NP241 TRANSFER CASE SUPPORT ROD

[Fabman]

Not trying to be sarcastic...but what SPECIFICALLY does the Transfer Case Support Rod actually do?

 

[nvrenuf]

It supports the transfer case.






Sorry, I had to.

I’ve never read a legit reason but I believe it’s to protect the tcase in the event of the front driveshaft bottoming out and pushing back on the tcase.

 

[HotRodPC]

Not trying to be sarcastic...but what SPECIFICALLY does the Transfer Case Support Rod actually do?

SO LONG AS, you kept all your motor and trans mounts tight, Crossmember bolts tight, as well as your bell housing bolts, then you should be OK without the rod. However, I'll assure you, it serves a purpose that GM thought necessary or they would not have spend the money and time to install it. Think of the millions they'd have saved by not installing it on all the 4x4 trucks they built. BUT, then there's this. Could it have been used to keep the Tcase, Trans and Engine all stable as it traveled down the assembly line and once mounted in the truck it really was needed? There are some thing that do work like that. Not sure if this is one of those or not. But I like to think anything that people say, Ohhh you don't need that, yes you do or GM wouldn't have spend the money and time to engineer it, the cost to have it to have it made, the time to install it, etc if it was NOT necessary. While all that is true, it is also true some parts are for just assembly purposes and it's worth it for GM to have those parts just to make it down the assembly line and held in place until bolted into it's permanent home, and then yes, it wouldn't be necessary any longer.

Point being, if you have it use it, if you don't, I wouldn't lose sleep over it.

 

[Ricko1966]

I am not familiar with all the different versions of transfer case support rods. I do know the purpose of some of them,so look at your application and use your head. They keep the transfer case from using leverage,inertia,or impact and moving forward or back,which would/could crack your transmission case. A good example would be you go into a Ditch a little harder than you wanted the frame twists a little and the transfer case pushes forward, but it going forwards tries to bend the transmission. So the brace is there to keep the distance from the back of the block to the transfer case constant.So you don't crack your transmission case.

 

[Fabman]

Lots of interesting responses to this question.....and all above posts have validity....And NO I don't have one - the prices in EBAY for this piece of round stock is OUTRAGEOUS !
My build is a bit different - certainly not a factory set up... My distances between the tcase and trans is not the stock set up - so I will have to fab my own . THANKS for all the info Guys !

 

[fast 99]

Torque is your enemy here. Aluminum bell housings both automatic and manual really aren't that strong. I had to replace bell housings on our tow trucks every 2-3 clutches. They would warp and become off centered to the pilot causing early clutch failure. These were 3500 HD 2WD trucks. Not the same application as yours but as stated previous GM wouldn't spend money on an additional 1" of wire if they didn't have to. That brace is needed.

 

[CalSgt]

Torque is your enemy here. Aluminum bell housings both automatic and manual really aren't that strong. I had to replace bell housings on our tow trucks every 2-3 clutches. They would warp and become off centered to the pilot causing early clutch failure. These were 3500 HD 2WD trucks. Not the same application as yours but as stated previous GM wouldn't spend money on an additional 1" of wire if they didn't have to. That brace is needed.

I think GM solved the issue with the LS platform because they don’t have them on the GMT800’s…. Full bell housings that bolt into cast oil pan at the bottom make the drivetrain more rigid I guess

 

[idahovette]

I think GM solved the issue with the LS platform because they don’t have them on the GMT800’s…. Full bell housings that bolt into cast oil pan at the bottom make the drivetrain more rigid I guess

Yeah, maybe.......I guess all my sh!t is gonna break........

 

[fast 99]

I think GM solved the issue with the LS platform because they don’t have them on the GMT800’s…. Full bell housings that bolt into cast oil pan at the bottom make the drivetrain more rigid I guess

Makes sense, there must have been a design weakness. K cases had those two additional braces that are a PITA to install and always in the way.

 

[Mike Gresham]

The rod was designed to prevent the transfer case from being torn from the transmission if the front axle were to be driven backwards from impact or catastrophic spring flex thereby causing the front driveshaft to compress beyond its ability to compress via the slip yoke. If & when the front driveshaft reaches its maximum compressibility and is pushed further rearward, it then exerts a direct impact to the transfer case, which in theory could fracture the 4-bolt attachment to the transmission adapter.

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[Fabman]

The rod was designed to prevent the transfer case from being torn from the transmission if the front axle were to be driven backwards from impact or catastrophic spring flex thereby causing the front driveshaft to compress beyond its ability to compress via the slip yoke. If & when the front driveshaft reaches its maximum compressibility and is pushed further rearward, it then exerts a direct impact to the transfer case, which in theory could fracture the 4-bolt attachment to the transmission adapter.

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Wow...Great Info Mike! Thanks !

 

[nvrenuf]

Man, I wish I had said that….

 

[HotRodPC]

The rod was designed to prevent the transfer case from being torn from the transmission if the front axle were to be driven backwards from impact or catastrophic spring flex thereby causing the front driveshaft to compress beyond its ability to compress via the slip yoke. If & when the front driveshaft reaches its maximum compressibility and is pushed further rearward, it then exerts a direct impact to the transfer case, which in theory could fracture the 4-bolt attachment to the transmission adapter.

You must be registered for see images attach

And so there you have it !!! Seems to make sense to me. I'd say you'd have to seriously be gettin' down with some wheelin' for this to me necessary, but it can sure happen. I'm glad I have one now., Or at least I thnk I do. Mine will be going from an NP208 and Th400 to a Big Block Fo Fitty Fo. Maybe with an RV cam, but very mild for sure. Nothing crazy.

 

[bucket]

I think GM solved the issue with the LS platform because they don’t have them on the GMT800’s…. Full bell housings that bolt into cast oil pan at the bottom make the drivetrain more rigid I guess

They also have IFS and a front shaft that doesn't really move much at all. I don't remember any GMT400's having the support rod?

 

[CalSgt]

They also have IFS and a front shaft that doesn't really move much at all. I don't remember any GMT400's having the support rod?

I guess they only had the bell housing support rods from the motor mounts, I was thinking they had the TC support too