Jump to content

Recommended Posts

Well,

While I'm waitin' to get all the parts identified and located for the front end rebuild, I'm still tryin' to get in my daily allotment of "tinkering"!

The steering gear was WAY out of center on my R600. The steering arm was mis-indexed on the steering box. And, the front end had a wicked bounce in it at highway speeds.

So, I knocked the drag link loose, and re-mounted the steering arm onto the steering gear output shaft, with the timing marks aligned. Somebody had used a 5/8" pinch bolt on it. I replaced that with a new 3/4" grade 8 bolt and nut.

With the wheels pointed more-or-less straight ahead, and the steering box more-or-less centered (about 3-1/4 turns from either stop to center), the drag ling stud would not re-engage. So, I screwed the adjustable ball (looks like a big tie rod end) in as far as I could get it. Could have used 1-2 more turns on that, as the steering wheel/gear is still a fraction of a turn off-center. But, at least it's a lot closer than it was before!

I now have full steering to either side. And, the relief poppets in the steering box are kicking in about right...just before the wheel stops make contact.

The steering is quite a bit tighter in the straight-ahead mode than it was before. So, maybe there is something to the vicious runor that the steering boxes were made with tighter lash in the center than at the extremes.

I also removed both front rims from the spoke wheels, cleaned the mating surfaces, and re-mounted them. I paid attention to the side wobble of the tires, tightening them in a sequence so as to minimize the side wobble, and torqued them to something in the vicinity of the Mack spec. The right front is now almost dead true, and the left front has very little wobble to it.

The difference this made in the ride and the controllability of the old truck was unreal! It will now run out to it's top speed (somewhere between 60 & 65 MPH) without the front end bouncing all over the road. The rears still have a bit of hoochy-coo in them, but the front is 10 times better than it was. I know the kingpins and bushings are shot. And, with the bent tie rod/tie rod end, the toe HAS to be out a little. But, this gave me a glimmer of hope that the world can, indeed, be a better place!

Not bad for a few minutes wrenching.

Now, when I can work on the rest of the front end, it should start to behave like a good puppy!

Kent

"Eagles may soar, but weasels don't get sucked into jet engines."

Link to comment
https://www.bigmacktrucks.com/topic/28073-minor-victories/
Share on other sites

Yup, steering gearboxes are made so they have a "tight" spot when straight ahead. Helps keep it going straight. There is an adjustment for this.

When mounting tires, place a hammer or a chunk of wood down next to the tire and roll it. Tighten the nuts and watch for runout. Adjust as needed to get it as true as possible. If you can get it closer then 1/8" runout, you're doing good. Takes finesse.

I had to adjust my toe in once I got new parts. It had too little toe in and had a shake as both tires tried to steer the truck going down the road. Once I got it around 1/8" toe in, it now steers smooth at 70 mph. One finger control running down the highway. To get it really good, I rotated the tires and watched for wobble. I watched carefully and found the midpoint of each tire and marked it with chalk. I put this chalk mark at the hub point(horizontal) and measured toe in. This helped take into consideration of the wobble. Working from the "middle" makes the difference.

Getting drag link on the box correctly is a good thing. Bought an old Cub Cadet tractor few years ago. It would turn fine to the right, but took the whole yard to turn left. Come to find out someone had the drag link off and had it all adjusted wrong. Once I centered the wheel and got the link adjusted properly the tractor now turns on a dime each way.

IMG-20180116-202556-655.jpg

Larry

1959 B61 Liv'n Large......................

Charter member of the "MACK PACK"

 

Link to comment
https://www.bigmacktrucks.com/topic/28073-minor-victories/#findComment-144042
Share on other sites

Yup, steering gearboxes are made so they have a "tight" spot when straight ahead. Helps keep it going straight. There is an adjustment for this.

When mounting tires, place a hammer or a chunk of wood down next to the tire and roll it. Tighten the nuts and watch for runout. Adjust as needed to get it as true as possible. If you can get it closer then 1/8" runout, you're doing good. Takes finesse.

I had to adjust my toe in once I got new parts. It had too little toe in and had a shake as both tires tried to steer the truck going down the road. Once I got it around 1/8" toe in, it now steers smooth at 70 mph. One finger control running down the highway. To get it really good, I rotated the tires and watched for wobble. I watched carefully and found the midpoint of each tire and marked it with chalk. I put this chalk mark at the hub point(horizontal) and measured toe in. This helped take into consideration of the wobble. Working from the "middle" makes the difference.

Getting drag link on the box correctly is a good thing. Bought an old Cub Cadet tractor few years ago. It would turn fine to the right, but took the whole yard to turn left. Come to find out someone had the drag link off and had it all adjusted wrong. Once I centered the wheel and got the link adjusted properly the tractor now turns on a dime each way.

Yep. That sounds like what I did to the front tires. I still have a lot of work to do. But, every little bit helps!

Thanks,

Kent

"Eagles may soar, but weasels don't get sucked into jet engines."

Link to comment
https://www.bigmacktrucks.com/topic/28073-minor-victories/#findComment-144060
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...