292 Chevrolet with SM420 Conversion (1 Viewer)

[975diesel]

Greetings All,

I am installing a Chevrolet 292 with a Chevrolet bell housing and a SM420 in my FJ40. Upon calling Advanced Adapters, I was informed that they only offer a 4.5” transfer case adapter (for use with a 350), which is waaay longer than I need. They do not offer a shorter transfer case adapter, but informed me that another adapter company may offer a shorter model.

Does anyone know of a company that make a shorter transfer case adapter, that will work?

Thanks in advance for your time.

 

[RockDoc]

Extreme bends in Vancouver offers a plate adapter for SM420 to the stock "one piece" transfer case. I'm not sure they have it on the shelf all the time though. Off the top of my head it's 3/4" thick.

 

[975diesel]

Extreme bends in Vancouver offers a plate adapter for SM420 to the stock "one piece" transfer case. I'm not sure they have it on the shelf all the time though.

Many sincere thanks! I’ll call them tomorrow.

 

[too tall]

SOLD - Toyota FJ40 420 Adapter

I have a new never used 420 to 3speed extreme bends adapter and install kit. 225.00 and you pay shipping from Marysville Wa

forum.ih8mud.com

 

[RockDoc]

Help comes so slow on this forum some times

 

[975diesel]

SOLD - Toyota FJ40 420 Adapter

I have a new never used 420 to 3speed extreme bends adapter and install kit. 225.00 and you pay shipping from Marysville Wa

forum.ih8mud.com

Just a quick question. I‘m a bit out of my depth on this subject. How is the flow of power transferred from the transmission to the transfer case? Is there an addtional part or coupling that needs to be utilized with the adapter?

 

[RockDoc]

The output shaft reaches through the adapter and into the transfer. First pic shows the input gear of the transfer engaged onto the output shaft of the SM420 (before retaining hardware), second pic shows the geartrain mated up before going into my FJ55.

 

[975diesel]

The output shaft reaches through the adapter and into the transfer. First pic shows the input gear of the transfer engaged onto the output shaft of the SM420 (before retaining hardware), second pic shows the geartrain mated up before going into my FJ55.
View attachment 2512093View attachment 2512095

Many thanks RockDoc! So just to be clear, the output shaft of the SM420 will engage the metric input gear of the Toyota transfer case without any modification? Also, can the Advanced Adapter twin stick conversion be used with this configuration?

 

[RockDoc]

10 spline shaft to 10 spline input gear - yes (may be a tight fit between), but my knowledge is limited to the 2 2wd SM420s I've worked with. I'm limited to the "3-speed" version of the transfer case as well, not sure if there's any functional difference with a 4-speed version. There are good threads on here that detail the use of a plate adapter, but my search skills on my phone aren't up to the task of finding one quickly.

 

[pbgbottle]

Nice I love that thin adapter. Looks great.

 

[975diesel]

10 spline shaft to 10 spline input gear - yes (may be a tight fit between), but my knowledge is limited to the 2 2wd SM420s I've worked with. I'm limited to the "3-speed" version of the transfer case as well, not sure if there's any functional difference with a 4-speed version. There are good threads on here that detail the use of a plate adapter, but my search skills on my phone aren't up to the task of finding one quickly.

That‘s excellent information! Do you know if that configuration will work easily with the Advanced Adapter’s twin stick conversion?

 

[RockDoc]

I built my own twin stick setup.... no familiarity with AA's.

 

[Dizzy]

@Roc Doc
Did you start with a 4-speed or 3-speed? What is the overall length with the EBI adapter of the transmission?

 

[FJ40Jim]

Many thanks RockDoc! So just to be clear, the output shaft of the SM420 will engage the metric input gear of the Toyota transfer case without any modification?

Just to be clear, the SAE standard 10 spline that toyota used in the early transfer cases and early clutches is a standard thing.
When they modernize to fine spline clutch hub on a 3B engine or a 19 spline transfer case input, then it's bespoke metric sizes.

 

[RockDoc]

@Roc Doc
Did you start with a 4-speed or 3-speed? What is the overall length with the EBI adapter of the transmission?

Was a column shift 3-speed truck with no installed drivetrain when I got it. SM420 is mated to a "3-speed" case. I'll try to remember to crawl under and measure for you this afternoon..

 

[RockDoc]

SM420 is a hair under 10-1/2" between front and rear mating surfaces, adapter is 3/4" thick.

 

[Dizzy]

H42 is 11.875" I assume that the bellhousings are the same length. I think that the 4-speed transfer is a tad wider, IIRC.

 

[FJ40Jim]

H42 is 11.875" I assume that the bellhousings are the same length. I think that the 4-speed transfer is a tad wider, IIRC.

Wider than what?