Fornt differential noise (1 Viewer)

[Seminole]

??? I have front differential whine (not grind) upon acceleration through first and second gear. I don't have any distinguishable noise upon deceleration. Some background/history: 223k, regular changes of diff fluid (every 15K), no evidence of contamination or axle seal failure, fresh fluid in now, some slop in drivetrain, ujoints and other components are good to go.
I did have the front pinion seal leak, but I got to it before it allowed for any damage and the pinion bearing was ok at the time (about 6 mos ago). I am about to do a full birf job and would like to get this while I have the front end apart, clean and drained.
Question is: is the noise more likely to be R&P related or pinion bearing related? I always thought that acceleration noise is R&P? I won't know for sure until I open it up. I need some help on this because I don't have alot of options locally for quality diff rebuilds, can't afford to regear right now, want lockers too and can't have the truck down for an extended period (work related). I don't NEED to regear yet because I'm still pretty much stock and will be for a while.
Any one have any experience with purchasing a built 3rd ( aftermarket or OEM replacement) and dropping it in? If so, who can you recommend (in addition to Slee, Randy's R&P)?
Thanks for any and all help suggestions.

 

[GXO]

Could have been damage done when the seal went (probably due to a possible loosened pinion nut).

This could be the progression toward failure.

Will wait for others with more experience up front.

 

[IdahoDoug]

At nearly a quarter million miles, I think some whine is acceptable but I'm surprised it would appear with such extremely high front diff maintenance and the lower output engine. Have you owned this since new, or did it come with meticulous records from a full on anal owner (that's twice as often as even the factory recommends!)?

How confident are you that the whine is NOT front shaft/joint, NOT birfield, and NOT center differential noise? And finally, have you done anything with it that may have caused minor damage, such as pulled on something with the truck in reverse?

Finally, my bro in law put an OEM drop in third member in his after letting the fluid get too low and causing the bearings to begin yowling on acceleration at certain speeds. It was quite reasonable ($850 part??) and was my suggestion.

DougM

 

[Brentbba]

I sure ain't a mechanic, but where is a fornt on our trucks???

 

[Eduardo96FZJ80]

[quote author=IdahoDoug link=board=2;threadid=16097;start=msg153872#msg153872 date=1084220330]


.... And finally, have you done anything with it that may have caused minor damage, such as pulled on something with the truck in reverse?



DougM
[/quote]

Doug,
I pulled my cousin's Suburban (stuck in sand) in reverseis this a bad practice? @ the time It seemed like a good idea, I could see what was going on vs. looking thru the mirrors :-\

 

[GXO]

ALWAYS pull forward. In reverse you can and will grenade things. :bust:

 

[Eduardo96FZJ80]

[quote author=DanKunz link=board=2;threadid=16097;start=msg153891#msg153891 date=1084221645]
ALWAYS pull forward. In reverse you can and will grenade things. :bust:


[/quote]
Thanks for the info! I'll myself one more time

 

[cruiserdan]

[quote author=Brentbba link=board=2;threadid=16097;start=msg153880#msg153880 date=1084220719]
I sure ain't a mechanic, but where is a fornt on our trucks???
[/quote]

it's the end opposit to the brack. :

 

[Seminole]

Apologies for the spelling, just now got recheck my post. Thanks for the replies and suggestions.
DanKunz- that's what I was thinking, I was pretty sure I got it in time. The seal failure did lose some fluid but I only went about 30 miles at a reasonable speed before stopping and repairing it.
IdahoDoug- I am the second owner and I have most of the records and the truck was local all its life. Yes the maintenance history is that meticulous but as I got in to the truck, I found that attention to detail was not a high priority. I have had the truck almost 4 years and 40k. The PO did a lot of towing with it (a small horse trailer for his daughter) and this is what I think is the root cause. I have not damaged any components except maybe when the pinion seal failed. I am reasonably confident that it is not the front DS or u-joints but not optimistic about the health of the transfer case(some slop), no evidence of birfield problems (they were last done at 180k and I am doing them as soon as I have a spare 3 days). The whine is definitely from the front diff and only on acceleration through 1st and second.
Well Cdan, what's the dogfood tab for a front third member for a 91. I am pretty sure I'll go this route and then have the old one sent off for rebuild, regear and arb install. 4.88's and 33 x 10.50 tires ought to be right for a 3FE?

 

[Brentbba]

[quote author=cruiserdan link=board=2;threadid=16097;start=msg153976#msg153976 date=1084230305]
it's the end opposit to the brack. :
[/quote]

hehehe

 

[IdahoDoug]

Sem,

Unless the whine is something you simply can't handle listening to (nobody like that here :) then just drive it. Ditto the center diff slack. These things are built like you know what and a quiet whine is just the gear set wearing. Keep the fluid topped and drive it. I honestly don't think you're anywhere near any kind of failure with the stock vehicle. Others may chime in here, but you should just drive it unless and until that sound makes a sudden change or until it eventually becomes the louder whine of actual torture. Until then, it's just the patina and character a mechanical device acquires at a quarter million.

DougM

 

[Cruiserdrew]

I'm not sure about this. Large trucks can go 750k and more without any problems with the R&P or pinion/carrier bearings. Maybe the damage from being low on oil was worse than you thought. In my very limited experience(1), it's the pinion bearings that wear out, not the R&P or the carrier bearings. I would get this looked at soon. Check out what Mark Whatley has to say about neglected pinion bearings in a Land Cruiser Diff in this month's Toyota Trails. One of his customers had one that locked the diff, then split the differential outer case. If you are sure the noise is in the front diff, you could pull it out and take the whole thing to a differential shop for a rebuild. All 4 bearings and an R&P set-up should be about $250.

 

[cruiserdan]

You can isolate the front diff for a road test by doing the following:

Remove the front driveshaft and lock the center. Remove both drive flanges and cover the exposed hubs with plastic or the like. drive a short distance and see if the noise is gone.

 

[Rich]

From a diff specialist's website: "If the gears howl while accelerating over a certain speed range, but not all speeds, it's likely that the gears are worn due to lubrication failure or overloading."

http://www.randysringandpinion.com/tech/techind.html

 

[GXO]

http://www.marlincrawler.com/3rd.html

$1500 for a brand spankin new one with an ARB and 4:88s.

Get a 4:88 set for the rear and plunk an aussie back there and you are set for big tires and lockers...

hehehe, bad influences abound!

You will see that this isn't a bad deal when you consider OEM replacement.

 

[Seminole]

Gentlemen,
Thanks for the links and the food for thought. I'll try Cdan's test this weekend. The noise is not torture yet but noticeable.
I've checked out those links and those a good options (4.88's, ARB and 33's ). I will do some more isolation and trouble shooting to confirm. I am really just trying to attack a whole problem and not waste time and parts ($$$) while I have the front end down for maintenance. Thanks again for the help.