solid front diff mounts finished!!!
 

I finally got them ready :D It makes all the difference in the world to have a shop now... and a lift :)
Now I only have about 20 something projects left :(
These have a new stud plate not in the picture. They also come with all-metal locknuts and the studs are grade 8.

http://vintagerotaries.com/images/diff/diff04.JPG

I take It there will be a massive production of these? Hence, now acquired shop and previous history of production-to-sell-parts? :D Details?

I'll keep making them as long as people keep buying them or I get tired of making them ;) they are $60 plus $7.50 shipping (within continental US) They are kind of heavy so shipping will go over every time.

I am curious to know how much more vibration and "jolting" get transmitted through the frame on a car with these solid mounts. Have you tested them yet in a car?

I have driven a car with a similar mount and didn't know it was not stock until much later. That was because we were talking about me making them and he asked if I was going to make them like his. He had his in for two years. Victor Sanchez '87 TII has a solid mount and he says it doesn't feel different from a good stock mount.

Sounds like a good deal for those of us ailing with bad differential mounts. Good work. :)

How hard would it be to install this mount since there is not much flex to it. And Great job the mount good price too!

It was easy as hell to get it in the one in the pic ;) hehe!!! You remove all the nuts and then wedge between the subframe and housing and force the front of the diff upward.
Keeping it forced you put the new mount over the studs and play it by ear from there.
If you have something forcing the diff up on it's own you can put the nuts on the studs and tighten it down.
If you are having to use a pry bar a grunt it be damn careful where you get your fingers. One slip and you could have a serious crunch :eek:
Alot has to do with where the housing tries to sit as you are bringing the mount down into the slots where the outer nuts go. Normally you would not have a lot of trouble.
Not getting your fingers jacked is definately the number one priority though so you do need to be careful.

We are doing one over the weekend and I will get good pics and do a full pictorial removal and install so everyone can get a good idea of what this involves.
Things are a lot different when you are under a car on your back looking up at them. The view from the bottom of the subframe is not real good.
That pic at the top is something you should look at real good so it will make more sense later.
The subframe is against the bottom of the car and you cannot get this viewpoint. But knowing where a nut is without seeing it can be a real help :D

Neato...good for all those random people who like to launch their cars on 15 yr old mounts :D

Is this the most comonly broken diff mount? Or are the two on top of the diff often broken too? I launch my NA ar redline and i'm sure i'll break a mount soon

when i launch my car at 3 it spins tires then pauses before picking up again....could this be related to my diff mounts?

By far it is the one that you will find has failed second the the motor mounts. If you are launching near redline on good tires that stick instead of spin you will definately break.
While we are on that subject;
Keep in mind that you that the weakest link law applies here. Unfortunately when it comes to racing you always have to worry about the weakest link.
The mounts and brackets I make will make the other components the weak link.
But that has always been the rules of drag racing.

Everybody brings up concerns about vibration and all but no one has mentioned what most people already know.... the better you stick, the harder you launch, the more you break.
That is the price you pay for that rush :( Unless you have alternate means of transportation you really need to keep that in mind.

I have a good day job so I ain't hurting to sell these things. At least half the guys I know only have their one car to get them around. But they never let a little thing like common sense get in the way of tearing up their cars. :( Instead of investing in making their cars go faster they should get them a dependable beater first :)

Sorry but I just had to get that off my chest ;)

Probably not. It could be you hit that awful 3800 RPM dead spot that so many FC's have a problem with.
If you launch hard with a bad diff mount it feels like somebody whacked you in the ass with a board and makes an unnerving sound like hitting an I-beam with a hammer :(
It immediately gives you no doubt that something just happened that really was not right.

Bastard! I just bought my MazdaSpeed Front Diff Mount last Friday! :( 100$ with the shipping and all :*( I am sad now....,but at least I know where to come when I break this new one!! :D

--Fritz

I hope you get a lot of years out of that mount. Those are urethane right?

I have no clue :( I just needed a diff mount at the time and it was cheaper than the stocker at Mazdatrix.com and it was JDM, y0 that meanz i will getz lyke 54 more hp, ov korse thtz aff'er I put thoze mAd TYTE kanji simblez on my car y0. Okay sorry for that :D But seriously the only thing that was different as far as I could tell was that their is no warranty and they are in no way liable if my car explodes when I attach it. ;)

I hope I get a couple years out of it too though. Good luck selling them I am sure I will be a buyer sometime in the future! ;)

--Fritz

where did u get the mazdaspeed one for $100 shipped?

Here s a pictorial of the diff mount conversion I did this weekend. We did my buddy David's '91 TII converted convertible.
Now I am not sure if the vert is exactly the same as the coupe or not.
At least for this we had to take off the two front subframe bolts as well as the hanger bracket.
The two nuts that hold the mount to the subframe are the trickier ones to get to.
But with some extensions you get to them easily after the front of the subframe is lowered a bit.
We had to take the exhaust loose at the front of the Y so we could drop it enough.
A "gearwrench' makes taking of the two nuts at the back of the mount off.
Lowering the front of the subframe enough to get the mount off was a bigger pain than I remembered.
Mainly because once you drop the bushings down below the mounting studs the whole assembly tries to get a little cocky.
It is definately easier with two sets of hands. A floor jack is just about a must to handle the subframe.


The first pictures are of the stock mount in its natural position. The first pic is from the rear.

http://vintagerotaries.com/images/diff/DCP_4434.JPG


This is looking at the two nuts from in front of the tire and over the subframe

http://vintagerotaries.com/images/diff/DCP_4435.JPG


This is from in front and below the diff


http://vintagerotaries.com/images/diff/DCP_4437.JPG



This is one of the two nuts that hold the front of the subframe up

http://vintagerotaries.com/images/diff/DCP_4438.JPG


This is with the passenger side off and lowered


http://vintagerotaries.com/images/diff/DCP_4440.JPG

Pull the bolt from the bracket. The block is where you need to wedge the diff and subframe apart

http://vintagerotaries.com/images/diff/DCP_4444.JPG



This is looking at one of the nuts that have to be done from above the subframe and the next pic is the extensions on it

http://vintagerotaries.com/images/diff/DCP_4442.JPG


http://vintagerotaries.com/images/diff/DCP_4443.JPG

Once you get the old bracket off be sure to keep the plate that goes over the two studs.
Here is the mount up and happy :)


http://vintagerotaries.com/images/diff/DCP_4446.JPG

http://vintagerotaries.com/images/diff/DCP_4447.JPG


http://vintagerotaries.com/images/diff/DCP_4448.JPG

The front mount I got from Mazdaspeed for 100$ shipped was from mazdaformance. Scalliwag have you heard anything bad or good about these mounts? They definitely have rubber on 'em so i am assuming it is only a matter of time before I kill this one.

http://www.mazdaformance.com/rx7.htm

--Fritz

I know that the Mazdaspeed motor and tranny mounts shown just above the diff mount look just like the OEM rubber. So I guess their diff has the same compound.
Even if that is the case the less horsepower and less traction you have and how often you drive hard will determine how long those last.

I am guessing you will get your $100 worth from them. Even running hard on them I would be shocked if they did not last a couple of years at the very minimum. It is more likely you would get over 5 though.
I would not sweat this if I was you.
With mine they should last forever.... but you will still break a lot of other stuff :eek:

Great job man. Still coming up with the products we all want and need, and at a great price too. Great write up as well. I take it you've pretty much completely moved into the new shop? Keep up the good work man, and thanks again for the products.

- Steiner

Yep the shop is coming along fine. I'm glad I have my day job so I can get some rest though :)
We got all my equipment out of my garage except a vertical mill that I plan on selling.
Added to having more room we got a lift , a 300 amp TIG welder (a cool story behind that :) ) a Miller MIG head for it as well, and we have a big ass Do-All bandsaw (cuts up to 9-1/2" round/ 8"X10" square stock!) and a few other smaller items to make our lives more easier.
To top that off we have a 1/4 mile stretch of flat concrete that we thought was a road but turns out to be a private drive ;)
We like to think of it as a private drag strip :D So we are loving the shop but it is a lot of work.

Right now I am just working on the simpler stuff. We still have so much infrastructure shit to do in there like building storage above the office and bathroom, shelving, wiring out 3 phase outlets etc. etc. etc. etc. that the R&D time just isn't there. So I make things I know will work and not take tons of time.
So the mandrel bender and housing resurfacing will have to be revisited later on :(
I just finished building a 25hp rotary phase convertor and have a thread about that and the welder over here http://vintagerotaries.com/FORUM/viewtopic.php?t=566