M1079 check those hubs!

Duckworthe said:

When you added the Lucas additive, how much did you add per axle?

Click to expand...

I was totally empty so I refilled with 50% Lucas in everything.

Suprman said:

Does it feel smoother driving with the additive? Once it gets warm I am going to switch to synthetic lube. The Meritor ref guide said 75w90 for my temp range I believe. Is that what you used?
Will

Click to expand...

Yup. 75/90. Not smoother. Mayhaps a bit quieter.

I took my truck for a 40 mile run today and here are hub temperatures I measured (all temps in Fahrenheit).
Outside temperature today was 62 degrees..



I am glad to see such low temps. I am sure in the middle of a South Carolina summer they will be higher.

All, Well I returned from my trip and have found that,Yes, my hub temps did come down using the LUCAS additive. Now I only put in one gal in the rear axle and it did drop from 140-145 temps down to 120-125 deg temp. I think that is a win in my book. I will try to add more at the next go round and see what I can really do with the axle. It says on the bottle to use 50-100%. I'm not even near 50% with good results. What I really was reminded of on this trip was just how lucky we are to be able to own such a great truck system. Everyone just loves these things. I hope you all get to enjoy yours as I do. Here is a pic of mine out in the mountains just west of our deserts in San Diego, called Valley of the Moons.

Duckworthe said:

All, Well I returned from my trip and have found that,Yes, my hub temps did come down using the LUCAS additive. Now I only put in one gal in the rear axle and it did drop from 140-145 temps down to 120-125 deg temp. I think that is a win in my book. I will try to add more at the next go round and see what I can really do with the axle. It says on the bottle to use 50-100%. I'm not even near 50% with good results. What I really was reminded of on this trip was just how lucky we are to be able to own such a great truck system. Everyone just loves these things. I hope you all get to enjoy yours as I do. Here is a pic of mine out in the mountains just west of our deserts in San Diego, called Valley of the Moons.View attachment 612421

Click to expand...

Nice ride, any pics of the camper unit?

Dave

Can someone explain how to check this again. Rotate hub drain to 4? If it leaks from that it's full? How many qts do they take

11-13 oz (0.33-0.38 liter) in the front hubs. Position fill port at 4 o'clock position. If oil flows from fill port when plug is loosened, let it drain to correct level. If oil is below fill port, fill hub with recommended fluid. Six o'clock to drain, 12 o'clock to fill.

Why can you pump fluid into the 4 position.

You could. I was just copying what is in the TM. It takes so little oil to drain and refill. I just did mine last weekend.

Kambaku said:

11-13 oz (0.33-0.38 liter) in the front hubs. Position fill port at 4 o'clock position. If oil flows from fill port when plug is loosened, let it drain to correct level. If oil is below fill port, fill hub with recommended fluid. Six o'clock to drain, 12 o'clock to fill.

Click to expand...

Just because I am getting ready to do this when I go to pick up, I wanted to read up on all of this and also the TM. I'm reading that the check AND fill are done at the 4 o'clock position (9-2320-365-20-3, pg H-18, (12.2) ). Filling at the 12 o'clock position would make no sense if it is checked at the 4. Is there somewhere else where 12 o'clock for fill is specifically mentioned?

I filled mine at the 4 position. I can't see why it would matter.

I was politely asking why it was reported as a reference in the TM when it was not. It's in the TM differently. Just trying to find out if there was something I was missing or if opinion was being reported as fact.

I think they have you fill at 12:00 just for ease of access. Assuming you just got draining it at 6:00 and you have to turn the wheel to refill then you might as well position it to make it easy, but I think if you're just topping off then having it at 4:00 is fine.

Ok i need some advice: I read up on the hub noise issue and successfully shimmed the front right hub (drivers side didnt need shimming). The growling noise was reduced by half or more with a bit of noise still coming from the rears (i think). The problem is that the right front pumpkin is still significantly warmer than the other 3. It was also warmer before i shimmed it. The bearings are good. New oil (75/90). Brakes are not dragging, also not pulling to one side at all. Equal air in front tires. My question is this; Why are the other 3 hub positions cool, but the passenger side, front is way, way warmer. I can hold my hand on it, but on a hot day and long milage i seriously doubt that i could. Could this be the outer gear that meshes with the 4 spider/bevel gears? Could it need shimming as well? Please advise.

Warmer means drag and friction. Wheel end spider still not set up right.

Kodyman said:

Ok i need some advice: I read up on the hub noise issue and successfully shimmed the front right hub (drivers side didnt need shimming). The growling noise was reduced by half or more with a bit of noise still coming from the rears (i think). The problem is that the right front pumpkin is still significantly warmer than the other 3. It was also warmer before i shimmed it. The bearings are good. New oil (75/90). Brakes are not dragging, also not pulling to one side at all. Equal air in front tires. My question is this; Why are the other 3 hub positions cool, but the passenger side, front is way, way warmer. I can hold my hand on it, but on a hot day and long milage i seriously doubt that i could. Could this be the outer gear that meshes with the 4 spider/bevel gears? Could it need shimming as well? Please advise.

Click to expand...

I would quantify "warmer" by getting an IR thermometer and checking (e.g. before, during, after trip). Mine don't get that hot (I don't remember exactly, but like 115°F, with good Royal Purple synthetic oil in them), and they only vary about +/- 7°F

As NDT said, if the gear set warms up and expands into zero clearance (or worse) the reduction set will heat up. Its better to have too much slack compared to having too little. What method did you use to determine how many shims to use to set the clearances? These gears are like valves, if you hear a little chatter, they are not too tight.

Awesomeness said:

I would quantify "warmer" by getting an IR thermometer and checking (e.g. before, during, after trip). Mine don't get that hot (I don't remember exactly, but like 115°F, with good Royal Purple synthetic oil in them), and they only vary about +/- 7°F

Click to expand...

It was 62 degrees here today and at the end of a 3 mile test run, the 3 cool hubs felt darn near the same as before i drove. Meanwhile the hub in question was at least 120 degrees. That is simply too much difference. By comparing all 4 bevels/spiders/shafts on all 4 positions, i found an average of about 20 thousands end-play on each assembly except the one in question. It in turn had almost 5 times as much end-play on its shafts according to the feeler gauges. Through trial and error i simply shimmed the large inner-gear until it mimicked the tolerance of the other 3 positions. But that's not the problem, as even before i shimmed it, the hub in question was still getting ridiculously hot on hot days (couldn't even touch it.) Something is dragging or rubbing now just as it was before, but i cant seem to find what it is. It drives straight as an arrow when letting go of the steering wheel and the brake was still cool. Bearing play is also more than acceptable. I wonder if one side on the lmtv front axial pulls more regularly than the other side. Unlikely i suppose but just a thought.

did you drive one way straight up a road then test? If so wonder if road crown could effect it?

This might be too obvious, but i ask it anyway. Could it be that there is drag on that wheel? Say from a badly adjusted brake shoe? Did you test to see if that particular wheel spins freely?