Sorry if this is a redundant question in this forum, but I briefly checked the FAQ and didn't find anything. The front diff is out of a 79-80 1Ton Chevy. (kingpin model) My inspection mechanic told me that the left side moves when he pried upward on a long bar. I bought the rebuild kit and replaced the lower race, bearing, and seals. On the top side I replaced the nylon piece and spring. I did not replace the kingpin itself, because I cannot see or feel any wear on the pin to warrant relpacing it. I would have to think that as long as everything were greased it would be pretty tough for the kingpin to wear. I have a 4" lift on the truck, so I have the spacer block with the solid "slug" inside to take up the space. I tightened everything up, seemed simple enough, but I still get movement on the left side when I pry upward with a long bar. What gives?? I'm sure the movement on the left side contributes to the occasional death wobble the truck has. Does anyone have any suggestions? Thanks.

Sorry if this is a redundant question in this forum, but I briefly checked the FAQ and didn't find anything. The front diff is out of a 79-80 1Ton Chevy. (kingpin model) My inspection mechanic told me that the left side moves when he pried upward on a long bar. I bought the rebuild kit and replaced the lower race, bearing, and seals. On the top side I replaced the nylon piece and spring. I did not replace the kingpin itself, because I cannot see or feel any wear on the pin to warrant relpacing it. I would have to think that as long as everything were greased it would be pretty tough for the kingpin to wear. I have a 4" lift on the truck, so I have the spacer block with the solid "slug" inside to take up the space. I tightened everything up, seemed simple enough, but I still get movement on the left side when I pry upward with a long bar. What gives?? I'm sure the movement on the left side contributes to the occasional death wobble the truck has. Does anyone have any suggestions? Thanks.

On the lower side, you have the seal caps that must be pressed into the lower bearing cavity. Did you drive it all the way in? When I rebuilt my D60 I had a similar issue as you, and when I checked it, I found it wasn't fully into the cavity. I addressed that, and it fixed the problem.

are you leaving the tire and wheel on when you left the truck up?

all that weight is probably compressing the spring when you hoist it.

On the lower side, you have the seal caps that must be pressed into the lower bearing cavity. Did you drive it all the way in? When I rebuilt my D60 I had a similar issue as you, and when I checked it, I found it wasn't fully into the cavity. I addressed that, and it fixed the problem.

I drove the race all the way in, using the old bearing race. As far as the seal caps go, you mean the light tin cap that the bearing sits in/on? I may have to look into that, as I tapped it in, but didn't want to beat on it too hard because of how lightweight the cap is.

are you leaving the tire and wheel on when you left the truck up?

all that weight is probably compressing the spring when you hoist it.


Yes, but when I do the same thing on the passenger side, there is no movement at all, and I've never touched the passenger side.

I will have to check what Muddin Manny said about the lower seal cap.

I also want to measure the "slug" to make sure it is the right height on the top of the knuckle.

I pushed the bearing seal cap all the way up into the bottom of the steering knuckle. I still am getting a little of movement up and down when I pick up on the bottom of the steering knuckle. Probably about 1/4" op and down. The one thing that is different between the left and right side of the diff is the 2 1/2" spacer block I installed under the cast steering arm to get the drag link to level out. I am seriously looking into installing crossover steering on this thing a little sooner than I had planned. until then, any help is greatly appreciated.

I pushed the bearing seal cap all the way up into the bottom of the steering knuckle. I still am getting a little of movement up and down when I pick up on the bottom of the steering knuckle. Probably about 1/4" op and down. The one thing that is different between the left and right side of the diff is the 2 1/2" spacer block I installed under the cast steering arm to get the drag link to level out. I am seriously looking into installing crossover steering on this thing a little sooner than I had planned. until then, any help is greatly appreciated.

I have a question on that steering arm block. It is also known with the D60 Kingpins that you double up on the top spring washer/spacer so that there is added tension on the spring. I don't know if you have done that. I'm also curious as to the construction of this "arm" you speak of. Is it solid on the side of the kingpin spring or does it have an indenture for the spring to help center that arm? If so, that may be where your slack is...

Have you gone to the technical bulletins here on Pirate and check out Bill Vista's D60 bible? Tons of info contained within to help you trouble shoot.

I have a question on that steering arm block. It is also known with the D60 Kingpins that you double up on the top spring washer/spacer so that there is added tension on the spring. I don't know if you have done that. I'm also curious as to the construction of this "arm" you speak of. Is it solid on the side of the kingpin spring or does it have an indenture for the spring to help center that arm? If so, that may be where your slack is...

Have you gone to the technical bulletins here on Pirate and check out Bill Vista's D60 bible? Tons of info contained within to help you trouble shoot.

The factory steering arm on the top of the left side steering knuckle. I'm sure it's steel, not cast, I don't know why I labeled it as such. I will have to flip the steering arm over and take a look at it to see if there is an "indenture" like you speak of to center up the spring. I didn't double up on the spacer/washer on the spring, but That was going to be one of my next moves. I'll have to take a look at the technical bulletins and check out the Dana 60 one.