Increasing line pressure and A/T life

[Falcon_LS]

I just got my tune for the Grand Marquis, part of which involved increasing line pressure every so slightly. The shifts are a bit harder now, but much firmer. It holds first slightly longer, although sometimes the shifts are just a tad hard. Under heavy throttle (half to WOT), the shifts chirp the rear tires very briefly. Apologies for the angle of this video, but this is what I mean:

Video

If you notice, right after it shifts, the speed suddenly jumps to 51 MPH from 44 MPH when the wheels chirp/spin.

I'm not too knowledgeable on transmissions, and I'm not sure how credible this information is, however I was told increasing line pressure kills the transmission in short order. The guy who told me this said he lost 3rd and 4th gear three days after the tune, and it did scare me a bit to be honest. Thanks!

 

[MuzzleFlash40]

Well, it's not really gonna hurt anything on a reasonable setting. Maybe if it is set too high. My 99 MGM I had, had a tune on it most of it's life. (was my step dads before mine, and had 150k on when sold) But, I never like REAL firm shifts. My 06 has the HPP on it with a diablo sport tuner and I have the line pressure set just one level firmer over the "performance 93 octane" tune on the programmer. It gives a little firmer shift without it being annoying.

I put the tuner on my 2006 at 29k, the fluid looks fine every change once a year. I get on the throttle a little often too lol

 

[SteveSRT8]

Most tunes are actually good for the trans. But they vary a ton and as such can easily set you up for failure if anything is weak or tired.

 

[Falcon_LS]

Thanks for the input.

One thing I have noticed is the ATF temperature is lower on my ScanGauge-II after the tune by about 10 degrees (I have an engine oil and ATF/PSP cooler).

I asked the tuner if line pressure is increased across the board in, or increased only during shifts. I prefer the latter to be honest, will be interesting to see what he says. I have emailed for a re-tune because of the following concerns, however:

1. The downshift points appear to have changed. I was doing 75 MPH and had to accelerate - the transmission stayed in 4th at half throttle. With the stock tune, when you depressed the gas a little further, it would downshift immediately.

2. The car feels like there's a bit of a drag on it...like it's stuck in 3rd gear and wants to shift into 4th. It doesn't have that "pushing a knife through butter" smoothness in 4th. When decelerating, as it shifts into second, I also hear a whirling noise; the sort of noise offroad tires would make on a lifted truck doing 80 MPH. Seems to be coming from the transmission.

3. Under light throttle, it holds gears too long. In traffic today, it would hold first gear until it go to 25 MPH but wouldn't shift into 2nd. As soon as the gas was released, it shifted a bit hard into 2nd.

 

[SteveSRT8]

The whine is usually the pump section protesting as the regulator holds the pressure up.

Calibrations are everything, with my tuner I go to Diablosport's website and download free fixes for those little things like that.

 

[ARB1977]

Why not do a valve body upgrade. I know guys in the Tacoma world who are supercharged upgrade their valve body's to increase line pressure.

 

[Falcon_LS]

Originally Posted By: SteveSRT8
The whine is usually the pump section protesting as the regulator holds the pressure up.

Calibrations are everything, with my tuner I go to Diablosport's website and download free fixes for those little things like that.


Thanks for the info! I think we need to tone down a bit on the line pressure.

Originally Posted By: ARB1977
Why not do a valve body upgrade. I know guys in the Tacoma world who are supercharged upgrade their valve body's to increase line pressure.


There's a valve body modification for this transmission (Ford 4R70W) known as the J-Mod. I plan to do this, but considering the unit has 190,000 original miles on it already, decided to overhaul and upgrade the clutches, etc. as well. This will have to wait a while though, as I need to prioritize a couple of other things.

 

[Mud]

Is this Lonnie that did the tune? Excellent tuner

I would suggest doing the jmod, it only revises the volume of fill/exhaust fluid to the servos and accumulators, not the pressure, and can be retained when you rebuild the unit. It compliments the tune line pressure change nicely and also allows you to dial down the pressure to the EPC solenoid (that's what the tune controls). Personal experience with tune and jmod on my 02 CV.
yes, your up and downshift speed and firmness are different, not necessarily worse, just takes some getting used to. There is now less overlap as one clutchpack engages while another disengages, or as the OD band engages/disengages. Regarding your comments about OD application, I'm not surprised at 190k miles, it's a pretty thin band.
Sometimes the tune/jmod is blamed for a failed transmission. If the unit was already in a high wear state, the factory tune typically masks this due to lots of overlap and moderate pressure settings. When the factory tune is replaced, the higher wear can be exposed, not created.
You've introduced significant changes to the character of the car that take a bit of getting used to

I've worked on a lot of these cars and they respond very well to these mods, really wakes them up

 

[zzyzzx]

How many miles are on the transmission? IMO, bumping up the line pressure on a high mileage automatic transmission is a good thing. I have around 209K miles on one as proof.

 

[Falcon_LS]

Originally Posted By: Mud
Is this Lonnie that did the tune? Excellent tuner

I would suggest doing the jmod, it only revises the volume of fill/exhaust fluid to the servos and accumulators, not the pressure, and can be retained when you rebuild the unit. It compliments the tune line pressure change nicely and also allows you to dial down the pressure to the EPC solenoid (that's what the tune controls). Personal experience with tune and jmod on my 02 CV.
yes, your up and downshift speed and firmness are different, not necessarily worse, just takes some getting used to. There is now less overlap as one clutchpack engages while another disengages, or as the OD band engages/disengages. Regarding your comments about OD application, I'm not surprised at 190k miles, it's a pretty thin band.
Sometimes the tune/jmod is blamed for a failed transmission. If the unit was already in a high wear state, the factory tune typically masks this due to lots of overlap and moderate pressure settings. When the factory tune is replaced, the higher wear can be exposed, not created.
You've introduced significant changes to the character of the car that take a bit of getting used to

I've worked on a lot of these cars and they respond very well to these mods, really wakes them up

Thanks for the input!

The tuner is a member over on CVN under the name Fahad_600, who's setup his own SCT tuning business in Saudi Arabia. He's literally done hundreds of Crown Vics over the past 7 years.

Literally got off the phone with him minutes ago, and what he's done is basically adapted my requirements (ARA3 idle settings, 180 F thermostat and 22C plugs with MZT) to a canned SCT tune on the SF3 with raised line pressure across the range. Says he wanted me to see the difference between a canned tune and a custom tune. He's working on the custom tune at the moment, and I specified line pressure to be raised only during shifts.

Modification wise, I've got:

- OE Bosch 25.6 lb/hr Injectors (0.5% Flow Matched by Hurst Injector Service)
- Autolite APP-103 Spark Plugs (One Heat Range Colder/Double Platinum)
- Standard Motor Products Red Box FD-503 Ignition Coils (Made in USA)
- Steeda Oil Separator
- Steeda Crank/Coolant Pump Pulley
- '04 PI Zip Tube
- Marauder housing with 80 mm MAF and WP-102 wiring pigtail
- 180 F Thermostat

I'm installing these this week:

- 70mm YC2U-BB throttle body
- Ported/Polished OE Ford Intake Plenum
- RJM Injection Technologies Intake Plenum EGR Port Block-off
- RJM Injection Technologies Metric EGR Header Cap
- Gates Alternator Decoupler Pulley

After this, my focus will shift to the suspension and a 3.73 locker rear end before I get to the transmission.

Biggest problem I had with the tune was my PCM catch code (SGA2) was not in anyone's database. Turns out all GCC vehicles got the Saudi programming whilst Kuwait had its own programming, and mine was the first to get a tune.

Originally Posted By: zzyzzx
How many miles are on the transmission? IMO, bumping up the line pressure on a high mileage automatic transmission is a good thing. I have around 209K miles on one as proof.


190,000 miles.

 

[rslifkin]

If the line pressure is cranked enough to blow out seals, it can kill the trans. Otherwise, it'll live longer, as the clutches will be slipping less on the shifts, so it experiences less ear.

If you're adding power to the engine, I'd want the increased pressure all the time so you don't have to worry about slipping the clutches once it's already in gear.

 

[dwcopple]

to each their own, but I can't believe you are throwing this much $$$ at a car with 190K on it.

 

[Falcon_LS]

Originally Posted By: rslifkin
If the line pressure is cranked enough to blow out seals, it can kill the trans. Otherwise, it'll live longer, as the clutches will be slipping less on the shifts, so it experiences less ear.

If you're adding power to the engine, I'd want the increased pressure all the time so you don't have to worry about slipping the clutches once it's already in gear.


Point taken.

When you talk about increased pressure, do you mean across the board or just during shifts?

Originally Posted By: dwcopple
to each their own, but I can't believe you are throwing this much $$$ at a car with 190K on it.


I love traditional American cars. I've had a '00 Crown Victoria, a '03 Grand Marquis LS and a '07 Grand Marquis GS. This one just holds sentimental value to me. I've wanted one since I was in high school and I've always remained partial to the '98-'02 models.

Having said that, living in a desert climate has its advantages. It may be dusty, but rust isn't a concern and if you take good care of them, they last a long time with proper maintenance. Next door neighbor has a '97 Grand Marquis LS with 498,700 miles on it, he's had the transmission rebuilt once, but the engine's original.

Compression figures are over 200, it's not given me trouble and is the last of its kind with body-on-frame construction, V8 and RWD. There's also nothing new that interests me. This puts a smile every time I get behind the wheel.

 

[Falcon_LS]

Just so nobody thinks this is a worn out rust bucket because of the mileage.

 

[rslifkin]

That just might be one of the cleanest Panthers I've seen.

And when I was referring to the increased pressure, I was talking about across the board, and not just on the shifts.

 

[mechtech2]

Originally Posted By: SteveSRT8
Most tunes are actually good for the trans. But they vary a ton and as such can easily set you up for failure if anything is weak or tired.


This is right.^^
The quicker shifts make the clutches last longer, and there will be less heat from slippage.

But when we get a trans tune, we generally beat on the car and that will cause more wear overall.

 

[TFB1]

The guys that live in northern areas can't seem to grasp the fact that not everyone has rust issues... I have a original paint '88 T-Bird that probably doesn't have a teaspoon of rust in the whole body & chassis combined...

I installed a B&M electronic shift improver on a '93 Grand Marquis that had a slipping trans on 1st to 2nd shift, lasted 98Kmi before it finally blew the front pump to housing gasket and started puking fluid... Replaced it with a rebuilt...

 

[Cujet]

I had a superchips tune on my 1998 F150 4.6L. After working with them to get the shift points correct and properly firm, it felt "just right". And, it's still healthy, functioning properly and reliable at 260,000 miles!

But, I will admit, at first, the shifts were too stiff.

 

[mechtech2]

You will unconsciously learn to modulate your foot in normal driving.