PDA

View Full Version : SM465 Orion


treerootCO
04-16-2009, 12:14 PM
A bit of an update today. This is probably the 5th time I split the transfer case/transmission and dumped all my lube out so....it got fixed. Machined out the adapter to accept bolts instead of the conical hex bolts and will try that for awhile. Each time I take it apart the adapter plate bolts are either broken in half or finger tight. I just don't think they have the clamping force needed. I am also going to remove the transfer case support and let it hang off the transmission. There has been some debate that the rear brace prevents the assembly from moving under torque and was probably why me adapter ate it.

http://forum.ih8mud.com/merchandise-storefront/20446-sm465-6061-alum-early-t-case-bling.html

Uncle Ben
04-16-2009, 12:51 PM
I didn't realize you were using the propeller mount. I can with all certainty tell you that is what is causing your adapter loosening! I have seen it soooooooo many times! If you were using AA's adapter instead of the plate adapter you would have be dealing with a cracked adapter instead of loose/broken bolts! The worthless propeller mount does not allow enough flex so your drive train is becoming a torsion bar!

mtncrsr
04-16-2009, 06:01 PM
I didn't realize you were using the propeller mount. I can with all certainty tell you that is what is causing your adapter loosening! I have seen it soooooooo many times! If you were using AA's adapter instead of the plate adapter you would have be dealing with a cracked adapter instead of loose/broken bolts! The worthless propeller mount does not allow enough flex so your drive train is becoming a torsion bar!

Please excuse my ignorance but is the propeller mount that you are referring to the brace on the back of the t-case that goes from frame rail to frame rail?:confused::confused: That is what I have on the back of my Orion and I had to weld some reinforcing gussets where it mounts to the frame bushing due to cracks in steel brace:eek: Also, If you don't use the brace how is everything supported? I have the SM420 then the Toy Box then the Orion.

Uncle Ben
04-16-2009, 06:16 PM
Please excuse my ingnorance but is the propeller mount that you are referring to the brace on the back of the t-case that goes from frame rail to frame rail?:confused::confused: That is what I have on the back of my Orion and I had to weld some reinforcing gussets where it mounts to the frame bushing due to cracks in steel brace:eek:

The frame on a 40 is designed to flex, thus the reason the cross members are riveted like they are along with the torsional tube cross member mid ship to keep the rails in alignment. The engine mounts through rubber cushions with vertical mounts as well as the bell housing. This also allows some give as the frame flexes. The AA mount (prop) is rigid mounted on the t-case...no flex! The sides of the prop mount are mounted to the frame with hard plastic bumpers......very little flex there. When you twist up the frame it is working as designed and allows flexing like an X....trouble is now you have the drive train secured in 6 places in about 4' of frame distance....something has to give! The location of the mount is not the bad thing but rather it's poor design. If you mounted the rear of the T-case with a "parallel to the crankshaft" pivot point it would allow movement of the frame while still keeping the t-case supported. Even if the pivot in the center was a cushion mount it would still allow flexing instead of the drivetrain trying to prevent the engineered movement of the frame rails. I'm sure most of the Cruiserheads here that have wheeled on harder trails have watched some poor soul have to tow his V-8 cruiser out as the adapter between the auto or 465 to cruiser T-case is snapped and dumping buckets of gear lube out.... With V-8's the problem is multiplied as the bell housing mounts have been eliminated leaving the torsonal twist to be restrained by rigid motor mounts and rigid T-case propeller brace.

treerootCO
04-16-2009, 10:12 PM
My drive train learned a few new cuss words today. :hill: It seems like only yesterday I wouldn't have thought twice about bench pressing a transmission into place.

wesintl
04-16-2009, 10:24 PM
Dude... you still drive that old thing (much less work on it) now that you have the ptarmigan? ;)

nuclearlemon
04-17-2009, 12:28 AM
I didn't realize you were using the propeller mount. I can with all certainty tell you that is what is causing your adapter loosening! I have seen it soooooooo many times! If you were using AA's adapter instead of the plate adapter you would have be dealing with a cracked adapter instead of loose/broken bolts! The worthless propeller mount does not allow enough flex so your drive train is becoming a torsion bar!

dave brown enlightened me years ago...among the best advice i've ever been given

MDH33
04-17-2009, 12:40 AM
Dude... you still drive that old thing (much less work on it) now that you have the ptarmigan? ;)

Those fightin' words dood.




Happy to see Mike still has some soul after building that latte-brewin' heep. ;)

mtncrsr
04-17-2009, 09:53 AM
With V-8's the problem is multiplied as the bell housing mounts have been eliminated leaving the torsonal twist to be restrained by rigid motor mounts and rigid T-case propeller brace.

So for a V-8 application like I have, what does a proper support look like so that the transfercase weight is supported but the longitudinal torque is allowed to occur during frame flex?:confused: Sorry that I am slow on grasping the concept of the "fix" but I definitely want to get this right so that I am not breaking open a t-case on a run. I did that once half way through my first run on Golden Spike, and I rather not repeat it.

treerootCO
04-17-2009, 10:29 AM
This was the brace I had on the back of the transfer case. It is something I welded up to support the Orion. It was a good idea at the time but it is no longer in the truck.

mtncrsr
04-17-2009, 10:40 AM
This was the brace I had on the back of the transfer case. It is something I welded up to support the Orion. It was a good idea at the time but it is no longer in the truck.

How does the weight of your transfercase get supported? The brace that I have bolts to the rear of the t-case, then spans over to the top of the frame rails where it attaches with vertical bolts and bushings. As far as I know this is an OEM item. Should this be removed? I believe that other than the motor mounts, that is the only thing holding up the drivetrain.

wesintl
04-17-2009, 10:49 AM
As far as I know this is an OEM item.

It is not. A stock rig has the 4 motor mounts. Nothing supports the tranny or case. Later like on some 60's and my bj 70 there is a mount for the tranny.

mtncrsr
04-17-2009, 11:32 AM
It is not. A stock rig has the 4 motor mounts. Nothing supports the tranny or case.

Wow! That seems like quite a cantilever of unsupported weight that would put a lot of stress on the connecting bolts. But if you guys say that taking off the brace and letting everything hang is the right thing to do then okay.

Uncle Ben
04-17-2009, 12:21 PM
This was the brace I had on the back of the transfer case. It is something I welded up to support the Orion. It was a good idea at the time but it is no longer in the truck.

Interesting! That cushion should provide some flex I would think....obviosly not enough! Is the ends of the cross member cushioned as well? :confused: