Stupid Forum!

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My front diff mount has been trashed since last September (never let a woman drive your 7!) It took this long to find a decent used one (dealer wants $200Cdn for new? Suck my ***! ) Props to Ernst at www.rx7world.com for the diff mount.


Now this is what the diff mount is supposed to look like:




And this is what I pulled out of my 7 tonight:



That's just how it was - COMPLETELY broken apart. I hope the bitch is happy.

It took 7 hours working alone (that includes time spent doing an oil change.) I took my sweet time about it and did it right. I also have my measurement for a pinion snubber and hopefully I'll have one in my paws by the end of the coming week.
If any of you out there race or otherwise push your 7 hard (especially dumping the clutch at take-offs) get yourself a pinion snubber. Put one on your 7 and you'll never have to worry about what you see above happening to you.

Driving home was almost spooky without the diff pounding the floor every time I used the clutch or the gas pedal. Now I just have to behave myself and not trash this new (to me) one before I get the pinion snubber in. Any bets on whether or not I make it?

 

i had the same proble with mine.
i also wanted to the the competition diff mount
it has no balance weight and stiffer rubber

 

Checkout Autoexe's competition bushing and mounts.
http://www.boomplustoys.net/autoexe_product.shtml

I purchased an entire set and I can feel better response on my car now.

 

Why would you go through the trouble of dropping the diff twice to install the snubber?

I can see having one on hand when replacing the front mount and installing it at the same time, but doing them on opposite weekends just seems cruel to yourself.

Taking 7 hours makes me think you don't have a hoist which is even more painful. I swapped in an LSD and welded my front mount in less than 3 hrs, and that included dropping the y pipe. (on a hoist)

 

Nope, no hoist. And I'm doing it in 2 steps because I have to. First I had to get the 'new' front mount in and then I could measure the gap for the pinion snubber. Trying to measure while there was a broken mount would have been pointless - the gap would have changed when the intact mount went in.

 

You installed a used diff mount? Why go through all of the trouble of having to drop the diff again when it fails? New mount would have been worth the money...

 

A shim of some form under the front of the diff would've allowed for you to measure to your hearts content while not having to do all the work twice.

You also might want to look at one of the posts I made in the other thread about mounting the snubber from inside the cabin.

 

I agree with Aaron. You drove it for like a year with it broken. Why not just save more and get one from mazdatrix or mazda? Or one of the many aftermarket companies.

 

September to Now equals 5 months.

Talked to my 7 mechanic repeatedly both recently and the last time I smoked the mount. Used is just as good as new, and with the pinion snubber there's no need to be concerned about the mount failing again. I complete the setup I have planned and I never have to worry about it again.

 

did you also change the rear diff mounts? there are two on teh car

 

Nope. Only the front one was trashed. I might go after the rears this summer when I do all of the links and bushings...

 

If you are going through the trouble of dropping the rear, do yourself a favor and do the **** right, get competition mounts and change everything.

 

Some of us don't have the $ for that. And some aftermarket goodies aren't as easy to find in Canada as they are in the states. We don't have pepboys (nor anything quite like it) here. I went looking for aftermarket bushings kits last month and all I got were shrugs from the parts shops that we do have...

And I didn't drop the rear. More like lowered/loosened it briefly.

 

One of the reasons I hate living here. I went to find a tap and plug set and everyone was like "wtf are you talking about?"

One guy even suggested drilling the hole to about an inch, jb welding a piece of ******* PLUMBING in. Then sitting a m10x1.25 screw into that. Jesus....

 

Oh cool they've got rx7's on Mars now? How much is the bus ticket one way to mars?

 

 

Whats a "pinion snubber"?? Is there another name for this?? <-- |\|3\/\/8

 

It's like a cylindrical rubber bumper with a stud sticking out of one end. You drill a hole in the body (under the seats/bins) and bolt it in place directly above the nose of the differential (just a little behind the 'Y' of the parking brake cables.) It blocks the diff from snapping upwards when you put power to the drivetrain and so saves the front diff mount from being pounded on all the time.
I'll post pics of it when I get it.

 

Pinion snubbers are used on solid axle vehicles to prevent the pinion flange from banging into the body.

http://www.competitionengineering.co...?CatCode=10006

 

Thanks

 

Think of this as The Idiot's Guide to Pinion Snubber Installation.

I had to 'loosen' the subframe to get enough room to get the pinion snubber (PS) in. To do this, you need to remove the nuts from the front subframe where it bolts to the body, and also the nuts from the rear differential mounts. Don't worry - nothing will clunk to the ground. It's all still being held up by your shocks (and your driveshaft, which you won't need to disconnect.)

The subframe front mounts.

This one's already apart. See the thing hanging down on the right? It has a 14mm nut holding one end of it to the body. After you remove the 22mm nut, remove the 14mm one and then either swing it out of the way (like I have in the picture) or set it aside.


The rear differential mounts.


I used a racheting breaker bar to remove and reinstall these nuts. If you don't already have one, GET ONE. They're invaluable.

I used a crowbar to carefully pry the subframe and rear diff mounts down as far as they would go. This still didn't leave enough space to get at the spot where I intended to place the PS, so on the right side of the car I slowly pried the subframe down as far as I could get it to go and then stuck a 4 inch bolt (head up, against the body) to hold it there. Now I had enough room.

With a long punch and a hammer I scootched under the back of the car. I picked out the mark where I had measured for the PS and used the punch to put enough of a dent there that I would be able to see it from inside the car. There was not enough room to drill from below.
Then, after pulling out the rear seat cushion (guys with bins - you're on your own ) I drilled through where I had punched.




Next I put in the PS, sliding it through the hole and putting on the nut from inside. Then I put the subframe back up (meaning reconnected everything.) I had to put a jack under the diff and lift it to get everything in place.

The pinion snubber. It came in a pack of two.



With everything set back up, I went back under the car and used my fingertip (and then a tie-wrap ) to gauge the gap between the PS and the diff. It was too much, so out I came and dropped everything again. I removed the PS and put 2 washers on it to act as spacers (see pic above.) I reinstalled the PS and then reconnected everything again. This time it was just where I wanted it.

My 7 mechanic, who first told me about the PS, said that you do not want the PS to actaully touch the diff. You want just a few c*nt hairs of space to allow a little play. And that's what I now have.

 

Get us a pic from below of the snubber installed.

We can then use all your hard work to locate where we want to use a hole saw to cut a circle in the floor to locate a snubber from above and mount it with the seatbelt attachment points using some bent bar stock.

Not having any preload on that thing will cause your used mount to fail again before the snubber does anything. The tip of the snubbers are tapered for the soft onset of the damping. The ones I've handled have always been pretty squishy (considering I can only squeeze about 50lb/ft bare handed) for the first 3/8", then they get pretty stiff. So while your snubber is compressing, your front mount is tearing again....

 

I would take a pic from below (I wanted to) but my POS cam can't focus that close.

I'l check for that tapering on the PSs that I got. I don't mind going in there and redoing the setup - I've got dropping that subframe down to almost an art.

 

Yeah, dropping it isn't so bad once you get over the fear of doing it. I'll be taking mine completely out to weld in some supports for my subframe connector links. (no hoist this time either)

 

Is there a way to get detailed instructions on how to drop the subframe? Like the location of the specific bolts and **** to loosen, that you havent mentioned?