My rear end is making a growing amount of noise - a constant whirring on the gas and classic gear chatter on deceleration - I suspect the pinion bearing(s). Is it possible to replace the front bearing without disassembling the third? I am weighing my options wheather to repair or replace with a junkyard third.....been quoted $250 from a local yard for a 4.56third.

advice.

 

No, you will have to remove and dismantle the third to get the bearings out.

What are the miles and condition of the used third?

 

Sure it's not a u-joint?

 

I haven't seen the third offered-I just asked for a quote last time I was at the yard - Briefly checked u-joints - they looked OK no play. We have had 2-3' of the white stuff here recently and now it is pouring rain - not the best weather to be working outside in! I crawled under the truck yesterday and felt the play at the pinion flange (drivshaft still attached) and within the play of the gears there was what seemed to feel like a rough bearing. I have access to a 'gear man' at a freinds work (Kenworth) who wound probably set up a third for a bottle of his choice. I haven't looked at what an install kit is going to cost me locally.

I will head out in a bit and take off the driveshaft and jack up the rear end and get a real feel for whats going on.

Thanks for the replies!

 

Play in the pinion flange = bad

Probably means the crush sleeve got deformed and you lost your bearing preload...

 

is there any way to reset the bearing preload without pulling the third??

 

No way. all the bearing load stuff is inside the third. If your getting diff work done i would scrap the crush sleeve and have a trail gear solid spacer installed while your at it.

 

So.... pulled the driveshaft, rear wheels off the ground - no play in either flanges - T-case or rear diff. Rear diff spun freely by hand, no noticeable 'bad bearing' feel. Pulled the fill plug on the rear diff and took a sample - milky gear oil - water in the diff.

So on the advice of a friend I drained the old fluid and put in a 50/50 Lucas heavy duty oil additive and fresh gear oil. Obviously this did not 'fix' anything - I am just trying to get by untill I find a replacement diff.

Now obviously the bearings are not happy (found some small metal shavings on the drain plug) When driving I still get the classic gear growl on deceleration - my thoughts are that the bearings are worn (DUH!) and the pinion is now wlking up and down the ring gear.

My question is - would I not feel this movement when I tried to move the pinion at the flange?

I am going to head down to a friends shop and check the bearing preload on the pinion.


Is there anything in the t-case that would make similar noises/ symptoms?


Started looking for a replacement third.

 

better check your trannie, TC and front diff fluid too...
this thread on ttora i believe the vendor had a limited number of used thirds
available:
http://ttora.com/forum/showthread.php?t=117978

 

Ya I will be checking/changing front diff, tranny, t-case tomorrow.

Thanks for the link but I think the shipping would kill me!