Diff\locker issues

[Gaz_n_Paj]

Hi all,

I have a '91 SWB Pajero with a rear diff that makes one hell of a noise at any speed over about 70kmh these days which is a loud whining noise and my Metallica now struggles to hide the horrendous noise at anything above 90kmh - There is a replacement one on Trade Me at the moment, but $950 is a little much for me to spend at the moment.

Have spoken to a lot of people who most have said not to worry about it, however I am choosing to worry about it and a fellow ORE member has kindly offered his services to help.

What we plan on doing:
Draining the diff
Checking the bearings (maybe replacing one/some or all)
Refilling diff with fluid.

Really I'm looking for instructions on how to do this, and an idea on what bearing\s is making the noise (pinion?) and where we can locate it.

I also got stuck around Red Rocks a few weeks ago while pulling some other guy out who go horribly bogged.. I threw the rear locker on and the wheel that was stuck continued to spin up and the wheel that was not stuck wasn't moving at all. I've been advised to check the pressure with a low gauge air pressure unit, any other ways I can test to see if it is working correctly?

Thanks in advance for any help.

Gaz

Edit: Wouldn't mind checking the diff breathers either to make sure they are doing their job??

[NJV6]

What does the light on the dash do when you lock the rear diff?

And if it goes solid instead of flashing, jack one back wheel up and see if it will turn with the transmission in N. (transfer case will need to be in 4HLc or 4LLC for the locker to engage and be doing less than 5mph.) You can hear the pump quite clearly when idling and you operate it.

It operates at about 7psi.

[WACKO]

when on the motorway, sitting at a constant speed, does the whine stay continuously? does it get louder or quieter if you accelerate (put engine under load) or take your foot off the gas?

like i said, i think its the pinion bearing but im not sure so will need to get this confirmed.

nj, you have any ideas how to check if the locker is getting enough pressure to lock?
was thinking drain the oil to check if chunks fall out like when you blew yours.

[NJV6]

Yea the bung is magnetic so it may have some parts of a locker stuck to it.

If the light stops flashing then it has got enough pressure. The switch on the diff can be dicky too like my new one, it flashes even when I know it is fully in.

You can hear the pump clearly and I think this is the 1st thing to establish, some metal filings from the locker won't have done the bearings any good however...

[Gaz_n_Paj]

Light stays on and you can hear the locker engaging. Found a new diff head, just trying to locate someone with the right tool to swap out the crown wheels etc out of my old diff head into the new one so that I keep the same ratio.

When I jacked my truck up, put it in low range 4wd and put rear lock on, the wheel didn't seem to want to turn?

[WACKO]

When I jacked my truck up, put it in low range 4wd and put rear lock on, the wheel didn't seem to want to turn?

that to me suggests that the locker is operating...

did you find another locker to replace the one in it? or have you just got a bearing rebuild kit?

[NJV6]

To check it, like you said, did you jack up just 1 wheel and have the diff lock light showing solid, (key on and in 4low), had the vehicle in neutral and hand brake off?

If Yes to all of them then it is working as it should. Even when locked the wheel you jacked up will be able to rotate a little as it takes up the slack in the diff.

[Gaz_n_Paj]

Well I owe you guys a beer for trying that's for sure, but here's how it went down.

Gave my truck to one of my mechanics, who drained the fluid for me today to replace the rear diff head and out came a lot of steel!! (like NJV6's) with NO teeth left on one side of the locker.. Thankfully he has tracked down 3 other diff heads to make one out of (hopefully 2 with letting him keep the 2nd). I forgot to take pictures, but it was similar to NJV6s picture of the steel teeth in his, just a few more.. Would explain why sometimes it worked and others it didn't, sometimes it found traction on left over teeth others it didn't. Crown was also rusty.. *sigh* I want to kill the previous owners..

In short tomorrow afternoon I will have a working QUIET truck WITH a rear diff locker (and a WOF - failed due to 1 1/2 inches of water in headlights - tehehe).

Unrelated but changed: Coolant, Oil filter and oil. Cleaned air filter last weekend, air con unit ripped out to improve airflow. Found out my truck has a 40mm or 50mm body lift which means I can do suspension as a much cheaper raise if wanted.

Also looking at buying these 'http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Mitsubishi/Interior/auction-188685864.htm' to put in the back as mud etc will just wipe off and it has arm rests with cup holders - how cool is that!? Anyone know if they will fit? I've asked him to measure too just incase.

Cheers!

[WACKO]

sweet as.. sounds like it will be sused in no time. dont suppose you will end up with a spare 5.285 c/w and pinion? i need to make an open diff so i get my spare locker back before the guys who owns the jero now sells it... hahha

know anyone who wants to buy a diesel jtop?

Sam.

[Gaz_n_Paj]

My 5.3 crown had some rust on it, I think the pinion was ok. I'll get them both off my mechanic tomorrow if you want them, but let me know before tomorrow at 3pm (you have my cell no#).

Depending on the JTop status itself I may want that.. otherwise not an entire truck no. However I will keep my feelers out there for you.

PS Any idea if those seats will fit in the back of our truck since we have identical?

Cheers

[pajeroboy]

hey wacko how much are you looking for the truck?what condishion is it in?mite no someone that could be interested.