G749 preservation

The engine may only produce 130hp, but these GMC's had a 15:1 reduction cone on the back of the Hydramatic for low range. Pretty darn low gearing. And they have a much heftier spring pack then the M35's. Both great vehicles, but if I was looking for a truck to haul lots of weight, i'd take a GMC over an M35 any day.

Great job, Dave. You have done good!

saddamsnightmare said:

November 10th, 2011.

I was never a fan of the M211 and M135's as they were rather slow and underpowered compared to the M35A2 (from practical experience), BUT you truck looks magnificent! I would almost corrupt me from the M35A2, but probably not from the Unimg. Keep up the good work!

Click to expand...

Yes the M35A2 does goe fast, but the M211 rides much nicer. If I ever get another duce it will be a M211/M135 family vehicle. They ride nice, they stop great and IMHO are a little easier to mantain than the M35A2...I should know I've owned both!

When I drove my 135 in traffic, I could keep up with the right lane, even if there weren't any semis. The only drawback to keeping up with traffic is your mileage drops to about 2 MPG. Its a lot more painless to get 'er out on the open road and cruise about 50 - then you'll get maybe 6 MPG.

If you REALLY want a great ride, balance the front tires. I hauled my new rubber in to a truck tire shop, and they spun them at 80 MPH. When the finished, they both looked like they had a 1# solder bar on the rim, but boy did that help the ride and steering. The GMC is fun to drive once you understand how to drive it. It's easy to steer, great brakes (esp. if you used the CDN surplus 1 3/8" wheel cylinders instead of the original 1 1/4" cylinders). One other trick is to adapt a set of the M35 west coast mirrors to your truck. You will wind up cutting and welding the support tubes to make them all work, but its a whole lot better than that original 4" diameter mirror that's out about 24" - as soon as you start it up, the mirror is useless.

Had to do it. This truck has already produced speeds over 80 so I needed to see how the knuckles and balls work to keep the front wheels on.

I'm throwing a schematic in because all the seals will be replaced when I find them. Maybe somebody out there has a package sitting all alone on a shelf with the big thick rubber seals and parts listed below. The search starts tomorrow and this part of saving the diff. must be expedited because Christmas is coming.

I'll be in Phoenix and the Arizona area after Dec. 8th to help the parts I need come home.

Levy part #'s

T - seal 8330750 would like 2
S - seal 7411303 would like 2
Q - retainer 7411302 would like 2
V - gasket YT 3659641 would like 2
Y - shims 7877241 4 different sizes..... would like 8

After removing the hub it was clear that someone packed the knuckle housing with grease at some point.

Is grease packing the knuckle assembly an acceptable option?

Ideally all the seals going back in and re---oiling the assembly would be the right thing to do however in her retirement an option may be to add a grease zert and keep it grease packed...... Any thoughts?

As the first pic shows the ww shaft part # 2277364 has a nice shine now but not without a few hours of buffing with an air grinder and sanding wheel. It's unlikely all the pitting can be removed and this will be a never ending leak problem.

The 4 different sizes of shims which are part of the original assembly can possibly be made out of shim stock.

Added a pic of the brake pad because they look so new it's as if the front brakes never worked properly......which is probably true.

The hubs show a lot of rust on the brake face but appear to be in good shape.

I was also able to find steering links off the donor trucks. Once again the beating this truck took must have gone on for a long time. The ball and knuckle on the steering arm was so loose we're selling it to Calgary for a wind chime.

It's such a blast seeing it come apart and with a little luck I can find the resources and pieces to build a fairly original Eaton. I'll detail a re-assembly once we get the parts together so we can all have a rear-end that doesn't leave trails.

Onward

I am sure he meant 80kph, as 80mph would have surely blown up the poor little 302.

Dave, Memphis Equipment has the front knuckle kits for $50 per side. IMO, don't worry about them. If they are not torn or badly damaged, just reuse both the rubber/felt seals. It was common for new seals to wipe the knuckles so hard it removed any grease, making them prone to rusting very quickly. In fact, I have even been told that new seals wipe the knuckle so hard it will cause hard turning until they get worn in. So much so, that the steering wheel may not return to center after making a turn!

I would fill the knuckle housings with as much grease as you can fit inside. The GMC DUKW's were always running around in water, and they used virtually the same banjo axles. Even the knuckle seal parts interchange. If I recall, part of routine DUKW maintenace was to pump the knuckle full of grease until 5psi was reached. That is A LOT of grease, but it will keep any and all water out. The knuckle seals are just extra protection. A pretty good setup, IMO. I like it better than the boot setup used on the M35's.

FWIW, my knuckle caps had no shims! Steering is smooth with no play.

GF, thank you, I'll deleat my post

Seals found

I missed something......and you are right gent's sorry,,,,, that's 50mph or 80kph and there's nothing more important about this hobby then doing it safe.

Thanks Gunfreak...Parts are ordered from the Memphis team.... The old seals will be cleaned up, cataloged and boxed for possible future use. They are not damaged badly but show signs of 55 years of wear and oil saturation. Everything will be torqued to spec and re-torqued after break in.

I'm anticipating the shims are there to allow control on applied pressure to the bearings so if they are needed we'll find a way to do it.

SuperDave suggested Cornhead grease from John Deere which will keep the knuckle lubed for a long time. We'll sub the oil plug for a grease fitting so maintaining them is easier.

Cornhead is nice grease, my steering gear box was drained of oil and filled with the stuff by the Military long ago. Looking forward to seeing ya on the 10th! You a Guinness Draught or Extra Stout man? I prefer the later myself.

Brakes M135

mmm Whiskey


This is the last brake to clean up so I'll post pics on the tear-down. It's easy when you read the TM's.
If your brakes were soaked in a coal mine before sitting for twenty years this is what they'll look like. These are probably as bad as it gets.


We already tore apart the left front. After soaking the parts in varsol, scrubbing for a few hours, replacing the cylinders and beating the seized adjusters, everything cleaned up real nice. A little coppercote on the adjusters and the parts are ready to go back on..... the left side.

The washer(s) in pic 3 acts as a seal and are prone to leak apparently, if not replaced after 55 years.

Axle removal

You are lazy! I beat on mine with a 5lb mallet for 20 minutes before I loosened all the rusted on tapered dowels. Good idear.....

Brakes

I'd say lazy is an understatement. More like comatose.



Pulled the rest of the brake apart without stripping any of the rust soaked bolts. Pic 3 shows the back of the "carriage bolt" that sits in the square hole on the backing plate. This ain't no carriage but it's a nice clean look which must be what they were going for. Once again a pic of the splitter and the 2 different size washers that must be replaced prior to re-assembly. The last pic shows the dirt in the bleed screws that will require some clean-up.


Spent another 6 hours scrubbing parts and now have a table full of clean parts.

Knuckle housing

Getting the knuckle casing apart is another easy task. Undo the top bearing cover and tap with a soft hammer in the appropriate place.

Removing the outer hub again with a few taps with a soft hammer.

Removing a tie rod end is a 3 hit adventure.....now that I know where to smack it the tie-rod literally fell out of the hole after a few good swings.......never felt thmarter.

Removing the back cover, seals and gaskets allows the knuckle cover to fall off the knuckle.

After pulling the bearings and seeing the smoothe races and tight bearings it's obvious that "some" work had been done to the truck at some point.

A little tug and a bit of levering on the axle and it comes out....and goes back in fairly easy.

the knuckle pics

Knuckle head pics

Inner seal help.

This is the last seal to find for the front diff. We'll give the Memphis boys a call on Monday but I'd like to find a modern alternative.

Has anyone found a replacement seal alternate for this axle?

The TM's part # is 7411307

Mine came with "modern" seals that appear much thinner than the NOS axle seals and they have a different part #. I'll see if I can get it tomorrow and post it. It's a common seal that any NAPA should be able to match up. Looking forward to seeing ya next week!

I picked up a second winch and a PTO today. With what we already have, the control levers and cable that you have found almost complete the set.

The least spendy thing to purchase, but shipping costly, would be the actual winch mounting brackets in the bumper.

If you could snap a couple of pics of that, I need overall length, and the offset from the frame rails. Just stretch out a tape line, and email me the high res pics, and I can make my welder guy earn his keep.

Thanks, and the other pics will be very helpfull for the coming installation.

Keep your eyes open for the Winch Operation Data Plate. That donor truck should have one.

Next time, I'm buying the beers! Lt. L


There is no way that I'll have this installed for the Legion Toy Drive,
but that is happening over the next 2 weeks,
and I think that I'll have enough toys to fill the M135, a WC52, and an M37.

I might even have to drag out the M105 , so that we can do all of this in 2 trips!
Then again, if my crew want to donate even more toys ...
I'll drive all day to help out Santa!

BTW, I think that I finally found part numbers for filters and gaskets.
Once I review the catalouge closer, I'll scan and post it!

Winch mounting

Witch winch is which.

The mounting plates seem simple enough. It's just under 4" offset and with the winch being 26" wide and the inside of the frame rails approx. 34" inside, it works.

The overall plate length is about 27" with 2" flange to frame and 11" mount to winch.

I have not looked for these brackets in the pile but if you don't get them made before spring........I can look.

Dave, what you've posted should work. I'm off to bug my welder

Seal update to current

This is Preliminary info because they are not in, running and non-leaking.... yet.

Inner axle seal

The "National" 'original' inner axle seal Part #2277317 (Mil-B-121E)

Levy # 7411307

Modern equivalent seal is CR (Chicago Rawhide ) 18025 716....I hope.

Inner Hub Seal

Original Levy #7411429

Found in hub CR 32519

Modern equivalent Timken 418028

Size....3.250 X 4.5 X 0.375

The difference between the two, as in the attached photo, is a rib running around the outside of the original seal.
Any thoughts on this being a problem?

We also had some time to get started on the rails. Work's a little slow so I had some volunteers jump in to start prepping. They will replace the worst boards, prime, paint and detail the hardware.

Should be done soon......sometime, real soon.