Fluid "Mod" 4R100

Reply Subscribe

Thread Tools

Search this Thread

Dec 6, 2019 | 11:40 AM

DavenTn

Thread Starter

Cargo Master

Joined: Jun 2013

Posts: 2,079

Likes: 63

From: Florida and Tennessee

Fluid "Mod" 4R100

Has anyone ever heard of the fluid mod? I was told by a transmission repair shop that the 4R100 needs an addition 3 qts of transmission oil and this simple addition of oil will prevent torque converter shudder.

First on me... anyone ever hear of this? In fact, their rebuilt transmissions come with modified dip sticks to reflect the new oil level.

Dec 6, 2019 | 09:50 PM

Mark Kovalsky

Frmr Ford Trans Engr

Joined: Aug 1999

Posts: 24,739

Likes: 2,669

From: SE Florida

That isn't a good idea. When the trans is that overfilled the rotating parts are going to be running in the fluid. That will whip the fluid into a foam. This GREATLY expands the fluid. It may have enough volume to force it out of the vent and dipstick. All of this fluid can cause a fire if it hits something hot, like the exhaust that's right there.

Also, foamed fluid doesn't lubricate correctly, so the trans isn't getting lubed like it should, which leads to increased wear.

All in all, it's a stupid solution to a nonexistant problem. The 4R100 isn't known for torque converter shudder. And additional fluid won't fix torque converter shudder.