Handling issue

I have a 1988 Chevy K5 Blazer. It feels at times like it’s skating down
the highway. This feeling gets exaggerated when I pull my 2500 sailboat.
We start to fishtail and it gets scary. Speeds around 50-60mph.

New Tires, new steering damper, alignment, even tightened the power steering gear.
Several mechanics have looked at it and feel the shocks are okay. The control issues seem worse going down a hill though it happens on flat ground too. We’re really stumped here.

Are you sure the new steering damper (just to confirm you are talking about the shock looking thing mounted sideways on your steering) is the right size for the truck?? That really sound like your problem, maybe you just got a bad new unit??

Thanks for the response…just had that installed today. the old one was shot. I can see
the new one is clean and shiny, so I know it’s new.

“Several mechanics…feel the shocks are okay”

That kind of thing always makes me queasy - the “feel” part. I don’t want someone to give me a vague impression about such things. I want to KNOW. How old are the shocks? What did these mechanics do to get the “feeling” that they’re ok?

I’m pretty sure they meant they just thought that although the shocks look old, the ride is still acceptable. They all drove the vehicle and gave me their opinion. It’s really a firm ride, doesn’t bounce around when going over railroad tracks, etc… It’s a former county sheriffs water patrol vehicle, so probably only drove in the summer months.

1988?? How many miles on it? When pulling a trailer, you want 20% of the weight ON THE HITCH! That’s 250 pounds tongue load. If your hitch is “light” things can get very unstable when towing…

If you still have problems, it’s time to replace the suspension bushings, sway bar mounts and bushings, everything. Get that rig tightened up…

K5 is 4WD, correct? And this truck should have a solid front axle? Check for play in the steering knuckles and front drive bearings and axles. Also check all the bushings, like Caddyman said. Something has way too much play in it.

62,000 miles. Yes, the very first thing we did was address the tongue weight. That helped some, but not enough. I think that’s correct now. The problem is there without the trailor, just not as pronounced. The trailer really makes it worse.

I agree something (and probably more than one thing) needs tightening up. I wish the mechanics that looked at would say, “yeh, that’s the problem!” They’[re not concerned about bushings and tie rods and such, saying they all feel fine. Are either of these things possible: a loose motor mount or a problem in the brakes? Someone suggested that but I can’t see it being brakes if it happens when I’m coasting. NOt sure what a loose motor mount would do…

Thanks for all the help here, friends. This problem is draining my bank account!

Check the power steering return hose to see if it is excessively hot. If you can’t touch it, its too hot.

Inflate tires to maximum pressure and see how it goes. For towing, you might want LT rated tires instead of P rated tires. They are stiffer. The Blazer has a very short wheelbase which compounds any handling problems.

I just checked and noticed that the problem happens even without the boat being towed. Do not tow with that vehicle in that condition! The U bolts holding the rear axle in place may have loosened (never usually happens). If they are tight and the axle doesn’t move, the wheel bearings could be loose. Jack up the rear end, both wheels, and see if you can move the tires in and out. Push in, pull out. If the tires move side to side a lot, have the bearings replaced or worry about the bearings at the differential.

Get another opinion of the condition of your rear shocks to make sure that they are working as intended. The tongue of your trailer may be too short. Can you move the boat back a little on the trailer to get the center of mass of your trailer load moved rearward? Also move the contents of your boat, if any, to the back of the boat.

I would try backing off the 20% tongue weight to 10% for a smaller vehicle. I have pulled many trailer loads with a variety of small cars with very light tongue weights and have never had a stability problem. I just make sure that I have a downward tongue force at the hitch and all is well.

The trailer will do that kind of thing with not enough tongue weight, ie too much weight in the back of the trailer. Since you have had some mechanical advice done, I think you might need to look at the sway bar links, and put more weight towards the front of the boat, or if possible adjust the trailer so more of the boat is in front of the boat trailer axle.

Since the vehicle is 24 years old I would suspect the rubber in the suspension mounts has deteriorated. To be sure you should find a shop that specializes in suspension problems.

Thanks everyone! I suspect it’s more the vehicle than the trailer. Will try to find someone else to thoroughly go over the suspension including bearings and bushings. I agree the problem must be in there somewhere. Just hard to believe these other mechanics could miss it when they are inspecting. Thanks again.

Another thought on suspension bushings. Checking them on a lift only identifies a badly worn or damaged bushing. A weak or marginal bushing can appear fine. It may even align correctly. But this truck is heavy, and bushings do degrade over time. With all the bushings being 24 years old, assuming none have ever been changed, each could give just enough lateral motion to allow for a combined system movement that is intolerable.

I’d consider changing out the suspension bushings just because of the age. The stiffer action of fresh bushings will make a huge difference. And if you go with polyurethane, like those offered by ‘Energy Suspension’, you will really notice a difference.

My understanding is that this buggy needs an eccentric bushing to adjust camber (see below). Has anybody done a full alighnment check on this thing?

http://www.carpartsdiscount.com/auto/parts/88/chevrolet/blazer/alignment/alignment_caster_camber_bushing.html?3593=291583