metal knocking in 4wd

I engaged the 4wd for the first time since having my van yesterday. When moving slowly and turning the wheel to the right, there was a loud metal knock right beneath my seat. It happened once turning right out of an alley onto the street and then once again in reverse with the wheel turned to the right. I unlocked the hubs and put it back in 2wd and there is no knocking. Except with the wheel turned all the way to the right when pulling in or out of a parking space. I think it may be a tie rod but honestly, this is the first vehicle that I have done any work on and I have had it for about 6 weeks.

When driving in 2wd at speeds between 0 and about 25mph there is rattling in the front suspension/ steering when I go over transverse cracking in the road. I have raised the front end and shook both wheels by grabbing at 12 and 6 o clock on the wheels as well as at 3 and 9 o clock. At first the front drivers side wheel had some play at 12 and 6 o'clock. I thought it might be the wheel bearings because I had felt similar play in bike wheels. I repacked both front wheel bearings. The play in the wheel at 12 and 6 o clock is gone but the rattling persists. The bushings in the stabilizer bar are worn and I have new ones from Toyota. I plan on replacing the stabilizer bar bushings when I fix whatever is causing the knock in 4wd and getting an alignment then.

What is the best way to find out what needs to be addressed?

My 2wd cargo bangsharsh on transverse cracking. My 4wd less so. When my 4wd knocked like yours it turned out to be bushings in from the wheel bearings. Previous owner = lack of maintenance. CV joint?Maybe Tim will answer and be more precise. For me, there are so many parts down there I am forced to go to a mechanic for stuff like that and then I eat a lot of rice for awhile.

It can be hard to duplicate knocks of this sort when vehicle is stationary & jacked up for testing. The thing to do is check all the easy things and eliminate them one by one. If you know the sway bar bushings are shot, then that's a good place to start. Lubing up all the grease zerks up there is also a good thing. Pay particular attention to your steering stops. These can be identified by cranking your steering wheel all the way (both ways) and then finding the spots that hit. There's a bolt head that comes into contact with a little metal trough and that thing can get really noisy if you hit a bump with the steering turned all the way. Originally Toyota put a little plastic cap on the stop bolt (to minimize harsh noises) but that is most likely long gone. All you really need to do is take a little grease on your finger and wipe it in the trough. There is one steering stop per side.

On the 4wd there are also grease points on the upper control arm bushings (so don't miss those). If you eliminate these easy things and it still makes racket, then I'd start checking for play in your front axle bushings and CV joints. Most good automotive shops I've worked in will diagnose these type problems for a reasonable rate (it's the actual repair work that gets expensive). So if you get stumped, it might be worth it to have a shop check it out. Most reputable places will take you out to the shop and show you what they found and explain things to you before it gets too expensive. Once you know, you can decide then if it's something you want to try repairing yourself. Good luck. Tim

I found the main issue with my 4wd knocking sound. The sound was coming from the front differential supports at the stoppers and mounting bolts. The stoppers and bushings for the front differential had been modified/ rigged with makeshift spacers, actually two eye bolts were used to space the stopper.
Attachment 428
I ordered new upper and lower stoppers as well as mounting bolts from toyotapartszone. It took a couple of months to get the parts but once I had them it only took a few minutes to change out and the knocking sound has gone away. I am a bit ashamed that I didn't see the eye bolts before I had posted this thread. Thank you for the reply.

It's okay. I'm a bit ashamed that when we pulled out the giant bushing on the inboard side of the front left axle and Toyota kept sending tiny replacements we didnt ask them to send a parts diagram. We had a machine shop make the giant bushing Toyota could not supply and NOW find that the reason behind the confusion was that Toyota released a service bulletin and upgrade years ago. The giant bushing is superseded by a small bushing and a needle bearing. Toyota missed asking 'is that the original part you have there my friend, because if it is you also need this bearing to go with the small bushing we sent you'. We should have caught on ourselves. Now I have restored the front end to 'factory' when the factory already decided that 'factory' wasn't good enough. Oops. Guess all that work gets redone this spring.

This is all very interesting to me. I have not heard of this issue or the service bulletin. I'm going to do some checking to see what I can find. If you have any more specific information on this it would be appreciated. Thanks. Tim

Edit: Due to some confusion with production dates there is some out-dated information in some of the following posts. The confusion is resolved and most current information is posted on the 2nd page. CLICK HERE to jump to final solution. Tim

Hi Tim.
Supposedly the bearing that is mated with the new smaller bushing is:
Bearing, Needle
90364-30011

I don't have the bulletin number.
I also don't like redoing work. I wonder if I can just leave my machinist made 'original' bushing and service the hubs and front dif religiously.
Bill

HB - I think I remember you mentioned you weren't able to machine the grease-ways in the new bushings,the originals have deep grooves.
I know nothing about making bushings, but would worry about cooling/expansion as much as lubrication. If they fail, would they take out the axles?
The replacements are easy to do, just ignore what the manual says. Only follow it for measuring axle endplay/clearance.

I'll try to get some more detailed information tomorrow.

BB

Tim - Where does one get metric grease fittings for the upper arms? They are NLA form Toyota.
Around here, everyone I ask, just looks at me kinds funny...
BB

I'm not sure about your location, but around here most auto parts have them in little kits right out in the store part. I've also seen these kits at Harbor Freight and some hardware stores. Here's a link to some at Amazon: http://www.amazon.com/Motormite-GREA.../dp/B000CZ3TZG . Larger kits are also available or they can be purchased individually. Tim

BB,That would be great. It seems like I should use the right parts. We didn't get grease journals cut and I don't even know what grade of material got used. They gotta go. All help and guidance appreciated!

I did a google search and found this discussion about the T.S.B. for the pickup's and 4runners from Yotatech.com-and I think Pirate4x4 had a discussion about it too. I think it's the same, number matches:

Quote:

---

There is an updated roller bearing avail for this.

Toyota TSB DL94-001 issued in 94 (90-94 runners/trucks)

It is to reduce noise in the axle in "extreme cold" conditions, but I like the thought of a bearing over a brass bushing.

90364-30011 roller bearing (2 needed to do both sides)
90381-32001 thrust bushing (2 needed to do both sides)
bearing grease

Dealer may be able to print the directions for you. I could mail them, they won't "cut and paste" from my info source.

---

It seems Toyota used these parts a lot. The page is here: http://www.yotatech.com/f2/question-...earings-67673/

Okay, I found the TSB & attached to this post. Thanks for bringing this to my attention. Tim

Although the bulletin doesn't include Toyota Vans and says it is only applicable to 4x4's made after 8/89. So it isn't for the van's?

Yes, I see that. Technically this SB only affects 1990 model year and newer vehicles. I know Toyota made a few vans after 8/89, but that was pretty much just to use up spare parts..............and they still called them 89 models. I really don't think they made any changes to anything van related after 7/89??? :?:

Interesting. I'm always driving around (half the year) in the -15 to 32 F range and my van is an 89. Toyota DID try to sell us the new smaller bushing. If the shoe fits, why not???

Also, I guess, if we can no longer buy the original bushing, is this TSB the answer to repairs for us?

My thought is your dealer was mixed up and the bearing won't even fit??? Has anyone here actually put one of these on a van? Harbilly, what is the manufacture date of your van (door plate gives month and year). Tim

Tim. I hear you. My van is in the shop. I should be able to get the manuf date fir you tonight or tomorrow. If we don't use the new parts I guess I need to find the part number of the orig bushing so I can 'help' my dealer. Unless my manuf date is the issue!!

The genius mechanic I go to (seriously!) lowered my ride height (thumping and bumping changing gears is gone) and put in the spacer (you know the spacer and clip that keeps front axles in the hub that sometimes is gone) and the grinding I have lately experiences with locked hubs after hitting bumps is gone.
Funny how 'left over parts' is bad.
I'm really lucky I have a guy to go to that can figure out things and put them right when I have no clue.

Anyone near Vancouver BC who is going to pay a shop and doesn't know where to go: Greg Calver. Calver Automotive. Abbotsford.

(Unless you can get Tim to to do it!)
ps Tim: I forgot to look at the door. I'll try to get that date for you tomorrow.