To preface this, my primary drive shaft popped completely out of the bottom of the truck when in 4wd, shearing my u-joint on both ends and breaking the clip to the rear differential. I don't know wtf but I'm really hoping it's the bearing in the middle of the shaft, like a mechanic suggested. He didn't have time for me to fill him in on the background of the truck, he just saw the shaft out and that the bearing and u-joint were definitely shot...

I put on the 4wd differential from my donor truck, test drove it in 4wd and there was a slight squeak but nothing that sounded too bad and all of the wheels were moving in unison as far as me and my friend who helped me could tell. After we thought it was road worthy I drove a few 100 miles trips in 2wd and all was going pretty well aside from a vibration that I was getting that I attributed to my cambers. I forgot to adjust them during the whole 4wd repair and I'm paying for it now. The tires are very tilted whenever I back the car up a few feet but seem to straighten themselves out as soon as I moved forward, so I chanced it and drove it assuming I could get firestone to do it with my lifetime alignment somewhere along 800 mile trip. I wasn't able to find a single firestone that had their "camber guy" in on Sunday so I had to say screw it and make tracks. As soon as I arrived to the driveway of my destination I needed 4wd so I locked my manual hubs and popped her in. There was a loud crashing metal sound the very fist instant I tried to go that was no at all like the test drive squeak. I got out and looked under with a flashlight looking for any sign of anything and there was nothing that I spotted. I hopped in and tried to move it again and there was a small pop and then I was moving quietly forward. I made it most of the way up the icy 4wd road until I got to the worst part and couldn't make it. I hiked up for bed and when I returned and inspected it in the morning the DRIVESHAFT WAS COMPLETELY GONE. ****. I realized right away that it had popped off way down at the beginning and after I found it I saw the rear u-joint just completely sheared through the metal at an angle. I freaked out and dropped my truck off to a recommended mechanic but he was too busy to shat and I was not able to ask him if the reason could be different ratios on the differentials. I am really hoping that this could all be attributed to the center axle bearing which he is pressing for me but I am skeptical and not that lucky. I still have the entire rear end from my donor truck which is in good shape, just 800 miles away, so I may be able to repair the driveshaft and 2wd it back home and then change out the rear end. I need some diesel brainpower and advice here.

 

the rations on the axel have to be the same of Sh## gets broke faster than you can say OOMPA LOOMPA and bearings tend to make funny noises when they go bad. also last question has any of the axels been changed out for another one?

 

If the dif you took out is in good shape, why did you swap it.
If your carrier bearing caused it it would have been vibrating something terrible on the highway. Which dif did you change.

 

Yes, the front axle was changed and came off the same truck that I grabbed the 4wd differential off of. Why do you ask? We moved pretty much everything associated with the front end off of the donor 89 and put it on the 93 turbo including the manual hubs which replaced the automatics. We did not change anything on the rear axle. I saw the tags on each case but did not make it a point to see if they matched. I feel like such an idiot but really I'm just ignorant so far and I don't have enough money to pay an expert.

Here is a link to some related questions I asked before I attached the differential, I really wish I had asked the correct ratio question now.

https://www.ford-trucks.com/forums/9...intenance.html

 

I would not put it in 4X until you get home and check the ratios, because it sounds like they are not the same. If you got off with the driveshaft you got off lucky here.
The 89 rear will not have the tone ring for your speedo, I'm not sure what you will have to do there.

 

The diff I took out had the yolk bearing and maybe more blown out by the previous owner. I had intended to throw the new bearing in and use the original 93 differential. After we had it all off my mechanic friend saw how rusty/sandy it looked and told me he thought there might be alot more wrong than just that bearing and getting to the bearing would be a hassle so he suggested we drop the one off of my 89 and see how it looked and it was nice and oiled and looked great so we chose to pop it right on.

The truck WAS vibrating something terrible on the highway and I may have incorrectly assessed it as the crooked-ish tires or cambers. I didn't think to check that bearing, it and the cambers are literally the only thing I can think of throughout the whole front end and shaft that was not meticulously cleaned, lubed, or replaced. To be honest I really didn't even know to look at either when I started this job, I was mostly relying on my friend who is a good mechanic(we hope). I'm mostly catching tools and gathering info and parts. I'm learning though... I really want to get it right and know it myself.

 

Jack up one side and and watch the driveshaft yoke while someone turns the tire one revolution. lock the hubs in and do the same to the front and see if the yoke moves exactly the same amount. Unless you can find the tags on the difs.

 

Whe nI was doing alot of mudding guys would intenionaly run different ratios. They would have smaller tires in the front, I never did figure that one out. When they were in the mud it was fine but if they hit any dry hard stuff..KAABANG! what a mess. If it is a difference in ratios you got of easy with just the driveshaft. Those guys usually blew the pig apart on thiers lol.

 

Different Ratios, not good, KAPOW!!!!!!

 

Ok so now I'm not sure what to think. In the beginning, I changed the differential and then test drove it and no KAPOW, clunk, or grind, only a slight scraping sound which I think may be the carrier bearing which was definitely bad. The test drive was on gravel road and I definitely without doubt had it in 4 wheel high and low and the truck was moving normally for four wheel drive, obviously they drive very different and this was in 4. I test drove it a few miles on my land and never heard anything more than the scrape noise and the whole time I kept tracing the sound to that bearing area but I never actually knew there was a bearing in there. I only ever heard the sound when 4wd was in gear and hubs locked although that is the same shaft used by the 2wd, this was confusing but I'm sure there is an answer. The truck was able to limp on it's fronts and actually drove quite well without the main shaft.

I guess my million dollar question is how possible is it that it was my carrier bearing and only my carrier bearing all along? It seems like a pretty extreme and rare circumstance that a new u-joint would literally get its cap and inner rod sheared off at a 45 angle, especially over a bad bearing, but I was having pretty bad vibrations for atleast my last 200 miles. The yoke and all parts aside from the u-joint and bearing are apparently still straight and in good shape.

 

OK if you drove it that far in 4 wheel and there was no binding then it probably is not the gear ratio difference that we've been talking about. In your original post it is not quit clear if it was the front or rear drive shaft you dropped? It would be most likely your carrier bearing took a dump and spit the drive shaft out. That carrier going bad could of been the scraping noise you heard. All of the drive line has to work in unison, so if one part starts going bad it tends to be hard on all the other parts down the line. Start from the tranny and inspect everything real close and remember not to force anything when installing a new part. These parts are designed to have pretty close tolerances and work well when put together correctly. You'll get it running, just take your time and do it right the first time.

OH by the way what's the cats name?

 

If you had a bad vibration, it is possible that your Ujoint was wore out and finally broke.
When you were test driving on the property and dirt road was it slick or dry. I would still check ratios.
You also mentioned it drove different in 4X can you elaborate. I have drove many a mile on slick highways in 4 high and they pretty much drive the same.

 

The front tires after backing up will always look like \ / and will straighten after moving forward. A lot of times after moving forward they go the other way, / \. When springs start to sag the tires will tip in at the top. Worn parts also make them not sit right.

 

Your buddy that is a good mechanic should have checked the ratios before any swapping was done.

 

When I back up my tires are / \ (bottoms out if you look at the truck)and when I move forward they get completely straight. Are you saying this is normal or some worn parts? I replaced all my ball joints and tie rods with some good moog parts, as well as each U-joint in the front axle.The only thing that I know of that I haven't done yet are the camber adjustment and the struts.

The truck is at a shop in town, it should have been ready yesterday but they didn't notice that the u-joint caused so much damage to the back yoke until they went to install it with me watching. I should have another yoke in there today and be able to give it a go.

I will post how things go as I get news, I still have a bunch of work to go on this thing that I would like to do myself. A few things in mind;


install another sensor to measure my radiator temp (maybe when I change the thermostat)
another oil pressure sensor
fix my cruise control and dash lights if possible
hopefullly change out the two seats for a bench.
there is more but my mind isn't working right now.

The cat's name was "Chainsaw", she is missed.

As far as the question about how it felt weird in 4 wheel, I think I was talking about on my way up the mountain after the drive shaft had popped out and I was using only the front 2 tires, it makes sense why that was kinda weird. The ground was pretty hard where I test drove it and still had gravel, my mechanic friend was outside of the truck watching me go back in forth trying to pinpoint the sound and I'm sure he would have noticed some slippage. I'm resting a little easier thinking that my ratios are correct but I should really know something this afternoon.

Also I read somewhere on this forum where people were reviewing the 10k lb Champion winch that Costco and Sams sold. So far it has saved my butt a few times and I haven't burned anything out on it. It definitely pulled my bug freaking truck up a mt enough to get it turned around.

Woah. The shop just called, I'm off to get my rig, fingers crossed.