Front Differential Mount Replacement Write-Up (PICS!)
 

Hey everyone, I replaced my front diff mount today. I found quite a bit of useful information on these forums but I never found a real step-by-step write-up with pictures. So here goes:

(This is from memory, feel free to correct me on the details. Though I just finished replacing this mount two hours ago.)

First, you'll need a jack. (duh?)

Lift the rear of the vehicle up. Use the subframe as a jack point. Place jack stands on the frame rails.

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Now you need to lower the subframe. Unbolt each side and remove the bushings.

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^ That's the mount point with the bushing already removed.

Now, finally remove another mount point - it's a mount that dangles from the body down to two prongs on the subframe. (Sorry no pictures of that) and you should be able to lower the subframe freely.

At this point, or maybe beforehand, you'll want to lose your exhaust y-pipe and maybe mufflers. (I removed one muffler and moved the other to the side, as you can see here:

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Here's my buddy Nathan removing the y-pipe.

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Now you'll need 17mm wrenches and sockets. (11/16ths will also work in some cases.)

Unless I've forgotten something, it's time to remove that old front diff mount!

There's the new diff mount set in place.

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As for my old diff mount... it came off in two pieces...

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But thanks MazdaTrix for the new one!! They shipped this mount really fast!

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You have 5 bolts to remove in order to get that diff mount out. Just examine the mount above and you'll get the idea.

Now do everything in reverse order and you're done!

This took about 3-5 hours of casual work. Well worth it! My 7 drives like a dream now! No more POPPING on shifting / acceleration!!

http://img.photobucket.com/albums/v6...i/thumbsup.jpg

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Yup, that's me. Don't expect to stay clean during this process!!

Cheers,
iSP33D-for-J3SUS :bigthumb:

Cool thanks.. Im sure my buddy with his 88' will appreciate this write up when he gets around to it. Btw, is it the pic, or do you always walk around with such magnified eyes? j/k :p:

If you can get the pics permanently saved so that we don't have to worry about pics not working, this thread could be archived.

I think you just smeared dirt all over yourself and let the friend under the car do all the work... ;)

wow, strong prescription

awesome wriiteup though, they should archive it after a week

Nice write up. I'm going to replace all 3 diff mounts. Just waiting for "freinds" to help when they stop the b/s. I don't have a garage. It's kinda frustrating. I'm about to do the damn thing in front of my apt. by myself.

This will come in handy....

bump for some hard work dont worry ill be doing this in a few days...

TwEaK

The pictures are up on my photobucket site. Unless photobucket goes down, these should be up forever. I have stuff on my photobucket from like two years ago or more.

And, yeah, I have magnifying glasses. :-P (Looking forward to corrective surgery once my eyes stop developing - around 18 - 24 - and I'm 18 now. After that I shouldn't need glasses at all except maybe for reading.)

Honestly, this job was well worth it. The rubber is much stiffer on the MazdaTrix competition mount. It drives great. It's not as big a hassle as it seems, just get a friend to help you and make sure to have some jack wands around for extra torque. (Especially on those subframe nuts.)

Cheers,
iSP33D-for-J3SUS :bigthumb:

did you have much trouble getting the subframe lowered or back up into place? We did my ex's FC on a lift (my fc now muahaha) and getting the subframe back up was a BITCH. No that my mount went just a day ago i'm going to have to do this. Along with dropping my tranny . . .

Nah, dropping the subframe was no problem at all.

Cheers,
iSP33D-for-J3SUS :bigthumb:

Thats nothing. I have a friend with maxed out contacts plus coke-bottle glasses. I think he's considered legally blind...
Great writeup, too. I'm another of the "I'm gonna do this once I find some time" group. I got the comp mounts with the car, and they've just been collecting dust. The ones in there aren't broken but I might as well do it while I'm waiting for money to do the rebuild. I've gotta drop the subframe for other stuff anyway.

Thats the first time ive seen somebody replace the front diff mount w/o removing the subframe

i thought it would be more cramped in there, however it seems you are actualy able to drop it pretty far

nice write up, hope it gets archived. as for the image hosting, would uploading them via rx7club work for a semi-permient hosting solution?

ok i just noticed this, but it seems you have the jackstands on the suspension arms? wtf?

I was wondering about that too.

awesome...thanks for the write-up ill be doing mine sometime next week

http://forumbinaries.rerev.com/rx7cl...ountpoints.jpg
http://forumbinaries.rerev.com/rx7club/rearshot.jpg
http://forumbinaries.rerev.com/rx7club/nate.jpg
http://forumbinaries.rerev.com/rx7cl...dshotfront.jpg
http://forumbinaries.rerev.com/rx7club/olddiffmount.jpg
http://forumbinaries.rerev.com/rx7club/diffmountbox.jpg
http://forumbinaries.rerev.com/rx7club/newdiffmount.jpg
http://forumbinaries.rerev.com/rx7club/thumbsup.jpg
http://forumbinaries.rerev.com/rx7club/meandthe7.jpg
http://forumbinaries.rerev.com/rx7club/jackthecarup.jpg
http://forumbinaries.rerev.com/rx7club/goodjackshot.jpg

Yup, do as I say, not as I do. When I first started I had the jackstands on the control arms (or whatever those things are) later I realized how dumb that was and moved them to the frame rails. I just took that pic before I moved 'em.

Cheers,
iSP33D-for-J3SUS :bigthumb:

Oh My God. I've Been Searching For This.

It Needs To Be Archived. (if it's not already)


This Is My Problem Indefinitely!!! Crazy what a little searching on the forum will find you.

So $68 and 3-5 hours of labor later, I'll have a good running FC again!

Thank You So Much.

+7 awesome points for this writeup. I'm going to have to be doing this at some point and now I won't screw up (as bad).

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:rofl:

nice good write up when i did mine i tried to find a write up but no one did. but now i have a solid mount on, i welded a piece of thick metal where the rubber part is at. works just as fine

+1 for the welded mount

-1000 for the welded mount, there is a reason it is rubber isolated. The correct way would be a pinion snubber, they are about $15, keep the isolation, but also don't allow the diff much upward movement.

Hmm, these links are dead. Were you trying to mirror them?

Like I said before, these photos are from my photobucket site, so unless photobucket screws up, they should be up here forever. Feel free to mirror them if you want though.

Cheers,
iSP33D-for-J3SUS :bigthumb:

Awesome man! Thanks I got that problem with my 87 T2 it fuckin' sucks!

cool

+1 should be archived :P

Sorry to dig this out again but I just did mine and thought I'd add to it alittle.

Be sure to remove the bottom mount bolt for the sub-link.

I was prying and jerking and twisting to no avail. Took out that bolt and the sub-frame fell out. Just my 2 cents.

Good thread. I just did my tranny mounts today. Going to do the diff stuff tomorrow.

-100 for welded diff mount

Where do you think the rest of the forces are gonna go if you eliminate that rubber? If you're gonna do that, might as well reinforce everything else so that they can handle the increased loads.

+100 for pinion snubber.

It's cheap, easy, and doesn't put much strain on the rest of the rear subframe. Think of it as an extra avenue for drivetrain forces to dissipate. It's an easy job to knock out once the diff mount is out. I've done it in my TII, haven't had a problem since, even with countless hard launches. I've eliminated my wheel hop issues too.

More info on this pinion snubber?

great writeup im gonna do mine myself now. thanks for savin me a shitload at the dealership

Man, just finishing this up. I don't know how you guys did this in that amount of time. Maybe cuz mines a turbo II. Theres a couple little extra things I had to unbolt to get the subframe to come down. Ended up dropping the whole diff. The rear diff mounts didnt want to go in smooth. Had to sand them down and bit and put a tbolt clamp on the top of one to shrink it down so we could ram it in .

this took me a full day to do. and i put the exhaust back on the next day. i dont know how it can be done in a few hours. just getting to some of the nuts took what seemed like a few hours. i didnt have an assistant though. but just getting to the mount seemed like 90% of the work. thank god for the hollow pipe from my floorjack. dont start this repair if yer not ready for some work. but it is a very worthwhile pain in the ass. i would add take both wheels off and dont do it without taking the catback section of the exhaust completely off. shortcuts will bite you in the ass on this one trust me. just take everything off and drop the subframe as low as possible. and have something to torque yer sockets with. most of what your onbolting here is torqued to hell. and have a u joint adapter and extender handy for yer socket wrench. great writeup should be archived:icon_tup:

Some helpful tips while doing this job:

-Have LONG extensions handy & breaker bar
-Know how to use the double wrench trick to increase leverage
-Use PB on every fastener to be removed
-Remove both rear tires
-Remove exhaust from y-pipe back
-Remove the 2 main subframe nuts & the parts that attach to it.

The rear nut(of 2) on the outside face of the diff mount can best be taken off with a 1/2 inch ratchet with a stubby extension, from the rear.

The front one can be removed with a wrench (I use the double wrench trick)

The subframe should drop off the studs and hang for about an inch below it. The nuts on the ears of the diff shouldn't have to be loosened.

I dunno if i am resurrecting this from the dead, but i am on a laptop doing this as i type. Now the subframe lowered for me fine and i didnt have any problems getting the mount out. I got the 3 nuts on that connect the mount to the diff but is there a trick to getting it to align with the subframe, i used a jack and raised the subframe so it was hitting the bottom of the mount however lost all my access. How critical is where these studs sit on the subframe is it possible to just lower it a lil then do em? And as for the guy that sanded down the rear mounts, if your read the FSM they require 2 tonnes of force to press in.

write up
 

This is a good write up. I just wanted to add something and give a warning to anyone doing this job. If you remove the nuts connecting the lateral links to the subframe be carefull. The nuts holding the lateral links have a different thread pitch than the nuts holding the front diff mounts. They are both 17mm heads and can get mixed up easily because they look the same.