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Telly
10-03-2012, 06:03 PM
I'm complete with the removal and cleaning of all the components for a full knuckle/wheel bearing replacement on my newly acquired 78 FJ40 and I'm waiting on my kit from Cruiser Outfitters. My plan was to simply reinstall the shims that were on the rig but I am now thinking I should check it. Looks like a straight forward process as long as you have the SST, measuring calipers and a fish scale. Can I rent a SST from someone or somewhere? Any suggestions on how to do it besides following the FSM? I'm done knuckles on two 80's but this is a new one for me.

Thanks. Doug

nakman
10-04-2012, 09:44 AM
Yeah, if you can get the SST then it's likely worth doing, though IMO the consequence is less severe on a part time truck compared to an 80, since those front axles won't be spinning most the time, and one of the benefits of a well centered trunion is getting the axle centered in the inner seal, right?



Subzali is the most recent guy I can think of who has done this, here maybe this will help http://www.risingsun4x4club.org/forum2/showthread.php?t=6635

DanS
10-04-2012, 03:11 PM
Your timing is awful.

I just carried my SST back down to NM last week. In about a month I can bring it back up here if you can wait....

Dan

Telly
10-04-2012, 06:34 PM
nakman, thanks for the link...very helpful. I had grey soup in my front diff so I want to cover all bases with the rebuild. Plus I have some slight scoring inside the spindle shaft...that can't be good.

DanS, my timing always blows. I have not priced one of these SST but I may have to consider buying one. I guess I could wait a month if the price is $$$. Thanks for the offer. :beer:

Another related question, both my axles have a very slight groove at the inner seal location. Is the rule of thumb to have a perfectly smooth shaft at this location or your just waiting your time? I'm using Marlin seals.

Doug

Rzeppa
10-04-2012, 08:57 PM
Hi Doug, unless there is obvious need to relocate the shaft, re-using the exact same shims is the normal practice. Doing a disk brake swap (involving a different knuckle than the one that came from the factory) is the typical reason to need to measure using the SST for different shims. Bearings are made to tolerances in the 1/10,000" range so simply renewing the knuckle bearings is not a reason to have to measure for new shims.

The grey soup is pretty typical of a worn out inner axle seal ("Birfield seal"). A little bit of grooving is normally not a problem unless it is so deep that you can catch your fingernail on it. With the part time locking hubs, you really won't have anywhere near as much to deal with as an 80 that turns all the time.

rover67
10-04-2012, 09:10 PM
Hi Doug, unless there is obvious need to relocate the shaft, re-using the exact same shims is the normal practice. Doing a disk brake swap (involving a different knuckle than the one that came from the factory) is the typical reason to need to measure using the SST for different shims. Bearings are made to tolerances in the 1/10,000" range so simply renewing the knuckle bearings is not a reason to have to measure for new shims.

The grey soup is pretty typical of a worn out inner axle seal ("Birfield seal"). A little bit of grooving is normally not a problem unless it is so deep that you can catch your fingernail on it. With the part time locking hubs, you really won't have anywhere near as much to deal with as an 80 that turns all the time.

I agree with Jeff... Just put it back together with the shims in the same spots they came from and go for it. I have used a borrowed tool on both my 60 and 40 and the shims remained essentially unchanged.

The only real reason I'd re shim is if I had a bare axle to work with or if I suspected that a previous owner jacked with it.

Rzeppa
10-04-2012, 09:25 PM
or if I suspected that a previous owner jacked with it.

One of the knuckle bearings in my '76 40 was a BALL BEARING. :eek:

No idea how the idiot thought that would fly, but I guess they figured the races were the right sizes so what the heck? Needless to say, not only was the seal shot but the bronze liner in the hub was worn unevenly where the shaft was way out of concentricity.

subzali
10-04-2012, 09:46 PM
Just to throw in my two cents - my shims were pretty far off when I went to measure. So someone had been in there before and messed it up. I at first put it back together the way it came apart but it leaked a few short months later. YMMV

nakman
10-04-2012, 10:01 PM
Just to throw in my two cents - my shims were pretty far off when I went to measure. So someone had been in there before and messed it up. I at first put it back together the way it came apart but it leaked a few short months later. YMMV

I think that's the test. Once you get it together, drive in 4wd for a while, then see if it's leaking. I guess 40's don't have ABS sensors on them do they... do they still have those square plugs? You can stick something down there to see if it's soupy.. but then again, if it is then you're doing the whole thing over again. I guess I'd probably lean towards the SST, if you can afford to have the truck on stands until you find one.

What's the width of the groove on the axle- is it thicker than the Marlin seal? Wait, did you pull a Marlin seal out of it? Or just get those to put back in... hypothesis being if you just got the 40, and the PO did Marlin seals, then maybe he switched the shims by mistake and there you go that's why the soup. which means you likely need the SST to sort it out.

subzali
10-05-2012, 08:24 AM
Telly - the seal lip will cause a groove over time. The Marlin seal should help with re-sealing that surface because the dual seal lips are in different locations than the OE seal lip.

Telly
10-05-2012, 04:49 PM
My guess is the birf grease/seals are original but who knows. I guess this theory would mean just reinstall the shims and go on with life. I was surprised the birfs and trunion bearings were in decent shape since they were coated with grey soup and not much grease.

However, since I'm an anal SOB, I'm going to attempt to locate the SST. I'm not digging the thought of finding mixed grease in the knuckle 6 months from now, tearing the whole thing down again and finding out the shims were wrong. I'm not in a huge hurry to finish this job but I do want to play in the snow soon.

Anyone have one of these SST laying around? I've got beer, cash, dip...

Rzeppa
10-05-2012, 07:40 PM
Telly - the seal lip will cause a groove over time. The Marlin seal should help with re-sealing that surface because the dual seal lips are in different locations than the OE seal lip.

It is true that the Marlin seal will seal in different places than OEM. However, the lip doesn't cause the groove, abrasive dirt and dust causes the groove. The lip just presses the dirt and dust against the shaft. Keeping the fluid clean and the dust seals fresh (<10 years between replacements) prevents the abrasives from accumulating to where they can allow the lip to score the shaft.

powderpig
10-07-2012, 08:41 AM
I have the tool, I will loan it to you. I will pm you my Phone number.

Telly
10-08-2012, 09:14 AM
Robbie, thanks for the offer but I've got one located. I plan to verify the shim sizes this weekend if my kit arrives from Cruiser Outfitters. I'll close the loop on this thread with my results. Thanks for everyone's help. Doug

subzali
10-09-2012, 08:45 AM
Post pictures of the patient! ;)

Telly
10-09-2012, 09:44 AM
Post pictures of the patient! ;)

Will do! Let me get her back together and I'll take some poser shots.:hill:

subzali
10-11-2012, 02:37 PM
Doug, here's a couple links I have saved in my bio:
OTC Tools - Axle Centering Tool (http://www.risingsun4x4club.org/forum2/showthread.php?t=5569)

DIY Rear Main Seal Installation Tool (http://forum.ih8mud.com/40-55-series-tech/96428-rotw-my-yoda-2.html#post1234896)

IIRC 1 1/2" Sch. 40 pipe is what you use to separate the inner axles from the birfs.

Rzeppa
10-12-2012, 06:58 PM
IIRC 1 1/2" Sch. 40 pipe is what you use to separate the inner axles from the birfs.

That's what I use and carry in my trail toolbox. Of course you have to hold your mouth just right...

:p:

wesintl
10-13-2012, 08:49 AM
piece of pvc will do the job too

Rzeppa
10-17-2012, 06:32 PM
piece of pvc will do the job too

Really? The ones I have been involved with, I (or whoever was doing the separating) really had to wail on that sucker to get it to come off the inner axle. More often than not it shatters the c-clips too, which is why I carry spares of those too.