Front Diff mount-bracket attached to car BROKE
 

Would post pics of actual breakage, but getting a good angle and lighting while in an apartment complex with nothing but jack stands was too hard so I pointed it out in a pic below from the Haynes manual.

Has anyone ever seen or experienced this and what would be a recommended fix?

I've thought about getting someone to weld the bracket back together, but it's so small and in such a tight space, I dunno if that's a practical approach to this. I haven't had much time to really mess with it, but it does seem to go straight across as depicted by the orange highlighter in the pic below, with the mount bolts still holding on to the other half of the bracket. The bracket has a nice thick factory weld at its base so cutting it off to put another (custom) bracket on there may be too much work. Open to suggestions...:)

https://www.rx7club.com/picture.php?...ictureid=42054

This is an everyday driver, might drive it a little hard every blue moon, and did nothing out of the ordinary the night before finding this problem (parked it one night after school, woke up for work the next morning and got a "THUD" in the back everytime I'd put any torque to the shaft, sure enough, the bracket broke, not the mount, but the bracket [face-in-palm]).

you will need to remove the diff, and subframe (if you want) to fix it.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/pinion-snubber-diff-mount-replacement-convertible-876959/

post a pic,you forgot it.

it is a common issue

Beyond common. Any time you hear a Thunk when you are shifting, it's more than likely (but not always) the front diff mount.

he's referring to ripping the mount points off the actual subframe, this is a semi common occurrence in drag and drift cars where the differential forces on the mount and subframe are well beyond what the car was intended to see.

there really is no easy fix for it short of replacing the subframe, getting a hardened mount and a pinion snubber. some people have built their own solid mounts to take more stress off of this area of the subframe. i have seen it once in person.

Thank you all for your input :nod:


After reading the post you linked to, it didn't sound like anyone dropped their diff completely, even when completely dropping the subframe, is dropping the diff truly needed when only replacing the subframe?
Not really looking to do more than what's needed to get the subframe replaced (unless dropping both IS truly needed; I dunno)

sucks, but that does sound best. After reading through some posts on dropping the subframe, sounds like it's not too terribly hard to get done.

Do you think it can be replaced with the car only on stands?

Never heard of a "pinion snubber" till today; according to posts HERE it looks to be just a dampener sort-a-deal that sits right above the diff, towards the front, is that correct?


aaand if anyone knows of any good sources of subframes, I'm open for business. All junk yards in or around Jacksonville are tapped of all older cars, trust me I've called around in the past and no one has any Rx7's.
(I'll also be posting on my local thread for replacement subframes as well)

1) Yes. 2) Yeah, pretty much. 3) And check your local or "regional forum"... SE For Sale/ Wanted/ Classifieds. Maybe make a "WTB" thread.

I welded my solid diff mount to the subframe...that was 6 years ago :-)

I reinforced the mounting point on mine. Cut the old stuff off but left a small bit there for locating the beefier 1/4" plate. I then gusseted that plate on both sides.

Mazda competition front diff mount, snubber, and MMR solid mounts in the rear. Haven't had any problems since.

you dont really have to remove the subframe, but it is so much easier and gives you less headaches to do so though. I too have taken the diff out with out dropping the subframe all by my self in 30f weather on the floor!!

Alright, so I got a new subframe on its way here and plan on being able to get it this coming week.

I forgot to ask one thing though;
When removing the subframe, should I be worried about the control arms when unbolting them from the subframe or will I be able to just disconnect the control arm links and toe adjusting link, and then push the control arm which ever way to work it free from the subframe? (im asking this cause I'm not looking forward to any unexpected consequences of leaving the rest of the suspension hooked up while replacing the subframe)

From what I've looked at and read, it should just be unbolt all linkage (on subframe), unbolt subframe mounts, drop old subfame, and then just bolt up the replacement. :scratch: I can't find a thread where the ONLY thing being replaced was the subframe: I'm not looking to drop anything but the subframe and bolt up a new/replacement.


I'm not too worried about alignment either as I have Tire Kingdom's 5year plan of free alignments, balances and rotations that I can exercise at any time. (only $200 and has already paid it's self off due to alignments costing $60-$80 each time :icon_tup:)

nvm to my last questions; forgot to check the service manuals that Icemark was so gracious to post for us all ie: http://www.cochran-racing.com/FSM/index.html, of course thanks to those who host this data for others as well.

The manual gave simple instructions for the removal of just the subframe and was able to put some worries to ease. I'll be sure to take pics, post experiences and do some donuts in celebration once I can finally get back behind the wheel :icon_tup:.

i have the same problem. go to mazdatrix.com and order a new one :)

Finished!
 

DONE! :icon_tup:

Big thanks to all of those who gave input!

Followed directions from HERE and HERE

everything went pretty well for the most part. Lateral Links proved a little anoying when pushing them out of the subframe, but I managed with the nut threaded, socket on it, and tapped for a while with hammer.

Here are some pics of my experience:

(pinion snub needed about 8 washers, but I only had 7 and it was getting late and cold so I'll get another time)

https://www.rx7club.com/picture.php?...ictureid=42327
https://www.rx7club.com/picture.php?...ictureid=42329
https://www.rx7club.com/picture.php?...ictureid=42328
https://www.rx7club.com/picture.php?...ictureid=42330
https://www.rx7club.com/picture.php?...ictureid=42331
https://www.rx7club.com/picture.php?...ictureid=42332

Great job... Awesome reference pictures, too!