Hi,
My '88 e250 has twin I-beams with kingpins. In order to adjust my caster (I need more positive) I need to find a shop that has the equipment to bend the I-beams. Is there a certain type of shop I should be looking for? My normal alignment shop can't do it and they didn't know anyone in town to recommend. Would a large truck/RV shop be more likely to be able to?

The van isn't terrible at hwy speeds, but it does require more input that I would like to track straight. Especially on uneven or rough stretches of hwy. I have already replaced the steering gear box and am looking at steering stabilizer options, but I wanted to get the alignment right first.

When I had it on at my normal alignment shop they checked the front end bushings and greased everything. I was told that nothing appeared to need replaced, but are there certain bushings I should look at?

 

Some suggestions might be a 4wheel drive shop or a shop that works on bigger trucks. I need to take my 88 e150 to have it lined up since I replaced the coil springs. It drives good but the bottom of the wheels still tilt inwards after 5 months. I have waited on mine thinking that the new springs would settle down after driving it a bit.
There is no standard alignment shop in the Atlanta area that can do it..

 

I'd say a truck shop too.

 

Yep, a truck shop.

 

Thanks. I will start calling around.

Any thoughts on bushings to replace prior to the alignment?

 

Make sure the king pins are in good shape. As far as bushings go, you've got the I-beam pivot bushings & strut rod/radius arm ( which ever you prefer to call them ) bushings. And lastly are the anti-sway bar bushings and end links.

Otherwise for the front of the van make sure all tie rod ends are in good shape. Also check shocks and front wheel bearings.

Basically you want to check the condition of all the steering and suspension parts. If any are questionable or bad replace them before the alignment is done.

 

Well, on mine, I just replaced everything but the king pin bushings because I didn't want to have to go back into it for years. I replaced the radius arm bushings, pivot bushings, springs, and shocks, tie rod ends. The king pins didn't have any play in them so I left them. I have heard that keeping them greased is the key to longevity with them. The only thing left on mine is the steering gear box and it only has a little play in it that I have gotten used to.

So it depends on how deep you want to go into it at this point and what your future plans are for the van. In my case the mileage is only 109k I plan on keeping the van long term. I was also fortunate to have a couple of guys that helped me out with the work in exchange for taking their family on a weekend camping trip to the mountains.. It only took us a couple of days including changing a seal on the steering gear box.

To me the parts were fairly cheep and the labor was free (since wanted to go on a trip anyway). I did buy an air chisel to cut the pivot pushing sleeves out with and used a loaner ball joint tool to reinstall them. Yours being a E250 probably does...

Fordman mentioned the sway bar and end link bushings. My van is a e150 and didn't have them.

 

What is your current caster measurements?
and what is the spec?

 

Thanks for the info. I would replace all the bushings. It is at 200k and I plan to drive it to atleast 400K.

Unfortunately, I can't find the sheet from the last time I had it in when I first got it. From the reading I have done it looks like about +5* is where it handles the best.

 

I have a question here about caster adjustment.. How do you adjust the caster on a TIB with king pins?
The only way to push the wheels forward or backwards would be us use washers/spacers at the radius arm bushings, wouldn't it?

The camber is also dependent on the weight on the weight on the front suspension too, isn't it? Like with my van since I changed the springs, the wheels tilt inward just a little at the bottom (positive camber). That is with me outside looking at the van.. If I have a passenger and myself in the front seat, lets say we added 300lbs, now and the front end is lower and perhaps the wheels are straight because the springs are compressed and the I-beams are raised up a little on the outer end.. If I add 2 more passengers in the middle seats, perhaps then the wheels would tilted out at the bottom (negative camber).

Now I did read somewhere that there are some offset bushings that can be put in the pivot arm to correct some camber. another article said to add shims under the springs if they are sagging and the wheels are in negative camber.

My manual says not to bend the I-beams
From an article here it says
https://adamseer.wordpress.com/2012/...ucks-and-suvs/
In the event the Twin I-Beam axles will be the forged range, which were employed from 1965 by means of 1981, camber is often corrected by bending the axle by using a hydraulic ram.
In 1982, Ford introduced lighter stamped steel axle Twin I-Beam suspensions on the F100 and F150 pickups. The exact same axle can also be applied on 1989 and up Ranger pickups. These axles shouldn’t be bent simply because undertaking so could weaken them.

Now I will have to look at mine again, but if i remember correctly when changing the pivot bushings, mine were not stamped steel arms. Perhaps that only applies to trucks?

http://yeckstireandauto.com/images/wheel_alignment.jpg

 

I have heard of defective arms, it is a casting, and it could have just been drilled wrong. I don't believe it is a product of the US. I would find "0" points of measurement and then cross them against arms on a vehicle in a yard, or one you could cross check.
May be as simple as swapping defective arms out. If they are defective they were since day one.

 

No offense but this conversation is not productive without some actual measurements.

And no the radius arm doesn't adjust caster. The radius arm does help to locate the axle fore/aft but that's not caster. Caster is the difference of fore/aft regarding the upper and lower king pins.

 

How so? Because I don't know what my caster measurment currently is?

My original question was asking if there was a certian type of shop i should look for to do my alignment since the normal automotive alignment shops don't have the equipment to do so. I also asked about front end bushings.since they can also effect steering, tracking etc.

Both of those have been answered, so the thread was not pointless to me.

 

I don't have time to reread everything right now, but the conversation was so heavy on caster that I thought it was the main point. Sorry about that.

 

I found a thread here that gives links to shops that might be able to bend the I-beams.
https://www.ford-trucks.com/forums/1...l#post15276155

here's the links
Locations-By-State

I am not trying to hi-jack the thread but learn with you on this subject.
I am just throwing out some thoughts here..
How does the caster get off from factory specs if the beam is not bent due to an accident? My guess is if the radius arm and pivot bushings are worn. It seems like once you replace the bushings the caster wold be back to spec unless the king pins were really worn.

Another might be the ride highth due to springs. If the springs are sagging it would cause the spindle end of the I-beam to raise up and tilting the caster clockwise. If like in my case where the wheels are tilting inwards at the bottom due to new springs, that would cause the I-beam to be tilted counter clockwise.
Again to me this seems like it is also affected by weight on the front suspension. If you have a trailer that is tongue heavy or allot of weight in the van, on or behind the rear axle, that would raise the front end up causing Negative caster as the i-beam drops and is pulled back by the radius arm. i hope that makes sense.

There are only 4 ways I have read of to adjust the caster on I-beams with king pins.
1- Adjust spring highth
2- twist the I-beam
3- install adjustable/offset pivot and radius arm bushings
4- replace the I-beams if they were damaged or defective


This pic is from a 1985