I lose 3-4 clutches, then forward sprag, soooo I have the hd alto 8or 9 clutch pack put in and a hd Sprag and new housing... Well I take it out first Time beat on it once come back and go to back in driveway ...no reverse no 1st..... Im getting tired if pulling trans lol car made 370 rwhp. Trans was originally "rebuilt" before the first two issues....... Have checked line pressure at 1k rpms and its roughly 110

Jimmy_d

iTrader: (3)

Is it just too much power for a 4l60e? Is it common to tear up all the time if its not a heavy built trans?

mrvedit

Here is sponsor RPM's thread of a 1000HP car with their 4L60E Level 7 in an 8 second car:
https://ls1tech.com/forums/automatic...en-record.html

So, its just not being rebuilt properly for performance use.
You mention 110 psi in 1000 RPM. More useful would be the pressure in Reverse and/or what pressure you have when you blip the throttle.

When properly built and tuned, a 4L60E can handle a lot of power. However they are also delicate - a small leak caused by careless assembly or even a bad engine sensor and can quickly ruin them. (Probably true for all trans, but perhaps more so for the 4L60E.)

While a Level 7 trans is very expensive, a Level 2 from e.g. RPM or FLT should suit you just fine. Cost is about $1500 plus shipping.

Jimmy_d

iTrader: (3)

Didn't check reverse. But when throttle is hit it does just up 200 ish. I was Hoping for a quick fix and a sale of the car but that didn't happen. He told me I should have the hd sunshell etc put it but I figured since the stock Trans held up for more then one hard pass down the road that it would be ok. I'm scared to spend the bucks and have it built and it tear up again.id love to 400 swap but have 4.11 gears ,wouldn't be real friendly.I dont race it,its on street tires, no nitrous,..surely a decent built 60 would last

mrvedit

200 psi when you blip the throttle is very good; no need to check Reverse then, but it also should be in the 150+ range.
Strange to lose both 1st and Reverse as they don't have that much in common. When the shifter is in D1, the low/reverse clutch is engaged in 1st gear, but not in D4/OD; it is also engaged in Reverse.
Lost reverse is often due to a bad teflon seal on the stator shaft, but that won't affect 1st gear. Same with a broken sun shell.
However, I don't have much real-world experience with broken transmissions. Little reason to try to figure it out anyway as the trans needs to be removed and rebuilt; and the problem should then be obvious.
It might be a problem with the low/reverse roller clutch which should be replaced during a rebuild.

Jimmy_d

iTrader: (3)

Seems all answer come back to a broke sunshell. Gonna pull trans and have it gone through