WPVT

I'm trying to do a compression test on a 1954 Dodge 218 flathead engine. When I pull all the plugs and use the starter, the Bendix drive kicks out, because of the speed. I can put two plugs back in and that slows it down enough to do the test. I'd like to test with no plugs in, though. Has anyone else run into this ?

Dale, That's good news. Don't assume, however, that the spacer is the right length. It may have to be shorter or longer to accomplish the objective, or you may be able to achieve the necessary condition by adding washers. As long as you understand the principle, you'll be fine. Good luck !

The replacement rubber you get may or may not be the exact size as your original. The important thing to know is the basic design principle of that Chrysler engine mount. The engine should just rest on the upper rubber mount by it's own weight, not be bolted tightly to the frame. The lower rubber mount should be held by the bolt, spacer, and washer so that there is a slight bit of clearance between it and the frame. The length of the spacer and/or washers may have to be adjusted to accomplish this. So the engine rests on rubber by gravity...its not bolted to the frame. The lower rubber mount prevents the engine from flying off the upper mount under torque or a bump. It's all a matter of the spacer being the correct length to prevent the two rubber mounts from being tightly bolted. Tightly sandwiching the frame between the upper and lower mounts with the engine bolted to the sandwich negates most of the mount's intended vibration isolating qualities. The design depends on the engine being able to bounce up and down a tiny bit. Bolt it down, and the engine will make the whole vehicle shake. Understanding the above should help you navigate the problems you may encounter obtaining exact replacement parts. I'm a little concerned that I don't see the spacer tube in your photo, as that's the most important part. It may have been discarded at some point, as with the motor in place, it can be difficult to remove without damaging it. If it's missing you can use a piece of steel tubing with an appropriate inside and outside diameter, cut to the the exact length needed. It doesn't even have to be welded to the steel washer. Just get the length right so you can tighten the bolt without pulling the two rubber mounts completely together.

This is a followup to my original post. The truck's engine was way, way, out of tune. A carburetor rebuild, vacuum advance repair, ignition timing redo, new plugs, points, wires, etc., and the truck runs great. The engine has very good low end torque. I let out the clutch now at a 600 RPM idle, and away we go. What a difference.

I assisted a friend with a 50's vehicle whose carburetor fuel bowl would often dry up after stopping the engine for a few hours or a day or two. The engine wouldn't start after that. As it turned out, the mechanical fuel pump worked well enough to pump sufficient fuel at engine speed, but couldn't refill the bowl at starter speed. Rebuilding the mechanical fuel pump solved the problem. With the newly rebuilt fuel pump, a few cranks of the engine would refill the empty fuel bowl and start the engine.

Just one last word. I drained the gear box and as I suspected, out came the thrust ball. I reinstalled it and took up all but a little of the backlash with the adjusting screw. "Just like old". This has been a fun and educational thread. Thanks to you all.

Thanks to all. The engine runs OK, and it sounds like the coil is probably good. It's not shorted out, gives a fat spark, and hasn't died when hot. Maybe I'll buy a NOS replacement, to keep on hand just in case. It did seem to me that resistance testing a high voltage coil wasn't really effective unless it was shorted or open. And turn my attention elsewhere. PS I like your coil testing set-up Ed.

The coil on my 1954 Dodge 218 flathead gives me a secondary reading of 4800 ohms. I've heard various numbers quoted as to the acceptable resistance range, usually 6K-10K. This is the original Autolite CR 4001 with the integral bracket, so if I replace it I'll use a NOS Autolite to match. I don't intend to upgrade to better than original. Is the 4800 ohm reading cause for concern or is it about where it should be ?

Thanks. That's why I backed it off one notch.

Thanks Ed. That's good advice and undoubtedly the result of many years experience. Unfortunately too late regarding adjustment of the box. That was one of the first things I tried. The worm shaft endplay is back where it was. The steering shaft adjustment screw, as I related, doesn't seem to have an effect. I'll probably just accept the steering as it is. The truck isn't something I drive around for pleasure....or drive very much at all. I just like to have everything working properly and the steering was last on the list. Your advice reminds me of what a tractor mechanic told me his dad used to say about repairs. "Sometimes the long way is the short way". Good advice. Again, thanks for all your help.

Thanks Oldtech. The parts list calls washer #8 and washer #20 thrust washers. It helps to imagine the wheels sitting on the pavement, and the weight of the axle and truck hanging on the steering knuckles. If you look closely at the drawing, you'll see clearance between #8 and the top surface of the upper steering knuckle, and #20 and the bottom surface of the upper steering knuckle. Note that the bottom of the axle and the corresponding surface of the knuckle have no real bearing surface to carry weight. The only place designed to carry the weight of the truck is the surface between #8 and the top of the steering knuckle. I loosened the castle nut one notch and filled the housing with 90W oil. Then I alternately loaded and unloaded the axle while rotating the steering wheel. This was my best effort to allow some lubricant to get between the thrust washer surfaces and the steering knuckle faces that they bear against. Because the wheels are movable and the axle stationary, it's easy to imagine that the wheels are hanging on the axle, but it's actually the opposite, unless the axle is jacked up. It also helps if you just ignore the bottom part of the kingpin altogether and focus on the top. The hanging weight load also tends to keep the taper housed in the axle.

Thanks Ed. I did try the wheels again today. With the axle jacked up, I was able to get the wheels to move the box and steering wheel if I really jerked them to get things moving. I didn't feel like I was fighting friction, just the wrong end of a 13:1 ratio. I think you are probably right, but I've never driven an old truck that steered as hard as this one. However...since you are unquestionably the steering box expert, I have one concern about the gearbox. The steering lever that's connected to the half-nut has an adjustment for end play. I can run the adjustment screw in or out and it has no effect on the end play, which is about 3/32". That doesn't seem right. That's screw #28 that bears against the trunnion thrust ball, #27. Unless I'm mistaken, this would control the clearance between the half-nut and the worm, an important dimension. If the 3/32" end play in that shaft is translated to 3/32" clearance between the half-nut and the worm, that's a lot of clearance and could possibly be causing problems.

My 1929 White Model 61 steering gearbox was made by Hannum. I'm attaching a schematic. The steering ratio on this truck is approximately 13:1. 2 1/8 turns of the steering wheel (1035 degrees) results in about 80 degrees of arc at the wheels. I don't know what a typical steering ratio would be in a 1 1/2 ton truck of this era. I wondering if this is a low ratio, making it quick steering yet requiring more effort. After all of my troubleshooting and speculation, it may be that this particular truck model was designed to steer quicker than most large trucks, and hence, requires more effort.

I've spent some time myself staring at that diagram. At one point I think I grasped what was intended. They were very good engineers. The fact that they used a castle nut meant that they wanted it not too tight. I can understand using a washer instead of a thrust bearing, just the way plain bearings are sometimes used when there are large low speed loads. I believe #8 is the thrust bearing, as is the one on the bottom. They were called out that way in the parts list as I recall. That's why I filled the upper cap with 90W. Long story short....I think the kingpins are working the way they were intended.

OJH and others, I agree, the idea of a tapered kingpin sounds screwy. I'll attach a schematic. The taper is just a refined way of fixing the kingpin in the axle....it doesn't rotate. The detail shows the setup with the thrust washer. The castle nut was screwed down tight , hence zero vertical clearance. I backed it off a little, thinking that this would allow some lubricant to reach the thrust washer bearing surface. That may or may not have had an effect. In my research I came across a post on a heavy truck forum that indicated that Mack truck kingpins had a similar design. A few weeks ago I was convinced that my kingpins were rotating, a situation that would explain steering difficulty when they came under load. A great theory, I still think. Unfortunately it wasn't the case.

Thanks. That's something to aspire to. It's more or less my approach....I try to have every part of a vehicle working properly, or at least working.

Edinmass, I'm greatly impressed by your work on steering boxes. Clearly, you know what you are talking about. Thanks for your helpful advice.

Thanks. Can you tell me what the steering ratio is on yours ? That would be the ratio between the number degrees on the steering wheel (turns times 360 ) relative to the number of degrees that the wheels arc. I loosened the top to bottom clearance on the kingpins (it was zero), put 90W oil in where the washers are located, then alternately jacked up and lowered the axle, theoretically giving the lubricant an opportunity to get in between the washers. Pretty remarkable really, to put the entire front end weight of the truck on two 2 1/2" washers. That's not much surface area. The designers knew more than I do, however, so who am I to question their work.

I haven't found the comfort zone in my truck...yet. It was designed to be a "high speed delivery", so 35-40 mph isn't bad. Though nothing is malfunctioning, things do get a little loud. It only has 12K miles on it, so it's pretty tight. I hear you loud and clear about disconnecting the linkage. I'm working my way up to it. You are right about the caster. My point being that the steering, stiff as I might find it, doesn't prevent the wheels from straightening out while in motion. I've had vehicles with stiff kingpins or stiff gearboxes that you had to crank back out of the turn to avoid going in a circle. A lot of work to drive that way.

By the way, I like your 1917. You've kept it in it's original condition, I see. Here is the truck. Same idea. (Note snow instead of palm trees)

The worm and half nut is similar to the worm and sector, just more contact between the threads. I have a diagram of the box that I'll post later in the week.

That's interesting. With the truck wheels off the ground, I cannot move the wheels through their range of motion. This is, however, a pretty heavy truck, and I would imagine they would have used a fairly high steering ratio compared to a car or pickup. Later this week I'll compute the steering ratio on this truck. Does anyone have an idea what a typical steering ratio would have been on a 1920's era medium weight (not a pickup) truck ? PS The steering difficulty is evident while making turns in motion, not just while stationary. As I mentioned before, the steering does return straight after a turn without having to crank it back. This one thing would seem to indicate that maybe the steering is operating properly.

Thanks Ed. The White is a very well designed truck. They even mention their steering gear box in the maintenance manual, their improvement on the usual segment and worm. They use a half nut for more surface contact. When jacked up, the kingpins and linkage are all very smooth with no friction. I addressed small problems within the steering column, and that no longer has any appreciable friction. The gearbox seems to be operating smoothly,and I have adjusted the worm end play to provide some clearance, but not bind. There is another adjustment screw for end play in the gearbox steering shaft (the shaft at 90 degrees to the worm). I'm curious about that, since it doesn't seem to affect the end play in that shaft. Maybe something is amiss inside. I think I'll try putting the front wheels on dollies or something, so I can load the kingpins, but not have the tires surface friction as part of the equation. A gentleman posted from NZ suggesting that with the axle jacked up, it should be possible to rotate the steering wheel by angling the tires back and forth. Looking at a cutaway view of the gearbox, that seems unlikely. The worm thread would have to be cut at a very steep angle for that to be possible. If I measured the number of turns on the steering wheel that it took to move the steering gearbox lever a given distance, I could compute the mechanical advantage. Trying to move the steering wheel with force on the tire would be a mechanical "disadvantage". Or am I mistaken ?

Thanks. That's good advice. I'll give it a try. Maybe a set of those wheel dollies would be just the thing. I expect difficulty when the truck is stationary, but this problem is evident when moving as well. I think it is interesting that it steers very hard, yet straightens itself out nicely after the turn.

The solution to this problem continues to elude me. When the front axle is jacked up, the kingpins and associated steering linkage have near zero friction. Likewise the steering column, and likewise the steering gear box itself. The steering wheel moves the front wheels through their range of motion quite easily. It is definitely not possible to turn the front wheels and make the steering wheel spin, however. It feels like the gear ratio within the steering gearbox wouldn't enable that. I've never given much thought to the ratio of a steering gearbox, but it must be designed either to be easy, or to be quick. In any event, once the front wheels are on the ground ( stationary or in motion), it requires an unreasonable effort to make a turn. (I've had plenty of trucks without power steering, so it's not a matter of perception.) It may be worthwhile to jack up the front end and try the steering with someone offering resistance at the tire. That will give me a sense of how much leverage I actually have at the steering wheel.