M1078 LMTV planetary hub setup

[DiverDarrell]

Buy the tools, they are not too much and you can do it no problem

 

[Adventure Driven]

Hub service is next on the list for me, do you buy chance have links to where I can purchase the big hub nut socket, as well as the seal driving tools?

Cheers
Seth

A year ago I had little knowledge on all of it as well. Being one of the first to write about the locker install as there was not much info on it. Learned a lot about the hubs here, and until you open one up first hand, they seem more complicated than they are. If your serious about the truck I recommend making the tool to set actual gear lash, get the big hub nut socket, as well as the seal driving tools. And first thing when you get it home, open one up and check it out. It will only cost the lube and some RTV to put it back together. I had a leaky oil seal on a hub that got me to first open mine up.

 

[firefinder]

Seth,

First of all, thanks for posting the great photos and videos of your vehicle and adventures!

I created a thread detailing some of the FMTV Special Tools. There are photos and a .pdf with details on the NSN, manufacturer and part numbers.

https://www.steelsoldiers.com/showthread.php?167478-FMTV-Special-Tools

I'm sure you have already found the discussion on the Special Tools List in Section III of the M1078 -24P or M1083 -24P-2 tech manuals. Sorry, I don't have some current links to purchase these tools though.

Stay safe and stay in touch,

firefinder

 

[coachgeo]

Here is a list of basic tools... both KISS version and detailed.

https://www.steelsoldiers.com/showthread.php?152218-Essential-Tools-to-have-for-an-FMTV-Add-your-02

 

[Adventure Driven]

Your sure welcome, we love our truck I sent you a PM about the tool

Seth

Seth,

First of all, thanks for posting the great photos and videos of your vehicle and adventures!

I created a thread detailing some of the FMTV Special Tools. There are photos and a .pdf with details on the NSN, manufacturer and part numbers.

https://www.steelsoldiers.com/showthread.php?167478-FMTV-Special-Tools

I'm sure you have already found the discussion on the Special Tools List in Section III of the M1078 -24P or M1083 -24P-2 tech manuals. Sorry, I don't have some current links to purchase these tools though.

Stay safe and stay in touch,

firefinder

 

[m-35tom]

Has anyone noticed that the hub reduction is actually 1.714:1 and not 2:1? The large bevel gears are a 24 tooth, the small bevel gears are a 14 tooth. 24/14=1.714

the small gears, spider gears if you will, have nothing to do with the ratio. it is 2:1

 

[scottmandu]

the small gears, spider gears if you will, have nothing to do with the ratio. it is 2:1

Thanks for the necro bump this was mentioned over a year ago.

 

[m-35tom]

yes I know but I am now being told the spider gears control the ratio, they don't

 

[Kodyman]

Ok; here is my own humble conclusions on the hub-rattle-growling-shim issue. After finding that my right front hub needed shimming and correcting according to procedure, i still only reduced the total growling noise by about 50%. I had noticed that both front and rear drive-shafts were out of phase, -meaning that the drive-line U's were not facing straight away from one another. This is critical is all vehicles of which i know in reducing or eliminating vibration. While i assumed, as do most, that the vibration was the result of a mis-shimmed hub assembly, it was in fact largely the result of misaligned drive-lines. After phasing the drive-shafts correctly, ALL OF THE VIBRATIONS CEASED.
Yes, part of the problem was due to the hub, yet at least half of the issue was the direct result of the drive line alignment. The only problem i have now is that my rear drive line was welded about 1/8" out of round from the factory. This causes a small amount of residual vibration although minimal. It is amazing how much difference it made by just phasing things correctly. My truck is actually reasonably quite at this point at road speed. I'm not sure, but i suspect that many drive-lines are wrongly aligned and i have personally witnessed many on the lmtv trucks. How they got this way is anyone's guess. I feel that many lmtv owners will save a lot of money by checking the drive-line issue 1st, before anything else. It will save money and time to begin here...so much more pleasant to drive my truck now...Hope this helps

 

[coachgeo]

.... The only problem i have now is that my rear drive line was welded about 1/8" out of round from the factory. This causes a small amount of residual vibration although minimal. ...

REPLACE or fix it. NOWW Not worth a tranny replace if you have any rear driveline vibes and even after the big D driveline replacements.... there has been approx 10 trannies out of the trucks released to civilians that has had tranny destroyed by rear driveline vibes. Your talking anywhere from 3 to 7 grand tranny repair or replace if that happens. Been there..... bent that. Got the trophy of destroyed parts

 

[Kodyman]

REPLACE or fix it. NOWW Not worth a tranny replace if you have any rear driveline vibes and even after the big D driveline replacements.... there has been approx 10 trannies out of the trucks released to civilians that has had tranny destroyed by rear driveline vibes. Your talking anywhere from 3 to 7 grand tranny repair or replace if that happens. Been there..... bent that. Got the trophy of destroyed parts

Got it! Will do; I've already made an appointment with Republic Diesel to either cut and align or replace the long tube of the rear driveshaft.

 

[Floridianson]

Ok; here is my own humble conclusions on the hub-rattle-growling-shim issue. After finding that my right front hub needed shimming and correcting according to procedure, i still only reduced the total growling noise by about 50%. I had noticed that both front and rear drive-shafts were out of phase, -meaning that the drive-line U's were not facing straight away from one another. This is critical is all vehicles of which i know in reducing or eliminating vibration. While i assumed, as do most, that the vibration was the result of a mis-shimmed hub assembly, it was in fact largely the result of misaligned drive-lines. After phasing the drive-shafts correctly, ALL OF THE VIBRATIONS CEASED.
Yes, part of the problem was due to the hub, yet at least half of the issue was the direct result of the drive line alignment. The only problem i have now is that my rear drive line was welded about 1/8" out of round from the factory. This causes a small amount of residual vibration although minimal. It is amazing how much difference it made by just phasing things correctly. My truck is actually reasonably quite at this point at road speed. I'm not sure, but i suspect that many drive-lines are wrongly aligned and i have personally witnessed many on the lmtv trucks. How they got this way is anyone's guess. I feel that many lmtv owners will save a lot of money by checking the drive-line issue 1st, before anything else. It will save money and time to begin here...so much more pleasant to drive my truck now...Hope this helps

You are the man and yes my front drive line is out of phase. I bought the tiger tool a long time ago so getting the joint apart will be easy. Thanks for the wake up call.

 

[m-35tom]

I do not understand what you mean about the driveshaft being out of phase? Do you mean it was welded in an incorrect place? Pictures of drawing please.

 

[simp5782]

I do not understand what you mean about the driveshaft being out of phase? Do you mean it was welded in an incorrect place? Pictures of drawing please.

The end yoke ears on the shaft and on the slip yoke are not in alignment. Basically a driveshaft that has the yoke ears on one end on the same spline as the yoke ears on whatever the opposite end is hooked to then the joint will not flex

 

[m-35tom]

so it is being talked about sliding the slip joint apart and putting it back in with correct alignment? If yes, then you will have a 50% chance of the shaft being out of balance since you will have no way to know how it was aligned when it was originally made.

 

[Floridianson]

https://www.drivelinesnw.com/part-trouble-shooting/vibration-analysis/phasing/

Willing to bet the person that was working on it before new not of what he did plus the shop foreman was sleeping caused the problem. Drive line balance should be fine finger crossed. Still needs to be corrected.

 

[m-35tom]

OK, when the shaft was new it was balanced. If you pull slip joint out and rotate it 180° it will not be in balance. So you have a 50% chance of getting it right when you are correcting the mistake someone else made.

 

[NDT]

OK, when the shaft was new it was balanced. If you pull slip joint out and rotate it 180° it will not be in balance. So you have a 50% chance of getting it right when you are correcting the mistake someone else made.

I'll take a 50% chance of out of balance vs 100% for sure destruction of driveline. I too have seen numerous LMTVs with the driveshafts out of phase.

 

[m-35tom]

I have seen so much stupid things done on trucks by military 'mechanics', they clearly don't sometimes know what they are doing.

 

[simp5782]

On alignment on a driveline when you realign the slip yoke the weights on the slip yoke and the driveshaft should be on the same side of at least close to it (one or two spine offset it find) the weights will not be on complete opposite sides