Re: '65 GMC 1500 project. From the Netherlands
 

Thanks for the compliment, Steve.

Indeed, as you said, the synchros were still good, but the wear cannot really be detected other than the "points" of the internal thread in the synchros getting duller, thereby needing more effort to cut through the oil layer on the cone. I have noticed improved shifting times, but this can also be psychological rather than factual.

Ended up ordering the kit from Transmission Parts Distributors in NJ. I ordered from them since they shipped worldwide and had the synchro's. Didn't contact Novak, I contacted them in the past but never got a reply. If I were to do it again I would order the Ebay rebuild kit. Saves a lot of money. I believe all the kits are the same, and the 63 and earlier transmissions seem to have a different front secondary shaft roller bearing. I got 2 bearings in the kit that I did not use.

I did notice that the input shaft bearing in the kit is a C3 style bearing, which is normally only used for 2 press fits (shaft and hub). These have greater internal clearance. Possibly selected for misalignment purposes? The trans has a press fit on the shaft and a loose fit in the case, therefore not needing a C3 bearing.
Anyway, the original New Departure bearing was also of the reinforced type with more ***** and a filling slot to accommodate. The new bearing is just a standard-size bearing, with a standard amount of *****.

I wouldn't be surprised if Novak just splits up the kits with the right parts for the transmission year.

As for the A/F, I am running just below Stochiometric at cruise on propane (around 14.5-15.0, Propane is around 15.2-15.5 AFR stoichiometric) and it runs really well. Idle it set to about 13.5. Haven't had any problems with a lean condition problem (no surges, just constant power @ cruise) so far. This might be because of the propane. Gasoline is kept as a backup only. Indeed, I have an AFR on the driver's side exhaust but could also tap into the passenger side exhaust, have a bung on it as well but it is plugged off now.

I like to tinker around but also try to listen to good advice... it is a fine line for sure.

Re: '65 GMC 1500 project. From the Netherlands
 

Not much to report other than that the truck is running great. However, the pinion bearings start to make a little noise. Via a guy in Germany I managed to score a rebuild kit as well as a 3.54 ring and pinion set! The 3.54 ratio should definitely aid in driveability and has been a wish of mine for quite some time. Granted, they are the cheaper DANA SVL sets, preferred OEM Dana but we'll see how these hold up. Still need a new yoke since the original R&P is 10 spline instead of 29 spline. Will probably order it from Rockauto.

Gives me a proper excuse to pull the old Dana 60, fully rebuild it, and give it a nice layer of black chassis paint.

Re: '65 GMC 1500 project. From the Netherlands
 

Pulled the old Dana 60 today. Went pretty smoothly. Broke off one of the U-bolts, see picture. I'll tell ya, when you're laying under the truck without hearing protection and you're breaking them loose using a big pipe and a wrench, these make a nice bang when they snap!

Glad I took it all apart, the lower axle retainers gathered a lot of crud and were corroding the U-bolts. I am planning to drill out the drain holes to 1/2" or so instead of 5/16". New U-bolts will be installed :teehee:

Got a new Spicer 29 spline yoke to fit the new gear set. Planning to take the whole axle apart and clean everything up, then start with the regear process. I'll use the old bearings as setup bearings, found a nice article describing the whole regear process. It takes a little patience to do it properly but in the end, the result makes it all worthwhile. Should allow me to do 60 comfortably instead of straining the engine. Usually drive around 55 anyways.

Re: '65 GMC 1500 project. From the Netherlands
 

More progress on the old Dana 60. Disassembled everything and cleaned up the outside. Lots of dirt and rust came off. It will be painted with epoxy chassis paint when the axle is finished.

The first step in the process it to make a case spreader. I designed my own, based on the original tool. The Allen head bolts fit into the holes in the differential case.

Man, this thing is filthy on the inside. A black goo of metal and old gear oil has coated the inside.
When I got the truck, it seemed like the 1965 gear oil was still in there. Sure left its mark on the components. The pinion bearings are funnily enough OK, still a lot of small indentations in the races of debris in the oil. The carrier bearings are shot. The non ring gear side has small pits from debris, but the ring gear side bearing has extensive spalling and the bearing also spun on the carrier itself :pullinghairout: Forgot to take a picture! Will do it later.

Luckily the damage is not too bad, it could have been worse...
Time to repair the carrier. Planning to make a sleeve to repair the damaged surface. Will continue tomorrow.

Then I can use the old bearings as setup bearings, and start the ring and pinion installation.

For fun, I checked the gear pattern before pulling the old carrier. The backlash is way out of spec, but the pattern isn't too bad considering its age.

As you can also see, one of the pinion preload shims came out broken. The pinion oil slinger was also damaged (not by me!) Maybe I got a Monday morning differential?

Re: '65 GMC 1500 project. From the Netherlands
 

Very similiar to the Model T Ford rear axles I been pulling apart. Between the 600W grease and the dissolved babbitt the gunk is undescribable. Getting enough of the original Hyatt roller bearings and sleeves (need 4 each) to complete one axle as an extra.

Re: '65 GMC 1500 project. From the Netherlands
 

At least you had gear oil in your. The previous owner of my truck had spindle seals and pinion seal leaking. What they did to fix the spindle is to pack grease in them. Didn't do anything to the pinion seal. When I removed the drain plug, I only got a table spoon of oil. When I open it up, everything was worn out. I had to replace everything.

Re: '65 GMC 1500 project. From the Netherlands
 

Good idea. Bet they will come in handy when you get another axle to overhaul.
Lack of maintenance (even as simple as an oil change, takes 10 minutes) seems to be a common thing...

Re: '65 GMC 1500 project. From the Netherlands
 

Hmm. That was quite the chore I'd imagine... Great solution by the previous owner... Pinion and axle seals are like 30 bucks total and take a couple of hours to install...

Re: '65 GMC 1500 project. From the Netherlands
 

A little insight on the Model T Ford - the engine and transmission shares the same engine pan - couple this to an enclosed drive shaft to the rear axle the engine/transmission oil has a free pass to the differential gears if any leakage occurs past the driveshaft babbitt and brass bushings - believe me when I heard (and believe) they leaked directly after they left the assembly line. Ok, rear pumpkin gets extra gunk from the engine/transmission pass the pinion bearing and raises the level in the pumpkin above the axle shaft level and then the mess runs or creeps pass mutliple thick felt washers that seal them at the wheel hub and drips out the brake drum onto the tire and ends up on the ground. Nothing but a oily, greasily, dissolved babbitt and metal particle infected puddle. But, I love it. :thumbsup:

Re: '65 GMC 1500 project. From the Netherlands
 

And coupled with very crude oils by todays standards it is likely to generate a sticky mess.