sm465/Atlas 4 speed combo (1 Viewer)

[matchan420]

I want to get lower gears with more options than my current set up with my 2f, h42 and Orion. After a lot of research and disapointment from marlin(no toy boxes available) I am considering getting a sm465/atlas 4 speed combo.

A little info on my rig-

Throttle body injected 2f, h42 , Orion, 4.88 diffs and 37inch tires, may go 39 eventually and fj80 rear axle..

I understand that first gear in the sm465 is not synced and can be a burden at times. With that being said, I think having the option of 3 separate low tc gears I could wheel primarily in 2nd and 3rd gear saving 1st gear for real technical obstacles.

The sm465/Atlas 5.4:1 will give me options of-

1st gear -63.9:1, 86.9:1, 173.8:1
2nd gear -34.9:1, 47.5:1, 95:1

The sm465/Atlas 10.3:1 will give me options of-

1st gear -86.9:1, 121.4:1, 329:1
2nd gear -47.5:1, 66.38:1, 179:1

I would prefer to stay with my h42 and strap on an atlas, but cant find a way to do it. The only reason I am switching to sm465 in so I have the Atlas option and to get a nice flat belly. The Atlas 4 speed also costs the about the same as an orion/toybox combo and it is about the same length.

Does anyone run this setup, and does anyone have any other reccomendations of a way to get an Atlas behind a 2f?


Thanks.

 

[EWheeler]

The cost increase is significant, but what about NV4500 & atlas 4 speed? I daily drive a truck with an sm465 and despise that transmission. For a vehicle like a 40 that you should enjoy driving, I don't think the 465 is a good fit. I understand the cost, availability, gearing options, and ease of the swap, but I just hate driving that transmission.

I thought I saw your rig for sale on Pirate. Change of heart?

 

[EWheeler]

Or H42 - NP203 2:1 doubler - Atlas 2 speed in whatever flavor you like.

 

[matchan420]

The cost increase is significant, but what about NV4500 & atlas 4 speed? I daily drive a truck with an sm465 and despise that transmission. For a vehicle like a 40 that you should enjoy driving, I don't think the 465 is a good fit. I understand the cost, availability, gearing options, and ease of the swap, but I just hate driving that transmission.

I thought I saw your rig for sale on Pirate. Change of heart?

Was for sale, found a way to keep it and keep a happy home. I wish I knew someone with a sm465 so I could decide how deeply I would hate it. I wish someone would step up to the plate and make a serious t-case for h42/h41.

Thanks

 

[matchan420]

Or H42 - NP203 2:1 doubler - Atlas 2 speed in whatever flavor you like.

How much longer is this combo? Can I make a flat belly with this?

 

[Tigerstripe40]

I have been running an SM420 now for about 7-8 years. I know its not the same as the SM465, but similar enough that I figure I can offer some input.

The SM420 was probably the second best mod I did to my FJ40. I got a new old stock unit originally designed for a gamma goat. On the street its essentiall a 3 speed transmission. It doesn't bother me one bit. It shifts as nearly as smoothly as the H42 I took out (I got sick of waiting for the Orion, which had been delayed a year and a half and was still another year or 2 before they were available).

Personally, I want to get a Toybox and then connect that with a split case. But as the OP mentioned, the Toybox isn't available from marlin anymore, and I don't think they will become available from Marlin again.

I don't think there is anything wrong with an SM420 or SM465. Sure its not a 'nice' of a transmission as the H42 or H55, but the trade off of the low cost and low gearing is certainly no big issue, especially on a Hardcore rig.

 

[Tigerstripe40]

How much longer is this combo? Can I make a flat belly with this?

6.5" according to Advance Adapter.
However, you will need to find an adapter from the H42 to the NP203. I am not seeing any options for that on AA's web site.

 

[matchan420]

6.5" according to Advance Adapter.
However, you will need to find an adapter from the H42 to the NP203. I am not seeing any options for that on AA's web site.

Thanks, I have only found adapters for gm trans...

 

[EWheeler]

Search Jerry Nichols here on mud for info on the h42 to 203 adapter.

 

[EWheeler]

Was for sale, found a way to keep it and keep a happy home. I wish I knew someone with a sm465 so I could decide how deeply I would hate it. I wish someone would step up to the plate and make a serious t-case for h42/h41.

Thanks

How is the Orion not a serious t-case? Pretty bad ass in my opinion if you are set and determined to keep it yota based on all of our other options. I would opt for the 3:1 if I was to go that route, 4:1 or 1:1 are just too big of a spread without a doubler. I love my h42-rock box-4 speed case gearing options in my 40. I really wish they made the 3.4:1 rock box to mate up to the split case. From what I have seen, the split cases really hold up to some abuse. I am a bit nervous about the 4 speed t-case, but my driving style reflects my concerns.

 

[bustanutley]

Any reason you arnt considering poping in an h41?

 

[matchan420]

How is the Orion not a serious t-case? Pretty bad ass in my opinion if you are set and determined to keep it yota based on all of our other options. I would opt for the 3:1 if I was to go that route, 4:1 or 1:1 are just too big of a spread without a doubler. I love my h42-rock box-4 speed case gearing options in my 40. I really wish they made the 3.4:1 rock box to mate up to the split case. From what I have seen, the split cases really hold up to some abuse. I am a bit nervous about the 4 speed t-case, but my driving style reflects my concerns.

I am not down on the Orion, it was the first big item I put in my 40, but I am at wits end with the fact there isn't other options for the h42/H42. It is what it is. My main goals are to have a flat belly and not have a ton of adapters/connections. My driving style also reflects my concerns, but I wish I wouldn't have to test my clutch do avoid stalling in the tough stuff. I would prefer to stay Toyota and avoid anything except a aftermarket tcase, that's why I am staying away from a chev eng swap, I love my 2f and h42.


Thanks

 

[matchan420]

Any reason you arnt considering poping in an h41?

This way my initial plan, still an option...I would like more options in my gearing. Seems like 95:1 wwould be nice, but the next lowest option of 55:1 isn't very flexible.

 

[jefishing]

Matt,
I run a 465/2.28 toybox/split case in my rig. In SD I usally ran the trails in 2nd or 3rd gear with the toybox in. You have a ton of options for gears but there are some draw backs to it. If I was to do it agian I would run a auto with a Atlas. Watching the auto guys it seems so effortless. With all those dam gears it seems like I am always searching for the right gear driving down the trail and maybe thats beacuse there is to many. It seems I am always to fast or two slow but when it comes to the climbing or tech sections of trail it's 2nd gear and drive like you stole it. For the steep down hills or coming down tech sections 1 st gear and not worry hell most of the time I have to use the gas. In town the 465 really does'nt bother me cause I know its not a sports car even though I drive it like one. Due to the low gear and 4.88's it's about 65 down the highway at 3000 rpm which is plenty fast for me. Crap after reading this maybe I like more than I thought

 

[bustanutley]

Gear steps from first to second in granny low transmission going up by a factor of 2 is pretty typical. You'll be in the same boat with an SM trans, I always thought it was fine. I don't think you'll want to be shifting your transfercases a ton.

To me the SM transmissions are a drag. They are a great cheap way to get low gearing but once you start added high dollar performance parts to the drivetrain their janky operation leave you doing

A 2F/203/atlas sounds like a really long proposition and remember the rear output of the atlas is in line with the crank, = really high. Getting a rear driveshaft to work with the rear axle still in the confines of the truck is going to be pretty tough. When my 40 was F/sm420/atlas the drive shaft angle was pretty extreme. A 2f/203/split case is much more doable.

But, I really think the H41 or (H55 if that is an option?) is your best bet. I think the gearing will be good and shifting will be good and you won’t be out a ton of cash. Further from that, Motor swap enters the equation. My 2uz/auto/atlas kicks ass.

 

[Tigerstripe40]

Further from that, Motor swap enters the equation. My 2uz/auto/atlas kicks ass.

This is what I think I want to do with mine, eventually.
That and a 609 front end and full floating rear end.
Now, where to come up with the cash...

 

[matchan420]

Thanks for all the feedback. Maybe an h41 for now and save, save, save for a v8 swap 1uz-fe?

 

[mookie]

if you look in the thread here in hardcore that i just started about custom 14B parts, that guy Ryan can make an adapter for pretty much anything for cheap.....give him a call. He made one of my buds a sweet clockable th400 to D300 adapter and he cut down and resplined the output shaft on the th400 to fit the D300.

I also have a friend who just swapped his sm465 out for a automatic, he has the sm465 and the adapter for the sm465 to atlas for sale, if you interested pm me and i'll get you his phone number.