Medium-built 4L60E transmission wish list, thoughts?

2010H3TAlpha · Aug 19, 2018

Per my other thread here, my 4L60E most likely has a damaged front planetary and needs to be rebuilt: https://www.hummer4x4offroad.com/forum/showthread.php?13351-New-transmission-noise-(Alpha-4L60)

I have decided to have a reputable local shop rebuild my 4L60E with some upgraded parts. I don't need to go too crazy (no 300m output shaft, etc.) but I wanted to share what we're looking at so far and see if anyone recommends anything additional while we have it open. Keep in mind that I am planning an LS3 next year, so being able to handle 500hp/500tq is important. Here's the list so far:

Sonnax Performance Pack:

1-2 Accumulator Valve Shim
TCC Pressure Limiter Valve & Spring Optional, eliminates PWM/EC3 function
Boost Valve with O-Ring .490"
Elevated Pressure Regulator Spring
High RPM Pump Slide Spring
Spacer
4th Servo Return Spring
Servo Cushion Spring
Servo Piston D-Ring Kit
3-4 Accumulator Piston Kit
3-4 Accumulator Spring
Servo Release Check Valve
Forward Accumulator Kit
Checkballs (8)
Separator Plate Plugs Not Shown
Twist Drills Not Shown
1-2 Pinless Accumulator Piston Kit
1-2 Accumulator Inner Spring
1-2 Accumulator Outer Spring
1-2 Accumulator Waved Spring

Heavy Duty torque converter
Sonnax Smart HD Reaction Shell
Heavy duty 3-4 clutch backing plate kit
Rear stator support bushing
Corvette servo
Heavy duty 2-3 shift valve
4th gear super hold servo

Anything else we should consider while things are taken apart?

Thanks!

CaseyS · Aug 25, 2018

7 clutches in the 3-4 stack. Takes 0.080 steels if I recall correctly.

kilroy · Aug 26, 2018

Didn't see a 5 gear planetary in that list. iirc Monster transmissions has a 4l60 package (or parts) with heavy duty sun shell.

2010H3TAlpha · Aug 26, 2018

kilroy said:
Didn't see a 5 gear planetary in that list. iirc Monster transmissions has a 4l60 package (or parts) with heavy duty sun shell.

Yeah though that is an expensive part and all builders are telling me that money is better spent on input shaft and drum. I have also been told that the stock H3 4L60E uses a 5 gear planetary and can be reused if it is not damaged. Anyone know if this is true?

atvspeed4 · Aug 26, 2018

2010H3TAlpha said:
Yeah though that is an expensive part and all builders are telling me that money is better spent on input shaft and drum. I have also been told that the stock H3 4L60E uses a 5 gear planetary and can be reused if it is not damaged. Anyone know if this is true?

The H2 4l65 only has the upgraded planetary from what I have found

amrg · Aug 26, 2018

When I rebuilt my trans I upgraded to a used 5 pinion planetary from an H2 transmission. The stock h3 trans has a 4 pinion planetary.
I did go for a billet pump rotor and a BW 29 element sprag.
Add to that a new reverse input drum to accomodate for the new wider band and a sonnax smart shell.

Sent from my SM-G960F using Tapatalk

2010H3TAlpha · Aug 26, 2018

Thanks guys, this is great info. They are tearing it down tomorrow, so I will be back with a full damage report soon.

Ordieh · Aug 27, 2018

Be sure to include an aftermarket metal 1-2 accumulator piston. With the buildup (Corvette servo. etc.) the OEM plastic one will split in half.
Good luck on your build.
P.S. The guys are right, the H3 4L60 doesn't come with five pinion planetaries.

2010H3TAlpha · Aug 27, 2018

The shop pulled the transmission pan and found metal; they think it might be a snap ring, but won't know for sure until full teardown tomorrow. They also noticed the transfer case was making noise so they pulled the fluid and found it to be black with a silver consistency. Is that normal or should I be worried?

atvspeed4 · Aug 27, 2018

2010H3TAlpha said:
The shop pulled the transmission pan and found metal; they think it might be a snap ring, but won't know for sure until full teardown tomorrow. They also noticed the transfer case was making noise so they pulled the fluid and found it to be black with a silver consistency. Is that normal or should I be worried?

Every H3 transfercase we have taken apart has very dark fluid and usually some metal in it. On some 2008+ transfercases there is a "bumper" for lack of better words that there is a thread on here about that can wear from being slapped by a worn chain and sometimes can come dislodged from the case. I would have them split the case and take a look at everything.

2010H3TAlpha · Aug 27, 2018

Yikes, this is getting fun/expensive! Thanks for the info, I'll have them break it open and see what happens. It makes sense since the tcase was freaking noisy, more so than I remember. I've been having too much fun in these hills

4speedfunk · Aug 28, 2018

Black fluid with shiny dust is unfortunately the norm.
Drag a magnet thru your t-case fluid. That will tell you if the metallic dust is steel or not. All of the really important parts are made of steel. The dust is usually aluminum or magnesium and won’t stick to the magnet. Clean the pump pickup screen when you have it apart. These are often clogged with debris.
Go ahead and plan for a new chain & a metal shift fork.

2010H3TAlpha · Aug 28, 2018

Thanks for the input, they are tearing down the transfer case tomorrow.

Verdict is in on the transmission, the reverse sprag blew up, but luckily didn't take anything else out in the process.

2010H3TAlpha · Aug 31, 2018

Transfer case issue found! I have a feeling this is a very common issue with our trucks. The chain guard screw had backed out, but no other damage was found. Whew!

Ordieh · Sep 1, 2018

Might consider installing a MAGNEFINE filter in the cooler return line. It will catch both ferrous and aluminum/magnesium particles. Again, good luck with your build.

2010H3TAlpha · Sep 1, 2018

Ordieh said:
Might consider installing a MAGNEFINE filter in the cooler return line. It will catch both ferrous and aluminum/magnesium particles. Again, good luck with your build.

Thank you, we are also definitely doing this because who knows what went in the cooler after the reverse sprag let go. The sliver of steel in the pan was enough of a concern. I am still amazed this thing didn’t explode on my drive home.

Alpha X · Sep 2, 2018

I've been watching this thread since my radiator failed a week ago and filled my perfectly running transmission with Dexcool. I'm interested in hearing how you like the upgrades to your transmission because I'm probably going to use your list when I have it rebuilt.

2010H3TAlpha · Sep 2, 2018

Alpha X said:
I've been watching this thread since my radiator failed a week ago and filled my perfectly running transmission with Dexcool. I'm interested in hearing how you like the upgrades to your transmission because I'm probably going to use your list when I have it rebuilt.

Oh wow, this is my nightmare, I am so sorry to hear that. How many miles did you drive after that? Did you immediately do a flush?

I’ll definitely share the final build, though I am going a little crazy in case I do an LS376 next year.

Alpha X · Sep 2, 2018

2010H3TAlpha said:
Oh wow, this is my nightmare, I am so sorry to hear that. How many miles did you drive after that? Did you immediately do a flush

Happened on the way to work. Trans slipped a little bit about two miles from work. I got to work, opened the hood and saw the overflow tank partially filled with trans fluid and coolant mix. I had it towed home. Flushed the engine first, did the transmission second after I separated the two systems. I have about 15 gallons of flushed out Dexcool/Dexron VI in buckets. It was a 3 month old AC Delco radiator that I installed, and a transmission with only 80K on it. I would strongly recommend to everybody to separate the two systems. This has been a hassle and I haven't even paid for a new transmission yet. It might last a little while with new fluid in it, but the water in the coolant damages the clutch material and it degrades quickly. Considering a 6L80e conversion.

2010H3TAlpha · Sep 2, 2018

Yeah I was planning to do a 6L80E and built L92 from a wrecked Escalade before my research showed so many little issues with the 6L80E. Selecting a gear in 4low being the biggest issue of all. I can’t even get TBMS to get back to me about it, and they unlinked their swap parts pricing page from their main site and replaced it with a “tell us your budget and we will see what we think” page which, to me, is a big red flag. I think they are having a huge issue with turned-down output shafts on the Trailblazers which does not bode well for us, in addition to the 4low gear selection issue. Don’t get me wrong, I would LOVE a 6speed for the performance and mileage gains, but I’ve also played the project car downtime game and I love driving my truck too much to have it sit for 6+ months due to minor compatibility issues.

Alpha X · Sep 2, 2018

2010H3TAlpha said:
Yeah I was planning to do a 6L80E and built L92 from a wrecked Escalade before my research showed so many little issues with the 6L80E. Selecting a gear in 4low being the biggest issue of all. I can’t even get TBMS to get back to me about it, and they unlinked their swap parts pricing page from their main site and replaced it with a “tell us your budget and we will see what we think” page which, to me, is a big red flag. I think they are having a huge issue with turned-down output shafts on the Trailblazers which does not bode well for us, in addition to the 4low gear selection issue. Don’t get me wrong, I would LOVE a 6speed for the performance and mileage gains, but I’ve also played the project car downtime game and I love driving my truck too much to have it sit for 6+ months due to minor compatibility issues.

Yes, I share the concerns about these potential issues. I emailed TBMS a few days ago and have not heard from them yet. I'm also told a 6L80 is more expensive to rebuild than a 4L60, much closer to the price of a GM remanufactured 6L80 transmission with a 3 year warranty.
I didn't mean to derail your 4L60 rebuild thread.

2010H3TAlpha · Sep 2, 2018

Alpha X said:
Yes, I share the concerns about these potential issues. I emailed TBMS a few days ago and have not heard from them yet. I'm also told a 6L80 is more expensive to rebuild than a 4L60, much closer to the price of a GM remanufactured 6L80 transmission with a 3 year warranty.
I didn't mean to derail your 4L60 rebuild thread.

No apology necessary, this is exactly why I started this thread. Yeah when you factor in a rebuild, the 6L80 budget jumps a lot, while low mileage 6L80s are expensive. Wrecked Escalades can be cheap, but also unpredictable and tough to find low mileage examples unless you are near a major Copart/IAAI yard. Eventually I’d love to do a 6L80E with Atlas tcase, but that’s $5k for just the tcase and shift controller. And then the lack of upgrade options for the front diff is a big concern.

2010H3TAlpha · Sep 5, 2018

Quick fun fact, my 2010 transfer case had a metal shift fork stock. I can't remember if there is documentation out there regarding which years have plastic shift forks vs. metal, but I thought that was pretty cool.

Fun parts arrive tomorrow. I went crazy with a lot of Sonnax goodies like 300m input shaft, Smart input drum, 300m output shaft, 5 planetary front/rear, HD overrun clutch, and a full page of other smaller upgraded parts like better clutches, accumulator, etc. I'm going to put everything into an excel spreadsheet so other people have a reference in case they want a cheatsheet from my countless hours of research. Then it should be ready early next week and I'm already planning my next wheeling trip, hopefully 2 or 3 before the snow hits the Cascades here. Can't wait!

Alpha X · Sep 5, 2018

2010H3TAlpha said:
I'm going to put everything into an excel spreadsheet so other people have a reference in case they want a cheatsheet from my countless hours of research.

Yes to this!
:thumbs:

2010H3TAlpha · Sep 12, 2018

Just drove my truck home and WOW, this just might be the smoothest auto I have ever driven. I went a little crazy and did the full Sonnax Level 3 build with 6 planetary front gear, 5 planetary rear, HD overrun clutch hub, HD input shaft/drum, HD output shaft, Smart Shell HD Reaction Shell, Kevlar intermediate band (over 1" longer than stock!). I can't believe how fast but buttery the shifts are, it makes my 5.3L feel wayyyyy under powered now. Here's a link to the Sonnax Level 3 build info and I'll scan the build doc later today when I get a chance (we added a couple extra goodies for good measure). Sonnax rates this level of build for 1khp/1ktq, so I should be good for a while, even if I do an LS376 next year. If you're in the Seattle area, Transmission Xpress is AMAZING. Not only do they know how to build a great transmission, they were extremely nice and professional throughout the entire build process.

https://www.sonnax.com/tech_resources/617-4l60-e-performance-heavy-duty-transmission-build-charts

Medium-built 4L60E transmission wish list, thoughts?

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