Why not TH400?

[scalpelarms]

Hey guys, Ive searched here and didnt find anyone in the HMWWV area talking about doing a TH400 swap, only the 4l80e swap. My understanding is that the TH400 is not electric and the 4l80e is, from what I see the biggest hurdle on the 4l80e swap is the electronics.

What do you guys think?

 

[Evil Dr. Porkchop]

A TH400 wouldn't really gain you anything.

 

[scalpelarms]

Never mind. I just realized the TH400 does not have a 4th gear.

 

[mkcoen]

If you need just a replacement HMMWV tranny TexAndy has some rebuilt units

 

[scalpelarms]

If you need just a replacement tranny TexAndy has some rebuilt units

Thanks, I was looking at swapping for a 4th gear trans. easier and more cost effective then a 4l80e but I dont see that happening.

 

[Wire Fox]

Thanks, I was looking at swapping for a 4th gear trans. easier and more cost effective then a 4l80e but I dont see that happening.

Some guys have gone the route of a 700R4 transmission since it's an all-mechanical 4 speed; however, it doesn't have the full weight rating the TH400 and 4L80E have, so you really need to consider if the 4th gear is worth sacrificing weight rating. As well, the transmission may be of a different length than any of the current units designed for the HMMWV, so it might involve custom fabrication. I haven't done it or intended to do it, so I never looked into the details of installing one.

 

[tobyS]

How about an Allison 545?

Where is the Indiana group you joined located (besides "Indiana")?

 

[bachman502]

Put an old school sm465 Muncie in it. 4 speed with granny. Then see if your drivetrain could hold up.

 

[Sparo2]

I'm sure a 700R4 would have no problem holding up in this case. I would look for a K-series 700R4 and have it rebuilt with heavy duty components. The K-series cases are thicker and were intended for 4 x 4 trucks which were similar in weight as a HMMWV.

I'm actually in the process of doing this very swap. I have already purchased a K-series transmission and I'm going to install it within the next few weeks. If all goes well I will drop it and rebuild it with heavy duty components. Then put it back in the truck and forget about it. The 700R4 is very similar in capability as the 4L60E transmission and that transmission comes equipped in a lot of full-size trucks weighing the same or a little more than a standard HMMWV.

 

[scalpelarms]

For the amount of "power" these things create. Wouldn't a "built" 700r4 work just fine? The 6.2 isn't a powerhouse, I won't be pulling anything but people and a few dead animals here and there.
The goal is to be able to hit highway speeds of 70-75 max to get to where I need to go. One hour long trips at a time. thats all

 

[Takai13]

700R4's are getting harder to find. And you need to be careful adjusting the TV cable. Not a hard thing, just particular. Wiring in a switch for the lock-up converter is pretty simple to.

It might be more expensive but several companies have some very nice controller set-ups (in the cab) to for adjustment on-the-fly.

Just some thoughts.

 

[kc5mzd]

Put an old school sm465 Muncie in it. 4 speed with granny. Then see if your drivetrain could hold up.

He is not looking for a 4 speed as much as a overdrive. An old muncie with granny gear would work great off road.

 

[Bobert]

I thought the 3 speed M998s came with a TH400. Does it not?

 

[TOBASH]

I'm sure a 700R4 would have no problem holding up in this case. I would look for a K-series 700R4 and have it rebuilt with heavy duty components. The K-series cases are thicker and were intended for 4 x 4 trucks which were similar in weight as a HMMWV.

I'm actually in the process of doing this very swap. I have already purchased a K-series transmission and I'm going to install it within the next few weeks. If all goes well I will drop it and rebuild it with heavy duty components. Then put it back in the truck and forget about it. The 700R4 is very similar in capability as the 4L60E transmission and that transmission comes equipped in a lot of full-size trucks weighing the same or a little more than a standard HMMWV.

http://www.bowtieoverdrives.com/catalog/catalog.php?Action=GETSUBCAT&CATID=B

Not cheap but this will be the route I eventually go. I will consider a better transfer case at the same time.

First fix her up and shake her out. Then upgrades.

T

 

[scalpelarms]

Coming back to this. The th400 does have overdrive gear doesn't it? So that would achieve highway speeds wouldn't it?
Sorry if I sound like I'm beating a dead horse, just trying to simplify the process.

Sent from my SM-G935T using Tapatalk

 

[scalpelarms]

Did some more research. There are some th400s that have overdrive and some that don't from what I've read.

Also I've also found the gear vendors overdrive kit.
Anyone ever used them? Its a $3000 unit but pretty simple it looks.

Sent from my SM-G935T using Tapatalk

 

[86humv]

There is no 3L80 [ 400 turbo ] that has overdrive...that didn't happen until the 4L80E.

 

[kc5mzd]

TH350 wide ratio small block v8 trans
TH400 narrow ratio used with big block larger v8 in heavier vehicles
700r4 one of the first v8 automatic overdrives

4=number of gears l=rear wheel drive? 80=size of vehicle the transmission is used in e=electronic
4l80e 4 speed electronic controll.
4l80 without the "e" was not electronically controlled.
6l80e 6 speed (double overdrive) electronic

3l80 3 speed rear wheel drive...

 

[scalpelarms]

so then you could get a 4l80 and not have to deal with the computer etc.?

 

[Wire Fox]

TH350 wide ratio small block v8 trans
TH400 narrow ratio used with big block larger v8 in heavier vehicles
700r4 one of the first v8 automatic overdrives

4=number of gears l=rear wheel drive? 80=size of vehicle the transmission is used in e=electronic
4l80e 4 speed electronic controll.
4l80 without the "e" was not electronically controlled.
6l80e 6 speed (double overdrive) electronic

3l80 3 speed rear wheel drive...

As far as I know, there is no 4L80...all models are "E" models. The closest thing would be for those that do aftermarket installs of manual valvebodies.