Shuddering whle accelerating

'98 4runner with 164k miles. I notice the shuddering at about 20mph, but it becomes very pronounced at about 40mph. Mechanic told me I need all new suspension. Not sure this is the problem since it only happens on acceleration. It goes away the second I take my foot off the gas. Any ideas?

Sounds more like bad drive shaft joints than suspension if it only comes with acceleration. The motor & transmission mounts should also get a good look. Did the mechanic drive it? Maybe you need another opinion.

What did this mechanic mean by “all new suspension” exactly?

New struts(shocks). Just doesnt make sense that I only get this when accelerating if that is the problem

It sounds more like u-joints, as mentioned above, or a driveability problem in the engine or transmission, such as a misfire under load. If you decide to get that “all new suspension,” I would suggest getting an “all new mechanic” to do that for you, as well as diagnose this problem.

A car this old may need new shocks. Can you hear the tires skipping as it shudder? Does the car bob a few times after you hit a bump? If the car doesn’t do neither of those, your shocks are fine.

Manual or automatic? Clutch slip may cause chattering. As mentioned, bad joints may be the problem as well.

When I took it in to get it checked out I specifically told them that I thought it was the u-joints. I am guessing that they never took the car out for a drive. When I hit bumps the still feels solid, doesn’t nose dive when I brake.

Its an automatic. really dont think its my shocks, handles to well.

You need to find a good mechanic and have the car test driven. I don’t understand how any mechanic can see or hear those symptoms and not drive the car. The only times I DON’T do a test drive as part of my diagnosis is for symptoms like fluid leaks, no brakes, or won’t start, or a routine oil change.

Did you ever figure out what the problem was on this? I have a 4runner with 170K miles and its doing the exact same thing. I am also getting a very strong pulsating/shuddering when I apply the brakes. Anyone have any ideas??