K1500 Rear axle swap (6-lug 10-bolt to 6-lug 14-bolt sf)

[ala.frosty]

I'm not sure that sanding the shafts where they contact the seals is good practice. I agree that it is important to protect the seals during installation of the shafts, but a sanded shaft, depending on the grit used in the sanding, could tear up the seal after installation. In my experience, the shafts I've had to deal with in axles have never had much, if any corrosion, probably because the axle oil coats them in use. The splines on the inner end of the shafts can damage the seals, and you have to be very careful when inserting the shaft.

If I wanted to clean up the surface of the shaft that rides on the seal, I'd use the finest 3M pad, or, install a speedy sleeve.

Hope I did not misunderstand the post I've quoted.

I cleaned off the rust with 120 grit and then used 200 grit to smooth it down. To your point, to clear the rust and polish the surface, I only run the sandpaper parallel with the seal. The seals were leaking already. In my experience, the reason the seals leak is that they got a bit torn from wear and abrasion against the axle. To clean the axles up, with the axles out a bit from the seals, I grabbed a wheel lug and spun it while holding the sandpaper against the axle. Similarly with the driveshaft, I put the truck in neutral with the rear wheels off the ground and spun a wheel with my foot to spin the driveshaft while I held the sandpaper in place. I wiped the surfaces with a rag afterward.

I agree that it might be a bad idea to sand either of these surfaces perpendicular to the axle seal.

 

[84cj]

I just did this yesterday to my 97 K1500. Picked up a SF 14 bolt with a G-80. G80 wasn't at the top of my list, it was nearby and available for decent $$ so I grabbed it.

I replaced brake shoes, wheel cylinders, drums, all hardware, axle seals and new brake lines. RuffStuff 5/8 axle U bolts and plates. These reverse the U bolts, so the plate is on top. A 1344 to 1350 conversion U joint was installed. All parts were on the shelf at my local Orielys, including the U joint. Only thing I didn't replace was the pinion seal, I'm sure it will bite me later. The drive shaft is about 1 inch or so further into the transfer case output. I cleaned the shaft with with a final of 2,000 grit sand paper. I did purchase a new output seal as I'm sure this one may get chewed up at some point in the near future, time will tell. Hardest thing to do was the E-brake cables. I tried hooking them up with the axle hanging, cables were too short. So I tried with the weight on the axle, had plenty of cable! Brakes work great, no locking up, feel comparable to the 10 bolt brakes, bit better pedal feel. I'm sure I'll feel the difference when towing/hauling. And once the shoes/drums are broken in.

The 14 SF is about 1 inch wider than the 10 bolt I took out, wms to wms. 10 bolt was about 67 inches, 14 bolt is about 68. Measured myself, numbers should be close.

I put a few miles on yesterday, and a few more on today than drained the rear to flush it out and filled with 75/90 syn gear oil. Took about 2.5 quarts.

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[95C1500]

@84cj
Did you use your 10 bolt e brake cables or did you need ones for a 14 bolt?

 

[84cj]

I usd my 10 bolt cables. Hooked right up, perfect length. No issues at all. All I had to do is loosen the equalizer/adjuster.

 

[95C1500]

I usd my 10 bolt cables. Hooked right up, perfect length. No issues at all. All I had to do is loosen the equalizer/adjuster.

Awesome. Thank you

 

[84cj]

Just an update on parking brake cables. Had to replace the driver side rear yesterday. I was getting some weird braking issues, seems the cable was partially sticking.... Anyway, I bought one from the parts store for the 11 inch SF brakes. The cable itself is about one inch shorter, the problem is the casing is about 5 inches longer, not allowing the equalizer to be mounted to the passenger side cable. Ends are the same. The 10" brake cable is also coated where the 11" was not. I returned the 11" cable for the 10" and all is well. I'm assuming, and only assuming if both rear cables were replaced together, the equalizer may work just fine?


And the strange brake issue I was having. When doing a hard stop, or just before a complete stop, the LR wheel would lock up. Apparently the shoe being pushed out a little combined with applying the brakes pushing the shoes out further would lock them up. So far since the cable replacement, no issues.

 

[95C1500]

Just an update on parking brake cables. Had to replace the driver side rear yesterday. I was getting some weird braking issues, seems the cable was partially sticking.... Anyway, I bought one from the parts store for the 11 inch SF brakes. The cable itself is about one inch shorter, the problem is the casing is about 5 inches longer, not allowing the equalizer to be mounted to the passenger side cable. Ends are the same. The 10" brake cable is also coated where the 11" was not. I returned the 11" cable for the 10" and all is well. I'm assuming, and only assuming if both rear cables were replaced together, the equalizer may work just fine?


And the strange brake issue I was having. When doing a hard stop, or just before a complete stop, the LR wheel would lock up. Apparently the shoe being pushed out a little combined with applying the brakes pushing the shoes out further would lock them up. So far since the cable replacement, no issues.

I'm having similar issues

 

[chevylyfe97]

Did this some time back and has had no issues but I was wondering if my 4l60e is really strong enough or should I replace with a 4l80e? 97 tahoe 4x4 Thanks in advance.

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[ala.frosty]

If I wanted to clean up the surface of the shaft that rides on the seal, I'd use the finest 3M pad, or, install a speedy sleeve.

Sounds like good advice to me. I live in a rust-belt, so everything on mine had a bit of corrosion. I don't think that a 3M pad would cut through the rust, but I'd give it a go if I had to do it again to stay conservative.

 

[ala.frosty]

A 1344 to 1350 conversion U joint was installed.

Thanks for adding info about the 1344 to 1350 conversion u-joint. I forgot to include that in the original post.

Follow-up: As of today, my pinion seal is leaking and my conversion u-joint is notchy. The G80 works great.

IIRC, I used the parking brake cables from the 14b axle. Under heavy braking when the bed is unloaded, I routinely activate the ABS and my rear brakes will both lock up at the same time under really heavy braking. With the bed loaded, the braking is fierce and the rear wheels don't lock up.

@chevylyfe97 asked if the 4L60E is strong enough for the rear end. The transmission doesn't have any more or less load due to the heavier-duty rear axle. I'm running oversized tires (275/65R18) and the trans and motor have a bit of a hard time getting the truck going. I started having some transmission issues a couple of months ago. When I took the trans pan down a few weeks ago, it was loaded with clutch material and a check-ball was stuck in the separator plate. After putting it back together, I lost 4th gear. The trans is now out of the truck and I'm going to throw a rebuild kit into it. I don't think this had anything to do with the rear end. The truck has over 270k miles on it.