Where is it coming from?

My roommate owns a 1987 Toyota Van. Those vans that have the Motor under your butt. Anyways, when we make a sharp turn (like fliipping a B***h) in either direction, we start hearing a thumping noise… It goes fast or slow depending on how fast your whipping around. We thought it was a CV joint, but, it looks like there isn’t a CV Joint (Axel) Would anyone know where I might have an idea where to start to solve this?? Cause even when it goes down the highway you go into the curve and your really hear it… The lug Nuts on the van are Tight, I’ve checked. We may think its a wheel barring… Anyone have an idea?

Maybe a bad engine mount or tranny mount causing everything to shift around on turns.

Is there a way to test this? Where might I look for these? I have to get half way under the van to get to the motor area…

Check the front wheel bearings as long as you are checking things.

I think those old ('87 era) Toyota vans are essentially front wheel drive, meaning there are CV joints. If it is a RWD van then I think it has independent suspension - meaning there are CV joints, I wonder how car savvy the OP is? Get the car to a mechanic and get it on a lift and if you have a bad bearing , CV joint, or Universal joint. This problem should not be hard to figure out.

I’m guessing a wheel bearing. Rear wheel is more likely suspect, if this is a front wheel drive. A bad rear wheel bearing on a front wheel drive car will make a sort of whaaaaa … whaaaaa … whaaaa … sound, can be loud, or can be quite soft, low volume … it could be described as “thumping” too … sort of thwhaaap … thwhaaap … and unless the bearing is super on the fritz, the sound is usually heard only during turning. Another clue is this sound is often heard even at low speeds, like turning while looking for a space in parking lots. If it is only one side that is bad, the sound will be loudest when turning the other direction; i.e. if the driver’s side rear wheel bearing is bad, the sound will be loudest turning right. One other clue to look for, if the bearing is getting very worn out and bad it can make this noise even when going straight, just not nearly as loud.

U joints can make thumping noises too. Often w/u-joints it will make the noise turning or not turning. Also with u-joints usually it is most noticed as a loud “clunk” when first starting out, or when changing directions, like moving backwards and frontwards when trying to parallel park.

CV joints on the fritz, esp the outer one, usually make more of a clicking noise, especially noticed when accelerating and turning, like when you turn right after stopping at a stop sign. The inner CV joint can make a thumping noise when turning, so that’s a possibility if it seems to come more from the front end of the car.

Front wheel bearings (on FWD cars) tend to make a roaring or growling noise that gets louder the faster you go, and occurs turning or going straight.

@UncleTurbo

OP’s van is rear wheel drive

And it doesn’t even have independent rear suspension

It has an old school solid axle

I’m certain of this, because my dad used to own one

There was a fairly uncommon AWD version, but for now I’m assuming OP doesn’t have that

I agree with @db4690. Rwd, solid rear axle on leaf springs. I knew two people that have owned these. You’ll need to check the motor and transmission mounts. Preferrably on a rack or ramps. Not unusual on a 26 yo van. Rubber does not last forever.