700R4 transmission in a HMMWV

Steel Soldiers is supported by:

Mogman

Member
87
8
8
Location
Papalote, TX
I have this question too.
If the input gear (NP218) is changed to a 27 spline then the stock NP241/700R4 transmission/transfer case adapter and original 27 spline 700R4 output shaft should work yes?
I have not been able to find a 32 spline output shaft but only the $500 Advanced Adapters kit for direct adaptation to the 32 spline NP218,
27 spline NP208 input gears are plentiful (same gear as the NP218)
 
Last edited:

87m998

Member
50
0
6
Location
Idaho
Best bet call advance adapters and they can explain all. I only had the short shaft, plate 4 bolts and o ring when I put mine together. The adapter plate can be mounted to the 700r4 two ways but only fits up to the 218 one way. With this set up no driveshaft mods are required. Hope that helps a little.
 

jdknech

Active member
1,096
4
38
Location
Jeffersonville, Indiana
I went with a 700r4 in my m998 a couple years ago. I used the kit from advanced adapters to mate it to the factory np242 transfer case, and had a local (trusted) trans shop build it to diesel specs. Hardest part was making the TV cable bracket. I would not recommend towing with it, but it was definitely worth the effort
 

Lazboytt

Member
Steel Soldiers Supporter
178
2
18
Location
Michigan
I went with a 700r4 in my m998 a couple years ago. I used the kit from advanced adapters to mate it to the factory np242 transfer case, and had a local (trusted) trans shop build it to diesel specs. Hardest part was making the TV cable bracket. I would not recommend towing with it, but it was definitely worth the effort
Do you have the part number for the adapter kit? Besides that adapter and having the trans built for a diesel truck and the TV cable bracket is there anything else that needs to be done?


Sent from my iPhone using Tapatalk
 

jdknech

Active member
1,096
4
38
Location
Jeffersonville, Indiana
Do you have the part number for the adapter kit? Besides that adapter and having the trans built for a diesel truck and the TV cable bracket is there anything else that needs to be done?


Sent from my iPhone using Tapatalk
I don’t have the part number handy, it wasn’t hard to find on there website though. I did have to change out the flexplate, but everything else bolted right up.. even the trans crossmember didn’t have to be modified, and the driveshafts bolted right back in place
 

jdknech

Active member
1,096
4
38
Location
Jeffersonville, Indiana
Do you have the part number for the adapter kit? Besides that adapter and having the trans built for a diesel truck and the TV cable bracket is there anything else that needs to be done?


Sent from my iPhone using Tapatalk
 

Lazboytt

Member
Steel Soldiers Supporter
178
2
18
Location
Michigan
Anyone know if there is a tv cable bracket available that would work or best way to make one?

I’m a novice with this so looking for any info.
The link to the kit is great information and should be stickied


Sent from my iPhone using Tapatalk
 

Lazboytt

Member
Steel Soldiers Supporter
178
2
18
Location
Michigan

suzukovich

Member
Steel Soldiers Supporter
334
18
18
Location
Gibsonton Fl
Not mistaken these are the guys who came up with the conversion kit for the HMMWV. I haven't done it yet but do know some who have and love it. You will have to get a new shifter. Transmission also comes with a park brake. Call them. Hopefully some will chim in who have done the conversion.

Sent from my SM-J727U using Tapatalk
 

USCDOC

New member
7
0
1
Location
CA
I’m in the middle of this 3L80 to 700R4 1D1EDF25-2A60-4158-B16E-A3C9622E98D4.jpegconversion. I used Monster transmission bc I thought they were legit. DO NOT USE THEM. I figured by using someone like them that’s been on TV and all that I would be getting a very squared away product. It turns out that I had to replace the output shaft because the wrong one was put in, that was easy, but multiple internal parts were USED and worn out requiring replacement. Only $500 to fix it. The reason why I paid for it is because they will not return my phone calls to honor the warranty for a tranny I haven’t even used yet. They also said they were installing a billet input shaft which was a complete lie. I had to reverse the $777 charge on my credit card. Terrible company. Terrible customer service. I did run into having to change the flex plate and the transmission crossmember does not lineup. The transmission support mount that they sent does not work either because it is not tall enough. I’ve seen that many people have said it does and it certainly does not. Going to have to modify this one(move it forward about 2 inches. That’s either going to require drilling new holes in the frame for the crossmember, or welding on an adapter plate. I have the advanced adapters kit and all lines up well otherwise. Any advice on crossmember modification? Looks like I will have to drill holes in the foot wells of the rear passenger area in order to get the bolts that go through the frame that hold the crossmember mount out. Tips or pointers? Tia
 

87m998

Member
50
0
6
Location
Idaho
I’m in the middle of this 3L80 to 700R4 View attachment 787745conversion. I used Monster transmission bc I thought they were legit. DO NOT USE THEM. I figured by using someone like them that’s been on TV and all that I would be getting a very squared away product. It turns out that I had to replace the output shaft because the wrong one was put in, that was easy, but multiple internal parts were USED and worn out requiring replacement. Only $500 to fix it. The reason why I paid for it is because they will not return my phone calls to honor the warranty for a tranny I haven’t even used yet. They also said they were installing a billet input shaft which was a complete lie. I had to reverse the $777 charge on my credit card. Terrible company. Terrible customer service. I did run into having to change the flex plate and the transmission crossmember does not lineup. The transmission support mount that they sent does not work either because it is not tall enough. I’ve seen that many people have said it does and it certainly does not. Going to have to modify this one(move it forward about 2 inches. That’s either going to require drilling new holes in the frame for the crossmember, or welding on an adapter plate. I have the advanced adapters kit and all lines up well otherwise. Any advice on crossmember modification? Looks like I will have to drill holes in the foot wells of the rear passenger area in order to get the bolts that go through the frame that hold the crossmember mount out. Tips or pointers? Tia


Knew there was something wrong with your pic LOL, the cross member bolts to the xfer case not the trans. All will be well when you mount the xfer case.
Cheers
 

Awol

Member
276
14
18
Location
MA
Monster Transmission is pretty awful. They built their company on paid advertising and sponsoring tv builds.

Not the first time I've heard of them using used and worn out parts in a "rebuilt" transmission.
 

USCDOC

New member
7
0
1
Location
CA
Omg I feel so dumb!!! Thanks so much. I was confused bc they sent a transmission mount with the transmission that is not necessary! Ha! Happy I don’t have to deal with that. Do the 2 extra wires coming off the 4L80 shifter hook directly to the 2 wires out of the transmission? Does it matter which?
 

87m998

Member
50
0
6
Location
Idaho
The wires coming from the shifter connect to the three wires you disconnected from the old shifter. Neutral saftie switch and such. I only had one connector coming off my 700r4 which I hooked to a 12v source from the gen for the lockup.
 

USCDOC

New member
7
0
1
Location
CA
The wires coming from the shifter connect to the three wires you disconnected from the old shifter. Neutral saftie switch and such. I only had one connector coming off my 700r4 which I hooked to a 12v source from the gen for the lockup.
Oh cool. I guess you used the old shifter? I say that Bc there are 5 wires off the new HMMWV shifter that came with the 4L80E transmission in the M998. 3 are the same. Wondered if it was reverse lights. That would be awesome bc I have a separate switch for that
 

87m998

Member
50
0
6
Location
Idaho
My new shifter only has three wires for ind lights and saftie switch. Would not know what the other two are for.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks