Does anyone have any experience with the bullydog shift enhancer for our E4ODs?

It's a kit with three springs, a valve, and a drill bit to increase the size of the transmission fluid feed lines for increased shift pressure and reduced torque converter slippage. Takes about an hour, and fits all '89-01 diesel E4ODs.

Details here at Bully Dog Shift Enhancer Kit for the GM Allison and Ford Power Stroke Transmission

I'd like to try this, I don't have any shifting problems now, but seems like a good idea to keep line pressure constant and shifting with less power loss.

 

I have installed the older version (3 heavy springs & accumulator valve, no drill bit) in my 94 e4od and my wife's 97 e4od, I did notice some improvement in both but have always thought it could be even better, maybe that's why they what you to drill something out now. I would like to see the directions on the new kit to see what is different.

 

Meant to say actuator valve not accumulator valve

 

I just did it electronically, by altering the duty-cycle of the pressure control solenoid - I end up with higher line pressure, and shifts are now nice and firm and almost instant, which is what I wanted. One thing to watch out for, apparently, is how high you go on line pressure - pump only supplies so much, and the more you ramp up the regular line pressure the less pressure you see at the torque converter lockup clutch (more likely to slip under heavy load), or something like that.

 

1dieselman - I will go ahead and get the kit after my January 2nd paycheck When I do that, I can try to scan the directions if you're interested.


MLSC, how does the increased line pressure cause a reduction in the strength of the torque converter lockup? Not to sound stupid but can this be solved by adding more fluid to the trans, or putting a bigger pump in the E4OD? Both ideas seem like they're asking for more trouble than they'll solve.

Doubt I'll tow anything over 7-8,000 lbs (tandem-axle car hauler or tandem-axle trailer for a 22-23' center console boat) beyond a 100-mile radius, and Florida's pretty flat. I think this Bully Dog shift enhancer kit will be okay for smoother shifts.

 

My understanding is that say the pump is making 100psi, but the solenoid only sends 40 psi to the drive clutches, the excess of 60psi is then used in the TCC lockup. Now say you modify your valve body or the solenoids to increase to line pressure to 60psi - it gives you nice and firm shifts, but now you only have 40psi left for the TCC lockup. So tis a tradeoff, normally not an issue, but can become one with stupid-high line pressure levels.

And yes, pump can be modified to take care of all that nicely, but that requires pulling the trans out of the truck.

 

Increasing the line pressure puts more strain on the seals, valves and piston in the transmission. If everything holds, it will shift more firmly. If however like in the case of the lockup clutch, you have a weak apply piston to begin with, the higher fluid pressure can cause cracks in the piston and this will relieve fluid pressure. This has more to do with a weak design of earlier E4ODs, but its why I generally try to discourage folks from using "electronic shift kits", like the banks plug and play trans command. To be fair, this type of failure can happen on stock E4ODs as well, its just more likely with one that has higher line pressure.

The springs (or solid spacers in some cases), are increasing the line pressure before allowing the fluid to pass and apply clutch pressure. This increases the pressure holding the clutch applied. The drill bits are usually used to increase fluid flow to the apply piston itself. Both line pressure and apply time are affected by these two methods, and the method is what you are really paying for when you buy a shift kit that is essentially a small assortment of springs in a box.

 

I'm able to get a brand-new Bully Dog shift kit in the region of $40, a local guy bought one for $75 and received two by accident.

So, yes or no? This is mechanical, not electronic. I'm inclined to go for it, since most of my driving around town is under 45mph from stoplight to stoplight. I was planning to change transmission fluid and put a new filter on the E4OD in a couple of months just to keep things fresh, and the shift kit seems like a good idea.

Assuming there's a 50/50 balance between line pressure and the torque lockup, is there a way to determine how much pressure is given to the lines and away (lost) from the torque converter?

 

Okay Dave, I don't think I get this - the hardware kits are increasing pressure before fluid is allowed to hit the clutches and apply pistons - well, the electronic tweak changes the duty cycle of the pressure-control solenoid, which in turn raises the line pressure everywhere in the trans, how's that increased pressure different than the pressure increased by the hard-parts kits? I mean pressure is pressure, whether tis regulated by a spring or a solenoid, right?

 

The TC lockup clutch is the most vulnerable in the transmission and when you up the line pressure electronically, you increace the strain on all the parts that feel hydraulic pressure.

When you use a mechanical shift kit, you are able to adjust the line pressure at the area you need it, so the strain is not as wide in the system. I would not want to increace the line pressure in the TC lockup, but the accumulator body and other apply pistons can more easily take the strain.

Another point is that to some degree, line pressure will affect temperature. More pressure, more heat. If you only have line pressure where you need it, again, the added strain is kept to a minimum.

Its really a risk verses benefit strategy. By increacing the line pressure at the EPC, you can slow the slip time and reduce wear and tear as well as heat, but the line pressure rise carries risks of its own, like potential heat, and strain on parts because the pressure is poped up all the way back to the EPC. By using a hardware shift kit, you can still rise the line pressure, but the difference is more isolated (typically to the accumulator body and related apply pistons) and you have the option to only pop the pressure on the shifts that you want.

However the BIG difference with a hardware kit, is you have the option to reduce the shift slip time without increasing line pressure. This is done by drilling or adding orifice holes that allow apply pistons to fill and apply the correct pressure more quickly. Some shift kits also remove check ***** to allow more fluid flow and improve response time in the valve body.

 

Aaaah, it all makes sense now. Is there a way to upgrade the TCC piston? Heat generation doesn't seem to be an issue for me with my monster cooler up front...

 

Well...yes, but you have to replace the torque converter with a built up aftermarket version. New OEM TCs are also supposed to be better, but still not as good as aftermarket.

Torque converters are like tires, buy as high quality as you can possibly afford.

I guess the short answer would be no....

 

Ah, kinda figured tis something like that, lol

 

Wouldn't it make sense to replace the converter if Your modifying the lockup pressure?

Seems like the TC is one of the major weak spots in the E4OD, anyways?

 

Well sure, but a properly upgraded TC costs a lot more than a shift kit! LOL