I just installed a C6 in my formerly manual 3-speed truck ('74 f100).

It fits, but the top of the tranny bellhousing is touching the underside of the truck, behind the firewall. I tried to get some clearance in that area by using a large prybar and bending the sheet metal away from the top of the trans, but it is a tough sell...

What am I doing wrong?
I have new motor mounts, new tranny mounts and am using the cross-member from the manual tranny.

TIA
GS

 

[updated:LAST EDITED ON 01-11-03 AT 08:46 PM (EST)]Did they offer the c6 with that engine in that truck? If I remember correctly, the c4 has a smaller bell on it. Also, check the condition of your body mounts. Maybe you never noticed it before, as the manuals also have a smaller bell.

 

I think the crossmember is your problem. Auto and manual trans used different crossmembers.

 

Next question...

How are the tranny cooler lines routed? Inside the frame rail or....?

 

>Next question...
>
>How are the tranny cooler lines routed? Inside the frame
>rail or....?


Inside. Plan the job on paper first. I assume your radiator was for a manual xmission and has no tranny cooler in the core and you'll be using an after market cooler.

If your radiator does have transmission cooler fittings, and you plan to use the radiator as a "pre-cooler" be sure you know which fitting will be the "hot" side off the C-6 that needs cooling, then route the rest of the piping to the new aftermarket cooler. Don't run it through the aftermarket cooler first, and then the radiatior or you're simply wasting your cooling effect.

Use only steel lines with the correct flare fittings and a tubing bender so you don't crush the lines. Don't try to use rubber hose except for very short (< 6 inches) transitions if necessary. If you do use rubber, be sure it's rated as transmission cooler (or power steering) hose and not low-pressure rubber fuel line etc. BIG problems otherwise.

The lines in/out from the tranny may run close to the exhaust for a few inches; try to wrap them w/ heat protection if you can.

Keep the lines along the entire route as up and out of the way of everything else as you can. Protect them from vibration and rubbing against other parts. Use some cheap 3/8" (or such) rubber hose, slit to go over the lines and mount them to the frame etc. If you want to get fancy (and cheap even) there's an item used for shock mounting electronics that works great for this. It's a steel strap sized for 5/16", 3/8" etc. tubing formed around a rubber isolator and has mounting holes already punched into the metal tab. Makes for a neat looking job.

Danger Will Rbinson..... Danger!!!! Despite what the after market tranny cooler instructions say..... don't use those sleezy nylon mounting straps that get pushed through your existing radiator fins to mount your new cooler..... If your radiator core is even a few years old, the core walls can be easily punctured or worn through with those useless straps and you'll be buying a new radiator. Seen it happen too many times.

Simply mount the new xmission cooler to the back of the grille with soft rubber mounts and heavy nylon "zip-straps." Just be ABSOLUTELY sure nothing of the new aluminum core pipe is rubbing on anything else; a few fins on the new cooler can rub ok without any problem.

I tried to be as descriptive as possible here, but if it's not clear, let me know and I'll try to describe it better.

Good luck.
John A.

 

You will need to cut out a clearance hole in the floor of the cab. The trucks with C6's and 4speeds had a cover bolted onto the floor to cover the clearance hole. In fact, you can see the pattern the cover's perimeter takes by looking at the pattern embossed into your floor. Don't cut it at the bottom of the groove - cut it about 1" inboard of that. You will see where the screws go.

Art
https://www.ford-trucks.com/user_gallery/displaythumbnail.php?&photoid=3467&.jpg

 

[updated:LAST EDITED ON 01-12-03 AT 02:05&nbsp;PM (EST)]2wd trucks don't need the floor cutout with c6

 

My '78 F-250 w/ the C-6 has a raised floor w/o the access panel. The '79 F-150 302/C4 parts truck I bought had a lower floor as compared to mine.
Doc

 

c6 auto crossmember is 1/2" lower than 3sp manual crossmember. I have four 73-79 trucks with c6 and the floor is not cut out like a 4spd.

 

Mount the crossmember on the bottom of the frame. This will tilt the engine down a bit but there is plenty of room. Makes the drive shafts job a little easier as well. About those lines..big PITA as far as I am concerned. I am considering some rubber/stainless steel covered high pressure line. Haven't found a source yet but I figure any hydraulic hose shop should be able to handle the job? Some aftermarket companies are building this type hose for brake systems.
William in Atlanta