# rebuild auto hubs



## ajriding (May 10, 2010)

First yes I know manual locking hubs are better and superior. Thank you for telling me that. I want to rebuild the auto locking hubs on a 87 pick up 4x4.
My question centers around fixing the hub, not buying the new hub, and I know from reading other forums that many will respond with, "buy manual hubs cause day better, derrr". Please don't.

Mine makes a clunk after a reverse. I have to shift and drive in 4wd a few feet then back to 2wd to make it stop- until I reverse again. I have narrowed it down to the left front hub. The thrust washer has a lot of forceful wear on the inner tabs. the tabs seem to be what locks into the outer hub. I don't really know how the hubs work other than that. If you know this answer, then is the worn thrust washer the problem, or is it the result of something else?

I tried just hammering the jagged edges smooth. Then later grinded it down, welded a little metal on and re-shaped it like new. Not sure I got it perfect, but not sure that is the issue. It seems to work in my hand, but Im not sure exactly of the function.


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## smj999smj (Jan 1, 2006)

The thrust washers were particularly prone to wear and breakage on the auto hubs. If your thrust washers are worn and since you apparantly want to stick with the Nissan auto hubs, your best bet is to purchase new ones from Nissan; they are only a few dollars each and I would recommend you do so on both sides. On the link to the parts diagram at the end of the post, I would replace the following part codes due to the age of the vehicle: 40256D, 40160E, 38514, 40259, and 40250E. I would also do a careful inspection of the "brake set," code 40267S, as well as making sure the wheel bearings are well greased and properly adjusted. Make sure you apply grease to the thrust washers and brake set prior to reassembly. Some general notes about the free running hubs: the engage going forward but disengage going in reverse when in 4WD mode and when they make noise, it is usually the one that is making the noise that is good (and the "quiet" hub that is not working properly). The Auto hubs are okay for street use and isn't a bad setup, they just aren't as reliable and effective as a set of WARN manual hubs (I know you didn't want to hear it...but, that's just my experience working as a Nissan technician for 16 years). 

Part Detail


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## ajriding (May 10, 2010)

Thankyou, excellent reply. I needed that parts link as was not able to find it myself.
I'm not sure which thrust washer to get, I do not know what all the two-digit letters represent. I actually have a 1986.5 truck, so do I need the first 40256D part?

40256D	WASHER-THRUST
**218-31G00	1985.11-1987.07	4WD. Z24. (SB. ST+ LB. ST) + 4WD. VG30. (SB. GST+ LB. ST+ LB. GST)	
$4.12
$3.31

40256D	WASHER-THRUST
**218-31G00	1987.07-1992.01	4WD. SE + FED. Z24. 4WD. T. LB. DX	

I assume "brake" does not refer to the stopping brakes.
And, yes, I just need 4wd for minimal use: snow, not getting stuck in dirt and getting around the back yard. I've been happy the first 340,000 miles with it so I think is good enough and I dont get my feet dirty.

Also, I just curious what mechanically happens when I put it into 4wd. I see how the thrust washer rotates and moves into a locked position, but what is it locking? I would not think the thrust washer is the link between the axle and the wheel. How do these little parts engage the hub? 
thanks


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## smj999smj (Jan 1, 2006)

As the axle rotates in a forward motion (after shifting into 4WD), it causes the coupling in the hub to engage in a "screw-like" motion. As you go in reverse, it often disengages, which can be bad if you're stuck in mud or snow and you are trying to "rock" your vehicle out of being stuck. Yes, "brake set" refers to the internal hub brake, not the brakes that stop your car. 

The parts diagram at NissanPartsZone gives part codes, but the part numbers the refer to put " ** " in place of the first two digits of the actual Nissan part number. Some Nissan online sites alter the genuine Nissan part number; I can only assume this is to prevent people from using their site solely for it's Nissan online catalog rather than to buy parts from them. Often, but not always, the first two numbers of the part code are the same as the first two numbers of the part number. For example, part code "40256D" refers to the number "**218-31G00." The actual Nissan part number is "40218-31G00."

As far as which "40256D" part you need, in this case, it doesn't matter as they are both the same part number: 40218-31G00. However, for other parts that may offer different part numbers, you would go by the production date of your truck. Your truck is an 86.5, so it would fall in the production range listed for the first "40256D" reference, which is 11/1985-07/1987. If you look at the next "40256D" part reference, it list production date range of 07/1987-01/1992.


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## ajriding (May 10, 2010)

thanks for all the input. I went by the junk yard and pulled the outer hub piece (heavy metal thing) and the thrust washer and spring. I think that is $300 and change online new. Showed it to the guy and he wanted $20, so I got the other side too just to have. Replaced and it seems to work just driving on my street. I will carry the spare good unit if I ever do serious off-roading. They seem to be identical no matter which side..


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## ajriding (May 10, 2010)

Turns out both my old hubs and the junk yard auto hubs had worn brakes, engagement brakes, not stopping brakes. That dosent explain the loud noises, but I just put manual hubs on now.


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