4L60 slipping when engine is warmed up

[HotWheelsBurban]

I just replaced the filter in WCJr because it's slipping after it gets warm. I'm going to get some fluid for it this afternoon and hopefully test drive it. Really hoping we all have success.

If not, do we have a transmission build-off? I've already priced out the rebuild kit with clutches and bands and a Corvette servo - about $220.

Seems like these modern transmissions are a lot more sensitive to fluid levels than the older generation of GM automatics (TH 350/400). Both the later burbs and 06 Denali get cranky if they're just a few ounces low. My fwd mopars are like that too; changed the fluid and filter in my intrepid and didn't ever think I would get the level right. I'd have to drive it a few blocks and put a little more in, then repeat the process. Finally got it happy but it took a while.

 

[Channeled 91]

well, I believe I have found the issue. Me being Polish... I forgot that you had to have the engine running when checking the fluid. I pulled the dip stick, checked it when she was not running, and the fluid read over full. Then I started her up and the dip stick read no fluid. So apparently she needs more fluid.

 

[BappleApple]

The noise sounds like a converter problem, such as a sprag or bearing failure. The reason it wouldn't move is probably due to debris being sucked up into to the filter, constricting the flow to the pump and causing pressure loss. After the vehicle sits for a while the debris will settle to the pan and allow fluid to flow to pump, only for a while until filter becomes blocked again.

 

[Channeled 91]

I tried moving her yesterday. She came out of the shop. Then when I put her in reverse, she wouldn't move. Tried putting her in other gears, and still no movement. I shut her off. Then started her up again, and she moved. I still get that whining sound when I put her in any motion gear.

 

[Channeled 91]

Still having issues. Here is the latest video of the sounds she makes.

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[Channeled 91]

Dropped the transmission pan. This is the fluid and the pan after 30 minutes if run time and a coupe hundred feet of driving, after I changed the fluid and filter.

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[PlayingWithTBI]

Time for a new/rebuilt one - sorry bud.

 

[df2x4]

^ X2. Although personally I'd take this opportunity to consider a transmission swap if I were you. I'm not a big fan of the 700R4/4L60.

 

[Erik the Awful]

Chunky is bad. I don't know if you saw on my build thread, but I contacted Sonnax about which parts to use in my 700.

To: SonnaxTechSupport
Subject: 4L60 Best Bang for the Buck?

I have been working on reviving an '89 Chevy Stepside. It now runs, but after a few minutes of driving it starts whining and has trouble pulling. I dropped the pan, changed the filter, and everything looked good except the amount of grey goo on the magnet. I think my 4L60 is on its last legs. I am considering rebuilding it myself - I rebuilt a TH700R4 twenty years ago in school and it ran fine on the transmission dyno.

My truck's purpose is to be a fun, light-duty tow pig. It has a 350 that should put out a little over 400 lb/ft of torque and runs on 275 width tires with a Suburban rear sway bar. It will occasionally get tasked to tow a 3500 lb race car on a 1500 lb trailer. I might even autocross it.

If I do rebuild my transmission, I will be budgeting $500 for transmission parts. What would be the best build sheet of Sonnax parts for that budget? I did see the 4L60E build sheet on your website, but couldn't find one for a 4L60.

Erik


Erik,
I would recommend:

SmartShell Heavy Duty Reaction Shell Kit 77749-02K
4th Gear Super Hold Servo 77767K
Line Pressure Booster Kit 700R4-LB1

Pair these parts with a good rebuild kit including GM High Energy Frictions.

Regards,

Jason Larochelle
Product Support Representative
Sonnax Transmission Company, Inc.

 

[letitsnow]

I have 2 trucks. One has a 4l80e, the other a 4l60e. If the 60e so much as hiccups, it'll be replaced with an 80e. No f*ing way I would remove that trans without replacing it with the 80e.