4WD Clunk! Help
 

truck is an 89 sr5. 5 speed.(not manual hubs)i went to go wheeling with my buddy the other day and when i got to the start of the trail i put my truck in 4 h, i started to take off and i heard a loud clunk and the truck jumped a little almost like i stalled. i drove a little further and the noise just got faster with increased speed. its a loud clunk noise, it was worse when coming down a hill in first gear (load). i tried in 4 low just for kicks and the clunk was worse. doesnt make any noise in 2wheel. i checked the front shaft and it seemed fine, havent taken it off yet to look at the u-joints. i do however have a broken cv boot. now i know this could make noise but would it ever get so bad that it would make such a vicious clunk??

anybody?

Possibly.

With a torn CV boot you are allowing all kinds of water, crud, and road debris to contaminate an area that isn't treated against rust. There are a lot of shiny machined surfaces inside the CV joint that would love to be attacked by water and grit causing it to bind up. Is that the case, who knows without repairing it to see if that eliminates your problem. It's very possible that part of the tripod is frozen or slow to act.

U-joints generally clunk when you are coming on and off load, torqueing and relexing allowing the joint to move around. At a constant speed you shouldn't continue to hear it.

put a new axle in the truck today, and the clunk is still there. it seems to be worse when turning the wheels. anyone have other ideas?

tranny mount or engine mount? have u checked them? do u hear it with it in 4wd with the e-brake on and using the clutch to put pressure on and off the drivetrain? just some odeas to look at...

where does it sound like the "clunk" is coming from. your transfer case or a differential?

its hard to pinpoint between the diff and t case, but its defiantly front end.

i drained the front diff fluid today and didnt see anything irregular, fluid was full and a good color.no metal, put new fluid in and it still does it. the clunk is very loud and aggressive, it shouldnt be this hard to figure out for such a loud noise! letting off the throttle it seems worse. and at very low speeds and turning the truck locks right up. i thought it was the diff because of this reason but im not sure. anyone have any ideas? diff issue or transfer case?

could possibly be mismatched ring and pinnion's / gear ratio's??

by putting in a new axle did you only replace the cv axle or the whole diff??

if it was the whole diff with a matching gear ratio your problem could be in the transfer care, if you left the diff alone it could be mismatched gears, chipped/cracked ring gear or pinnion. im guessing you've used 4x4 before without problems right?

just my $0.02, i would also look into motor/tranny mounts and clutch issues, but it would clunk it 4x2 if it was the clutch

drive it in 4wd while its on jack stands or a lift. better help pin point the noise

Hey there! Did you ever figure out what the loud clunk in 4WD was? I have the same problem on my '85 4runner

thanks,
Tyler

I'm new to this forum because I just became an owner of a 1994 Toyota 4runner so I didn't know where I could post my question and this may not be the proper place and if so please let me know but here it goes........

I purchased the vehicle a couple days ago knowing that the 4wheel drive has some issues. It will shift in 4H or 4L with no problems but it will not go, it seems locked up. I had no problems in 2H, actually I drove the over a 100 miles to get it home the other night without in problems.

Can anyone give me some suggestions on what could be wrong. And is it ok to drive the vehicle in 2H until I can get some money saved up to fix it. I would only be driving a couple days a week to and from work which is about 40 miles one way.

First of all, you may want to repost this question as a new thread, rather than adding it to a 3 year old thread. You'll probably get more responses that way.

If the truck runs smoothly in 2H without odd noises or clunks, you're probably fine running it that way until you can figure out the 4wd problem.

A couple of things you can do to try to figure the problem out further.
- With the truck in 2H and the engine off, crawl under it and try to rotate the front drive shaft. It should rotate smoothly and fairly easily by hand.
- Start the truck and put it in 4H. Make sure the green 4wd light comes on, but don't try to move the vehicle. Now shut off the truck. Jack up both front wheels off the ground and try to rotate them. One should go forward while the other goes in the opposite direction. Both should rotate freely and smoothly.
- Without restarting the engine, lower one front wheel (or block it from turning) and shift the lever to 2H. Rotate the free front wheel. It should rotate freely and smoothly. Check to see that the front drive shaft is rotating when you rotate the wheel.

Report back the results of these tests. If they all pass, the most likely problem is mismatched gears in the front and rear differentials causing binding when driving on hard pavement.

RJR,
Thank you for the response, I took it to a guy that specializes in Toyota's and he found out that the problem was that the vehicle has the wrong rear axle in it. Basically the rear end is out running the front end.

That'll do it, for sure.

Thanks for posting the resolution - it's always good to know what the final cause was.