TH400/NP208 Crossmember

[SIK5]

Bare with me gang!

I have searched all day and cannot find a simple enough answer lol

I have swapped out my NP203 and TH350 for a NP208/TH400 setup. Now, I am using the TH350/NP208 crossmember and have some serious rubbing issues with the fron drive shaft hitting the crossmember itself.

I have 2 options maybe:

1. Shim the existing crossmember in an effort to adjust the angle of the shaft and make some more room between it and the tcase

Or

2. Scout around at the local junk yard and find the correct one. The question is...What vehicle should I look for that might have the correct crossmember? I think I need to look for a 81'-87' K10/K20 or equivalent right? These trucks came with NP208's from the factory. Does anyone have a pic they can share of what they are using in this situation?

Thanks in advance!

 

[nvrenuf]

For a th400 set up you'll need to be looking at 20 & 30 series trucks.

Which adapter do you have, tall or short?

 

[SIK5]

Ok Cool, I'm using a tall adapter

Any contacts for a K20 or K30 crossmember by chance?

 

[nvrenuf]

I'm sorry but I misspoke - you want a crossmember from an '81-'84 Suburban (w/ th400 - 3/4 ton only?), CUCV K5 or K20 truck. I'm not sure what year GM stopped using the th350 but at that point the th400 became the "base model" 3 spd auto trans.

A crossmember from a K30 will not fit your frame correctly, it will not have enough drop.

Also, if your driveshaft is just barely rubbing, check to be sure the crossmember is installed with the built in recess under the driveshaft. The crossmember will fit in either direction.

 

[SIK5]

Ok thanks! I called a local junk yard and they have an early 80's burban. Can someone please post a pic of their K5 with whatever crossmember they are using please so I can verify it. I'm a visual person and it will give me the warm n fuzzy lol. Slowly but surely this project will be on the road soon hopefully!

 

[82355]

Post a picture of what you have going on.

Martin

 

[SIK5]

I will when I get it out the tranny shop. I currently have a TH400/NP208 supported by a NP203/TH350 crossmember. That crossmember is not allowing clearance of the fronnt drive shaft as the suspension articulates. So, I need a newer 80's version crossmember that was for the TH400/NP241 setup. It's the wierd W shaped crossmember. I found one yesterday at the junk yard. It's tweaked on both sides that bolt to the frame...hopefully the mechanic can heat them up and bent them back.

 

[RECKLESS_TRENT]

Just put a few washers under your tcase adapter on top of your rubber mounts so that it wont rub on the crossmember any more.

 

[SIK5]

Well my tranny tech was able to make the "newer" W style cross member work and got all my clearances squared away. I have purchased a torque bar as well from eBay. It connects the Tcase to the bell housing to help protect the aluminum NP208 from cracking.

Thanks for the help guys!