The Stovebolt Site Forums The Parking Lot Big Bolts T170 2speed rear axle fluid questions?

Well now that I think about it I did swap out my 1 overload leaf spring to the 3 pack overload springs that were on the donor truck so maybe since I got more spring power it won't move as much as before. But I did go ahead and put a zip tie on the end and pushed it up against driveshaft part that moves, so let's see what happens when I get her on the road.

Also a little preventative maintenance so I don't get road salt and dirt and crud in the u bolt axle shackles to fester. Grease don't corrode metal and everything that would try to get in there will just get stuck to outer layer creating a cement like material that can be cleaned off if needed. But main goal to keep other b.s. out and preserve my parts for ever!!! Lol

And grease is water proof so...... that should speak for itself.

Another good preservative to use in places like that is the spray lubricant used on big winch cables and exposed chain drives. It sprays on, and then the solvent evaporates and leaves a sticky residue of water resistant lubricant.
Jerry

Hmm I'll have to keep that in mind for future issues like this.

On another note I'm still filling my rear end with gear lube ahhhh! It's taking so long cuz of the cold weather. I been refilling it for 2 days now it's so slow. And I have also realized that this rear end holds a lot of gear lube. Like over 2 gallons cuz my 2gallon jug is almost gone and it still hasn't spilled out the full plug. So I might have to get more gear lube.

One other thing I was gonna ask about the u bolts, the torque spec for these u bolts say 300ft lbs, I do not have a torque wrench that goes to that. How should i guestimate 300ft lbs? I have a torque wrench that goes to 150-200 ft lbs or so. I guess max that out then get breaker bar with cheater bar on it and go a couple more turns??????

Make the torque wrench handle twice as long to double torque. Put jug of gear oil in kitchen sink and fill with hot water, make sure it doesn't tip over since oil is lighter.

Ed

I have been bringing the jug inside at night to get house temp then outside during day probably should have brought it back in between funnel fill ups but I'm almost done now and gonna have to get another hug cuz it's not to the fill plug yet after 2 gallons added.

And do you mean if i set my wrench to 150 and double handle length it will click at 300 or I'm just suppose to know when to stop haha? Cuz I don't wanna strip my u bolts giving it all I got.
Should I just torque to my max torque I can do accurately then go around giving each of them 1-2extra turns then drive for a week and do all of them again 1-2 more turns? Then just check weekly for loosening and I guess after a couple months of them not loosening I can stop worrying haha. Changing u bolt s always makes me worry a bit after doing it but they always end up fine but I haven't had to crank any down with a higher torque spec then I can do accurately so I'm really gonna worry lol.

Increasing the handle length only makes it easier to reach the max on the wrench, it does not increase the capacity of the wrench. You need to increase the distance of the wrench to the nut. That would need to be done with an offset adapter, not a normal socket extension and it needs to be in the direction along the long axis of the wrench, from handle to socket. Depending on the type of wrench, that offset adapter might need to specialized to that particular wrench.

Easier would be to get a long breaker bar use a spring scale hooked to the handle and used to turn it. Spring scales are known to be inaccurate so it would need to be calibrated using gravity and a know weight of some other method. Length in feet times pounds give you the torque in ft/lbs.

You might also consider how much force you can pull with both hands on the wrench and your feet against a tire, times the length of the wrench and call it good. Then check to see that they stay tight.

Sweepleader, you're right, not thinking straight.

Ed

Use a 3 foot cheater pipe on a 3/4" drive breaker bar and "GIVE IT A GOOD GRUNT" like my first boss used to say. I used to use a 300 ft/lb 3/4" drive torque wrench with a doubler to tighten 220 Cummins cylinder head studs- - - - -1" diameter studs with fine thread nuts and flat washers that torqued to 600 ft/lbs- - - - -18 of them, 6 per head! That was a good workout even for a 30-something year old guy! I wouldn't attempt it now!
Jerry

Well I rented one from orileys and the plastic handle broke inside my cheater bar. Plastic!!! Why the heck would you think oh let's put a plastic handle over the guts of the torque wrench??? Anyway fell short everywhere else I called for rental. So i used my so called 700ft/lb. Kobalt air tool to tighten the rest of the u bolts down. I did get the first one torqued i used the rental on to 250ft lbs according to their wrench before it broke, then when I went for a second click on it boom plastic busted inside my cheater bar. I did torque all others to 150ft lbs with the torque wrench I own. Then when I busted out my air tool it didn't move the one i got to the supposed 250ft lbs, but it did move all the other ones past the 150ft lbs spot I had them to. So my air tool when hooked up to my 6-8 gallon Hitachi roofing compressor it doesn't have the 700ft lbs it claims to have . But I'm just gonna call that good and after a month of driving it I'll bust out the air tool again and give them some more love for the heck of it. I don't think they are going anywhere.

A 300 ft lb torque wrench is not all that expensive and would be a nice addition to your tool box...or after you get it together drive it to your local big truck repair garage and ask them to re-torque them for you, but that may cost more than the wrench

Mike B

Yeah I found one that goes up to 250ft lbs for 85 bucks at harbor freight and it has the metal handle like mine so wont break. And yeah having one that goes to the next level of torquing for these bigger bolts will come in handy I'm sure, and definitely once I start the rebuild on this old mf diesel tractor I got. But first my dump truck has to get back on road. And my shop manual for this truck says the u bolts should be torqued to 250-350ft lbs. So if I get the torque wrench that goes to 250ft lbs I'll torque it to that and then use breaker bar to give a little extra and that should be fine there cuz I'll be in the torque spec range. The company I bought the u bolts from reccomend 300ft lbs so that's where I got that from.

And btw I'm getting close to having it on the road. Jacking up each side rear one at a time to take wheels off to paint rims, brake drums, and the hub so it's basically a brand new rear end. And also to get the sand particles outta my brake drum from when I sand blasted the inner section on axle. Don't wanna groove up my drum with sand between brake pads. Its gonna be a slick looking ride once I get all that painted and then I'll have to plan a date to paint the whole truck to bring it all back to life.

I retract previous statement. The torque wrench at harbor freight is actually 300ft lbs idk why I confused that with the rentals torque specs.

Well never mind painting the hub/brake drum, I didn't realize you had to disassemble the axle to get to the brakes... this is kind of a silly design. You have to drain gear lube low enough to not drain out the axle shaft once you pull the axle out of the housing and then I'm guessing the hub might come off, but I'm guessing the bearings are somewhere behind all this madness and they will have to come off as well before finally pulling hub/drum to even see what the brakes look like... I bet truck shops love when they see one of these come in with a brake job needing done$$$$$$$$. That labor charge for just being able to look at the brakes will be high. Lol. I'm going to just paint the rims and the separator thing for now and bleed brakes to see if there is any leakage then if no leakage I'm gonna drive it to the car wash and power wash the leftover sand grit outta the drum threw the dust cover crack. Luckily I have a car wash about 4 blocks from me so the sand shouldn't do to much grinding around in there. I wish I had known this issue before I spent the last 2 days filling the rear with new gear lube. Oh well the brakes are just gonna have to wait till they are grinding or leaking before I feel like taking on a brake job like that. But once that time comes around I'll go ahead and paint up the hub and drum so everything has been preserved.

Pulling the wheel,hub,drum assembly off is not that hard a job and there will not be a great deal of oil leakage. Jacking one side up will tip the housing and the oil will run to the other side. Pull the axle shaft and removed the nuts holding the bearing in place. Put a fabricated dolly under the dual tire assembly and pull the wheels, hub and drum assembly off as a unit on the dolly. The jack under the axle will allow vertical adjustment so the dolly takes just the weight of the wheel assembly. No need to take the wheels or drum off the hub.

I fabricated a dolly with 4 large casters and 2x4s, about 2 feet square and to hold the tires about 1 inch off the deck. You need a hard surface to work on. If you have a smooth concrete floor, a sheet metal skid can be placed under the assembly in place of the dolly and the floor greased to allow things to slide smoothly.

Caution must be used that the truck is blocked up properly while the jack is in use adjusting the height.

The wheel assembly can be removed with just the 6 or so axle retaining bolts and two bearing nuts in about 10 minutes, not counting fabbing the dolly. Still some heavy work but I have done it by myself.

A pallet jack can also be used in place of the dolly by inserting it under with the tires between the legs of the jack.

Why do you want to create an insulating layer with paint that will cause your brakes to overheat? The thermal energy the brakes absorb by friction must be dissipated by air blowing over the drums. Painting the drums makes that difficult to do.
Jerry

Well I'm not planning to pull it until I have a need to cuz at this point I'm running into needs.... as I was bleeding brakes, back ones on the "new" axle seems to bleed good and not leaking. But once I got to the driver side front, i was bleeding it and my dad pumped it up and the brake hose started leaking at the crimp piece so im gonna just replace all three of the flex brake hoses since that one gave up and the rest are just as bad so it was time. And of coarse the brake lines that connected to them were seized and nuts rounded. So had to cut the line and now need new brake lines as well lol. How did the rear axle swap turn into a full brake line/hose job haha.

But hotrod I'll definatly skip painting the drums then, I didn't think about that causing any issue like that. But I'll for sure get the built up grease/dirt off them cuz that's pretty thick and I can definatly see that being somewhat insulative.

There was once a flat black paint used on radiators that was fairly heat-conductive, but since copper-core radiators are pretty much a thing of the past, finding any of that stuff might be a challenge.
Jerry

Eastwood has a product they say is for radiators.

Dennis

What about the rustoleum high heat paint for automotive parts,grills, and stoves? Would that be a heat conductive paint? Since I'm planning to paint everything to do with rear end I would like to paint them with something so they don't just collect surface rust.

Somewhere in my travels I read that bare, rusty, cast iron has greater heat dissipation capacity than any color of any type of paint. It may have been Hot Rod magazine, to which I subscribed back when hotrods had drum brakes. If you're building a show truck that will be trailered to shows this makes sense. If you're going to drive it loaded, any paint will burn off eventually and you'll be back where you started after cooking the linings. That will happen around here anyway, where 5,000 foot mountain passes rising from sea level in 20 miles are not uncommon.

My grandpa bought a 1913 T-model Ford new. He and his brother ran it from La Grande Ore. to Pendelton over the Blue Mountains one fine summer day. Remember that Henry Ford lived in Michigan where it's flat, so he thought two-wheel external contracting brake bands were plenty. Anyway, about halfway down locally infamous Cabbage Hill the brakes had heated to the point that even using the reverse pedal no longer worked to slow the car. So grandpa found a sapling and tied it to the rear of the car with the rope they kept for horse teams to pull them out of the mud. They quickly found that he couldn't hold back the car, which got away with brother Clarence at the wheel. Around a bend and out of sight grandpa heard a loud crash and running down the road soon found Clarence sitting by the side of the road throwing rocks down at the Ford. A teamster came by and used the rope to pull the car back onto the road. The sapling was a good lever to straighten the bent fender to clear the tire. Off they went again down cabbage hill at a much slower pace. He told me this story about 50 years later when I began hauling hay over the same road with a '54 Mack semi and no jake brake. At that time there were no truck runaway ramps; lose the brakes and you're on your own. Another time on another mountain route the main airline blew off the air compressor but that's another story for another day.

"Well now that I think about it I did swap out my 1 overload leaf spring to the 3 pack overload springs that were on the donor truck so maybe since I got more spring power it won't move as much as before. But I did go ahead and put a zip tie on the end and pushed it up against driveshaft part that moves, so let's see what happens when I get her on the road."

Unless you have quite a long drive shaft, 3/4 inch doesn't seem like enough travel from empty to loaded and going over bumps loaded. If the slip joint is too short, that is, if the driveshaft is too long, the joint will "bottom out." The weak point is the spring center bolts, which will shear off the first time that happens; then the steering will seem very vague as if suddenly you have bad king pins. If that doesn't happen it may split the female part of the slip joint and you will discover that they aren't cheap. I had to buy one recently and got it for $75 used from the driveline shop. Also, rough shifting (often a problem with inexperienced two-speed axle operators) will cause the slip joint to get sloppy and then they vibrate like the dickens and will loosen all the screws in the cab and drive you nuts with the noise. Rough shifting is also hard on u-joints. A drive-shaft shop can point you in the direction of a pamphlet that tells how much travel you need and how to set up the u-joint angles for minimum vibration. Spicer publishes such a pamphlet. It's free.

Because you changed axles, you may have to put tapered axle-shims between the spring perch and the spring to get the angle to match the transmission angle. The u-joint angles should match within a maximum of 1 degree. Half a degree is better; that's the motor-home spec. Consider also what the axle angle will be when the overloads are fully engaged. If the distances between the overload perches and the overload-spring leaves aren't right, the axle will torque one way or another and the u-joint angle will change once you're set down on the overloads. So it may not vibrate empty but will vibrate loaded or vise versa. What is happening in this case is that the u-joints are fighting each other as their angles don't match. That will greatly shorten u-joint life no matter how much grease you put in.

Wowzers. That's quite a story. I'm from southern illinois so we don't have elevation like that I think the highest point near me is like 900ft lol. But I did just travel across the country to Portland, Oregon with a uhaul and hauling a car on a trailer and its was quite the trip threw the mountains. And those runaway ramps off to the side are nuts!!! I couldn't even imagine having that experience let a lone before those ramps were there Haha. I did see a semi up one of them ramps at one point and he was out at the bottom taking pics of his rig up there. I bet he had to clean his seat and change pants before he even took those pics Haha. I was nervous just running the image of it happening threw my mind.

I couldn't even imagine driving my truck threw the mountains.... I know it would pull up them no problem my issue would be the coming back down part.

I'm settled I'll just wire wheel them till they shine and let mother nature do her artistic work cuz you are right my truck is working not a show truck. And not to mention you can't even see the drums from the outside, only from behind and under.

Now about the other thing you said, are their shorter slip joints that will give me more room to slide or is this a driveshaft length issue?

Like I said before there is only maybe 1inch length difference with the new axle. Basically once the "new" axle was centered on the springs the drive yoke on the axle sits maybe 1in further forward maximum then the original rear axles drive yoke. And this is what took my extra sliding room for driveshaft away.

And I know of a guy who owns 60acres of these medium duty trucks that he started collecting as a salvage yard. So I can probably find different length driveshafts or slip joints I'm sure on one of the many trucks he has if they made these in slightly different lengths, like what I would need to get more sliding room. But did they actually make these parts in 1inch length differences???

My driveshaft is 46" tip to tip (including u joint mount) and my slip yoke is 7" tip to tip.... if I could find a 45" driveshaft or a 6" slip yoke I'd be set... are their other driveline setups that have these dimensions for driveshaft or slip yoke?

The shafts are usually measured from center to center of the u-joints. Also remember that a shorter yoke still has the bottom in the same place and will bottom out on the same spline shaft with the same travel, a shorter yoke will gain you nothing.

Ok so if my driveshaft is 45" u-joint center to u-joint center, then I would need a 44" center to center driveshaft to give me the room I need. Would this size be likely to be on another c50/c60 of a different style??? Or would this be a rare thing to find?

My opinion would be that it would be tough to predict finding one on any given truck. You could cruise a bone yard or two with hope in your heart or have your current one cut down.

The u-joint of course needs to match which should be more likely than the shaft length, but not guaranteed. I would verify that on any used shaft.

The cup diameter and cross length would be two things I would check to be sure.

Well I know of a single boneyard that has at least 100 c50/60/70s of 1960s-1990s chevys and probably has the same number of 2 tons fords as well. This guy has a 60acre boneyard that I'm sure he has been collecting since the 80s and is still buying newer medium duty trucks for the next guy in the family to take his spot. I hope Anyway, cuz when this guy kicks the can if it gets scraped that would be terrible for the old truck community. He is a little bit on the pricey side with some things and a bit of a drive for me but if I have to I have to.....

Anyway I feel like these trucks had so many options for drivetrain lengths cuz of the different wheel bases they made,different engine block lengths, transmission lengths, and different rear end lengths, I would have thought they made different length rear driveshafts. Cuz how else would you be able to offer so many options without having slightly different size driveshafts for this issue I'm running into now. Cuz I'm sure the donor trucks driveshaft isn't the same length as mine cuz it had a 366 with a spicer 5speed trans where I have a 350 with the gm 4speed trans. But the donor trucks driveshaft is bent from the fork truck guy at the scrap yard, so its unusable and getting a accurate measurement would be challenging too with the bend in it.

What are the lengths of some of your guy's rear driveshafts?

Does anyone have same engine and trans as me but with original 2 speed rear?

Now about the other idea you said.... cutting my driveshaft down 1". Would this be a safe option? Could I do this myself? Or would this need to be a specialized fabrication? And what do you think a professional would charge for something like that?

Obviously the fabrication would have to be perfectly cut and rewelded so there wouldn't be any wobble. But would there be any other issues of going this route?

Actually scratch that last post. The reason I'm second guessing your statement of it being rare to find a driveshaft of that difference is because of the driveshaft i found online being the exact 44" i need. No offense to you just trying to be as factual as possible.

And I have done more thinking/looking at my book and I'm just gonna throw my thoughts out there and maybe someone with some expertise can chime in..... I'm doing a h-150 to t-170 rear axle swap. By looking at my books model data page it shows that every model truck with the standard h-150 rear has the optional t-170 rear. So what I'm trying to do isn't out of bounds according to the books guidelines on this.

This is where I think the driveshaft difference is part of the optional rear end. So if I found another truck with a t170 rear axle and took its driveshaft it would be the length i need. Obviously I'd measure it but what I'd be looking for is a truck with a t170 rear axle and the drive shaft would be the length I need, assuming my thoughts on the books data is correct but that's the choppy part I need help with haha

I have done it on a 12" shaft on my '62 K10, between the TH400 and the transfer case. I had access to a lathe that would handle the shaft.

A 4 foot long shaft needs a longer lathe. If you look at the ends there are almost always centers drilled in. The shaft gets mounted on those centers and one weld cut away. The extra inch is trimmed off and the parts pressed back together for rewelding. Then it needs to be balanced. I have had this done a couple of time in Minneapolis, for about $70 to $100. Most big truck places, some specialty drive line shops can do it. It is a simple process that needs to be carefully done or a mess can ensue.

I just said the same thing as Sweepleader in the previous thread...find a driveshaft shop and they will tell you what you need to know.

Mike B

Ok well if it's that cheap of a job then I might just do that cuz I was thinking that it would be way more expensive Haha.

So to get my dimensions straight before going into a big truck shop.... how much of the splined shaft should be in slip joint with no load? I'm guessing at least 2" ......?

Like Mike said, the shop will tell you, likely similar to what it was with the old setup.

Mike, you want to measure the distance between the two U-joints on the truck (where that shaft goes). Take that measurement along with your drive shaft to the shop and hand the shaft and measurement to them and ask when it will be done. To be on the safe side, call them first to confirm exactly where they want you to measure...

Mike B

Ok so do you mean remove driveshaft from differential yoke and remove u joint from slip joint so slip joint and shaft are separate? Then slide slip joint back on spline shaft to the desired spot like it was before(old axle) but without driveshaft.... and then measure from diff yoke u joint center to slip joint u joint center? And that's my new driveshaft length?

Sorry to flood you with questions. I just want to get this right without any issues or more expense. Im already over my assumed budget for it right now. I didn't realize how much stuff I was gonna have to replace and alter for the rear end swap.

Drop the drive shaft out of the truck from U-joint to U-joint (the slip joint should now be in the middle of the shaft, right?). Then take the shaft with the u-joints on both ends and the slip in the middle to the drive shaft shop and they will shorten it based on the measurement you took between the two yoke u-joints that are still on the truck.

Mike B

What Mike said, good advice.

I have fabricated driveshafts considerably longer than the ways on my lathe by simply removing the tailstock and supporting the shaft in the middle with a steady rest. The tricky part is getting the shaft tack welded back to the U joint yoke or stub spline with minimum runout before doing a full weld pass, getting the spline and U joint clocked properly, and then balancing the whole assembly. For minor driveshaft balance problems I use a big hose clamp and a 1 ounce wheel weight with the vehicle running at highway speed on jack stands, and move the weight around until the shake goes away. Then I weld a flat washer the same weight onto the sweet spot I found with the hose clamp.
Jerry