Front Differential Replacement

I’m starting to wonder if there is a difference between the auto and 5-speeds... and if my motor mounts are collapsed enough to make this harder.

Going to pull the flange today and see if that helps. Then lift the engine a bit. Crazy stuff.

 

Bench pressing the differential up and rotating it forward does work but it's not as easy as when you disconnect the driver side motor mount and jack up the engine an inch or two along with releasing the vacuum and breather lines so they don't get hooked on the power steering line. I honestly don't know how removing the side mounts would help with removal. The mounts aren't hitting anything when you're trying to remove it. It's the flange hitting the bell housing and the top of the differential hitting the oil pan.

@bkg have you released the driver side motor mount and jacked up the engine at least an inch? If you're still wrestling with it, jack up the motor some more and maybe even release the trans mount like we did in the video. In the video, Fred's truck had a body lift which allowed us to move the transmission up a little higher which probably helped, but if we would have released the driver side motor mount, it would have made it even easier.

Last week I helped remove a front diff on a 3rd Gen 4runner with a 4 cylinder engine and manual transmission. I thought it would come out easier than the 6 cylinder with an automatic transmission but I was wrong. We still had clearance issues getting the stud to clear the cross member and getting it to rotate out without hitting the oil pan. After we disconnected the driver side motor mount and got the metal lines out of the way, it came out super easy. If I ever do this job again, which I probably will, I'm not even going to try getting it out until I jack up the engine first and get those metal lines out of the way of the power steering line.

 

I have another idea now, thanks to Timmah!’s last post. Since the front end is nearly completely apart, and I had already planned to install new uni-balls in the Total Chaos upper arms, I’m just going to “do it all.” Ordered new Total Chaos a-arm bushings and energy suspension steering rack bushings... did TRE’s a few weeks ago, lower arms and BJ’s and cv’s are only 8k miles old... so I’m going all-in. This should allow me to get some more room by yanking the rack.

Shoot. Should have just called FRORF and ordered a diamond front end. Lol

 

That’s what I was thinking, maybe it’s the manual transmission! But I honestly think it’s the little bracket I took off, as soon as I took that bracket off, it came right down. And I didn’t have to worry about the power steering line!!


Super easy to disconnect and reconnect!!

 

I had that off as well.

It’s all moot now. I built a little piece that bolts to the forward front diff mounts that holds the engine about 1.5” up w/ DS Motor mount undone. That did it for me.

So now it has a 4.88 diff. And when I started to put the engine mount bolts back in, I noticed that the tabs on the driver side motor mount perch are... broken off. Broke right through the bolt holes.

Yay me. That’s gonna be fun to fix.

 

Just take your time and I'm sure you'll get it fixed.

 

Since I clearly hijacked this thread....

Thanks again to @Timmah! for the vid. I’d probably sill be cursing the removal of it wasn’t for this thread!

 

For anyone looking at this thread in the future. I was able to get the front diff out by myself without jacking the trans or engine. I used @Timmah! video as a guide and did everything they did. When it came to take the diff out, the rear diff mount has two bolts that connect it to the diff and the stud that connects the rear mount to the frame. I was able to remove the inboard most mount to frame bolt and break the outboard bolt free. I used a 17mm boxed wrench on the inboard boltand an open end break the outboard one. This allowed the mount to rotate freely around the outboard bolt. I finagled the mount and diff a bit and got enough clearance to remove the outboard bolt. Once it was out, you're able to easily remove the rear mount. From there, it was relatively easy to get the diff out. See picture below for reference.



If I was going to do it again, i would break free those two rear mount bolts first before removing the other mount bolts. When i did it, the diff was already loose so it was a pain trying to hold it steady and break those bolts free. I would also recommend removing the breather bracket lines bolt so they dont get hung up, 12mm head bolt on top.

Hope that helps someone.

 

Has anyone been able to replace the ADD without taking the differential out? how can I maneuver it in and out?

 

You'll have an issue getting to those bolts if you pulled off the tube at the end (whether ADD or manual hub).

There's also the whole not having the socket for it either as some use e-torx versus metric head.

 

Here's a Part 2 for this job. I cover the easy way to get the diff out that I detailed in earlier posts on this thread and I also cover other helpful additional information.

People have told me another technique to getting the diff out easier is by removing the support arms from the differential. They say by removing the arms, you don't have to lift the engine a little to facilitate getting the differential to come out easy. I have not tried this technique yet but I'll probably give it a shot soon when I help a guy remove and reseal his oil pan due to a leak.

https://www.youtube.com/embed/bOOxfDFUFsA

 

It can be done. My buddy Rich broke off the end of his passenger side CV shaft on the Hells Revenge trail in Moab, UT and shaft was stuck in the differential tube. He was able to pull the tube off so he could work at getting the shaft out. You'll need an E14 External Torx Socket.