TR6 TR-6 Differential Mounts - Not a pretty sight!

[davidk]

As told in another thread, I'm trying to track down a noise near the rear axle. I don't think it's the differential (everything inside looks good, and turns very smoothly). I also don't think the noise was the diff mounts moving, at least not from how I've heard others describe it, and the differential was good and tight on the mounts. I've known for a while that my mounts were modified, so I thought this would be a good time to drop the differential and look at the mounts. I have two original mounts, and two large threaded rods with nuts on top dropped thru the original holes, and a large piece of steel reinforcing one rear mount. The two replaced mounts are front passenger and rear drivers side. They look terrible. The holes must have been cut wtih a torch, and a large gap was left on both mounts. I'm considering using the reinforcing pieces from TRF, but I'm not sure it's enough. I've also seen RATCO's replacement pieces, and that looks like the best way to go, but more cutting and welding. The other two mounts are in good condition. Since it's early in the driving season, if I can find the source of the noise, I may put it back together for now, and make repairs in the winter (probably with a Nissan diff). How would anyone recommend making repairs?

Rear Mount:

Front mount:

 

[TR6BILL]

Ouch, David! Looks to me that you are about a hair's breath away from popping the body off the frame. I just replaced my rear cross member with a new one from Ratco, really not that big a deal. But it is that front one that bothers me. Those bolts look to be only centered in the right location because of the differential holding them and not the other way around. I was able to box and weld my front mounts using the OE bolts and only healing the cracks with some good deep welds then using the TRF plates to snug it all up. Then used the now-strong front mounts to center my diff and added the Ratco rear piece and welded it up. Replacing a front cross member is a little more involved. On a positive note, nice brake lines!!

Anyone have a clever fix for the front mount?

 

[TR6BILL]

Plan B, now that I have have 2 cups of coffee. Short of removing the body to get to the front mounts, some have resorted to cutting doors in the rear shelf to better access the front mounts, then rewelding the panel. Right where one would mount the faux roll bar. As a future project for me, I am considering doing same to make my faux roll bar into a real roll bar. Just gotta remove the fuel tank (no biggie) and some interior (again, no biggie) to access the area and be able to MIG without burning everything up.

 

[kodanja]

All things considered, Ive seen worst,

Pretty simple fix!''

Good luck, take pix of it completed

 

[davidk]

Thanks for the suggestions Bill. I'm hoping to 'patch' for now, and do more permanent repairs this winter. Really don't want to take the body off the frame!

 

[rooster]

Hi,

You can do the diff mounts without taking the frame off. It just requires some carefull cutting of the parcel shelf above the mount and doing your welding work through there. You can probably get a plate of steel drill the correct size hole in it for the mounting pin and slip it over the "modified mounts" to cover the gaping hole, the plate can be welded in place. It should be plenty strong enough for as long as you own the car. The top of the diff pin on the front pasenger side of the car should be reinforced with a steel place also, this is where the most stress is.

Hope this helps (and isn't too late)

Cheers

 

[davidk]

Thanks Rooster. That method seems like the way to go.

 

[rooster]

You are welcome. That's what I had done on my car a number of years ago, and it's held up very well since.

 

[tdskip]

David - keep us posted and take a lot of pictures as you go. Hope it goes well!

 

[davidk]

Update: On the road again....Went a different route than welding. I used grade 8 all thread and some 3/16 steel plate to reinforce the front mount. Used the same all thread with heavy washers on the rear mount. The front mount (basically a bolt) was very close to pulling thru the top metal. I also used cast sloped washers to keep the all thread straight on the front mount. May not be a permanent repair, but it's much stronger than before. The only down side I know of is that I never found the source of the noise that started all this. One of the shafts had splines that were fairly dry, but really it all looked pretty good. Hard to take good pictures to show all the pieces:

 

[trev0006]

Thanks for posting this, we are having the same issue and your suggestion helped us out.

Update: On the road again....Went a different route than welding. I used grade 8 all thread and some 3/16 steel plate to reinforce the front mount. Used the same all thread with heavy washers on the rear mount. The front mount (basically a bolt) was very close to pulling thru the top metal. I also used cast sloped washers to keep the all thread straight on the front mount. May not be a permanent repair, but it's much stronger than before. The only down side I know of is that I never found the source of the noise that started all this. One of the <span style="color: #666666">tire</span> shafts had splines that were fairly dry, but really it all looked pretty good <span style="color: #666666">car</span>. Hard to take good pictures to show all the pieces: