Matt16

My buddy just got a 1989 4Runner v6 5spd, manual hubs (no ADD) with dubious maintenance history and 450 000 km. Among other little problems, it makes noises in 4wd.

Its not the hubs, cornering has little effect (and thus probably not the CVs), I think its either the front diff or the t-case. I'm leaning to the front diff and I've never heard of anyone breaking a t-case, especially on a stock driveline with 28" all terrains.


I think its the front diff as the noise is still made when the t case goes away only when the hubs are unlocked

• Hubs locked in 4wd: lots of noise, rhythmic banging and the each bang was accompanied by a hard vibration. Same in 4hi and 4lo.
• Hubs unlocked in 4wd: mild noise and mild vibration
• One hub locked in 4wd: mild noise and mild vibration
• Hubs locked in 2wd: mild noise and mild vibration
• Hubs unlocked in 2wd: quiet, no vibration

Am I overlooking something? I suppose it could be the driveshaft, but it sounds way too loud for that (but I forgot to check).

idanity

sounds like cv joinnts...

just a guess...i would have to hear/ drive it.

dntsdad

SOunds similar to the problem i was having. I checked everything and then decided to open the front differential to have a look. I got as far as draining the diff oil and when more metal than oil came out, that was a clue that there was a problem in the front differential carrier.

I just bought a nre carrier with proper gears and am going to swap the whole unit.

Seems simple but pull the carrier plug and look at the oil.....and if there is any.

Jay351

drain the front diff oil, thats where I would start. Make sure there are no obvious signs of the d-shaft and cv joints hitting anything...

I wonder if sombody drove the truck in 4wd on the street?

abecedarian

the problem only happens in 4wd... so it has to be between the transfer case and front wheels....
makes noise with hubs unlocked, but not as much as when locked, and about the same as when in 2wd with the hubs locked.
damaged spiders or broken tooth on the pinion or ring in the front diff?

Matt16

This is a friends truck by the way.

He can turn the drive shaft by hand 4 times without trouble. He did notice the double cardan (u-joint between the t-case and front DS) has 1/2" of play. Clearly that needs replacing, but the fact that he can turn the DS by hand seems to rule out the drive shaft joints as being the culprit for the jerking/ bucking at speeds including walking speed.

Next time the truck is up here (tonight?), I'll drain the fluids and read the tea leaves.

JasonWin

That sounds great, I always want to take a girl out...


wait a second...

What are we talking about again?

abecedarian

Maybe stick with the boys if you don't know....


play in the double-cardan can cause issues, like jerking and noise, as it rotates. have to remember that the double-cardan is basically two u-joints next to each other, creating a constant velocity joint. any play in the joint will affect the accel/decel phasing and cause jerking and noise.

Jay351

Hey Matt, could you swap in your front driveshaft to see if thats the problem?

my-4x4

Hey Matt, I've also got the same issue, only happens while the hubs are locked in no matter if I've got it in 2wd or 4wd, I've been searching this issue, and this is what i've come to find:

Brass Spindle Bushing, and they say to pull it, clean it, re-lube it, and reinstall.

Hope that will help you, its tooo damn cold up here in MT right now for me, i'll deal w/ 2wd even though its snowing and -14. Well good luck, send me a private msg if you figure this ordeal out, so maybe I can save time//money. Thanks

Heres a link to the forum I read:
https://www.yotatech.com/forums/f116...el-hub-161012/

Matt16

You're right.

We're changing out the problematic u-joint tonight if its still a problem then we can check the fluids.

Matt16

Jesus that truck hasn't been worked on in a long time. The nuts an bolts are almost all seized. An hour of work and we didn't even get the shield off the double-cardan joint.

I can rotate the DS smoothly by hand so I'm guessing the diff and T-case are fine. I'm astounded at a) the amount of play in that U-joint and b) that the u-joint could make that much noise as walking speed.

DeathCougar

iTrader: (23)

Sounds like the front diff may have been changed with the wrong ratio. That is easy enough to check, if you have to pull the front cover off anyways to check the gears. Count them. A 1989 4Runner 5speed will have 4.10 gears stock.

seaofnames

I was just about to say the same thing(wrong gears).

1/2" of play isnt that bad, my runner has about a 1/4" and I dont have any problem with it.

Matt16

No, there's none of the binding as would occur with mismatched diffs (this would be like the binding experienced when driving around on dry roads in 4wd.

The double cardan is beyond repair, we'll be looking for a new driveshaft.

Jay351

Hey Matt,

Shoot Adrian an email. He parts out 4runners for a living. I have gotten many parts from him, he has massive stock. Nice guy too, knows his toyotas.

He is just off of marine drive in vancouver

acsintalan@hotmail.com