View Full Version : 89 SR5 4X4 noise when backing

01-24-2009, 10:00 PM
I have an 89 SR5 that makes a loud screeching noise when I try to turn while backing up in 4 wheel drive. The truck will come to a complete stop if I back off on the gas. The noise is like metal rubbing against metal. Not a grinding noise, more like the frame flexing. I had a mechanic open the pots to look for broken parts or evidence of trouble. He found everything in good order except a little play in one of the front out put shafts. He said that he could find no spec for how much play is acceptable. I pulled a 3" stump the other day and immediately had the right rear wheel begin to drag on the pavement. I got it out of 4 wheel drive and everything was ok. Auto hubbs standard tranny.



01-25-2009, 09:36 AM
weird. It's only in 4 wheel drive that it happens? My 82 was locking the rear wheels in reverse but it was due to the bell cranks being seized. Happened in both 4 and 2 wheel drive though.

Something in the TC I guess?

01-25-2009, 11:11 AM
I don't remember about the auto hubs, unless you're talking about ADD and not regular auto hubs. In 1989 I think it was manual or ADD only, but in the middle 1980s Toyota did have a few truck with auto hubs that pop in going forward, pop unlocked when you backed up. I hate those type.

Can you locate the noise, seem like it's coming from the tranny hump, under the truck, front, rear?

So wheels straight, no issue, no noise? Just turning in reverse? If it only happens in reverse while turning, I'm not sure it's the t-case or anything from the front diff back (driveshafts, etc), since none of that stuff cares if the wheels are straight or not on a IFS truck.

If it's an ADD truck, then you eliminate hubs since they just have drive plates on the front wheels. Could it be a bound CV axle or a partially engaging ADD yoke? I'd be thinking CV axles personally any time there is an issue turning in 4WD. But the way the rear wheel locks up in odd. If it doesn't do it in 2WD then probably not a rear axle problem.

Are you sure it's coming from the drivetrain, even? In reverse, wheels locked, 4WD, sitting still and turning the steering wheel, you would be straining the power steering pump pretty hard and that could make some weird noises.

Sorta stumped here. I'd put the truck up on 4 jack stands and go to town trying to isolate weird sounds, spin everything, turn the wheels, listen for weird sounds, etc. Or get someone you don't like much (but trust to give you a fair diagnosis), ratchet tie them to the underside and drive down the road and see if they hear anything.

01-25-2009, 05:17 PM
The noise is not a a power steering belt. I can turn a little, in reverse, without noise. If I try to maneuver, as if to back a trailer into a tight place, that is when the noises begin. The wheel dragging was only only right rear and only in 4 wheel while going forward after a pull on a small stump. I had a competent mechanic look at the brakes as well as CV joints U joints and both pots. The auto hubs were OEM on the 89 SR5 V6

01-26-2009, 12:24 PM
Hey wait a minute? backing up and turning in 4x4 on dry pavement? Well yeah, that'll bind up your driveline, "Tighter than a spandex saddle on a corn bloat cow" -Edward Abby
Simply poor form.

The screeching is the front stub axle shafts binding in the spindle bushings under extreme load. I've heard that sound on slickrock. (Think about the turn around going up/down Elephant Hill.)

If you had manual hubs, you could back up that trailer in low range (4x4) with the front hubs unlocked and nothing would bind up. The auto hubs are engaging (they'll do it going forward or reverse) and giving you 4x4 when you really don't want it.

I'm surprised your auto hubs are still on there. I think they were the first thing to get changed on my 1989 SR5 4runner. Mine tried to engage on REALLY cold mornings. Usually at about 55mph on the highway. (parasitic drag in the t-case due to thick oil would slowly turn the front driveshaft which triggered the autohubs to engage at 2 mph when the wheels were going 55.) I have NO regrets going to manual hubs. I don't mind hopping out of the truck a handful of times a year to lock/unlock the hubs.

That right rear wheel dragging was because something has to give when you turn in 4x4 on dry pavement. In this case, the tire dragged on the pavement (which is much better than blowing axle shafts, u-joints or transfer cases). It was a rear because there is less traction on the rear tires due to less weight. You can drive around straight in 4x4 on dry pavement without trouble because the fronts and backs are traveling the same distance. Start turning and the back takes "shortcuts" on the corners leading to driveline bind.

01-26-2009, 08:29 PM
I don't run in 4 wheel drive on pavment except to pull an ocassional stump, then it's a straight pull forward. Moving the trailer is in soft dirt and grass when I make firewood. I just took the SR5 out empty, on dirt and had the same result when backing.

01-26-2009, 08:41 PM
I would like to thank you guys for taking the time to respond and give me somethings to take to the mechanic. I can fabricate and weld anything you can draw a picture of. I can do it in steel, stainless steel, aluminum, and repair cast iron, but I am not a good mechanic. So thanks for the thoughts and time

01-27-2009, 09:46 AM
OK, well glad you are on dirt there with that trailer.

Then my vote is for dry spindle bushings. I imagine they haven't been lubed in 20 years now. Might be due.

So pull the lock-out hubs off, and put the needle fitting on your grease gun.
There will be enough play to stick the needle in between the stub axle shaft and the spindle. Pump in grease. Repeat at 3 more places around the stub axle shaft.
You can also push the stub axle shaft IN a little bit too. The goal is to try to get fresh grease into the spindle bushings without pulling the front drive shafts all the way out because that is a bunch of work when it is this cold out!

Some people have bothered to make a spindle greasing tool.

While you are in there with the hubs off, you can either switch to manual hubs, or try to clean-regrease the auto hubs. (Which could also be the squeal source too!)
You will need a new wheel bearing nut, locking tab, and lock nut as well as IFS manual hubs.