Hi Everyone.
I'm not only new to the forum, but also new to Ford SD trucks! It has been a very interesting learning curve for me, because I don't have any mechanical background. I simply try to tackle new projects on the truck and most of the time they turn out well.

I purchased a 2000 F250 XL with a Triton 5.4L V8 Gas engine and 300,000kms on it. I got it at auction for a very good price, but my only complaint is the gas mileage. I've been trying to provide the truck with upgrades and mainly use it for hauling a 16ft utility trailer with an average load of 6,000 lbs.

One major concern is the shifting strategy with the current transmission. I have to be so careful on how I accelerate, otherwise it feels like I'm riding a kangaroo. It mainly happens when switching from 2-3 gears and when not under load.
I believe I have the 4R100 tranny in there ( i think ) and I have heard people speak of shifting kits from Transgo and SONNAX to help fix this.

My questions is this: Most threads speak of diesel engines. Can the same kits be used for my gasoline engine to fix this problem? Because I would imagine Ford modifies the transmission a little bit for gas and diesel. Is the valve body the same/similar enough for this application?

Thanks in advance!

 

Welcome to FTE!

I would recommend the SCT X3 tuner with custom tunes from Mike at 5 Star Tuning. It will not only improve the performance of your 5.4L engine, but it will adjust the shift points of your 4R100 transmission. IMO, it is "the best bang for the buck" out of all of the aftermarket options.

5 Star Tuning | Custom Dynomemeter Chassis Tuning Products and Services

 

Further define kangaroo? Harsh shift, bump-slide shift, delayed shift, slipping shift etc...
With an unknown service history I would be inclined to drop the pan and inspect for debris and fluid condition first. If there is a large amount of trash and the fluid is anything other than pink I would advise against adding a shift kit. Reason being is the kit will only make a worn out trans die even quicker. First try a flush of ALL the fluid and change the filter and see if that improves things?
If things look healthy then yes a shift improver kit can improve "things" depending on what "things" you're looking to improve. So further definition on what riding a kangaroo feels like will help us steer you in the right direction.

 

Like I mentioned, if I'm driving without a loaded trailer and accelerate, I have to either keep my foot to the floor for it to make a smooth shift or take my foot off of the accelerator a few hundred RPMs before it shifts, for it to make the smooth transition.
Otherwise it bucks. It feels like it wants to jump forward and I cringe at the thought of what is happening inside my transmission.
I haven't done a fluid swap or filter change, only because I wanted to decide if I was gonna modify the valve body and because on the dip stick the color of the fluid is a healthy color. I simply didn't want to 'waste' fluid by having to change it twice within a month.

Another question, why would you advise against a shift kit? From reading various posts and forums, I was under the impression that aftermarket kits would greatly improve tranny performance either way.

I will be checking out tuners to increase general fuel mileage and tranny performance. What kind of bettered fuel efficiency can I expect? I will be making another thread soon, to get suggestions on how to improve my fuel economy. At the moment, on highway I'm doing somewhere around 25 L/100 kms (9mpg). So I think something might be wrong. But one thing at a time I guess.

 

ive had three different trans fixs so far on my truck. First was the black box Superchip tuner, it was total junk! Then i went bone stock but the crappy soft slow shifting drove me nuts so i installed a Factory Tech Valve body and i loved it at first, shifted fast and firm for normal driving and at WOT it would chirp 1-2 sometimes. Then my trans started to get this weird shifting, sometimes soft and other times extremely hard. I removed the valve body and went bone stock again but this time i bought a custom tuned X3 from Mike at Five Star. shifting was spot on and beautiful for a few months but then i got my weird shifting again, sometimes very soft and other times heard in 2-3 shift. Its been two years and i stil have the same problem, trans hasnt blow up yet so im leaving it. Listen to my advice, change the filter and do a complete flush and see how that helps, if it does id do either the Transgo tugger kit or the Sonnex kits. BUT go easy when u first install, drive the truck and see how it shifts a little firmer if need bee go a little bigger on the holes and stop. Im a true beliver that once u get too firm on the shift points things break and wear ut just like leaving it stock with soft slow shifts.....

 

By your description, it sounds like the line pressure is being raised to compensate for slipping. She's wounded, and it's just a matter of time before it needs to be rebuilt. Putting a shift kit in it would be like putting a band-aid on a hernia. I have a 2001 F250 with a 5.4 and it was doing exactly as you're describing. Being a plow truck, I had it rebuilt in the off-season to ensure reliability during plow season, and it's been flawless since. If reliability isn't as important, you can try an additive with fresh fluid and new filter which may prolong it's life some.

 

r_chr_chard,
The only reason I or any transmission person would advise against a shift kit would be in the case of a trans near the end of its service life. You don’t want to bandage a hemorrhage as wizardsr put it. Nor waste time and money.
In a worn transmission many soft and consumable parts are at the end if their expected life service. The friction material on the friction plates (and or band(s) if so equipped) wears off and this allows slippage between it and the steels in the clutch stack (pack). So no matter how hard the shift or how high the line pressure is increased there simply isn’t enough material left for grip. A shift kit does just that; it increases fluid volume and pressure in the various hydraulic circuits. This will eventually lead to the loss of that gear (clutch pack). The trans controller could be compensation for this already and is increasing the line pressures causing your buck-board shifts. Basically there’s more clearance in the clutch pack allowing fluid to bypass rather than hydraulically locking up the clutch pack. With a heavy load on you are inducing slippage so the hard shift you normally feel without the 6K load is cushioned/masked.
In a new clutch pack (steels & frictions) there’s plenty of material for grip. In this case a firm shift is actually more desirable for several reasons. One is less slip, two less friction which equals less heat. Less slip also improves economy, slightly. In this case I like a shift improver kit.
The reason the factory cushions the shifts is mostly due to the fact that the general public likes a smooth shifting transmission. The performance minded people know soft shifts equal more heat & less trans life.
There are several other trans experts who frequent FTE and they will pipe up and give their opinions.
Also do a search here on this subject.
My advice stands installing a shift kit on a worn out trans. But yours may not be worn out? You did indicate you have changed the fluid and I'll assume you didn’t find anything out of the ordinary? There could be other simple troubles. Such as a bad learned shift sequence, failing shift solenoid etc…As a trouble shooter I can advise you to start with the simple and move towards the complex.
From your description you definitely have a problem… dauh you already know that.
Not 100% sure on the 4R100….You may be able to disconnect the battery for a minute to clear the memory on the controller? Hook back up and test drive it. I know this is true on a Torque shift (thank you Mark K.)
If the fluids ok, no fault codes found on the TCM and you did the memory clear thing (if applicable) then the next step is to get it in to a reputable trans shop for diagnosis, key word here is reputable. They will monitor line pressures and electric signals to pinpoint the trouble. If you catch small troubles early sometimes you can avoid larger failures.

 

Thanks for the in depth answers and help guys! I will be looking for a reputable transmission shop in my town to see if they can't pin-point the problem as mentioned by droldsmorland.
Will try to post back to see if it was something really messed up or simple, like a clutch pack going bad!

 

Actually most ppl don't know but the diesel and the gas motors actually share thr same transmission yes they may beef them up a a lol more for the diesel MAYBE but both gas and diesel have the 4R100 transmissions its really weird but Kool at the same time

 

@Mark Kovalsky Mark is the 4r100 expert here on FTE.

 

This thread is over five years old. There is no point in resurrecting it.

 

Didn’t even notice that, sorry to waste your time....