I apologize if this goes against this forums etiquette. I’ve left a trail of posts the most recent which is buried in my own confusion but now know the right question.

2001 DRV 3500 5.9L. My front axle rating is 4000# per the door sticker. This is an extended passenger van w/8 lug hubs so 4000# makes sense. I just mistakenly had new upper control arms w/ ball joints installed but for a 3600# rating, not 4000# and one of the upper ball joints is already moving around after about 200 miles.

The new 3600# control arms themselves were a perfect fit as far as their installation. When I look at pics on CarParts.com of the 3600# & 4000# control arms themselves they appear identical in every subtle curve, hole and feature (despite different part no.s and prices) so I’m not surprised the incorrect 3600# arm bolted right in.

If the 2 arms are also identical as to how the slightly different 3600# & 4000# ball joints are seated in them then all I need is 4000# ball joints. If the seating differs then I need both new 4000# ball joints and 4000# control arms.

Unless anyone knows for sure that a 3600# control arm can work with a 4000# ball joint then I will have to buy the 4000# combo set of arm and ball joint. Either way I’m almost there.

 

You wont like my answer ... ..... I do not know the correct answer to your question.
Really incredible there is a difference of 400 pounds and they actually changed the parts .... why would they go through R&D for a difference of 400 pounds ....

The parts numbers are different, you know the 3600 does not work with what you have .... obvious there is a difference.
I think you know the answer here ... how long do you want to mess with this issue?

My chebby truck is kinda sorta the same .... it is a extended cab so by default that makes it a heavy duty 1/2 ton and it used different suspension parts then a normal single cab 1/2 ton.

Another thing that was really popular, they would take a 3/4 ton truck and put 1 ton suspension under them. This really helps for payload for a person that wants to occasionally haul a trailer, but does not want a heavy duty 1 ton dually truck. Many states require a extra tonnage fee to register a 1 ton ... but not a 3/4 ton.

I had a Ford 3/4 ton van for a work van. When new it was a airport shuttle van for a hotel and it had 1 ton suspension.

Now that you know what you have, you need to buy the correct parts for it .... even then new reproduced parts are a crap shoot.

 

As to why different parts for only a 400 lb difference I’ve read in several locations that the heavier vans were having issues with the standard ball joints. Heavier vans had the 4000# axle so the 4000# ball joint was a fix.

The only difference appears to be the ball joints that come pre-installed in the control arms- it’s easy to see the ball joint difference. Identical control arms sold with different ball joints attached would each require a different part no..

As far as how long I intend to try and get answers from others before correcting this that would be until tomorrow. At that point I’ll order the 4000# combo control arm/ ball joint set and the 4000# ball joints by themselves. First the mechanic will try the 4000# ball joints alone and if that doesn’t work the 4000# combo goes in. Whichever way it goes the parts not used get returned.

Either way, in the end I’ll be the one posting the answer to this question so it might help someone else in the future. I suspect there are plenty of DRVs on the road with incorrect ball joints because the 3600/4000# axle difference was overlooked by many who just see “this part fits your vehicle” without even clicking on the “figment note” that sometimes but not always appears.

 

Question becomes, are the mounting holes for the joints the same size? You could pick up some 4K ball joints, and see if you can install them...... Save having to buy yet another set of control arms.

 

Exactly! In my ignorance I phrased the mounting holes match as the ball joint “seating” match into the control arm. If the seating matches then all I need is the 4K ball joints.

It will cost me quite a bit more money to have the mobile mechanic come by twice. Also would be the loss of use of my van if I ended up having to order the control arm sets and waiting on them if the ball joints alone didn’t fit. That’s why I intend to have both new ball joints and control arms on hand.

EDIT; A better idea- I order the two 4K ball joints and one 3.6K ball joint, see if the mounts are the same and go from there.

 

Don't still have your old original ball joints?

 

First parts I've thrown out since forever.

 

Oooops.

 

When in doubt look up the factory part # and see if the other aftermarket ones match that oem part #.
https://www.oemmoparpartswarehouse.c...tzGCrwDb5u_hS0

 

Simple...save $10/vehicle, sell 1M vehicles, save $10M