converting a 66 F-100 4X4 to a C-6 question

[maddogs1965]

Hey Guy's...

So i am converting a 66 F-100 4X4 truck from the original 4 speed to a C-6 with a Dana 205. I know i need to grind out the rivets from the stock cross member and move it back to match the new C-6 transmission mount, but what are you guys doing to re-support the trailing arm brackets that hang off the bottom side of the frame that the stock cross member is attached to?

I know i cant leave the cross member out, the trailing arm brackets will just fold in the frame with out the support of the cross member.

I thought about re-using the stock cross member again, but it sure looks like it will be in the way of the C-6 transmission pan.

Rick

[dsrtjeeper]

Hey Guy's...

So i am converting a 66 F-100 4X4 truck from the original 4 speed to a C-6 with a Dana 205. I know i need to grind out the rivets from the stock cross member and move it back to match the new C-6 transmission mount, but what are you guys doing to re-support the trailing arm brackets that hang off the bottom side of the frame that the stock cross member is attached to?

I know i cant leave the cross member out, the trailing arm brackets will just fold in the frame with out the support of the cross member.

I thought about re-using the stock cross member again, but it sure looks like it will be in the way of the C-6 transmission pan.

Rick

You are thinking of the wrong cross member. You need to move the cross member under the tail of the tranny where the tranny mount is bolted.

[William-in-St George]

You will need to grind off the rivets so you can install the C6 (the bell is huge) and reinstall the crossmember (in the same place) using grade 8 bolts. The tail shaft crossmember may need to be moved but this is simply a matter of drilling a couple of holes. Also consider transmission cooling lines and a new radiator, kickdown linkage set up, shift linkage (LoKar floor model) and that all important neutral start and backup light switch. Hell grinding some rivets is the easiest part of this entire deal. IMHO.

[maddogs1965]

Hey Guy's...

So i am converting a 66 F-100 4X4 truck from the original 4 speed to a C-6 with a Dana 205. I know i need to grind out the rivets from the stock cross member and move it back to match the new C-6 transmission mount, but what are you guys doing to re-support the trailing arm brackets that hang off the bottom side of the frame that the stock cross member is attached to?

I know i cant leave the cross member out, the trailing arm brackets will just fold in the frame with out the support of the cross member.

I thought about re-using the stock cross member again, but it sure looks like it will be in the way of the C-6 transmission pan.

Rick

You are thinking of the wrong cross member. You need to move the cross member under the tail of the tranny where the tranny mount is bolted.

Nope, not thinking of the wrong cross member, the stock 66 4X4 truck tranny cross member is incorporated/riveted into the brackets for the trailing arm brackets. So since i removed the stock cross member, now the trailing arm brackets are hanging on the bottom of the frame with no side to side support.

I wish grinding the rivets for the cross member was the easiest part of the job, maybe it is on a 2 wheel drive truck, but not on the 4X4 model. There are 4 rivets on the bottom side of the cross member that attach the cross member to the trailing arm brackets. Then there are 4 rivets on the very top of the frame (2 on each side of the frame rail) between the frame rail and the bottom of the cab. So needles to say you have less than 1 inch to try and grind or cut the rivets from the top of the frame. Needles to say, my sawzall, grinder, and anything else i have in my arsenal to remove steal rivets were not long enough to reach the rivets seeing how the floor board is in the way. This would be such a easy job IF the cab was removed from the frame I must say those pesky rivets were some tuff buggers. Even the bottom rivets on the trailing arm brackets that i could get to easily were a pain in the you now what, even after grinding them down flush, i could not drive them out with a air chisel or a punch, i had to drill them almost half way before i could get them to come out.

So after fighting for over 2 hours trying to remove the upper rivets, I gave up and just cut the cross member out with the sawzall. So now i will be ordering this new cross member http://www.flashbackf100s.com/stock_items_page_2 and installing it under the C-6. Then after i have the tranny hanging bye the new cross member and i see how much room i have, i will be
fabbing a new cross member to tie the mounting brackets for the trailing arms back together so the side to side motion will not try and pull the frame apart. What sucks about that though, is when you want to service the tranny and filter, you will need to un-bolt the cross member and remove it to be able to remove the pan for the C-6...ho well!!!! the things we do to up grad our rigs...

I can post pics as i go if you guys are interested. I think most everybody has done the C-6 swap on a 2 wheel drive truck, but not the 4X4 model....

Bye the way, the new flex pate is mounted, and the tranny is mounted to the motor, and the torque converter is bolted up, so now i will be waiting for the new cross member.....

Rick

[dsrtjeeper]

Interesting. I honestly didn't think there would be much difference in the cross members between a 4x2 and a 4x4. Post up some pics when you get a chance. Those rivets suck but they do their job well.

[maddogs1965]

Interesting. I honestly didn't think there would be much difference in the cross members between a 4x2 and a 4x4. Post up some pics when you get a chance. Those rivets suck but they do their job well.

Well!!!! to be honest with ya i am a Chevy man so working on this 66 Ford is a new one for me, but i love anything old.

So here is a pic of the 66 Ford i am working on for my customer. She is a pretty clean ole' truck...



Here is a pic of the 4X4 cross member that i just ended up cutting out...



Here are a couple of pics of the C-6 installed, if you look on the right and left in the pics, you can see what is left of the old cross member were it is riveted to the top of the frame...





I am at a stand still until i receive the new cross member that goes under the back of the C-6, then once i have it installed and see how low or high the C-6 is going to sit, i can fab up the second cross member to tie the trailing arm brackets back together again....

[Toyz]

Welcome, and NICE truck!
Just bring the truck to Slickstock! We can fix you right up!
Paul

[maddogs1965]

Welcome, and NICE truck!
Just bring the truck to Slickstock! We can fix you right up!
Paul

Not my 66, but thanks!!!!

I wish you guys were closer, i am in Cali.....

[maddogs1965]

So a little more progress on the automatic conversion. I am still waiting for the 2 wheel drive cross member to show up (should be delivered Wednesday), so i decided to tear into the Dana 205 T-Case.

Bill (the owner of the 66) purchased the 205 T-Case used, and as bulletproof as we all know they are, he also purchased a complete gasket/seal kit for it. So i completely disassembled the T case and inspected all the bearings and gears. The good news is everything looked great. So i re-assembled the T case with all the new gaskets and seals, and she is awaiting her new home behind the C-6 tranny under the 66

[maddogs1965]

Finally made some more progress on the 66 today...

After waiting for almost a week and a half for the new 2 wheel drive cross member to show up, IT WOULD NOT WORK
The 2 wheel cross member had 3 things all wrong for the 4X4 models. It pushed the transmission up so high the motor was tilted forward so the oil would not drain too the back of the heads, the cross member was directly in the way of the front drive line going to the front diff, and the adapter for the T-case was hitting the bottom of the floor board as you can see from the pic...



So I guess we will just chalk it up to school of hard knocks...

So after debating about reinventing the wheel and making my own cross member from scratch, i decide to see if i could not make the original 4X4 cross member work. As it turns out, after installing the C-6 tranny, the transmission mount was ruffly 1" further back from the 4 speed tranny...HECK!!!! i can make this work...

First thing was to re-install the original cross member back in-between the trailing arm brackets with bolts, then instead of welding the cross member back to the brackets that i sawzalled out since you cannot reach the upper rivets to grind them out, i fabbed up 3 brackets to be able to bolt the cross member back together again. The reason i did not want to weld the cross member back in again is because to remove the C-6, you have to be able to remove the cross member, so if i was to weld it in solid again, somebody else wold be cutting the cross member out AGAIN if they needed to remove the C-6 for some reason down the road....

here are some pics of the brackets i fabbed to bolt the cross member back together...





So know that i have the cross member bolted & secured down again, it was time to move the transmission mount to line up with the new C-6 tranny. Lucky for me the bottom part of the tranny mount was just bolted to the original cross member with 4 bolts, so i removed the bolts, bolted the top portion of the tranny bracket to the bottom part of the bracket and set the transmission down on the cross member, and just welded the the lower portion back to the cross member again. As you can see from the pic, i only had to move the bottom bracket back about 1"...



So know the C-6 is finally hanging on its own again from the cross member instead of a jack



I plan on installing the Dana 205 T-Case tomorrow, and then i can get some measurements for the new one piece rear drive line for the drive line shop.

[maddogs1965]

A little more progress today, i installed the Dana 205 T-Case on the back of the tranny...



Also since the 205 is such a heavy cast iron pig, i also drilled the frame and added the side support bracket that helps support the 205 so it does not pull so hard on the back of the aluminum C-6 & T-case adapter...



Also got some measurements for the drive line shop, so hopefully bye the end of next week we will have front & rear drive lines.
One step at a time, i think we are on the down hill slide now....

[maddogs1965]

Some more progress today...

I mounted the 4 wheel drive shifter threw the floor board, amazing enough the 205 shifter aligned up with the original hole that the Dana 21 popped up threw, and i only had to trim the back of the original hole less than a half of a inch to have full motion for the 205 linkage. I also removed the clutch pedal.



I also fabbed up some brackets to mount/hang the new trans cooler on so it was not mounted to or hanging on the radiator and tearing at the radiator fins, and plumbed in all the cooler lines.





we are getting closer every day, she will be back on the road before we know it...

[maddogs1965]

Well the 66 is all but done.

Rear and front drive lines are in, i need to remove the Edelbrock and jet it down for our elavation, and she will be good to go.

We are still waiting for the Lokar shifter to show up, Bill ordered one that is powder coated black so it will still look like the original 4 speed shifter...

I will post up some pics when we receive it and it is installed....