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HORRIBLE crunchy sound while in 4wd only
Posted: Wed Sep 10, 2014 6:04 pm
by macro
Tried the 4hi today after not using it since last winter. Driving straight forward or back it makes an ungodly racket. Like crunchy and grinding almost. I didn't even try turning the wheels. In 2wd it's totally serene.
Reading up on other forums a lot of people say it's the front axle u-joints, just thought I'd post this here for your thoughts as well before I tackle it.
FWIW I changed and repacked the CV boots and wheel bearings (inner/outer) this summer. Maybe I put it back together wrong?
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Thu Sep 11, 2014 5:47 am
by Big-Bird
Even in 2wd the Delica's CV axles always turn with the front wheels, the differential also turns....in reality the spider gears rotate and do what is referred to as 'gear walking'...and is quite normal for spider gears
It might be your CV fix because under load from the engine the CV joints will torque and flex while in 4WD...when they re just free spinning when the Deli is in 2WD, there is no load and they don't protest (grind) under the stress.
Other areas to check as well:
Front driveshaft......u-joints or the slip joint
Front Differential....a bearing for the pinion may have failed (there are 2 bearings 1inner/1outer)
Transfer case damage
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Thu Sep 11, 2014 7:53 am
by Feds
Big-Bird beat me to it. The CV's are always rotating. Another thing might be the axle disconnect might not be engaging properly. Are your 4x4 lights flashing at all?
Here's what I'd do: Put it up on 4 stands (4 good stands!) Start it, put it in drive in both 2wd and 4wd. Very carefully (avoiding the spinning bits) try and isolate the location of the nose.
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Sun Sep 14, 2014 6:11 am
by macro
Big-Bird wrote:Even in 2wd the Delica's CV axles always turn with the front wheels, the differential also turns....in reality the spider gears rotate and do what is referred to as 'gear walking'...and is quite normal for spider gears
It might be your CV fix because under load from the engine the CV joints will torque and flex while in 4WD...when they re just free spinning when the Deli is in 2WD, there is no load and they don't protest (grind) under the stress.
Other areas to check as well:
Front driveshaft......u-joints or the slip joint
Front Differential....a bearing for the pinion may have failed (there are 2 bearings 1inner/1outer)
Transfer case damage
The front driveshaft seems fine, I haven't used 4wd since last winter and it was fine then so I'm thinking it was my fix too....
Any tips on how to check the diff/t-case? Nothing seems to be leaking oil.
My 4wd light DOES flash sometimes when I start the van up. I never knew what that meant though and it always stopped. Do you think it's worth it to try and get the CV's rebuilt or order new ones?
Anything else in the front hub assembly that's worth checking? Perhaps a retighten or replace?
Thanks for the help guys!
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Sun Sep 14, 2014 7:56 am
by Big-Bird
macro wrote:Big-Bird wrote:Even in 2wd the Delica's CV axles always turn with the front wheels, the differential also turns....in reality the spider gears rotate and do what is referred to as 'gear walking'...and is quite normal for spider gears
It might be your CV fix because under load from the engine the CV joints will torque and flex while in 4WD...when they re just free spinning when the Deli is in 2WD, there is no load and they don't protest (grind) under the stress.
Other areas to check as well:
Front driveshaft......u-joints or the slip joint
Front Differential....a bearing for the pinion may have failed (there are 2 bearings 1inner/1outer)
Transfer case damage
The front driveshaft seems fine, I haven't used 4wd since last winter and it was fine then so I'm thinking it was my fix too....
Any tips on how to check the diff/t-case? Nothing seems to be leaking oil.
Checking the differential is done by feel and by ear and it requires some technical experience to know whats right and wrong about the 'feel' of the gears. Smooth rolling, no sticky spots, clicks or thumps in the differential.
My 4wd light DOES flash sometimes when I start the van up. I never knew what that meant though and it always stopped. Do you think it's worth it to try and get the CV's rebuilt or order new ones?
Flashing Super Select lights at start up is normal its a self test the tranny computer performs. As long as the lights don't continue to flash....I wouldn't worry here.
Anything else in the front hub assembly that's worth checking? Perhaps a retighten or replace?
Take your CV's out and make sure you assembled them properly....Did you take the hubs apart or just removed the C-clip on the splined shaft to slide the CV axle out?
Did you torque the bolts that hold the cv flange on the differential flange? Check the engagement actuator at the front differential. It a small metal can with a vacuum line coming out of it. It engages the front differential and if its sticky or jammed the system would only engage part way. A little cleaning with a rag usually does the job.
Thanks for the help guys!
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Tue Sep 16, 2014 5:40 pm
by macro
Alright, dear readers,
I did pull the CV's apart when I re-did the boots. It was a complete disassemble. Everything was put back together and regreased and torqued as needed.
Crawled under the van again today, front driveshaft is fine, no play anywhere.
All diff fluid is full and looks ok.
Engaging 4wd is the usual 'click' and everything is doing it's job underneath (checked with a camera).
CV's aren't loose, cir clips are in place and bolts are tight still.
Tried the 4wd again today, the noise wasn't as bad as last time. Last time it made a racket as soon as I started to move. Today, drove forward, fine. Turned onto the street, little noise. Gave it a bit of throttle and you could hear it again. I tried to get video of it but the engine noise is all you hear. Here's my word description "poppity crack pop crack poppity crack".
No different when turning, going reverse or forward. Definitely only in 4wd and mostly only under acceleration.
I've had CV's go on cars before and know what the popping sounds like, this sounds almost more like something's binding and then popping.
I can get new CV's for about $200 a side. Or rebuild mine for $160 a side. I'm wondering if by the time I replaced my boots the CV's were already shot, I unfortunately didn't check the 4wd BEFORE I tore into it. Lesson learned.
Any other way to diagnose this myself without replacing the CV's and hoping that's it?
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Tue Sep 16, 2014 5:42 pm
by macro
Big-Bird wrote:
Did you torque the bolts that hold the cv flange on the differential flange? Check the engagement actuator at the front differential. It a small metal can with a vacuum line coming out of it. It engages the front differential and if its sticky or jammed the system would only engage part way. A little cleaning with a rag usually does the job.
Thanks for the help guys!
[/quote]
I didn't have 3/8" torque wrench so I just tighten the christ out of them instead.
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Sat Oct 25, 2014 10:18 am
by macro
So I finally got around to pulling the outer hub off, engaging 4wd and going for a short drive down the block. Zero noise at all, nothing when turning or anything. This leads me to the conclusion that the CV's are toast. I'll order them up from RightDrive on Monday I suppose!
Re: HORRIBLE crunchy sound while in 4wd only
Posted: Mon Dec 22, 2014 4:30 pm
by macro
Alright!!!!! I like to clean up any resolved issues in my threads to possibly help anyone searching in the future.
Turns out it was a couple things.
Firstly, the 4x4 wasn't engaging properly. I crawled underneath and the actuator on the front axle wouldn't budge at all. Took it into my mechanic and we put it up on the lift (with me in it) and played around with the 4x4 engaging, disengaging, forward, backwards, everything. The vacuum was good but it just wasn't doing it. Took the can off (vacuum accumulator?) cleaned that thoroughly. Pulled the diff apart, cleaned it out completely, replaced any hoses that looked not great. Checked all the solenoids and made sure they were working.
Put everything back together and the 4x4 engages and disengaging like a dream!!!! ONE of the nasty noises is gone!!! But, there's still a not great sound from the front left, determined it's the CV so I ordered one up.
CV comes in after only a few days from RightDrive. Drop the van off at the shop this morning and picked it up a few hours ago. They pulled the axle out and there was a PIECE MISSING OUT OF THE CV!!! On the outside joint, the outer shell that holds the bearings in, there was a chunk AND a ball bearing missing. How that happened I have no clue at all. So, all the grease flew out of it obviously and pretty much became one. It was almost unfixable but my mechanic is awesome and he gently torched off the hub. The spring clip was rusted in and it wouldn't come off otherwise.
So, I am happy to report, everything is working as it should, thank you all for your help and advice!
Mat