Truck is an '86 F-250 Supercab lifted 4" with a Dana 60 front. 4" spring sup front and shackle reversal in back with shims to correct pinion angle. 35" tires.

Last Saturday I was on vacation about 500 miles from home. Coming back to where I was staying down a bumpy old road my steering pulled hard left and would pull funny, then go straight. When turning sharp it would continue to pull as returning to center, then once centered it would pull opposite, then back toward other direction, then drive straight. Couldn't drive 500 miles home towing my boat with it like that. Jacked up the front and found one tie rod slightly loose, replaced that and aligned. Same symptoms just not as bad. So loaded up and drove home.

Got home and found my track bar moving slightly as well as front shackles when turning the wheel. Got new track bar bushings and shackle bushings (upper). Tightened up some more but still has symptoms just not nearly as bad (one upper shackle bushing was completely split, other was well worn).

Looking at it today I see drivers side frame rail is flexing as I turn the wheel. Frame rail moves in and out a hair. Passenger side moves slightly but much less. I see the front crossmember rivet on the drivers side right under the steering box must be loose. The frame rail moves but crossmember doesn't. The rear of the crossmember moves with the frame rail, tight rivet and transfers load to other side of the frame.

Anyone seen them fail like this before? My plan is to grind out the rivet, clean teh area, replace with a bolt/nut, and thinking I should weld the crossmember in the the frame rail so it can't separate. Was also considering finding a 460 crossmember and putting that in for factory oil filter clearance as the truck was originally a 351w and not has a 460 with remote oil filter. Just looking for some input before I try to repair this.

 

GR8 Bolts and Prevailing torque lock nuts ... Do not weld on the frame.

If I had to replace the rivets and I had a correct cross member, I would swap! Well as might at that point.

-Enjoy
fh : )_~

 

I totally concur.

Welding on a frame, while done by many, is not a good idea in my opinion. Too many variables that can cause problems down the road.

 

I have heard of guys having this problem, but found out they really abused their trucks, mud bogging and jumping ditches, etc. I don't know if you do that or it has seen that with a previous owner.

 

just make sure your frame isn't cracked, or that it doesn't stay tweaked after the removal of the crossmember.

 

I just spent 3 days stripping, repairing & reassembling a 4WD Scottsdale with a similar problem for a customer, but he had broken his chassis rail completely through & torn the end of the crossmember by the steering box - some time ago. Surprisingly, you couldn't feel it driving, braking, or anything else.

I wouldn't weld a crossmember to a rail.

If you use bolts it's best to ream each hole out to size (using bolts slightly oversize to the original rivets) so that the bolt is a tight hammer fit on clear shank (no thread); then, once fitted, go to the next one & so on. Doing this every bolt/rivet shares load, & reaming will give you a round hole again that will stay tight - an oval hole won't.

If there is even very slight clearance, which you will get by just drilling, the bolts will slowly slog out the holes, & sooner or later,you're back to square one.

 

I often wondered about the "don't weld on your frame" warning that everyone gives out, with no explanation. I believe this is an explanation, I forgot where I picked it up.

When steel is bent and worked with, it gets "work hardened". Just like if you work on a dent on the body, beating it out, you will find the metal gets stiff and sometimes will want to rip and tear instead of bending back into shape. To get rid of this problem, a body man will heat the area with a torch, and this relaxes the metal and softens it, so it can be worked again. The body man does this over and over till he gets the metal where he wants it.

Apparently the factory uses this "hardening" affect to their advantage when building the frame. The frame starts out as a flat piece of metal, and they hit it to form it into a c- channel. This process of forming it, and also punching holes in it, makes the metal stiffer and thus stronger. The front crossmember is the same way. It has lots of corners and folds that have been formed to make it strong and make the metal stronger.

I believe the big problem with welding on the frame and crossmember is the heat it generates. The heat will relax the metal making it softer and not as strong.

Frames are welded on all the time, and I believe in certain areas it would be ok. But I think experience and know-how would probably come into play, and I will be the first to say I don't know everything you would need to know to make a decision about the proper way to weld on the frame.

 

I think I'll grind out the rivet, fix the hole if elongated and install a shouldered bolt. I'll see where that gets me, hopefully will tighten up the frame. If not I'll find any other weak spots, worn riovet holes, etc. and repair as necessary.

Another thought was to build another smaller brace/crossmember at the front of the truck near the rad support, since the rad support is tied in with bushings nad allows a small amount of movement of one frame rail relative to the other. I believe they do similar modifications to Dodge trucks that get flexy up front at the steering box.

I checked a friend's '93 and to comapre frame flex and his flexes a little but nowhere near as much. His seems to flex about the same as mine does on passenger side, which is fairly minimal. Of course his crossmember is still solidly tied to the frame.

 

ive seen a couple like you discribe, and both of them had a crack in the crossmember under the stearing box as well as loose rivets. gouged and welded the crack, and put a support bar between the frame rails using the bumper bolts to mount it. both where broncos with bigger tires and i know for shure the one is still holding almost 1 year later running "37 tires

 

The other night I removed the rivet and replaced with a shouldered bolt that I had to hammer in, and used a lock nut on it that I tightened insanely tight. Crossmember seems to be tightly tied to the frame rail now. Frame rail still flexes a little, very slightly. Still have funky steering. Tonight I replaced the steering box. Steering would be hard to turn past center sometimes, like two hands tight when standing still. Feels tighter just moving in driveway and no tight spot, but haven't test drove. I'll find out tomorrow if it's fixed. Bumper only has two bolts in it though, so have 4 new bumper bolts coming in mail tomorrow. Frame is not cracked or damaged under the steering box.

My friends lifted '93 F-250 with Dana 60 front the frame rails flex a little when turning wheel when stopped. Less than mine, but still flexes slightly. His drives straight with no issues. I'll post again tomorrow after I test drive.

 

That will help a lot. I had to take the bumper off my f150 to put my snowplow on, and had terrible frame flex till I put a bar across it to tie the frame back together.

 

Still pulls to one side or the other, still have to turn box past center to get it to go straight, then pulls one side then the other until it settles in going straight.

This is driving me absolutely nuts. Everything in the steering linkage is tight, tie rod ends drag link, king pins, wheel bearings, steering box, spring eye bushings, shackle bushings. Every piece is either new or under two years old. Only worn piece is the rag joint (thought I had a new one on the shelf but didn't, will replace at some point maybe this weekend) but that wouldn't make it pull, just leave some slop in the wheel. Still don't see any flex or movement between either frame rail and the crossmember so my shouldered bolt is still holding that tight.

 

The king pins could be frozen (rust). My 1/2 did this and drove just as you describe. I couldn't tell that was the problem until I disconnected the drag link and tried to turn the wheel...it took massive effort. That was the reason mine would not center and would pull one way or the other.

Kenny

 

I'm only guessing....... but it sounds like the steering box adjustment has been over-tightened - or tightened up at some point other than straight-ahead position - which would then make it bind each time it passed through the center.

But this wouldn't have caused the frame flexing.

 

This reminded me of a guy I work with that did have rusty frozen balljoints on his Bronco that caused a problem like this.