As you may have recently seen in the Transgo install procedure thread, I broke down the differences (as far as I could tell) between Transgo's E40D-HD2 and 4R100-HD2 "Tugger" kits. I think they're great, and when properly installed, will yield excellent improvements in both transmissions. Both Transgo Tugger and Sonnax Sure Cure utilize the same ideology to make fix the 4R100 slush box, but it seems to me Sonnax takes it up a notch in designing a more comprehensive, better engineered and more user friendly kit. You can read into that whatever you choose. Know this though- I'm not here to sell anyone anything!!! I'm simply trying to decide for myself which one I'm going to go with and help others in a similar situation (Pop) decide for themselves. Again, I'm just your average shade tree mechanic, so take it for what it's worth. Here are the features of the Sure Cure, which while it includes all the parts typically referred to as the "Sonnax (tricumulator) shift kit", do not confuse the two. They are not the same thing.

The Sonnax SC-4R100 "Sure Cure" at around $160, is a highly engineered "reconditioning" kit that features all new accumulator valve body (AVB) replacement control valves and an oversized (0.427") line pressure modulator valve. Instead of drilling holes in a "calibration plate", Sonnax controls shift firmness with variable numbers of shims (none to 4) behind the control valves, allowing more fine tuning AND the ability to go back if you went to firm. If 4 shims don't get 'er done, you can still enlarge the accumulator feed holes in the stock separator plate. I'm going to go out on a limb here and say I probably won't have to do that. But if I do, I can. I also appreciate the beefed up valve spring retainers that go in to bolster the spindly little OEM clips that are known to fail. Sonnax does include a modified EPC relief valve, of a slightly different design. All the above, of course, can be installed without dropping the tranny.
<O</OThe Sure Cure makes no modifications (as far as I can tell) to the solenoid pack or solenoid regulator piston, which (I guess) '99 and later 4R100s don't necessarily need. But, that may be to keep them in good standing with FMC?

<O</OSonnax also includes their torque control clutch (TCC) control sleeve assembly, which is not the same as the similar single valve On/Off lockup kits. However, the Sure Cure DOES NOT include parts to improve L/R clutch holding issues. But their additional HD L/R modulator sleeve kit (36947-09K) does, which is definitely a must do. Understanding the differences in the way Sonnax and Transgo address both the TCC issues and the L/R issues is better understood by a transmission expert than it is by me. As far as I am concerned, they both tackle the problem, and I am sure they are both quite effective. Likewise, I know there are better, way more expensive cures (ie. new $1000 plus converters)- and cheap, easy short circuit, trick the PCM fixes- for the inept factory torque converter, neither of which warrant discussion in this thread.
<O</O

The Sure Cure kit includes a modified front lube/modified drainback valve, a new one piece case bushing, and overdrive end play shims (which Transgo does not), as well as their version of an improved overdrive (4th clutch) retaining spring. Another key feature Sonnax utilizes is O rings on their line pressure modulator valve and boost pump valve. And while O rings are totally intolerant of burrs and ridges in the accumulator and pump valve bodies they do improve fluid sealing and reduce wear. So inspect these bores and hone if necessary, especially if your tranny has seen extended hard use or you are already having significant problems. For similar reasons, since this kit replaces all 3 shift control valves with new ones (vice using the original worn ones), the bore sizing tool (36948-12) is a must!

So that's it. No valve body drilling, no "calibration" plate (shims instead), and since you don't have to pull the stock separator plate no ***** to mess with. And for us novices, I'm happy to report I'm dead sure the Sonnax installation instructions and their customer/tech support is far superior to that of Transgo. Those few things alone help make the choice easy for me. However, if anyone has personal first hand experience with the "Sure Cure" kits effectiveness and/or can compare the Sure Cure directly against the Tugger, please ante-up. I'm all ears (eyes). I know they both work and do what they claim to do, but that's where it ends for me. If I made any incorrect technical statements, please let us know. Thanks!<O</O<O</O

 

Just curious how you determined the Sonnax tech support was superior to TransGo? I've had dealings with the TransGo tech dept regarding a piece missing from a kit. I don't think they could have handled the situation any better.

 

Cole,

Your comprehensive evaluation of these two is very similar to my own, and bolsters my thinking about preferring Sonnax. Alas, so far it's only "on paper" for both of us, and hopefully we'll get some "hands-on" contribution to this thread.

Good that you pointed out the need to install the heavy-duty Low/Reverse Modulator Sleeve Kit to any modification, and I feel Sonnax might want to just add this to the kit to be sure it isn't overlooked.

I think Sonnax is often overlooked on this forum, and Transgo becomes the default recommended by most, in spite of the chance they might not be the superior product.

Nice analysis!

Pop

 

Sorry Chris, not going there. I'll take you on your word though. Perhaps I should have left that out.

Instead, let's talk about the effectiveness of the Sure Cure. And compare it with actual personal first hand experience to the Tugger.

There is plenty of data and opinions about the Tugger as it stands alone. and all the others, B&M, etc. But little to no information on the Cure. And absolutely no direct comparisons on it's effectiveness. I've already extensively covered the basic differences and similarities between the two kits today.

Who's running the Sure Cure??? Who has run both??? thanks-

 

They're both effective, they just go about it in different ways. Since we talk about how they change the "feel" of the shifts then any discussions here are simply subjective.

Personally the only shift feel I like is the one that comes from a 3rd pedal.

 

Interesting reading. Does the Sonnax kit have any parts for the 4th and coast clutch snap ring issue? I use an exhaust brake and upgraded the coast clutch drum to a 3 plate (PTO) unit. So far, the trans has been working great and I have been very satisfied with the Transgo kit. However, I do have another truck and might have the need to upgrade it's trans someday. If/when that time comes, I might just give the Sonnax kit a try (if they address the snap rings and have the PTO clutches). For reasons unknown...the trans in my other truck is the PTO model.

 

Chris- roger missing the 3rd pedal. Perhaps I need to be more specific. I don't care how they feel. I can make them feel anyway I want. That's determined by how you set the kits up. everything on the forum is a subjective opinion. otherwise, all 360,000 of us would have to cram into someones 500 acre shop and start tearing things apart and beating the crap out our trucks. A few of us have already done that and do so on a regular basis. These are the "subjective" opinions I am interested in reading.

What i want to know is how well the Sure Cure does what it claims to do, other than simply firming up the shifts. And thus, I want to hear from those who have extensive experience with the Cure. If they also have extensive experience with the Tugger, that's all the better.

If that's all I was interested in I'd just bump the line pressure with a flash tuner and head down the road. That is until my transmission puked it's guts all over the highway, with me, the ol' lady and my dog all on our happy way with my 10K RV in tow. In the middle of the night, on a narrow 2 lane, down a steep descent, in the pouring rain.

Do you catch my drift on the purpose of this thread. I don't think I can make it any more obvious without insulting someone. thanks- Cole

 

Greg,

Is this what you are referring to?
http://www.sonnax.com/product-lines/...ion/parts/3155

Pop

 

Chavez- see paragraph 4 of the OP on the fouth disc snap ring. Clutch packs, no. It's a $160 "reconditioning" kit, not a transmission rebuild kit. Visit their website- it's tip top.

 

Here's the whole SureCure:
http://www.sonnax.com/instructions/SC-4R100HD-IN.pdf

Pop

 

Yes. The photo looks exactly like the photo in the Tugger kit. Cool, looks like it's included.

Never heard of a re-conditioning kit. Is this a kit designed to be installed in an already working trans without having to do a complete tear down and rebuild?

 

That's the idea, except I suspect at least SOME of it needs to be installed in a semi-torn-down trans.

Pop

 

I have now installed the entire Sonnax Sure Cure HD in my '02, with the exception of the rear case bushing and center support gasket. I only went as far into the tranny as to replace the inadequate OEM piston return spring retaining ring with the Sonnax ring. All Sonnax pump body, valve body mods and other are done... as well as a firmer TC regulator valve spring from Precision Industries. Came with the Stallion converter I installed, which is how/why I got to the pump. yuk, yuk.

Just to note: to get to the overdrive piston return spring retaining ring, you still have to pull the accumulator and main valve bodies (again, in my case), in addition to the pump body.

Sweet shifts now in all load conditions. OD engage feels like as extra gear!!! Tranny temps running about 5-10* less (from new TCC install and pump mods).

My SCT tunes haven't been recalibrated yet for the 300 rpm lower stall speed (need to call Eric). So that should help my low end torque values. The 1-2 shift is sometimes actually a little harsh, but still good! I am going to tweek that with my SCT. It should be much more responsive to line pressure adjustments now. But right now, anywhere low mid-range to near WOT, this 4R100 will put it down with no hesitation. Need better throttle response though.

But I'm going to baby it anyway (most of the time) because although the original tranny only has 10,000 mile on it- all the rest of it is still OEM. I'm trying to prolong the premature failure of the dubious 4R100, or at least reducing the odds of catastrophy for years of worry-free RV towing. Why does it still feel like a crap shoot??? If I start romping on it, all that extra strain is going to fall on the OEM clutches, and we know they can't take much.

Thought about bypassing the bypass, but have not. So short of dropping in a BTS, Woods or Suncoast- that's about all I know to do. I guess an inline, spin on filter would be good...

 

I like that external filter idea.

Yours is the one I'm watching most carefully right now, as I suspect that that kit goes a LONG way toward making these things live better.

Cleaner fluid can't hurt, either!

Pop

 

hey Marv- no suprise to hear from you. I was going to PM you to make sure you saw this. I do have a Magnafine inline right before the 6.0 cooler, but the bypass would be nice. I am, of course, running fully synthetic tranny oil. New every 30K, now from here on out. So I guess I'm there on this one. $300 for the Sonnax and $999 delivered for the TC. 1/3 the cost of completely rebuilt.