Trans and Tcase crossmeber advice

[cheroking]

I have a 6.0 chevy th400 and a 203-205 NWF doubler in my buggy. I recently broke the rear of my of th400 case where people normally break right before the adapter mounting surface. I am pretty sure when I hit my skid really hard and the rocks bent it up and rested on the 203 it put enough upward force to crack the case. I am going to address this with additional plating under the 203. I wanted to get yalls advice on my crossmember setup though in case that might be a problem as well. I have poly bushings on the motor. I do not have the tranny to 203 adapter mounted to anything. I do have the NWF adapter hard mounted to the crossmember and I have supports on the 205 hard mounted to the same crossmember. The crossmember has polly bushings where it mounts to the frame. My question is do I need to have the mounts on polly bushings or is it alright the way it is. Also does the tranny to 203 need a mount on it too. Thanks for any help.

Ben

 

[kid rok]

You need to run some braces off the back of the cross member to tie it in to the frame or cage. I hard monted everything in my buggy, motor, trans, tranfercase. Never a problem and I had some pretty hard licks from underneath.
I also think I read somewhere that most of the Tennesse rigs are the same way. It works.

 

[wontwork]

Hard mount everything. If your poly in one spot and hard mounted in another its gona break. Go all one way or the other, but hard is better.

 

[cheroking]

Maybe I am not clear. I do have poly bushings on the crossmember. So you are telling me that it since I have poly on the motor, the poly on the crossmember where it attaches to the frame, is not going to work.

 

[gomer pyle]

hard mounting the motor would be better but more bracing on the cross member is needed. also, maybe some 3/8" plate so rocks only put force on the crossmember and not tranny or t-cases

 

[blacksheep10]

I'm not seeing where skid attached. It needs to be on the frame. If you poly mount everything at the same width it will work if properly braced
The skid needs to be mounted separate and be sturdy enough that it will never get to the tcase cmember.

 

[cheroking]

I'm not seeing where skid attached. It needs to be on the frame. If you poly mount everything at the same width it will work if properly braced
The skid needs to be mounted separate and be sturdy enough that it will never get to the tcase cmember.

That is what I was looking for Blacksheep.... My mounts on my motor and the crossmember are pretty close to the same width, so maybe i am ok there. For the skid, it is mounted to the frame on the front and the crosmember on the back using the two tabs. So based on what you said, I may need to rework it and put the skid completely to the frame.

 

[blacksheep10]

That is what I was looking for Blacksheep.... My mounts on my motor and the crossmember are pretty close to the same width, so maybe i am ok there. For the skid, it is mounted to the frame on the front and the crosmember on the back using the two tabs. So based on what you said, I may need to rework it and put the skid completely to the frame.

for sure. If you skid was on the tranny/tcase mount, every time you hit a rock the drivetrain flexed up the amount that the poly let it move. Isolate that **** and get the skid away at least 1/2", stuff moves more than you think in the heat of the moment under throttle.
I also finally quit breaking cases when I put a solid strap (just 1/4" x 1" ) from the front of my head down to the frame rail on the left side. It is not solid mounting, but it is limiting some of the engine torque that deflects that left front engine mount so badly under hard throttle. I also always make sure you support the side of the 205 by the front output and run a strut rod from one or both of the boxes on the front output up to the engine (like the rod from the side of a chevy to the bellhousing bolt). After 5 400 cases and a 350 case I did these 3 things and was able to beat it harder and not break.

 

[cheroking]

I also finally quit breaking cases when I put a solid strap (just 1/4" x 1" ) from the front of my head down to the frame rail on the left side. It is not solid mounting, but it is limiting some of the engine torque that deflects that left front engine mount so badly under hard throttle. I also always make sure you support the side of the 205 by the front output and run a strut rod from one or both of the boxes on the front output up to the engine (like the rod from the side of a chevy to the bellhousing bolt). After 5 400 cases and a 350 case I did these 3 things and was able to beat it harder and not break.

Thanks for the advice. Kinda lost me on the strut rod. When you get a chance I would love to see a pic of your set up. I will be working on it in the coming weeks and would like to have some pics for reference. Do you not worry about the torque of the motor and that strap pulling your head bolts out.

Thanks Ben

 

[patooyee]

Kinda lost me on the strut rod. When you get a chance I would love to see a pic of your set up.

x2 ...

J. J.

 

[blacksheep10]

x2 ...

J. J.

You guys know on a chevy 205 there is a 1/2" rod that bolts to the side of the 205 by the front output and goes up to the bellhousing bolt below the dipstick tube (middle of the 3 righthand bolts). I have like 10 of those rods here from all the truck part outs so I made one attach to my last doubler plate and up to the bellhousing to take some force off the rear of the tranny.

I don't put the strap to a head bolt, it put it in one of the accessory bolts on the front of the head. A gr 8 - 3/8" bolt properly tightened will ruin that strap or shear off before hurting the engine. Mine never sheared, and were in iron vortec heads.
No pics as the rig is gone.

 

[cheroking]

I know it is a horrible picture but is anywhere in this picture what you are talking about on the 205. May have to come back to it when I get more of the parts removed and can get a better pic.

 

[blacksheep10]

that a chebby? all of mine are tapped there on the raised area that's 1" wide adn 4" long.
Either way, I brace to the adapter plate or some variation of that. On my last one I made the plate between the tranny adn range box out of 3/4" plate so I braced to that.

 

[cheroking]

I thought that may have been the spot you were talking about based on the description. I go to thinking about it and my divorced case was tapped there. I will figure something out. On another note, did you put your 1/4 bar stock between the accessory brackets and the head. Did that change your belt alignment?

 

[blacksheep10]

I thought that may have been the spot you were talking about based on the description. I go to thinking about it and my divorced case was tapped there. I will figure something out. On another note, did you put your 1/4 bar stock between the accessory brackets and the head. Did that change your belt alignment?

I had old school accessories, so the drivers head was bare

 

[cheroking]

I had old school accessories, so the drivers head was bare

Do you think it would work putting it on the back side of the motor toward the firewall where that other hole is. I have the space to put it there.

 

[blacksheep10]

yeah lots of people brace off back of head.
I'm not saying this strap is a good idea, it was a way of me controlling my out of control engine movement, partially caused by bushings that were clapped out (and me too lazy to change. )
If your engine moves too much I'd say brace. If not, rock out.

 

[kid rok]

Basicly you want to make the motor the trans and the transcase one unit. If the motor moves and the trans doesn't you fail. and so on with all those parts. Now, if your frame flexes and you have everything braced to it your back at square one. When your underneath your truck and looking around, think of every way a rock can smash into your skid pate. if you think it will move it, when it hits it at a certain angle, put a brace to stop it.