Delica Canada | Mitsubishi Van Club

Recently have developed a growl in my driveline. It happens at pretty much any speed but you can really hear it when you get past 40kph. lifting the rear and rotating by hand doesn't get it moving fast enough to hear anything abnormal.

I know the sound is comming from the rear as I have the rear lifted off the ground so I can drive in place.

I thought it was brakes since they needed to be done. replaced all around and no changes, no my brakes are not draging, no the dust seal labyrinth on the drums is not contacting.

Currently think it is my steady bearing along the driveshaft(I have the strada, not the delica..2 piece rear driveshaft). this was replaced 2 years ago and it doesn't look like its the culprit.

I'm going to do some more digging hopefully tonight by removing the second driveshaft from the steady bearing to the differential, if the sound remains, I have eliminated the rear axle and differential as the culprit.

next step would be to remove the driveshaft from the transmission. hopefully the sound disappears at that time and the steady bearing would be the culprit.



Other than what I have listed in my process, what might be another cause for a growl in the driveline??

Maybe a wrong driveshaft joint?Stuck,loose?out of balance driveshaft?
Low oil differential level?

Strada 92 wrote:Maybe a wrong driveshaft joint?Stuck,loose?out of balance driveshaft?
Low oil differential level?

none of the above, all good...I did a bunch of investigating this weekend.

I believe i found the problem. The clutch is slightly engaged even when it's not suppose to be. when I have the rear end up on jacks, turn the truck on and leave it in neutral, the tires start to spin. They spin slowly and you can stop them from turning with one finger but this is still something that should not be happening. I also realized that the driveline growl immediately disappears when the clutch pedal is pressed in. (ie. take it up to 40+kph, noise is loud enough to hear, press the clutch pedal, noise disappears, release clutch pedal and press 'go' pedal, noise comes back.) If i were to just let off the gas and not touch the clutch pedal, the noise slowly dies down with the driveline rotation.

When under the truck, i can move the slave cylinder/clutch fork about 1/8"(along the cylinder rod direction) and this disengages the driveline(have not tried this at speed to see if the noise disapears)

So, how/why can my clutch be slightly engaged?
How bad is it to continue driving?
do I just need a new clutch?
can i make a slight adjustment to alleviate whatever is rubbing to create contact?

When you have the rear end up on jacks, turn the truck on and leave it in neutral, the tires start to spin,it's totally normal because the clutch is engaged,no one in the truck pressed the clutch pedal to disengaged
the clutch!The transmission is in neutral but all the gears are running because of the kinetic energy.So it's possible that the drive line spin slowly but like you said,you can stop it with one finger.No problem
here.
Perhaps the differential needs adjustment?When the ring gear or the pinion is not adjusted properly, then the contact between the gear teeth is improper and causes friction.Friction will play its role and damage the ring and pinion.The humming rear differential noise will get slowly converted to a growling sound over time.
Have you checked if there was no water in the rear differential?If the pinion seal is gone,water and impurities can enter the differential damaging bearing and other component.And if the oil level is low enough, there will be no oil leakage through the seal.

Quality of lubricant?80w-90 is ok but a little too thick in cold weather. On my Strada,i use 75w-90 synthetic all years long.perfect.

Don't know.Hope this help.

Ok, thanks for clearing up the clutch delimma. I was thinking about it in the wrong way.

I know the differential is not the culprit, I had the driveshaft disconnected and the sound was still there. I've eliminated the entire rear axle as a problem. I also checked the diff fluid, completely topped off and no water whatsoever. drained it and checked the magnetic plug, just small standard metal dust, no chunks or scrapings or shavings,...

Now
clutch engaged, driving, noise is there
clutch disengaged, driving, noise is not there
as soon as I press in the clutch pedal, the noise disappears. THat means the noise is comming from the clutch backwards.

-transmission fluid maybe?
-labyrinth seal at the output of the transmission, maybe that is slghtly warped and rubbing on the outside of the transmission?

-can the transfer case make this noise? as long as I dont have it in 4x4, the transfer case is doing nothing. correct?

I've got more investigation to do.

THanks for your input so far, its been a great help confirming my thoughts.

Ok,maybe it should be a good idea to change transmission fluid.Use 75w-90 synthetic again.Fill it just a little bit more than the filling hole.Work good for me.
And yes it can be the transfer case,in 2WD the gears and bearings are running,not engaged,but running.Again oil level or improper grade oil.
Can it be a worn out transmission mount,loose or damaged?Even an engine mount?

Are the lights in the dashboard are working ok?(wheels lock and 4WD)Maybe there is a auto locking hub stuck?

I'll have to check the transmission and transfer case fluids.

I'll have to check for mounts as well, although they would not result in a rotational noise.

lights in the dashboard are working fine, except for the seatbelt warning, its been pesky flashing whenever it feels like for over 2 years. still don't know the cause for that one but amperage/voltage play a role (1/2 fan, light is on/blinking.....full fan, light is off)
4wd, hubs etc. they all work perfect.

I was thinking only about wheels lock light and 4WD lights.If they were not working,it's hard to know if auto lock are disengaged in 2WD.And if they are always engaged,it might cause a noise.
Often over the years, the wiring of these two lights wears on the transfer case, near the top bracket, causing fuse to blow intermittently(back-up lights,stop lamps)

Clutch release bearing anyone? If it was failing/has play, it could be vibrating, and when the clutch is pressed down the pressure locks it all together.

yojimbo wrote:Clutch release bearing anyone? If it was failing/has play, it could be vibrating, and when the clutch is pressed down the pressure locks it all together.

X2

X3 for the release bearing.

I woke up to my trucks rear end on the ground!!! word to the wise, soft ground and jack stands(without a bottom plate) do not mix.. everything looks like it should be ok but I'll find out tonight when I get it back in the air.


is there anyway to distinguish between pilot bearing/release bearing/input shaft bearing?
I'd like to eliminate the input shaft bearing as that would be the worst of the 3 to work on...

anybody know of a source for a clutch release bearing where it won't cost 100 bucks.
MR195689 is OEM.

really?

tell me you are not actually crawling around under that thing with "soft ground and jack stands(without a bottom plate)"??

it was hard when I started. spring thaw got to it.
truck had been in the air for a few days, and i woke up to it on the ground one morning.

got it back up lastnight, currently on blocks and tires are on!!!

Gearbox input shaft bearing will make noise all the time, but the noise will change when under load.

Pilot bearing noise will go away when the clutch is engaged (foot off the pedal) because the input shaft and flywheel are turning at the same speed- hence the pilot bearing isn't turning. Pilot bearings hardly ever wear out, since they don't take much load and only turn while you're changing gears. In the old days of bronze pilot bearings they would start to squeal during gear changes, which was always a bad sign.

Release bearings tend to rattle when the clutch is engaged (foot off the pedal) because they're held against the clutch spring fingers by a light pressure spring- so the release bearing is rotating at engine speed, but without much pressure to prevent them rattling. When you disengage the clutch (foot on the pedal) the release bearing is under much more pressure and so the rattle goes away- but if the bearing is close to failing it may produce a rumbling noise.

If you're replacing the release bearing it's usually a good idea to replace the entire clutch and the pilot bearing while you're in there, because if you don't you'll surely be tempting Murphy's Law.