I have a 1968 C600 boom truck and have had it for almost a year. When I got it, the shifter linkage seemed a bit sloppy, but I have been able to work with/around it. I have a small truck parts yard and use it to pull cabs, and load them, beds and chassis onto customers' trailers. The total distance that it travels back and forth around the yard might be 200-300 feet or so, so it only travels in first gear or reverse. It is not in daily use and sometimes can be a couple of weeks in between jobs for it to do. Up until last week, I could finagle and encourage the shifter to find either of these gears, sometimes using certain language to aid my attempts. I started it and moved it about a week ago with no problem. Three days later when I started it, all of a sudden the clutch felt very weak with the pedal going virtually all the way to the floor. It went into reverse with no problem, but when I loaded up a bed to move, it would not go into first gear. I don't know if I over-compensated or gave a little extra oomph to coax it into a forward gear, but now the shifter is locked into first gear and I can't get it to budge. Don't really want to use the same method just described to try to get it to "unstick". Are the clutch and new "forward only gear" problems related, or just a coincidence? Also, any thoughts about how to take the slop out of the linkage, once I get it unstuck? I would love to post pics of my truck here, but I'm pretty technologically challenged.

 

Think I figured it out. The picture loading part. That turned out to be the easy part. Not the real problem.

These are pics from when we brought it home.

 

sounds like it needs brake fluid in the clutch master cylinder....easiest way with cab
tilted up put brake fluid in a pump oil can, peel the rubber boot back and fill with
brake fluid. weird setup but thats the only way.

 

Thanks Big Job. I traced lines everywhere yesterday and could not figure out where to fill it. I knew there had to be something I was overlooking. I'll give that a try and see if that solves at least the soft clutch problem. Thanks!

 

Here is the VIN tag. Can someone help in decoding it? I'm curious to see what I have.

 

Nice looking truck! And way too cool to boot! Hope you got your shifter problem fixed.

I'll try and help with some of your VIN decode. I have a '73 truck manual that I can use to try and do some decoding on your '68, so please bear in mind that not all the following information may be complete or even accurate.

VIN# C61BUD69967
C61 = C600
B = 6 cyl. I-6 1V HD
U = Assembly Plant (no U shown in my '73 manual, perhaps closed by '73)?
D69967 = sequential serial number, which month & year of manufacture can be determined (albeit not with my '73 manual, which only shows '73 data).

Other info:
135 inch wheel base.
No color code, may indicate prime gray and custom color or customer painted.
Model C611 = Model Code.
Body 4B91 = (4B) Black Vinyl Interior, (9) Platform, (1) Full-width bench seat.
Trans. O = My '73 manual shows 2 possibilities, New Process 542FL 5-speed, or Fuller T-905B 5-speed. Rather odd, all other codes only show one tranny per each.
Axle 62 = Rockwell F-106 15,000 Lb. capacity 6.20 Ratio. No third digit may indicate a Ford 5000 Lb. capacity front axle.
Max. G.V.W. Lbs./Cert. Net H.P./R.P.M. = fairly self-explanatory.
D.S.O. 654552 = 65 is the District Sales Office, not shown in my '73 manual, perhaps closed by '73? Balance of number probably sequential order number.

Hope this helps you out for now. Maybe someone else with actual '68 information can chime in and provide any corrections and/or complete information.

 

Thanks, FBNengr! Yeah, that shifter problem has me dead in the water right now. Hope someone can set me on the right course!

Thanks for the VIN decoding. That's a big help and fills in some of the blanks about what my truck has. I was stumbling around on the old interweb over the weekend and found some info on another site. It was pertaining to "F" series information, so I don't know if it applies much to mine, but the sequential build order looks like mine was built in December 1967 and it looks like it was ordered out of the Oklahoma City location. I found the truck in Vinita, Oklahoma, so I guess it probably stayed in that general area most of its life, until I brought it to Texas. Hey maybe that's what's wrong with the shifter!

Do you think my shifting problem lies in the shifter itself or the point where it goes into the transmission? I checked everything along the way and it all seemed good until you get to the transmission where it seems there is some play as it goes in. With my extra "encouragement" trying to get it to go into gear, I may now have a problem at each location.

 

Fix the clutch problem first. The slave cylinders require reasonably frequent overhaul (I mean less than the truck is old by a very wide margin), and I also used to have a problem that the vent/refill hole in the bottom of the reservoir would plug up. Not a big deal, it was just a tiny hole. I had to deal with it by poking a wire through the hole. If it's not totally empty, those issues could be the clutch problem.

 

Following info from 1964/72 Ford Truck Parts Catalog:

C61 = C600 (gas).

B = 300 1V I-6.

U = Louisville KY Assembly Plant.

D69967 = 1968, assembled August 1968 / August 1968 serial number range pertaining to 1968 trucks: D68,000-D81,999.

135" Wheelbase.

COLOR: Blank.*

C611 = C600 (gas) .. 22,000 lbs. GVWR

4B91: 4B = Black all Vinyl / 91 = 91A Standard Cab / 91 is the body style for 1957/86 C Series Tilt Cabs.

O = New Process 541 5 Speed Direct (see pic of gearshift mechanism below).

62 = Timken model F106N Single Speed Rear Axle / 6.20-1 / 15,000 lbs. Rear Axle Capacity.

22,000 lbs. Gross Vehicle Weight Rating.

139 net HP @ 3,600 RPM

654552:

65 = Oklahoma City OK Ford District Sales Office, where the original selling dealer ordered the truck from.

4552 = Domestic Special Order number. Truck ordered special by the original purchaser, not "bought off the lot."

*No COLOR code stamped on the Warranty Plate: Truck painted a non standard color per the original purchasers order. This makes it a Domestic Special Order.

 

Wow, that is a REALLY great looking cabover! I like the two-tone paint. I also love those old boom trucks and would love to have one for my collection some day, although I don't know what I would do with it.


My '77 C900 also has problems shifting into 1 and R. I had the PTO cover off the other day and I could see where the R gear was badly ground down from trying to stuff it into gear many times over the years. So I will be VERY interested in how you solve this problem because it could be similar for me.


By the way, I greased and oiled the entire gearshift linkage the other day and that REALLY helped with gears 2-5. But did nothing for my problem in R and 1. I think it's a clutch problem like yours. Keep us posted!