Waking up a Texas M151A2

[rickf]

Don't bet on it, I put some 1/2" plywood followed by 1/2" foam insulation and some carpet. Mainly because the floors get so hot and I have my dogs in there. But the noise was still there. You still have the sheet metal hood and front floors plus flat sides and fenders and the fact that the diffs are mounted to folded sheet metal that is part of the structure which transmits the sound throughout the vehicle.

[m3a1]

Well, I'm really just spitballing here. I have no conceptions that I'm so with it that I'm going to magically solve a problem that's been going on since forever but I suspect that cutting down on the resonance will make some improvement as the noise that I find most objectionable is coming from the rear and it is resonating through the flooring which quite clearly amplifies the sound. It is that amplification that I'm attempting to stifle, not the production of noise by the rear end.

It's very clear to me that the military was attempting to do just that with the rustproofing which, in my truck, was generously applied, but only to the areas immediately behind the fuel tank well and tool locker. It's pretty clear to me that's what they had in mind when they applied it as it is unusual for them to take half-measures. It was a good idea, true, but poorly executed. In the long term I'm not going to be keeping two big bags of potting soil or the like in the back of the truck just for the sake of noise but I think the idea does have merit and should be explored somewhat.

I have heard and read stories that some outfits placed sand-bags in the rear of their M151s in an effort to improve handling. Perhaps that claim to better handling might be true in the case of M151 variants that had suspensions designed to allow them to carry heavier loads and weren't always loaded but, I'm doubtful that straight M151s would see any real benefit from adding weight to the rear. Could it be that they were also attempting to cut down on the noise?

Cheers,
TJ

[rickf]

And to keep mines from blowing their gonads off!

[m3a1]

Cleaned up the axles today. Looking over everything, I found one of the U-joints had a grease zerk that was stuck open. These don't appear to be of a type that can be replaced, seeing that the base of the zerk is round, rather than hexagonal and I didn't want to fiddle with it until someone on the forum said it could be replaced. Do they screw out?

Another thing happened that really intrigues me. During the clean up of one axle, I had the tape securing the U-joint caps removed because I was working with solvents. I had a cap that really wanted to come off...so much so that I was going to put a dab of fresh grease in there to help it stick while I was handling the axle. So I removed the cap and discovered that one of the roller bearings was missing! DANG! Apparently this is something that can be gotten away with for a while but I really think it should be sorted out. I can borrow from the Alley Cat for the time being so it's more of a annoyance than anything but this leads me to the big question and that is, who is the go-to source for U-joints?

Cheers,
TJ

[rickf]

Considering you are in Texas I would say Red River or Rapco. I usually just watch for people selling them online and buy a few here and there.

[m3a1]

Thank you, Rick. Of late, I've managed to pick up a whole raft of web gear all of which dates within the time periods applicable to the MUTT. So much so, that I'm now toying with the idea of purchasing a mannequin to put out when I display the truck. The one thing that's really keeping me from it is that, for now, my truck is being kept in it's barn-find appearance.

Still patiently waiting for some parts that will finish off the very cheap and badly mistreated Airsoft M14 I picked up for a few bucks. I'm giving the M14 a complete makeover, filling the screw holes that don't belong, sanding off the high points on the plastic stock that don't belong and finally, painting it up using my old model-making skills. Making the plastic stock look like wood is going to be something of a challenge but I'm told there is a kit out there somewhere made just for that purpose. It should make a nice throw-down piece for display; something that I won't have to worry too much about getting mishandled, or even stolen.

Have made a new friend from the G838 who is local and has a late 1970's MUTT. Shout out to xloflyr....I enjoyed your visit the other day!

Cheers,
TJ

[m3a1]

So many days have gone by and the critical parts for getting back on the road are still nowhere to be seen. Doubled down on a few parts by making a call to Rapco (thank you, guys) and ordered a few more parts just to have some spares because this waiting is killin' me.

I decided I could make some progress by installing the rear differential and the drive shaft which would have effectively made my truck mobile again without fear of losing the back flange of the transfer case.....that is, if I hadn't encountered other problems..



I didn't clean up the drive shaft much but I saw that it was going to be much easier to lube the u-joints while it was still out of the truck. I also did a little focused clean up to ensure the mating surfaces were good.


Everything went so well and so quickly that I decided, since I was already down there with all the tools, to move forward and lube up the front drive shaft (which is why you see I've clamped the caps in place). The front u-joint had the usual grease build up. I didn't like the fact that the rear u-joint of that shaft looked totally bone dry. I put the grease gun to it and found that I couldn't press any grease into the zerk. As a lucky result (and as a result of grim determination) I pulled the whole shaft out, checked the zerk and, finding it unobstructed, went into the joint itself, expecting to find hard cement-like grease. What I found was not much grease, or anything else for that matter...like it had been been barely lubed at all and then only on the end caps. In fact, closer inspection ultimately revealed a defective joint. It had never been drilled to allow grease from the zerk to the rest of the joint! I got in there with a pick and poked around and ...nuthin. This is the first time I had ever encountered such a thing with a u-joint.....totally bizarre and probably made on a Friday at quittin' time..... and here are the pictures to prove it.






Note the heat marks on the end caps - not a good sign on any u-joint. So, I'm going to replace it. I will keep the old one, lube it up manually and set it aside as a last-ditch spare.


So, here we have another disaster narrowly avoided. So glad to have found this now, rather than later.

[m3a1]

Here we have the axles, nearly sorted at this stage. Problems discovered were that one of the u-joint caps was missing one pin roller bearing and one of the sleeve bushing caps was cross-threaded on (but only barely.) The lessons here are - Good mechanics thoroughly examine old components that are to be reused! -and- Never assume that the last guy was a hot-shot mechanic.

I did a cursory clean-up with a wire wheel and some solvent and an old rag (around here, old tee shirts and such get washed, cut up, folded and recycled for projects such as this). I went direct to paint with a Rust-o-leum that claims to require no primer. I'm not looking for sand-blasted perfection here...just some basic paint protection. I will still need to replace the u-joint and more on that process later. I suppose I could have gotten by with a borrowed bearing but who knows how long that's been that way. The bottom line is, it's not correct and having gone this far, I'm not gonna risk it so we're waiting for a new u-joint and will set the old u-joint aside in the red-lined bin.

[rickf]

It's a good thing you did not try to run with just the rear shaft because the front yoke on the tranny would have popped off and drained the transmission in about ten seconds while you were driving down the road, There is nothing to hold those yokes on and they will slide right off without the shafts in. And that is weird about the grease fitting, I have seen many u-joints without any fittings but none with a partially drilled fitting.

[m3a1]

Yes, this was a first for me; an extremely rare (and lucky) find. Some times it pays to be particular about certain things.

I have the kid working with me from time to time (when he isn't too busy being an X-Box Commando) and I've been taking time to explain some of these processes in detail, so he's getting a real eyeful with stuff like that. Maybe some day after I'm long gone he'll drag another pile of old bones home and try to turn it back into something he can putt around in (poor him!) and maybe he'll think of ol' Dad.

Anyway, these old ranch-use trucks are often just "rode hard and put up wet" until they won't go anymore and things like u-joints are a prime candidate for little or no maintenance. Of course we haven't gotten into the front axles yet so I'm sure there will be something to find there as well but for now, I want to wrap up the prop shaft and rear axles and get them put back in so we can see how we did with the differential. I really hate having a pile of parts out of the truck all at once.

Cheers,
TJ

[m3a1]

The parts from RAPCO came in today. What a quick turnaround! Wham-Bam. So, we now have the defective u-joint replaced and the front prop shaft back in the truck. Mobility restored! I did take the defective joint, cleaned it up and lubed it by hand. After that, I put it aside, clearly marked as an emergency-use-only part. It will work fine in a pinch.

I was sorely tempted to put the axle back together with the other new u-joint I got from RAPCO but I have another half axle on the way with a new u-joint already installed so I'll try to be patient and wait for it to arrive, slide it on and call it good, thereby keeping the other new u-joint in reserve..... because we still have two front axles on this truck that are, as yet, untouched. Murphy's Law is a muther and better to be safe than sorry.

Cheers,
TJ

[m3a1]

Finally, SUCCESS! I am back on the road! The axle shaft component came in today and I put everything back in except for the new shocks which are still in transit. Having no rear shocks makes for an interesting ride but I was just putting around town at about 25mph. As an aside, if your shocks are junk or you have no rear shocks (as is my circumstance at the moment), using first gear is a no-no....unless you're churning butter.

Drove around town for about 45 minutes and thus far, I have no leaks at the differential. That alone was worth all the effort. In all I ended up with a much quieter truck and I suspect that flange/yoke was the major noise-maker. There is still some sloppy-gear noise in the differential and and I think we're going to be in for an overhaul of the differential at some time in the future but for the moment I am good to go.

To recap - replaced a rear axle u joint, replaced a front drive shaft u-joint, replaced all four seals at the differential, renewed the rear axle shafts, replaced a drive flange on the differential, lubed everything in the rear.

[Hambone]

Where did you purchase the rear shocks?

[m3a1]

Ebay, TeeJeeper, Thailand

[Hambone]

Is Mark (Rapco) out? He still shows them on his website, took me a while to find a set at a decent price.