rebuilding a GM 14bolt rear end

[highdesertranger]

ok some of you asked for it so here we go.  sorry it took so long but I am basically working 3 jobs at the moment and my camera gave up the ghost.  got a new camera so here we go.   this is more than a rebuild here's what going on.
1.  rebuild rear end.
2.  add air bags.
3.  repair shock mounts.
4.  add a Detroit locker.
5.  new brakes.
6.  new driveshaft.
I had already started this job so I will jump in were I am at now.
first a little background,  about 10 years ago in the middle of nowhere Nevada I punched a hole in my diff cover.  needless to say my fluid leaked out and before I knew it I toasted a pinion bearing and snapped my pinion in two.  well I rebuilt the rear end there,  but there was a problem one of my pinion races spun in it's housing I spiked the housing and installed the race.  everything held up fine for all this time but it's been in the back of my mind that I needed a new housing.  so last year while driving home from work I threw my driveshaft.  I was at a stop light when it happened so I just reached under and pulled the driveshaft off the slip yoke(2piece driveshaft) stuck her in 4wd and drove home.  I changed the u-joint and it's been fine or so I thought.  about a month ago I was on the freeway doing 65 and the truck started vibrating,  seconds later the driveshaft let loose.  at 65 this was a little exciting. I was going fast enough to coast of the freeway again I put it in 4wd went back got the drive shaft and drove to the ranch.  when I got there I inspected the driveshaft,  it had a hug dent in it,  obviously ruined.  then I checked the yoke on the rear end,  again ruined.  in hindsight it probably had a problem last time the driveshaft came off that I didn't notice.  so I decided it was time to fix everything and here we are.  highdesertranger 

 

[highdesertranger]

so like I said I got a new camera and I went to post a pic and they are gone. AAGH. the folder is there but the pics are gone. I'll be back. highdesertranger

 

[GotSmart]

It is amazing what you can do at the side of the road. At least to other people.

 

[Lafnbug]

Good deal HighDesertRanger, thanks for taking the time to post this. I am short on time myself, so I understand time commitment. Appreciated.

 

[highdesertranger]

ok I will try pics again.  it seems my new camera's pic files were to large to upload.  so I cut the file size down and retook the pics.  first pic is an old upper shock mount and a new one.
View attachment 3131
on the left you can see the old style factory 1 ton rear upper shock mount,  on the right my version.  the old style mounts are riveted to the frame if you look close you can see the rivets.  then the stud is welded to the mount.   if you break one the is no way to fix it except to weld a new one in.  a previous owner tried this on mine.  but the weld failed on one side,  and the other side was cracking. 

I had 2 factory mounts I removed from a truck I parted out. I simply cut that part of the frame out,  then I remove the rivets.  I was just going to use these but then I thought I would just make new brackets that would except the replaceable studs like on the 1/2 and 3/4 ton trucks.  that's the bracket on the right.  this was easy because I could build these on the bench because I had the frame pieces.  here's a pic of the replaceable stud on one of my new shocks.

here's the driver side mount temporary mounted in the frame.


in this pic you can see on the outside of the frame where I removed the rivets.

here's a pic of the driver side I had to lift the bed of the frame a couple if inches to access the upper bolts on the shock mounts.  more to come.  highdesertranger

 

[highdesertranger]

ok I will get this sooner or later.  the first and last pics didn't post because I guess you are limited to 5 per post.  so here's the first pic.  mount on left is factory on right is my design.

the next pic is the driver side of my truck.  I had to lift the body off the frame to access the rivets(now bolts) on the top of the frame.

next pic is the new housing all cleaned up.

last pic,  this shows the third pinion bearing in the 14bolt.  you will not find this bearing on any other light truck rear end.

that's all for now.  will update soon I hope to get some more work in Friday.  highdesertranger

 

[ttpadilla]

I'm so impressed with you mechanically minded people, and how calm you are when things like this happen. "So, this happened, guess I'm gonna rebuild it." I'd have no choice but to throw in the towel and get a new vehicle.

 

[GotSmart]

I'm so impressed with you mechanically minded people, and how calm you are when things like this happen.  "So, this happened, guess I'm gonna rebuild it."  I'd have no choice but to throw in the towel and get a new vehicle.

Or put out a call to the community for a helping hand.  

I know I would rather tear something apart than sit doing nothing. 

 

[cdiggy]

I like that pinion gear design! I have never seen that before. Support for the very end of the gear. Brilliant. You do nice work HDR!

 

[gypsychic]

I'm so impressed with you mechanically minded people, and how calm you are when things like this happen. "So, this happened, guess I'm gonna rebuild it." I'd have no choice but to throw in the towel and get a new vehicle.

Nana - I'm always grateful for these threads that share so much knowledge. Since I have such little to reference what is sometimes being discussed I bought a really basic book and look stuff up online. I may not be able to rebuild a rear end of a truck but I hope to be knowledgeable enough to know when a mechanic is being straight with me.

Here's what I looked at as I was reading this thread. No joke.

I'm also planning on doing some of my own work on my van. I thought I'd start on something a little less intimidating than what HDR is doing though. [emoji6]

HDR - sincere thanks for taking the time to document this. It's doubtful that I'll ever be of the skill to attempt this type of work but watching quality craftsmanship is always a pleasure.

 

[MikeRuth]

Nana and Gypsi your both gonna love this video of how a rear end differential works. And best of all it was shot in 1937! But still accurate today.

Enjoy

 

[Almost There]

Nana and Gypsi your both gonna love this video of how a rear end differential works. And best of all it was shot in 1937! But still accurate today.

Enjoy

Science made easy...I love it!!

But uhoh, I realized watching that video that I remember having to deal with transmission humps...   How old does that make me feel...

 

[ttpadilla]

Nana and Gypsi your both gonna love this video of how a rear end differential works. And best of all it was shot in 1937! But still accurate today.

Enjoy

You're right, I loved the heck out of that. Thank you!

 

[highdesertranger]

update,  didn't get as much done as I thought I would.  I did get the old rear end out and the new one in place,  to start mocking up the brackets for the air bags and shocks.  so without any further delay,  here we go.

always chock your tires,  when jacking.

getting ready to pull old rear end.  always use a appropriate size jack.

I pinched the rubber brake line with vise grips.  this keeps the fluid in the master and contamination out.  I am replacing this rubber line.  if I was reusing I would not have done it this way.

I modified the long forks on my fork lift,  with pieces of angle iron with saddles cut into them.
more to come.  highdesertranger

 

[GotSmart]

Use of a fork lift is cheating!!!

Keep the pictures coming. I love it!

 

[highdesertranger]

getting ready to modify the brackets that came with the kit.

hey hey I know I don't have the guard on the mikita.  I can control the cuts better this way.

some old guy cutting.  wait a minute that's me.

Robert and scout taking a break.

old rear end.  notice the oil on the backing plate around the brake drum on the right side.  leaky axle seal.  of course this will get fixed.

new axle housing in place.  with one of the air bags set in place.  in the pic you can also see a new cross member.  this is where the upper bag will mount.  nothing is welded yet,  until I get everything in place and am satisfied with clearances,  then I will weld everything together.  note the new cross member is bolted to the frame.  the lower brackets will get welded to the axle.  the reason for all this air bag modification is they don't make a kit for my truck.  I bought this kit that was for another truck but was never installed.   more to come on another day.  highdesertranger

 

[highdesertranger]

got smart when you get on in years you learn to use every advantage available. that axle is pushing 700 pounds. I didn't feel like wrestling with it. highdesrtranger

 

[GotSmart]

got smart when you get on in years you learn to use every advantage available.  that axle is pushing 700 pounds.  I didn't feel like wrestling with it.  highdesrtranger

That is one tool I can not fit in my van!!  

Nice to have a strong "friend" available.

 

[Gary68]

look at the size of those drums,a disk conversion would probably save 100lbs,aero and weight are always on my mind(yes,i will stay up to 2a.m. to watch f1)

airbag heaven,are you going to take some leafs off or just let it be?

 

[highdesertranger]

gary no disc conversion.  my truck is a manual trans,  I need an good working emergency brake.  disc brakes make lousy e brakes.  I did the conversion on a previous truck and then put the disc e brake on the drive shaft,  didn't work.  for know all the leafs will stay.  just for fun here's a pic of the old truck that I did the disc conversion on.

highdesertranger