I have a 1966 Ford F-250 Camper Special with a Cruise-O-Matic, 3 speed automatic transmission (old cast iron case). I recently replaced the tranny with an old but remanufactured one (never installed after rebuild) that I bought from a salvage yard. I was told by the yard that back in the 70’s and 80’s, they had a contract to supply and install remanufactured tranny’s for U-Haul. They still had several left that had not been used/installed since they had been sent off to be rebuilt (over 20 years ago). These still had the tag from the rebuild, all holes in the case had been sealed up with plastic plugs, and they were painted U-Haul orange. Since the price was right, I bought one. Upon opening up the pan and tail housing and looking inside, I found it to look like everything (valve body, bands, hard parts) looked like they had been replaced with all new parts. Also, it was very clean and still was lubed up pretty good. I replaced the front and rear seal and put it in the truck with a new torque converter. It worked perfectly (at first). All shift points were smooth and correct. It felt like a brand new transmission. Now after getting the chance to drive it for extended periods, I have noticed a problem when shifting in to drive, 2<SUP>nd</SUP>, or Low (forward gears) and need help diagnosing the cause. Here’s what happens:

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Problem is a delayed initial forward engagement. This problem only happens AFTER it’s been run a while and it is up to operating temperatures. When the engine is cold, the problem is not there. Everything works perfect! Once it heats up and I put it park, reverse or neutral, then try to shift it into a forward gear, it has a delayed engagement and shutters a bit, then as pressure build up, it goes into gear (about 3 seconds). Once, it’s in gear, it works perfect and smooth (no slipping). It will not do it again until I shift it out of a forward gear and back again. There are no problems with reverse. Does anyone have any ideas of what I can do to correct this? I have been told that maybe my forward band needs adjusted or the vacuum modulator is bad. If this was the case, wouldn’t it have a problem on a cold motor? I’m thinking that maybe the problem doesn’t show itself until it heats up and thins out the fluid, allowing it to pass through a seal and doesn’t completely shift into gear until pressure builds up enough to overcome the leak. I also think that maybe it doesn’t happen when cold because the fluid it thicker. Are there any tranny guys out there familiar with the old cruise-O-Matic that can help? Thanks

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Have you adjusted the forward band? Typically heavy fleet stuff is bench built a little loose then adjusted after installation to suite the application. I know the Fed Ex trucks I worked on years ago had the same engine/tranny combo in the 1ton vans and the 3ton box trucks 300/c6. The rebuilt trannys we got needed to be adjusted after install every time.

 

Band adjustment or bad vacuum modulator. OP's truck has an MX Cruise-O-Matic. U-Haul trucks today are considered Frankenstein Monsters, because they were built by Ford to U-Haul specs. Beginning in 1968 (and up to the early 1980's), all the F350 were built with either a special HD 300 I-6 or a 330 Medium Duty FT engine. In some instances, the 361 FT was also used on certain applications. No 1968 and later F350 U-Haul truck offered a FE engine.

Check the vacuum lines for cracks or crimping before replacing the vacuum diaphragm (modulator)

C1AZ-7A377-B Diaphragm, Vacuum Throttle (Motorcraft TM-1)

 

No, I didnt do any band adjustment before I put it in. It looks so good on the inside, I figured whoever put it together must have known what they were doing and I didnt want to screw it up with my unexperienced hands :-) I guess I should know not to assume...

I dont know what model it came out of, but I believe it is a 1968 case. The numbers on the metal I.D. tag are PFBD1 010975.

I'll try the band adjustment and check the modulator. This time, I'll put a drain plug in the pan to make it easier next time it needs pulled.

Oh, by the way, I fixed the vibration I was getting. Problem was tires and bad kingpins.

 

I don't think you have to pull the pan. Not sure on the cruise-0-matic but on the C6 band adjusters are external.

 

PFB-D1 = 1968

PFB-D = 1967; PFB-D2 = 1969; PFB-D3 = 1970/72 (all C/M)

 

Yeah, the front band for the COM is internal. The rear band is external. I may just take it to a tranny shop and let them do it as I do not have the correct torque wrench. My Chilton's manual says for the FMX (are they the same as COM?) to pull back on the actuation rod, and insert a 1/4 inch spacer between the adjusting screw and the servo piston stem. Then tighten the adjusting screww to 10 inch pounds. Remove the spacer and tighten the screw an additional 3/4 turn. Then tighten the locknut to 20-25 foot pounds. I dont have an inch pound torque wrench, so I may just leave this up to a tranny shop. I'm sure they will have the reference material to ensure it's done correctly....uh oh........there I go assuming again...........

 

I wouldn't get too hung up on the torque issue. 10 inch pounds is little more than finger tight, they just want to assure you have all the slack out. 20-25 foot pounds is also only hand tight with a wrench, just enough so it doesn't come loose. This isn't brain surgery.
I can assure you, you'll be way more **** (at least I am) than the guys trying to figure out how to adjust the bands on a tranny they haven't seen in twenty years...if they were even born then.

 

Prostock is right. I did mine and finger tight is all you need to use. After that if you have a torque wrench for the 20-25 ft-lbs. then you can use it or simply use the appropriate wrench and maybe tighten it using two fingers rather the the whole hand. He is probably right about the guys at any tranny shop not knowing what you have. I use a pretty good independent parts guy and he still had a time trying to get the right filter and gasket for my COM.

 

For the 1/4" spacer I use a 1/4" allen wrench just make sure it's on the flats and not the points.

 

It sounds easy enough. I'll give it a try. Great idea on the allen wrench for the spacer. I know what you mean about finding the right filter and gasket being tough to find. I ended up making my own gasket because I couldnt find one. I had ordered 2 different ones at the local parts houses, but they were both wrong. I guess I have until the weekend to try to find a source. I think I might try changing out the modulator first though. It would be nice if the problem was that simple. Why do you guys think that I dont have a problem when the motor/tranny are cold?

 

Would have to do some reading. Take my C6 in the big Merc which is slow to go into a forward gear when cold yet goes in fine when warmed. Just the opposite of you and when cold can take minutes to get into drive.

Oh, will check tonight the part # for a filter and gasket set since I acquired spares to be forever safe.

 

Increase the throttle valve pressure by removing the vacuum line off of the vac. modulator, insert a small screwdriver into vac. nipple on the modulator and screw in counter-clockwise in 1/2 turn increments until acceptable.

 

Filter and gasket manufacturer is ATP and part # is B-41.

 

I have found that torque sequence and amount are critical when bolting the screen back up, you can slightly warp the valve body and leak pressure off as well as hanging the valves if you get overzealous with it.