[Gatuncrocs]

My vehicle is a 2004.5 2500 Cummins with the 48re.
The truck had a transmission rebuild right before I purchased it and everything works fine.

I want better shifting & to make the transmission last longer, so I decided to install the TransGO sk48re kit along with the following Sonnax parts: manual valve 22771-09, lube regulated zip valve 22771a-02k, front servo cover 22827-01, billet piston kit 22841-04k. A DNJ gm governor solenoid kit was already installed by previous owner.

I currently have the valve body apart and have read through the TransGO shift kit instructions and have decided NOT to do the following steps (please correct me if I’m wrong):

I won’t drill these holes:

I will not perform this notch, since I’m using the Sonnax valve:

I will not install this green spring:

I will not install this gold spacer (I have tv cable & no issues with shuttle shift):

I will not grind the switch valve:

I will not use spring, shim & PR valve from kit since I’m using Sonnax valve:

I will perform the rest of the steps, although I’m unsure if I should drill this hole or not:

Is my plan flawed somehow? Thanks for any input!

 

[Gravel]

Other than stuff TransGo says is optional, I’d suggest following all the steps. It’s a balanced system and if you don’t do some of the stuff it might turn out to have some unexpected problems.
Ive read a few reports about the TCC lockup holes, they all said it wasn’t harsh even with both holes drilled. And quicker lockup will probably help your stock converter live longer.

 

[Gatuncrocs]

Thanks for your input. I am a bit worried about doing some steps and not others, that’s why I decided to ask questions on here. I’ve read lots of complaints on this forum about people who weren’t happy after installing a TransGO kit. I’m aiming to get the best results from mixing the kit with the Sonnax parts…. Some more feedback from people who’ve done something similar, or just have a bunch of experience with different builds would be awesome

 

[Gravel]

Mines a 48re-hd2 Transgo kit mixed with a DPC billet servo kit so sorta similar to what you’re planning, it’s been working pretty good even with the wrong spring in the front servo. Trans guy apparently had a brain fart when putting it together, he was scheduled to take it apart and check out the intermittent flare between 2nd and 3rd, then the poor guy passed away.. So I researched the symptoms, swapped out the wrong spring for the right one myself, I’ve got no complaints at all about how it works now. I skipped some of the optional steps like the TCC lockup holes and the “max firmness” 1-2 shift steps because I’ve got a 3 disc converter and didn’t want any harshness.

Good luck!

 

[Daisyland]

Find a trans shops that will put your VB on a bench testing machine with all your swaps.

DON'T Drill any holes for TCC Lock up. the sk and hd2 kit may have different parts for TCC circuit.

I also have the hd2 kit installed

 

[Gatuncrocs]

Yeah, I’ve read lots of people recommending to not drill that one or two holes for the TCC lockup.

Unfortunately, I don't have a good transmission shop nearby….I’m not in the USA.

Am I wrong in assuming the Sonnax valves are superior to the TransGO supplied units? From what I’ve read, I thought using them meant I didn’t have to do the notch & grind the valve….which sounds good to me, but I don’t have experience.

 

[Bookworm]

I don't reply on this forum much anymore, but I did almost exactly the modifications you are contemplating. I did the mods about 10 years ago.
2005 2500 2wd 48re. About 60k miles at the time.

I used the Sonnax PR valve, the manual valve, the lube-regulated kit, the billet piston and cover, the billet strut, etc. Everything you are doing.

I did not drill the holes for a firmer lock-up, as I'm running a 3-disc TC.

I do not remember if I filed the groove across the valve body, but I'm betting I did.

I did drill through the body and used the plug. I also spent an extra $50 (at the time) on a steel pan with a drain plug.

I have had no problems whatsoever with the Transgo and Sonnax parts working together. I did purchase a pressure gauge and spent some time checking and adjusting various pressures, with the truck up on jack stands.

Good luck. Just take your time, you'll do fine.

 

[Gatuncrocs]

Thanks Bookworm, that’s very helpful!

I did read somewhere that the notch is for when you drive in 2nd gear manually…so in Drive you wouldn’t notice anything. I’m still leaning towards not notching.

I already drilled the hole in the body & plugged the hole. There are two other holes that the kit wants you to plug which I did as well (no idea what that accomplishes). I also enlarged the two holes on the separator plate & drilled one extra hole on the small lower plate, per the instructions.

I’m definitely not going to drill the one or two holes for TCC lockup & I’m leaning towards not notching the body or grinding the switch valve, unless someone else with experience chimes in here.

I would like to hear opinions on whether I should use the PR springs, washer & shim that come in the kit in conjunction with the Sonnax PR valve. I’m guessing that I shouldn’t, because the Sonnax instructions want you to leave the pressure regulator adjusted at .030-.035” which is basically stock location and the TransGO kit wants you to adjust almost flush with plate.

 

[Bookworm]

& shim that come in the kit in conjunction with the Sonnax PR valve. I’m guessing that I shouldn’t, because the Sonnax instructions want you to leave the pressure regulator adjusted at .030-.035” which is basically stock location and the TransGO kit wants you to adjust almost flush with plate.

I did install the Sonnax PR valve, but I don' remember if I installed the springs from the Transgo kit with it.

I do remember that I had to pull the pan more than once to get the pressures down to a reasonable level (I don't even remember what that level was, it was a long time ago), adjusting the pressure regulator so it was no longer flush.
That leads me to believe I did install the TG kit springs, but I can't swear to it.

I also remember installing the Sonnax valve because I didn't like the idea of grinding the stock valve and reinstalling it.

However, on a later install - in a different pickup, we did grind the factory valve. It worked just fine.

I wonder if I can find the Transgo sheet from when I installed the kit. It may have notes on it. I'll go look.

 

[Gatuncrocs]

Interesting. Yeah, sounds like you must have put the TransGO kit springs on the Sonnax valve. My plan so far is to install using factory spring & adjust according to the Sonnax instructions, which is very close to stock settings.

I must say, part of me is saying just to forget the Sonnax parts and do everything according to TransGo instructions. My only hesitations are all the negative things I’ve read on here about harsh shifting & the loss of the core value, which will be an issue down the line when/if I do a complete transmission overhaul at which time I’d probably install a Goerend kit, TC & valve body.

Decisions decisions!

 

[Bookworm]

Okay, I went through my install notes from way back when.
I did not file the groove. My notes indicate a conversation with Transgo product support, which suggested to skip that step.

I installed 3 Sonnax valves; the lube-regulated valve, the PR valve, and a spooled switch valve (which regulates the TC lockup).

The pressure adjusting I did was to RAISE the pressure after installing the Sonnax valves. Transgo wants 75psi at idle. Moving the adjusting screw IN raises the pressure. I initially had the screw all the way out, and had to open the pan to raise the pressure.
Which means I apparently did not install the extra springs from Transgo, along with the Sonnax valve.

I'm glad I went and looked.

 

[Gatuncrocs]

Excellent information, thanks! So, if I go with the Sonnax valve, I guess a good starting point is to not install the kit springs & shim & to adjust to the recommended specs supplied by Sonnax instructions. Then pressure test & go from there.

 

[Bookworm]

I think that would be a good starting place.

But then, I ain't nobody special🙂

 

[Dynamic]

I'll give my standard responses for guys that are dead set on using the Transgo kit.

1. The PR spring setup is the only thing of much value in that kit. That part they got right.
2. Their manual valve is junk. Use a Sonnax valve.
3. Do NOT grind the switch valve land.
4. Do not install their TV PR spring.
5. You don't need the Sonnax PR valve (see point #1). It won't hurt to use it, but it's not necessary.
6. You need to make the mods to the OD accumulator in order for their silly plate to work.

 

[Gatuncrocs]

I think that would be a good starting place.

But then, I ain't nobody special🙂

Your information is appreciated! I just ordered a pressure tester because of it!

 

[Gatuncrocs]

I'll give my standard responses for guys that are dead set on using the Transgo kit.

1. The PR spring setup is the only thing of much value in that kit. That part they got right.
2. Their manual valve is junk. Use a Sonnax valve.
3. Do NOT grind the switch valve land.
4. Do not install their TV PR spring.
5. You don't need the Sonnax PR valve (see point #1). It won't hurt to use it, but it's not necessary.
6. You need to make the mods to the OD accumulator in order for their silly plate to work.

Thanks! My tentative plan is in line with your advice, except for the option of using the transgo pr valve + spring instead of the sonnax unit. Still need to decide on that one….perhaps I’ll install the transgo first and see if I like it. I can always go back & put the sonnax in.

I did do the mods to the accumulator housing & plan on installing their plate….I had to get another plate because I made a mistake and drilled a hole in it when I was supposed to drill it in the smaller lower plate. Transgo is sending me a new one for free (which is why I have this time to get wisdom from all you transmission gurus).

I’m curious why some people like transgo & others don’t. Why do you think their plate is silly?

 

[Dynamic]

Transgo doesn't send a PR valve with the kit, so your choice would be to either use the OEM PR valve, or use the Sonnax PR valve you said you got. You can use either and you'll never know the difference. The Transgo PR spring setup accomplishes the same thing as the Sonnax valve does.

That plate is used as part of their way of reversing the hydraulics of the OD accumulator. It works, but it's a fairly convoluted way of doing it.

 

[Gatuncrocs]

Transgo doesn't send a PR valve with the kit, so your choice would be to either use the OEM PR valve, or use the Sonnax PR valve you said you got. You can use either and you'll never know the difference. The Transgo PR spring setup accomplishes the same thing as the Sonnax valve does.

That plate is used as part of their way of reversing the hydraulics of the OD accumulator. It works, but it's a fairly convoluted way of doing it.

ah ok, I understand. So my option is to use the stock pr valve plus transgo spring + shim, or the sonnax pr valve with stock spring, right? in that case, I’ll just go with the sonnax if it achieves the same thing.

also, what exactly is accomplished by reversing the hydraulics of the OD accumulator?

 

[Dynamic]

No, you want to run the Transgo PR spring setup with either PR valve. The PR spring setup is what raises the line pressure and ensures lube/converter oil even at maximum line pressure.

 

[Gatuncrocs]

Ok okay! Thanks for clarifying. 👍

And is 75psi line pressure at idle the ideal? I bet I’ll have to go back in & adjust afterwards.