Clocking tcase and keeping support brace

[mrk5]

The General never had the extra support brace for the transfer case that runs from the side up to the bellhousing. So when I clocked it, I never added support. I only clocked it half-way, and now I'd like to full clock the case. I've been thinking about the extra brace. I think if GM engineers felt it was necessary for the standard tcase position, it would be even more important on a clocked tcase.

This is the idea that I have:

Basically using the standard round bushing assemblies many of the vendors sell. One side would be bolted to the factory brace spot and the other side attached to the crossmember.

All bushings will be poly: engine mounts, trans mounts, and new brace.

I think my one concern would be the new brace idea I have is too rigid. Of course this is going to make exhaust routing even more fun.

 

[miniwally]

I think that will make you break transmissions and transfer cases.



It ain't broke and hasn't broke why fix the problem?

 

[cegusman]

Why would that break trans or tcases? I think it will help.

 

[mrk5]

I think that will make you break transmissions and transfer cases.



It ain't broke and hasn't broke why fix the problem?

There is a bushing in the round area of my drawing. Does that make a differene in your opinion? Or do you think it's still too rigid?

I just started getting concerned about it again because I found a 32spline 241 in the JY that I'm going to replace my 208 with. It gives me a little better low range, ability to add SYE easily (although not cheaply), and I feel the 241 is stronger than the 208.

Anyways, that tcase had a support rod on it when I pulled it and that also got me to thinking again. I guess I want to protect my new-to-me tcase because they aren't easy to come by.

 

[Blue85]

The support brace is obviously intended to control the position of the T-case relative to the bellhousing. Your idea provides more strength, but in a totally different way.

 

[miniwally]

Why would that break trans or tcases? I think it will help.

There is a bushing in the round area of my drawing. Does that make a differene in your opinion? Or do you think it's still too rigid?

I just started getting concerned about it again because I found a 32spline 241 in the JY that I'm going to replace my 208 with. It gives me a little better low range, ability to add SYE easily (although not cheaply), and I feel the 241 is stronger than the 208.

Anyways, that tcase had a support rod on it when I pulled it and that also got me to thinking again. I guess I want to protect my new-to-me tcase because they aren't easy to come by.

With that brace I think you will introduce the frame flex into the drivetrain. The frame will flex more than the drivetrain IMO and the bar will try to twist off the back of the transmission.

This goes back to that old debate of how stiff is the chassis vs. the drivetrain mounting.

You have a ramp right Scott?

take a few measurments to areas on the frame from the T case while sitting on the ground. Then max it out on the ramp and take the same measuments. See what the difference is. Maybe I am thinking to far into it


BTW I have the poly motor mounts and the Double adapter hanging off of the cage in the buggy. I don't have any kind of anti rotation bar like that at the t-case. I don't run a tranny mount either.

When I installed the tranny in the buggy it had a cracked bell housing that I noticed late int he game. I have monitored that same crack for four years. It hasn't changed.

I really don't drive it that hard as you know but sometimes the parking stops at the mall suprise me and I hit them a bit hard so it has seen some abuse

 

[GEORGIA GABE]

I broke mine in half.... I think it was a combo of frame flex and my front driveshaft being just barely too long... when flexing it out on a ramp initially to get the correct length of the front shaft there seemed to be no problem... but then I did this.

 

[mrk5]

I broke mine in half.... I think it was a combo of frame flex and my front driveshaft being just barely too long... when flexing it out on a ramp initially to get the correct length of the front shaft there seemed to be no problem... but then I did this.

Was that with out without a brace?

That would seem to be a front driveshaft break. I would expect the brace to prevent a crack or break near the adapter.

 

[GEORGIA GABE]

without a brace... I was actually trying to support what was being said about frame flex... my frame flexes a pretty good bit and I think it contributed to the break... the front shaft was measured at full flex, but not force flexed. I shortened the shaft and it did fine... I just wouldnt put too much support to something made from aluminum
gabe

 

[mrk5]

With that brace I think you will introduce the frame flex into the drivetrain. The frame will flex more than the drivetrain IMO and the bar will try to twist off the back of the transmission.

This goes back to that old debate of how stiff is the chassis vs. the drivetrain mounting.

You have a ramp right Scott?

take a few measurments to areas on the frame from the T case while sitting on the ground. Then max it out on the ramp and take the same measuments. See what the difference is. Maybe I am thinking to far into it


BTW I have the poly motor mounts and the Double adapter hanging off of the cage in the buggy. I don't have any kind of anti rotation bar like that at the t-case. I don't run a tranny mount either.

When I installed the tranny in the buggy it had a cracked bell housing that I noticed late int he game. I have monitored that same crack for four years. It hasn't changed.

I really don't drive it that hard as you know but sometimes the parking stops at the mall suprise me and I hit them a bit hard so it has seen some abuse

I think the parking blocks and speed bumps are larger here in CO than they are most places.

I was thinking about ramp testing. I was even getting geeked out enough I was thinking about taping a marker to the tcase so it would draw on a piece of cardboard taped to the frame. This would illustrate how much movement there was between the two.

I did have a chance to see what you are talking about with the frame vs. drivetrain flex. I have a skid plate bolted the cross member and I added a second brace across the frame further back:

I have the skip plate unbolted from the cross member now. We were cycling the steering tracking down a popping noise. I'll bet there was almost 1/2" movement difference between the skid and cross member; this was side to side not an up and down gap. That was just from the forces of crossover steering.

I wonder what kind of force or weight is being exerted from the front output. I can understand the necessity for a brace on the old heavy 203. I don't see there being much weight on a 208 or 241. I guess the other force would be torsional from the front driveshaft.

 

[mrk5]

without a brace... I was actually trying to support what was being said about frame flex... my frame flexes a pretty good bit and I think it contributed to the break... the front shaft was measured at full flex, but not force flexed. I shortened the shaft and it did fine... I just wouldnt put too much support to something made from aluminum
gabe

I kinda thought that was what your point was, but I wanted to make sure.

 

[Chaddy]

Here is my crossmember for my 241.

 

[twoslo4five0]

sorry to hijack but more info on the driveshats in your truck??

 

[jekbrown]

also not trying to hijack, but what is the consensus on these types of supports if frame flex is not an issue? My truggy is gonna be so overbuilt, I don't think the frame will be able to move all that much...

j

 

[mrk5]

Here is my crossmember for my 241.

So it looks like you didn't add the extra brace?

 

[mrk5]

sorry to hijack but more info on the driveshats in your truck??

In the front he has a 2pc front shaft like what's found in some LWB pickups and burbs. The carrier bearing is mounted on the crossmember.

Oh and they are painted black.

 

[driney]

The support brace is obviously intended to control the position of the T-case relative to the bellhousing. Your idea provides more strength, but in a totally different way.

I think you are right. I originally thought the brace was to help hold the TC up but now I think it serves to brace the TC front to back also. As hard as I have high-centered my truck I think I would have broken my case without the brace. I haven't clocked mine yet but when I do I think I will modify and reinstall the brace.

 

[twoslo4five0]

In the front he has a 2pc front shaft like what's found in some LWB pickups and burbs. The carrier bearing is mounted on the crossmember.

Oh and they are painted black.

did he make all the parts himself or is there a write up on this im missing??

 

[mrk5]

I think you are right. I originally thought the brace was to help hold the TC up but now I think it serves to brace the TC front to back also. As hard as I have high-centered my truck I think I would have broken my case without the brace. I haven't clocked mine yet but when I do I think I will modify and reinstall the brace.

I think maybe you're right, but I don't see how that scrawny rod really keeps the tcase from doing anything. Doesn't really seem that rigid or strong.

 

[mrk5]

did he make all the parts himself or is there a write up on this im missing??

I don't think he's done a write-up, I just know I've seen him post about it several times. If you search his posts a bit, I know he posted a good explanation a while back.

Or just wait for him to reply again in this thread.