85 300SD eats tires!

[10fords]

My 85 300SD that my son has been driving to school every day is wearing the inside of the front tires to the cord in less than 1000 miles I know it at least needs an alignment, but I would also like to replace some parts while I'm at it as it has 290K on the clock and I wouldn't be surprised if nothing has been replaced. The SD suspension is a little more complex than my beloved 240D so I'm not sure which parts could cause my problem. I was thinking of starting with the lower balljoints and the upper control arm/ balljoint assemblies. Probably do the tierods and draglink too. Anything else that could cause this problem that I should consider replacing? -Scott

[pawoSD]

The primary cause of that happening would be a very-off alignment, caused simply by the tie rods being way off, or way worn out. I'd be inspecting ALL components. If you replace all the things you mentioned you'll be in pretty good shape.

BTW, the suspension between the 240D and 300SD is nearly the same...only minor differences. Same overall design.

[10fords]

Originally Posted by pawoSD

The primary cause of that happening would be a very-off alignment, caused simply by the tie rods being way off, or way worn out. I'd be inspecting ALL components. If you replace all the things you mentioned you'll be in pretty good shape.

BTW, the suspension between the 240D and 300SD is nearly the same...only minor differences. Same overall design.

Thanks Pawo- I'm going to inspect everything, but not sure how to check ball joints. My FSM says something about putting a 150mm pipe on them, but from what I could gather that is after you disassemble them, and if I go that far I'm going to replace them. The tierods are easy to inspect. What about the other parts- guiderod mounts, trackrod mount, subframe bushings, etc. (may not be correct terminology) I will look for obvious cracks and looseness, but is there a correct way to test them if nothing is blatantly damaged or worn?

I rarely get around to fixing non emergency things so I want to do it once and do it right. However, since my 16 yr. old son is driving the car and will probably wreck it at some point, I don't want to waste time and money replacing parts that are still serviceable.-Scott

[josha37]

You check ball joints by jacking the car up by the control arm as close to the ball joint as possiable and only lift it until your bar fits under it and pull up and have someone watch for movement. It can be a pain, dont open pandora's box if you dont have to. Just go get the alignment and tell them to inspect it for you.

[vstech]

a simple way to check our cars for bad ball joints is one to look at the torn and rusty joint itself. aside from that, if there is less than 10mm between the lca and the spindle face. it's pretty obvious if the lower ball joint is bad. the uppers look quite odd when they are bad as well. the upper spindle face usually will TOUCH the upper control arm! it'll also sit at an odd angle when it's bad. most times the bad tire wear is related to tie rod ends being bad or control arm bushings being worn/damaged.
simple thing to do is park the car where you can see the steering components. I've used metal ramps, but it's visible on the flat surface of a driveway. park the car wherever, and have someone turn the steering wheel back and forth over and over while you look at each part of the car for play. it'll be obvious if the tire wear is that bad.

[10fords]

Originally Posted by vstech

a simple way to check our cars for bad ball joints is one to look at the torn and rusty joint itself. aside from that, if there is less than 10mm between the lca and the spindle face. it's pretty obvious if the lower ball joint is bad. the uppers look quite odd when they are bad as well. the upper spindle face usually will TOUCH the upper control arm! it'll also sit at an odd angle when it's bad. most times the bad tire wear is related to tie rod ends being bad or control arm bushings being worn/damaged.
simple thing to do is park the car where you can see the steering components. I've used metal ramps, but it's visible on the flat surface of a driveway. park the car wherever, and have someone turn the steering wheel back and forth over and over while you look at each part of the car for play. it'll be obvious if the tire wear is that bad.

Good info! Thanks!

[Diesel911]

When the same issue happend to me (over the course of only 3 days the Wheels were obviously tilted) it turned out to be the Lower Control Arm Bushings shot. Symptoms were excessive inner front Tire Wear and the top of the front Wheels tiliting inwards.

[funola]

Pry the joint in a direction to take weight off/ on it, simultaneously with your other hand wrapped around the joint. You should not feel movement if joint in good. It's more sensitive to feel than see movement.

[10fords]

Originally Posted by Diesel911

When the same issue happend to me (over the course of only 3 days the Wheels were obviously tilted) it turned out to be the Lower Control Arm Bushings shot. Symptoms were excessive inner front Tire Wear and the top of the front Wheels tiliting inwards.

Were you able to tell they were shot by a visual inspection or did you have to disassemble them to see the damage? -Scott

[Diesel911]

Originally Posted by 10fords

Were you able to tell they were shot by a visual inspection or did you have to disassemble them to see the damage? -Scott

On mine I could only see that the exposed Rubber was a little rotted looking; other than that they looked normal. So in my case just looking at them I could not tell.
The Lower Control Arms and the Upper Control Arms actually pivot on the elasticity of the Rubber. When I removed the LCA Bushings it looked like the solid Rubber had shear internally.

[josha37]

Suspension parts are a safety item, i really think you should just let a shop inspect them on a lift where it is much easier to see/test by (hopefully) a trained professional. If you feel like you need to do the work yourself you will atleast have a good starting point then.

[layback40]

Scott,
You can generally try an move the wheel in & out top & bottom & side to side while some one looks at the suspension components for movement.
The lower ball joint gets a hard life & if the rubber boot is bad, it will be bad. The LCA & UCA inner bushes often look good on the outside but often the rubber has collapsed on the inside.
There are a few DIY wheel alignment pages around, I think there is a bit of info on this site.
The LCA inner bush center bolt has eccentric washers on it. As a first quick fix, you could loosen the bolt an turn it so as to move the LCA arm in a bit. This should stop the tyre carnage. It also ads a little toe in that probably is needed.

Best of Luck With it.
Hope your lad learns from the experience!!!

At 300k miles, you are going to end up replacing everything once you get into it. BTDT.

[mike240dds]

Originally Posted by Craig

At 300k miles, you are going to end up replacing everything once you get into it. BTDT.

I agree with you Craig. I just purchased a 300d a couple of weeks ago real nasty tire wear as 10Ford describes. I just went ahead and ordered ucas' lca bushings tie rod ends and ball joints. Especially approaching 300k miles replace it all you know you dont have to look at again for some time.

[winmutt]

And use quality parts. Not the ebay kit.