Front Diff and Suspension issues

[Stepbyrd]

1999 K1500 w/ 3" lift. 35x12.5x20 Tires. Approx 310,000 miles.

Bought the truck in late June. Sometime mid-July, the front differential started making a noise. I ended up taking it to a shop because I didn't have time to work on it due to other obligations. The shop found that a bearing in the front differential had seized up and mangled the case. They found me a replacement but are unable to get it installed due to a clearance issue. The new differential hits part of the suspension frame and they can get it aligned. The old differential has been shaved about 1/4 to 1/2" (via grinder or machine shop?) to clearance this area. There are still some of the "viens" left but they have been reduced. At closest there may be 1/8" left before it gets into the case body itself. I don't know the brand lift that was installed and the guy I purchased it from is not responding.

This is my first time dealing with a lifted truck. I'm having a hard time deciding on the best option to move forward.

1. Grind the new one down to match the old? Is that substantially weaking it?

2. Is the lift installed correctly? Should I replace it? (I don't know the brand)

3. ?????? Enter other option here?


Does anyone have any thoughts on the matter.

 

[Hipster]

Having to grind/clearance the diff housing is common with most diff drops.

 

[Stepbyrd]

Having to grind/clearance the diff housing is common with most diff drops.

Thank you, that helps me feel better about it. Do most just use a disk grinder or have a machine shop do it?

 

[SNCTMPL]

I use a grinder to do it.
If you know what brand lift it is you could probably find the installation instructions and see what they say.

 

[Stepbyrd]

I use a grinder to do it.
If you know what brand lift it is you could probably find the installation instructions and see what they say.

I'm definitely going to have to dig into things a little deeper once I get the truck back. When I first got it, I spent my time fixing the minor mechanical issues it had. Replacing broken door handles, fixing inoperative windows, etc. Other than replacing the MAF Sensor, the truck was running well. Who could have guessed a bearing would have sidelined it within 200 miles of me buying it.

 

[Hipster]

The 1500 diff has never been known for durability in hardcore off-road applications, but rebuilt should serve well if treated accordingly.

 

[Stepbyrd]

Update - additional questions. So I got the truck back about 6wks ago. I’ve been working on fixing electrical issues and all. Found the short in the wiring harness so now the 4wd works.

1. Today is the first day I tried to run the truck in 4wd. Drove it a couple of hundred yards to try everything out. When I went to disengage the 4wd, the truck jumped like it was in a bind.

Is this normal?

I tried reversing it before disengaging but it still does it.

2. Had the truck on jack stands while I changed the oil and worked on fixing an oil leak. Truck was in park and 2wd. My daughter was talking to me and started spinning the front drivers tire. The tire spun freely for about a quarter turn then started turning the front driveshaft leading to the transfer case. It spun about one revolution then stopped. As she continued to spin the tire it did it again.

Is that normal? The passenger side didn’t seem to do it.

 

[Schurkey]

1. Today is the first day I tried to run the truck in 4wd. Drove it a couple of hundred yards to try everything out. When I went to disengage the 4wd, the truck jumped like it was in a bind.

Is this normal?

I tried reversing it before disengaging but it still does it.

Was the truck rolling when you disengaged 4WD, or standing still?

Is this a floor-shift/mechanical linkage transfer case, or one of the electrically-activated ones?

2. Had the truck on jack stands while I changed the oil and worked on fixing an oil leak. Truck was in park and 2wd. My daughter was talking to me and started spinning the front drivers tire. The tire spun freely for about a quarter turn then started turning the front driveshaft leading to the transfer case. It spun about one revolution then stopped. As she continued to spin the tire it did it again.

Is that normal? The passenger side didn’t seem to do it.

Passenger side is not connected to the differential/ring and pinion in 2WD because of the axle disconnect system.

Driver's side tire is ALWAYS connected to the differential/ring and pinion, so it may spin the driveshaft if that takes less effort than spinning the spider/side gears in the differential. That seems normal to me. MAYBE it's indicating an issue with the spider/side gears...perhaps there's a worn spot, or damaged teeth that bind-up for awhile and then the driveshaft spins instead of the gears.

 

[Stepbyrd]

Was the truck rolling when you disengaged 4WD, or standing still?

Is this a floor-shift/mechanical linkage transfer case, or one of the electrically-activated ones?


Passenger side is not connected to the differential/ring and pinion in 2WD because of the axle disconnect system.

Driver's side tire is ALWAYS connected to the differential/ring and pinion, so it may spin the driveshaft if that takes less effort than spinning the spider/side gears in the differential. That seems normal to me. MAYBE it's indicating an issue with the spider/side gears...perhaps there's a worn spot, or damaged teeth that bind-up for awhile and then the driveshaft spins instead of the gears.

Standing still.
I'm sorry I wasn’t clear, it is the electric pushbutton version.

I'm still learning. All my previous 4wd experiences were with a manual shift/ manual hub 91 Bronco.

 

[Schurkey]

Check your owner's manual, but with my '88 or '97 (both with manual floor-shift) I don't shift in or out of 4WD at a standstill. 2--3 mph up to about 80 is fine.