NV4500 to HF2AV Open Source Adapter Plans

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Dec 23, 2013
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About a year ago I decided to build my own adapter for the NV4500 to HF2AV. I'd now like to share the plans that I used to build my adapter with anyone interested. I built this adapter and ran it in my 6BT powered cruiser without issue. However, I am not in the adapter business. and would encourage everyone to do their own homework etc. Please do your research etc and use these files as a jumping off point.

DISCLAIMER: Use at your own risk. Poster accepts no liability for damages resulting from use or misuse of these files :)

Hate that stuff...but just want to be clear :)

Ok...here's the fun stuff! Building an adapter to put the NV4500 onto the HF2AV is SUPER EASY!!!! There are really two parts to the adapter: 1) a new main shaft for the NV4500 and 2) the adapter plate to bolt the NV4500 to the HF2AV. I've attached files for both parts to this post.

Part One: The Shaft

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To make the shaft buy a new 2wd mainshaft from your favorite parts vendor. I bought mine of ebay from a vendor in Texas I believe. I recommend buying a kit that includes all the syncros, bearings etc for the NV4500 as well because you are going to have to pretty much tear the transmission all the way down to put in the new shaft so might as well freshen it up while you are in there. Don't be intimidated by this...there are TONS of youtube videos on how to rebuild the NV4500 as well as books etc. It was a fun and straightforward job! Anyways, back to the shaft. You'll need to cut about 3.25" (assuming dodge trans...the chev is 2" longer I believe so make changes accordingly) off its length and then have the 19 splines for the HF2AV machined into the shaft. Most machine shops could do this if they wanted but its a lot of set up if you don't do it everyday. I recommend you ship your shaft to Dutchmen Motorsports in Idaho. They specialize in axle and transmission shafts and can do this no problem (they did my shaft and I've attached the drawing from them). I don't want to put a price in the post as I'm sure things change...but it was cheaper than I expected. They do like it if you can send in your input gear (or a spare) from the HF2AV so they can cut the shaft for a perfect fit. Once you get your shaft back, tear down the trans and install.

Part Two: The Plate

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The plate is made out of 1" thick material. I made mine out of 6061 aluminum, but you could use steel as well. The side of the plate towards the NV4500 has a boss machined into it that locates the plate on the output of the NV4500 using the internal bore of the output housing on the NV4500. The HF2AV is centered using two 12mm dowel pins (amazon). I measure their location with respect to the bore with a Coordinate Measuring Machine so these should be pretty good dimensions. These are the only real critical dimensions as the rest are just bolt holes with clearance. Any shop should be able to make this plate for you. I made it on a manual mill using a rotary table and DRO. If I were going to do this for real I would have them water jetted, lasered, and/or CNC'd. Finally you need to order the factory seal for the trans to tcase in the toyota application and have this pressed into the center of the plate. I believe the correct toyota number is: 90311-48016. This seal has a 62mm O.D. Make sure your machinist makes the ID of the plate a light press for that seal.

Note: When I was done and assembled the plate I realized I should have cut more of a profile to match the tcase on the passenger side of the vehicle. The result was I needed to grind off a bit of the plate where it contacted the tcase. I'd love to modify the drawing for this, but alas I have sold the truck and don't know how much. It wasn't much but just thought I'd note it here.

Dodge vs Chev NV4500
This adapter was built using an early Dodge gas NV4500. I believe all the important dimensions for this swap for all the dodge NV4500's are the same. However, the chev uses a longer tail housing...about 2" longer I believe. Also if you use a chev NV4500 you should check the internal dimension of the housing to make sure it matches up with the boss on the adapter plate as that locates the transfercase on the mainshaft. I believe there may be a difference in the clocking of the bolt pattern between dodge and chev for the NV4500 so you should check that as well. I'd recommend using the dodge as I was able to use STOCK drivelines etc by doing so in my FJ80. However, I plan to do an LS swap in an 80 in the future and will use a variation of this adapter to mate a chev NV4500 to the HF2AV.

Assembly
Assembly is pretty straight forward. I used grey rtv on both sides of the plate and had no leaking issues.

I hope this is helpful for folks. Here is my build thread if you want details about doing this in an 80.
6BT/NV4500/HF2AV Build Thread - New Adapter

Many thanks to wheelingnoob, mrcimmaron, and mryanangel for pioneering this! I am not on mud much these days as I'm building an expo rig over on expedition portal so I may be slow to respond to questions.
 
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Joined
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oh wow thanks for posting. although I probably wont have a need for this in the future I'm certain others will and this is excellent info!

also a plug for Dutchman motorsports. They did an amazing job cutting some long splines into a front axle for a cable locker install I did. Very reasonable pricing.
 
Joined
Aug 18, 2017
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Austin, TX
Is anyone interested in ordering some parts?

I'm thinking about giving dutchmen motorsports a call and ordering the output shaft. Might get better prices in quantity.
I’m interested in an output shaft. I dont have a core though.
 

cody c

 
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I'm thinking to just call dutchmen motorsports, offer to put down a deposit for the cost of the ebay parts and some towards machining maybe. And see what they will charge for doing multiple shafts.

If they can source cheaper than ebay then more profit margin on their end.

I'm content on just doing the first component, then ordering the adapter plates from whatever machine shop(s) a bit further down the road when I've got some more budget, that may or may not be ideal for you gents, but I'm in Canada so I may get better pricing without shipping from local anyways.

Your thoughts?
 

PAToyota

Keystone Cruisers
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so now we need an adaptor from 1hdt to NV4500 and all is set!
Why do you need to adapt an NV4500? Doesn’t Toyota make a 5-speed that is bolt-on for the 1HDT and HF2AV into the 80 series?
Except that the 1HDT being asked about isn't a Cummins…

I understand the Cummins/NV4500/HF2AV setup, but less reason to go 1HDT/NV4500/HF2AV when there are Toyota 5-speed options that will bolt to both the 1HDT and HF2AV stock.

[EDIT] Sorry, guess there aren't really Toyota 5-speed options in the US market.
 
Joined
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so now we need an adaptor from 1hdt to NV4500 and all is set!
Except that the 1HDT being asked about isn't a Cummins…

I understand the Cummins/NV4500/HF2AV setup, but less reason to go 1HDT/NV4500/HF2AV when there are Toyota 5-speed options that will bolt to both the 1HDT and HF2AV stock.

[EDIT] Sorry, guess there aren't really Toyota 5-speed options in the US market.
The H151F is a direct replacement transmission for the auto trans for both 1FZ and 1HD motors. It is available for purchase brand new from Toyota. The only reason to use the NV4500 is for a Cummins swap.

Maybe I’m missing something? Are you trying to save money by using the NV4500 instead of the H151F?

80 Series H151F 5 Speed Manual Transmission Swap - Includes RHD HDJ81 & LHD FZJ80

Toyota H151F 5 Speed Transmission [H151F] - $4,995.00 : CruiserParts.net, Toyota Landcruiser Parts
 

cody c

 
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5 big bills for a toyota 5 speed. Rudiculous, I would go with an adapter to a NV4500 as well if I had a 1HDT with auto.


Anyways, seems like the thread direction is more interested in talking about different adapter options than getting an NV4500 to HF2AV adapter components ordered. I'll leave it be.
 

cody c

 
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I'll call in the next day or two, maybe just ask for pricing if 2 or 3 are cut.

Also got some pricing for the adapter plate from china (alibaba), don't know what shipping and duties would be yet, but the initial pricing for 3-10 units looks pretty good.

I did change the ID of the seal hole for the CAD file (not the one linked above) to make it 61.8mm for the 62mm seal. not sure if that would be too tight, but it may be something adjusted quickly with the right power tool.

Edit:

One of the vendors on alibaba quoted $65 a piece for the adapter, and $50 shipping (each) but with duty not included for a 3 unit order. $17 less combined ($98) on a 10 unit order)

Being that I'm in Canada and most of you are in the US, it would probably be cheaper to ship to one person central there, and then network ship out. I need to check there quote info to make sure the scale and thickness is correct.
 
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cody c

 
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Im looking at a local source for adapter plates, price looks like $142USD /$186CAD a piece for me in Calgary. The order will probably go in shortly, I have two fellas that want in. If anyone else is serious, "last chance for underpants!" cause this order will go in (adapter plates ONLY) shortly.
 

Mr Cimarron

DRIVE, BREAK, FIX, REPEAT
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Im looking at a local source for adapter plates, price looks like $142USD /$186CAD a piece for me in Calgary. The order will probably go in shortly, I have two fellas that want in. If anyone else is serious, "last chance for underpants!" cause this order will go in (adapter plates ONLY) shortly.
Thats a good price! I'm still holding out to see if my friend can do it for a case of beer.
 
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