LMTV FMTV front axle outer seal replacement

[MatthewWBailey]

This is going to suck!!!!

Those 4 Dave Anderson Videos of installing lockers in the carriers were very detailed on the full disassembly of front and rear since he had to pull the axles to get the centers out. Might be a good video prep?

 

[Keith Knight]

Do you have a link to those videos?

 

[MatthewWBailey]

Do you have a link to those videos?

Yes here's part 1&2. It's called FMTV 3.07 front diff gears. He's got links to the other 3 parts on his channel. It's actually 5 total videos. I was wrong in that there's another 4 videos just for the rear!

 

[MatthewWBailey]

Do you have a link to those videos?

Part 3 &4 for front... this has some detail on the inner and outer seals

 

[Keith Knight]

Thank you.

 

[Keith Knight]

I’ll have to do a video on these seal replacements and post on my YouTube channel. nomadventures360

 

[MatthewWBailey]

Do you have a link to those videos?

Part 5 front

 

[MatthewWBailey]

I’ll have to do a video on these seal replacements and post on my YouTube channel. nomadventures360

I'll watch!

 

[hike]

This is going to suck!!!!

What special tools do you have or need?

We just noticed gear lube coming out the rear axle vent; traced it to the right rear CTIS axle seal, there is gear lube in the banjo bolt =/ Not as big as the front axle job though—

 

[GeneralDisorder]

What special tools do you have or need?

We just noticed gear lube coming out the rear axle vent; traced it to the right rear CTIS axle seal, there is gear lube in the banjo bolt =/ Not as big as the front axle job though—

Yep. Seems like most of these trucks need CTIS seals. Lack of air system maintenance and sitting. Definitely a must-do job while the hubs are apart for ECO hubs, etc.

 

[hike]

@Keith Knight have you found a CTIS hub seal driver? Or what's your plan?

 

[Keith Knight]

Ok back to this job looming over my head. I've purchased ECO Hubs to do as well. Now the total job is going to be the 4 axel seals #59 & 9 two of each, front and rear pinion seals, change front and rear third members from current 3.07 gears to go back to 3.90 gears, reinstall rear locker into the 3.90 carrier, and ECO hubs.
I'm trying to make a final decision on a couple things. The vehicle has 33,000 miles on it 30,000 I've put on it. Never mud bogging it and always keep it clean.

1st I've spoken with 3 different companies that work on these axles and they all say that they have never seen Bushings #11 & 61 go bad. Plus all my searching they are extremely rare to find them and I've been told Meritor stop making them. I did find some but I feel like I shouldn't need them. Opinions???

2nd Concerns the U-joints, I greased them before each big trip. Shouldn't those u-joints last a couple 100,000 miles? Opinions???

Thanks in advance

 

[GeneralDisorder]

Bushings I wouldn't worry about.

U-joints should be greased every 3-5k miles. Replaced every 15k miles on the high angle drive line trucks. The rear shaft for sure anyway. They are cheap and easy to change - don't risk a failure. You'll be looking for a new truck.

The speeds these turn at the angles they run is well beyond the operational design envelope. As such no "manufacturer recommendations" apply. Remember the Army's expected lifespan on these trucks is 35k miles. Meritor says 100k mile service intervals.... But Meritor didn't design the truck or the drive line angle. Stewart and Stevenson did. And they did it wrong - as evidenced by the high pinion rear axle adopted on the late A1R and up through current production A1P2 trucks. If that were not the case they would not have bothered making that change. From this and from the lifespan expectations you can infer that a not-insignificant number of trucks experienced driveshaft/u-joint failure well within the 35k miles chassis life expectation while in service with the Army. Otherwise they wouldn't have spent the money to change the 4x4 rear axle to the high pinion variant.

Edit - you're talking about the front axle steering u-joints? Those I wouldn't worry about. Grease em every oil change or more often if you feel like it. They will give plenty of warning before failure.

 

[Keith Knight]

Thanks for the advice, i was referring to the front axle steering u-joint.
Now you got me thinking of the drive shaft u-joints. Are the front and rear drive shafts the same u-joints? Spicer R-279X?

Edit: the lmtv parts spread sheet has that part number.... is it supposed to be 5-279X?

 

[Ronmar]

Thanks for the advice, i was referring to the front axle steering u-joint.
Now you got me thinking of the drive shaft u-joints. Are the front and rear drive shafts the same u-joints? Spicer R-279X?

Yes, all type 16 driveshafts…

 

[Keith Knight]

I think the LMTV parts spread sheet has a typo, is it supposed to be 5-279X?

 

[GeneralDisorder]

Yes 5-279X will work.

 

[MatthewWBailey]

Thanks for the advice, i was referring to the front axle steering u-joint.
Now you got me thinking of the drive shaft u-joints. Are the front and rear drive shafts the same u-joints? Spicer R-279X?

Edit: the lmtv parts spread sheet has that part number.... is it supposed to be 5-279X?

I just balanced mine and replaced 4 of these. They all said R-279X on the box. And 5-279X as a "replaced" number

 

[GeneralDisorder]

Things like the type of bolts used, type of grease seals, etc. stuff that really doesn't matter. The newer Meritor joints come with break away bolts that snap off at the correct torque. Older ones come with normal bolts, etc. They all work fine.

 

[Ronmar]

yea there are half a dozen crossed P/Ns