Sonnax

One of the first things I noticed about my Excursion was the shifting was sluggish, especially the first to second shift, and under more power it was even slower. This just how the Ford 4R100 tranny’s shift behind the big diesel. That led me to find the Sonnax Valve and Tricumulator spring upgrades to the valve body. The stiffer springs increase line pressure in the tranny to make the shifts more crisp and firm and quicker. The modulator valve and sleeve replace the stock unit that is prone to wear and letting oil past the valve causing the soft shifting. Eventually after excessive were it will hang up and cause harsh shifts. For future upgrades this was a must, without it adding more power can multiply these effects and toast the tranny. I ordered mine from www.puredieselpower.com for $50 with shipping.


	The plug was pulled and the tranny drained then the pan was removed. The valve body that is to be removed is the very front of the tranny and is situated left to right. It is held in with eleven 8mm bolts and two 10mm nuts.


		Next remove the valve body and let all the fluid that is in it drain all over your arm and driveway. There is a black plate that will stay up in the tranny along with a small screen that comes out with the valve body.

	Due to Federal Witness Protection program rules, I can not show you Jeff’s face. All of his tattoos and visual scars will be covered up also.


	Add in the 2 springs on one side and replace the valve and and add a spring on the other side. They are all held in with black clips and the spring covers can be pulled out by threading one of the 8mm bolts from the valve body into it and pulling

Nice and clean and ready to go back in. The valve body bolts and nuts get get torqued to 80 inch pounds. The pan bolts are 10 foot pounds, except the ones in the back that are covered by the damn cross member, those are done by precision feel. After putting the valve body back in and putting the pan on, we poured in 5 quarts of Mercon fluid (DO NOT use Mercon V) pulled the shift lever through through park to low and back again then topped off the fluid.


	I could tell on the first test drive down the street that this was a HUGE improvement. The shifts are quicker and much firmer, but not harsh. Even with my foot mashed the 1 to 2 shift is nice and quick and firm. All the other shifts are firmed up also and it makes for a much smoother downshifts, no more sloppy shifting. This should be number one or two on anyone’s mod list.

[BigdaddyDiesel] [Tech] [01 Excursion] [03 F350]