Ford C6 transmission question

Neighbor called me Sat evening asking what I knew about a Ford C6 transmission. Unfortunately my answer was not alot. That said, my naming of the parts might not be perfect but I'm basing the names on what I have been able to find myself.

Anyway, what had happened was he removed the vacuum modulator diaphram from the rear of the transmission to test it and wound up droping/losing the push rod that went between it and the actual modulator valve spool. He had looked online and found nothing relative to the rod itself, only refferences to the diaphram (((((there were a couple of choices but his has a green stripe)))) and the valve spool itself. I've been looking myself and have been having about the same luck.

Anyway, the truck is currently his only ride so he was desperite to get it drivable. So, I looked in a few of my books with transmission breakdowns, and it looked to me like when everything was are rest the rod fit tight between the diaphram and the end of the valve spool itself. Still, beyond the pics there was never any mention made of the actual push rod or any specs given for it anywere. Given that I took a few measurments and made him a rod out of a piece of 1/8 8018 TIG rod that was as close as I could get to 1 21/32 long. I test drove it after we put it in and it seemed to shift and work properly so if I was off on the length it couldn't be much.

Granted it's drivable now, but ultimately, my question is this. Does anyone have any idea where I can get the dimensions for the little pushrod, or better yet where a new one can be obtained? Any help would be greatly appreciated. Wayne

Hi Wayne,

Any transmission shop worth any merit should have/be able to get you the real McCoy.

However, I think you did just fine. If you allowed/left enough clearance so that the gasket at the modulator doesn't leak you're pretty darned close. The modulator should tighten down WITHOUT any spring pressure against it.

Secondly, pull the vacuum off the modulator and take 'er for a drive. If it doesn't wanna upshift, you're good to go.

Tell him next time he wants to test a modulator, just look in his rear view mirror. It's bad if he sees a fog of smoke. :>)

Allan

If the tag is still on the trans, you can get it right from Ford. Otherwise, call Transgo at 626-443-7456 and talk to their techs. Based on your results,I wouldn't mess with it. I'm just curious about what malfunction was occurring to make your friend suspect the modulator, given the fact that the trans works with a homemade modulator pin.

He was still thinking it was bad when he asked me about the whole deal so I tested it for him and it was fine. All I had to do was suck on it and see if the rod I made got shorter, and once it stopped moving cover the end of the tube with my tongue and see if it extended back out. Given the manual suck test it passed with flying colors...... And no jokes about how my redneck test proceedures methods suck .....LOL

In taking it around the block I didn't see any problems with anything under normal driving conditions. The only problem I saw was if you floored it from a standstill or slow speed it might not shift exactly right, and doing the same at higher speeds it didn't shift exactly right. I told him that he probably needed to check the adjustment on the kickdown linkage for one. Too, more than likely, I also think he has the vacuum line either plumbed in to the wrong port or he needs a vacuum canister on the system. I think it's something along those lines since going to wide open throttle will cause a momentary loss of vacuum in the system, that will cause an immediate loss of vacuum on the modulator diaphram that is going to effect the shifting of the transmission. The problem is it's an old Ford truck with parts from various other, newer, vehicles so there's no real book on how everything needs to be set up to work right together.

For the record, a green stripe modulator rear hose is manifold vacuum, front hose is ported vacuum, I.E. somewhere near the throttle plate. Other than that, feign ignorance on this one. I know you're not, but you're trying to fix someone else's F.U., on a trans with programming problems, unknown mileage, from Lord only knows what origin. Worn transmissions can hardly ever be made to shift right, and I hate to see you banging your head (unless it's Iron Maiden) against the wall, probably no pay trying to do someone a favor. The first sentence of your post says it all. I'd stop there.