Remember the Dodge truck we talked about in the January 2015 issue? The 2003 Dodge

Ram 3500 5.9 diesel? This is what happened to the front clutch (figure 1).

The truck came in with the front clutch blown apart; the shop replaced the drum, only to blow the new drum apart while it was still on the lift.

After replacing the valve body with a new, stock valve body, the pressure dropped down to where it belonged. I inspected the old valve body and found it was severely worn out, with pieces missing.

Now we’re looking at a 2005 Dodge Ram 2500 5.9 diesel with high line pressure; 110 PSI (760 kPa) at

idle and 160-180 PSI (1100-1240 kPa) at stall. The pressure should only be 50-60 PSI (335-415 kPa) at idle, and stall should be no more than 95-100 PSI (655-690 kPa).

So I sent a call tag to have the shop send the valve body to me for inspection.

STREET SMART

by Mike Brownmembers.atra.com

BLOWN AWAY by High Pressure

26 GEARS May 2015

Figure 1

1brown515.indd 26 4/29/15 10:48 AM

Mid State Transmissions May 2015.indd 1 4/29/15 12:45 PM

Figure 2

Figure 4

After receiving the valve body and cleaning it up, I performed a complete set of vacuum checks: All the valves passed. The spring adjustment on the pressure regulator valve was 1 5/16” (33.3 mm) — right where it belonged — so what could be causing the high pressure?

Since this valve body doesn’t use any gaskets between the channel plate and the separator plate or the separator plate and the valve body, it’s very important for the surfaces to be flat.

To check the valve body for flatness, I used a piece of glass and a sheet of 220 wet/dry sandpaper. I wet the sandpaper with a mix of liquid dish

soap and water, then I sanded each surface of the valve body. I used a figure-eight motion, running each piece over the sandpaper lightly a few times. Then I checked the results.

Here’s what I found. Notice the uneven the surface across the upper valve body (figure 2).

Figure 3

Figure 5

To check the valve body for flatness, I used a piece of glass and a sheet of 220 wet/dry sandpaper. I wet the sandpaper with a mix of liquid dish soap and water,

then I sanded each surface of the valve body.

28 GEARS May 2015

Eliminate Valve Body Leaks by Flat Sanding

1brown515.indd 28 4/29/15 10:48 AM

Why gamble when building your next Honda or Acura transmission?

Build with confidence and quality, with transmission parts you can trust!

“We only sell what we build with”

8727 Rochester ave, Rancho Cucamonga CA 91730, PHONE: (909) 476-7252WWW.GEARSPEEDPARTSSTORE.COM

GearSpeed_May2015.indd 1 4/29/15 12:47 PM

Then I spent a little time flat sanding the valve body; look at the difference (figure 3).

Next, I turned the upper valve body over and did the same thing. Look how bad the contact area was on this side (figure 4). Notice the area over the boost valve: That’s a major leak! And the other side, where the shuttle valve cover plate goes; that’s pretty bad too. Once again, a little time flat sanding and you can see the difference (figure 5).

Now let’s look at the part of the valve body where the governor plug plate goes (figure 6). That surface is really bad; and once again a little time flat sanding was all it took to flatten things out (figure 7).

But wait! Look at where the limit valve housing goes (figure 8 & 9); another major leak.

You get the idea: Every surface on the valve body was seriously warped. Kind of makes you wonder how it worked at all.

I spent about an hour and a half flat sanding this valve body. Then I put it all back together and torqued the bolts to 35 in-lbs (about 4 Nm).

I boxed it up and sent it back the shop it originally came from. They installed in the next Dodge truck that came in and checked the pressures.

What do you know? The pressure at idle dropped from 110 PSI to 70 PSI (from 760 kPa to 485 kPa); still a little high but not unreasonable. The pressure at stall was 160-180 PSI (1100-1240 kPa); now it’s 100-105 PSI (690-725 kPa).

Wow! What a difference simply by flat sanding!

So, if you take the time to vacuum test, flat sand, and torque your valve body to specs, you’ll be able to look forward to more consistency in your rebuilds.

And that’s not just smart… that’s street smart!

30 GEARS May 2015

Figure 6

Eliminate Valve Body Leaks by Flat Sanding

Figure 7

Figure 9

Figure 8

1brown515.indd 30 4/29/15 10:48 AM

LifeAuto_May2015.indd 1 4/29/15 12:49 PM