GS450H Adapter Plate

Topics concerning the Toyota and Lexus inverter drop in boards
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robertwa
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Re: GS450H Adapter Plate

Post by robertwa »

HerbP wrote: Mon Nov 03, 2025 3:07 pm Just curious if you ever created an updated DXF? I was just about to send one of these off for mfg.
@HerbP, the LS600H bellhousing is a completely different shape than the GS450H
Building: 1964 International Scout 80. LS600H transmission with ZombieVerter, B250e battery pack
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Re: GS450H Adapter Plate

Post by jrbe »

HerbP wrote: Mon Nov 03, 2025 3:07 pm Just curious if you ever created an updated DXF? I was just about to send one of these off for mfg.
It's been a while since I looked at and worked on this. If I remember right I drew most of this up but there were some missing dimensions to finish it.

If there's interest in this and you can wait a couple weeks I can help on the cad side. If that works let me know the dimensions / confirm what's here.

I drew up some z bends for the ninja star/ spline hub. It can also work with solid spacers.
I also made a pem nut / weld nut plate that floats a bit to allow for some error in manufacturing / positioning to allow some wiggle while tightening down.

There were also questions about mounts hanging off this plate to help the overall build. A few extra holes while it's being cut aren't much extra. I can do a few simple configurations too if it makes sense.
If someone has a large digital vernier that would help with alignment feature references.

And if you guys have the ls600h bellhousing pattern and can share it, I can make that version too.

You can get thin sheet laser cut fairly cheap to verify dimensions.

I'm in CT USA down by the shore (Madison area) if anyone is local that has one or both. Or share a 3D scan, cardboard template, etc. and I may be able to work from that.
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HerbP
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Re: GS450H Adapter Plate

Post by HerbP »

jrbe wrote: Tue Nov 04, 2025 10:22 am And if you guys have the ls600h bellhousing pattern and can share it, I can make that version too.
Another forum user just did a 3D scan of the ls600h transmission and transfer case. I'll let him chime in to offer up the file. I was going to take my ravigneaux section down to a friend's place to have the tail end of the transmission scanned and can also have him scan the bellhousing but maybe the other user can get the file to us sooner. It's a 4hr drive though so I've been putting it off.

I might also be able to figure out how to import his 3D scan into On-Shape and create a body from it but this is new territory for me.

I turned my own adapter from a Toyota 3B clutch disc (same splines) with intent to weld it to the bellhousing plate.
PXL_20251102_161919756.jpg
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Re: GS450H Adapter Plate

Post by tmhb16 »

Here's the 3d scan of the LS600H. Not the best quality but may be good enough to work from.

https://drive.google.com/drive/folders/ ... drive_link
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Re: GS450H Adapter Plate

Post by HerbP »

tmhb16 wrote: Wed Nov 05, 2025 3:19 am Here's the 3d scan of the LS600H. Not the best quality but may be good enough to work from.
Well, I was unable to get OnShape to load the .3mf bellhousing before it ran out of Browser Memory, so I guess it'll have to be someone with an actual CAD program.
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Re: GS450H Adapter Plate

Post by jrbe »

tmhb16 wrote: Wed Nov 05, 2025 3:19 am Here's the 3d scan of the LS600H. Not the best quality but may be good enough to work from.

https://drive.google.com/drive/folders/ ... drive_link
I downloaded the files, thanks for sharing them. Bellhousing looks pretty good, thats all i've opened so far..
image.png
Should be enough to work from
image.png
The pin doesnt have enough scan data to use and the other pin is not in the transmission / scan. I dont think anyone is worried about the pin for this.

Last up are holes for mounts. Need some input here on what people are doing / need / want.

It will be a while before I get to this.
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HerbP
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Re: GS450H Adapter Plate

Post by HerbP »

I was planning to make a custom cross-member that bolted to existing bolt holes on the bell housing so I don't need anything special and if others want ears or what have you, I can always cut them off or use them. I would likely have to modify whatever design to adapt my clutch plate adapter anyway or I can draft a plate to adapt to your design.

In short, I'm flexible. I have all the room in the world.
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Re: GS450H Adapter Plate

Post by jrbe »

HerbP wrote: Tue Nov 04, 2025 1:53 pm I turned my own adapter from a Toyota 3B clutch disc (same splines) with intent to weld it to the bellhousing plate.
PXL_20251102_161919756.jpg
Gregski wrote: Sun Dec 08, 2024 2:27 pm I actually plan on using eight M10 bolts to hold my star down, 4 in the stock OEM closer to center holes that are already there, and 4 on the outside which we need to enlarge ie drill out
We also don't have the ninja star bolt circles (Greg, which disc is this?) or the 3B clutch hub bolt circle or the hole diameters. I know Herb you plan on welding but it would be nice to have a bolt in option.

Greg mentioned using M10 bolts, did that require drilling?

I'm not sure I ever found confirmed stack heights of the assembly. Not sure if stack height is different 450 to 600.
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Re: GS450H Adapter Plate

Post by Gregski »

jrbe wrote: Thu Nov 06, 2025 1:06 pm We also don't have the ninja star bolt circles (Greg, which disc is this?) or the 3B clutch hub bolt circle or the hole diameters. I know Herb you plan on welding but it would be nice to have a bolt in option.

Greg mentioned using M10 bolts, did that require drilling?

I'm not sure I ever found confirmed stack heights of the assembly. Not sure if stack height is different 450 to 600.
I believe I saw somewhere that we can just use TOYOTA clutch plates which have the same splines, this is on my to do list to find which MAKES will work, I am bumping it up my list now. Anyone know off hand any 2007-12 era manual transmission Toyota car Models or there abouts?

I may pick some up at AutoZone today to try for fitment and then once we have some part numbers...

Top Tip: To find a discount on a clutch disc from RockAuto, use the "Wholesaler Closeout" section on the website to see items on deep sale, which RockAuto states is 30% off the normal price. Alternatively, look for "closeout" parts by navigating to the bottom of part categories and clicking on that link.
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HerbP
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Re: GS450H Adapter Plate

Post by HerbP »

Gregski wrote: Thu Nov 06, 2025 2:05 pm I believe I saw somewhere that we can just use TOYOTA clutch plates which have the same splines, this is on my to do list to find which MAKES will work, I am bumping it up my list now. Anyone know off hand any 2007-12 era manual transmission Toyota car Models or there abouts?
I only know about older (80-98) Land Cruiser applications. My notes say:

Toyota 3B/13BT 31250-36230
Toyota 1HZ 31250-60223
Toyota 1HZ 31250-60431 (I believe this number is for all 1HZ's including current ones so you might even find these in the parts system as recent as 2019. However, that might only be available in Australia, or Canada for Mining trucks.)

One sample application should be a 2019 Toyota Land Cruiser HZJ-79. Any model with a prefix of HZJ-* should use that clutch disc in a manual configuration (those are also available with automatics).

My notes from a couple decades ago also say but I can't confirm the truth of it:
Isuzu NPR clutch disc which happens to have the exact same spline and
input shaft size. It's Daikin Clutch number ISD134, Isuzu part number
8-94462-789-3.
I added a note on the GS450H wiki page:

https://openinverter.org/wiki/Lexus_GS450h_Drivetrain
another option is to use the clutch disc from a Toyota 3B (probably also 13BT, 1HZ). These clutch discs have the same 21 spline/diameter configuration. One application is a "1983 Toyota Land Cruiser BJ-60 5spd manual". One Toyota part number is 31250-36230 (there are many depending on vintage) and you will find lots of crosses to 3rd party parts.
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Re: GS450H Adapter Plate

Post by HerbP »

jrbe wrote: Thu Nov 06, 2025 1:06 pm I know Herb you plan on welding but it would be nice to have a bolt in option.
Welding is simple for me but I'm not averse to there being a bolt pattern and I can CAD my own adapter plate to match the bolt pattern you decide on, to mount to my shaft adapter+clutch plate. It just means having two pieces machined instead of one. The advantage to that though is that I can have the lockout plate machined out of aluminum and adapter machined out of mild steel which might be cheaper shipping. Or I can butcher my own adapter plate on my manual mill.

I'm all kinds of flexible.
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Re: GS450H Adapter Plate

Post by jrbe »

You may be able to find one of those plastic clutch disc alignment tools for the gs450h / 600 that has the splines in it and work backwards from what that fits to find clutch discs that could work.
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Re: GS450H Adapter Plate

Post by Gregski »

tried a 2007 Toyota Camry clutch disc and No Dice, the diameter is too small and won't fit onto the Lexus GS450h splines, also the disc is way too small and too flimsy. I plan to try one out of a Toyota truck next.
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Re: GS450H Adapter Plate

Post by robertwa »

Gregski wrote: Fri Nov 07, 2025 9:40 pm tried a 2007 Toyota Camry clutch disc and No Dice, the diameter is too small and won't fit onto the Lexus GS450h splines, also the disc is way too small and too flimsy. I plan to try one out of a Toyota truck next.
Here are a bunch of options:
viewtopic.php?t=1901
Building: 1964 International Scout 80. LS600H transmission with ZombieVerter, B250e battery pack
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