Sonnax HD overrun hub
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TECH Enthusiast
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From: Roxana, IL
Sonnax HD overrun hub Just wondering how much the Sonnax HD overrun hub is needed? @FranksCustomTrans especially when using your overrun mod...
Iv actually cracked the tabs on one before. A stock one that is. But, it was in a 6k lb truck, AWD, and a ProCharger. I have one in my Camaro, its a nice piece. Not a cheap piece but nice
Last edited by 2BFAST; Feb 10, 2025 at 09:20 AM.
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From: Poplarville, MS
I have had problems with the hub stripping from the sprag race when using the Sonnax HD 2-3 shift valve in some units. I have not had the opportunity to try Frank's overrun mod, but I would expect it to be even harder on the hub than the Sonnax valve. When installing the Sonnax HD overrun hub I didn't have any more stripped hubs. As 2BFAST says it's not cheap, but it did solve my issue.
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From: BERWICK PA
To date I have not seen a stock one fail with my overun mod literally 1000s of units.
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Thread Starter
TECH Enthusiast
Joined: Jan 2019
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From: Roxana, IL
Thanks @FranksCustomTrans that's kind of the answer I was looking for.
I too have used 4 or 5 without any issues. The first one I ever used was because the guy manually pulled the transmission lever from 4th to 2nd for a roll race and heard a bang.
Now I have 2 to do, 1 is for 600hp all motor and the other is turbocharged. We are going to use the 4L79 drum, factory 4L70 hardened input and a Sonnax output on both.
I was curious if it was required or not... It would be good insurance even if it is $220...
I too have used 4 or 5 without any issues. The first one I ever used was because the guy manually pulled the transmission lever from 4th to 2nd for a roll race and heard a bang.
Now I have 2 to do, 1 is for 600hp all motor and the other is turbocharged. We are going to use the 4L79 drum, factory 4L70 hardened input and a Sonnax output on both.
I was curious if it was required or not... It would be good insurance even if it is $220...
Thanks @FranksCustomTrans that's kind of the answer I was looking for.
I too have used 4 or 5 without any issues. The first one I ever used was because the guy manually pulled the transmission lever from 4th to 2nd for a roll race and heard a bang.
Now I have 2 to do, 1 is for 600hp all motor and the other is turbocharged. We are going to use the 4L79 drum, factory 4L70 hardened input and a Sonnax output on both.
I was curious if it was required or not... It would be good insurance even if it is $220...
I too have used 4 or 5 without any issues. The first one I ever used was because the guy manually pulled the transmission lever from 4th to 2nd for a roll race and heard a bang.
Now I have 2 to do, 1 is for 600hp all motor and the other is turbocharged. We are going to use the 4L79 drum, factory 4L70 hardened input and a Sonnax output on both.
I was curious if it was required or not... It would be good insurance even if it is $220...
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From: BERWICK PA
When I first started using the OR mod years ago it was something I did worry about , But literally 1000s of trans later as I said never seen a failure in that area.
The OR mod is a super simple easy mod that just works lol .
In addition it changes the feel of the trans in lower gears a much more solid feel during kickdowns etc much like an old th350 400 or even a manual trans. Hard to describe till you feel it.
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Thread Starter
TECH Enthusiast
Joined: Jan 2019
Posts: 677
Likes: 490
From: Roxana, IL
I have never see it be an issue with the OVERUN MOD with the stock one. However the sonnax one is nice too. The OVERUN MOD actually reduced stress on it as its always on in 1-2-3 and does not rattle around so much.
When I first started using the OR mod years ago it was something I did worry about , But literally 1000s of trans later as I said never seen a failure in that area.
The OR mod is a super simple easy mod that just works lol .
In addition it changes the feel of the trans in lower gears a much more solid feel during kickdowns etc much like an old th350 400 or even a manual trans. Hard to describe till you feel it.
When I first started using the OR mod years ago it was something I did worry about , But literally 1000s of trans later as I said never seen a failure in that area.
The OR mod is a super simple easy mod that just works lol .
In addition it changes the feel of the trans in lower gears a much more solid feel during kickdowns etc much like an old th350 400 or even a manual trans. Hard to describe till you feel it.
https://ls1tech.com/forums/automatic...d-3-2-1-a.html
I spelled out my version of the 4th overrun mod in post 38. I was going to drill a hole. Frank has you cut the gasket. The two modifications are moving the same D4 oil from identical passages and redirecting them to the identical overrun feed passage.
This spring I want to apply the mod to my personal transmission, so I may feel the difference for myself.
In the next few weeks I have 2 500hp builds to do. Bottom line for the post was that. I was curious to hear if I really need to add the $200 hub to the build price or not...
So @FranksCustomTrans I thank you again for both sharing your version of the 4th overrun modification and confirming my belief that the OE hub will do.