Dakota caliper issues

[280Z Turbo]

My dad and I are trying to figure out how to fix the caliper problem on his '98 Dakota. The threaded mounting holes for the calipers have become all screwed up. They are simply too small for such a heavy vehicle.

These are the threaded pins that the calipers slide on, aparently. They are covered by a rubber bushing and have a torex head on the end.


The pins and bushings fit in these holes on the caliper, as you can see:



Here is a picture of a knuckle from a '95 Dakota (which appears to have the same problem). The threads are too small and theres not enough of them to secure the calipers over time.


Right now, the calipers are held on by a helicoil insert or something like that. Sometimes the brakes will get stuck and my dad said they turned the rotors blue from heat once. If you stomp on the brakes hard enough, they get all messed up and it tends to jerk the truck to the right side of the road while locking up the right front. The passenger side threads are worse, but the driver's side is catching up.

Anybody have any ideas of how to fix this for good? My dad and I were thinking about having the holes in the welded in and redrilled and tapped. Is this safe and would it work?

He called the local Dodge dealer and they quoted him $987 for the parts, I think.

He also called the local junkyard and other people already got to those parts because this issue is so common.

I'd like to see the holes enlarged because I'm betting it will come back. Is there any way to do this without re-engineering the whole front caliper?

BTW, This kind of engineering is inexcusable in this day and age, IMO. The mounting points for the calipers on the Z are probably twice the size, and those brakes were originally designed only to stop the 2350 lb 240Z. You want to know why I think Chrysler is a shitty car company...here's an example for you!

[AutobahnSHO]

I don't see why the weld/ drill/ tap wouldn't work better than what you have going on right now. IF someone knows what they're doing it shouldn't take extremely long and should be quite durable..  They'd have to get that hole in just the right place on the re-drill, use the right kind of weld (so it would tappable and so it would hold up over time)

How expensive are just the pins?? 



---Just my (very inexperienced) opinion.

[VTEC_Inside]

I'd be concerned with making sure you located the holes spot on again if you welded them up, but that shouldn't be TOO hard.

If it were me I'd have my machine shop buddy also fab up pins which retained a larger diameter at the threads, ie as large a diameter as the rest of the pin.

[S204STi]

I'd be concerned with making sure you located the holes spot on again if you welded them up, but that shouldn't be TOO hard.

If it were me I'd have my machine shop buddy also fab up pins which retained a larger diameter at the threads, ie as large a diameter as the rest of the pin.

There ya go.  Then you can retap the threads in the knuckle to the new size.

[280Z Turbo]

Not that simple, guys. The threads on the pins need to smaller than the OD of the pin itself. That step needs to be there or else it wouldn't be able to stop.

[S204STi]

Well, I'll tell you one thing: there is no way I would weld on and then try to perfectly re-drill your steering knuckles.

[VTEC_Inside]

Not that simple, guys. The threads on the pins need to smaller than the OD of the pin itself. That step needs to be there or else it wouldn't be able to stop.

Then its not that much more difficult. If you were to have pins machined from scratch, you could leave a step there to stop.

I'm probably understanding this wrong, but if you only threaded up to the same point on a larger diameter, the pin would stop threading where the threads stopped anyway.

[S204STi]

Then its not that much more difficult. If you were to have pins machined from scratch, you could leave a step there to stop.

I'm probably understanding this wrong, but if you only threaded up to the same point on a larger diameter, the pin would stop threading where the threads stopped anyway.

Pretty much.  You might be able to force it, but then that would be dumb.

[280Z Turbo]

Well, I'll tell you one thing: there is no way I would weld on and then try to perfectly re-drill your steering knuckles.

Well, I'll bet the bushings could take up some dimensional inaccuracies. If the whole end of the pin is threaded in a die, that might work, but will it be enough?

If the threads are any larger than the pin, it would get just right on going, and come out the other side.

I think I may end up having the Dakota checked out by a mechanical engineer friend of mine.

[93JC]

I still don't understand what the problem is...

[280Z Turbo]

I still don't understand what the problem is...

The calipers shift around because the mounting hardware for them is undersized and broken.

[S204STi]

Well, I'll bet the bushings could take up some dimensional inaccuracies. If the whole end of the pin is threaded in a die, that might work, but will it be enough?

If the threads are any larger than the pin, it would get just right on going, and come out the other side.

I think I may end up having the Dakota checked out by a mechanical engineer friend of mine.

So long as there is some amount of a shoulder on the pins just beyond the threaded portion you won't have to worry about spinning it all the way though.

[93JC]

The calipers shift around because the mounting hardware for them is undersized and broken.

Buy a new set of pins and call it a day?

[280Z Turbo]

My dad already replaced the pins once.

The threads in the caliper bracket are all chewed up too.

[S204STi]

Helicoil and blue threadlocker?