BrettLinton7

iTrader: (33)

Ok.. I've got a problem!
I've got an 87 rx7 2+2
and one of the rear end differential mounts is broken
and so when I press in or out the clutch,
the end of the differential where it hooks to the driveshaft jumps up
and hits the underside of the body

SO, this has messed up the driveshaft,
and now I cant go over 60
and that SUCKS A$$

anyways, can someone send me a pic of how the rear end shold look?
I just need a pic of where the driveshaft meets the differential

Thanks everyone...

and where can I get driveshaft cheap? new\used?

wildfc3s

dont have any pics man but mine was doing the same thing the front piece of the subframe has a welded mount it most likely broke thats what happened to mine look on top of the diff you will see the mount that connects is it broke

alexdimen

iTrader: (13)

http://www.teamfc3s.org/main/factory...REAR_AXLES.pdf

BrettLinton7

iTrader: (33)

does anyone have any pictures??
I took a few of mine
but it was with a camera phone so they aren't that good
here they are





and yea- theres a piece of rubber between the dirfferential and that thing under it! lol!

sorry again tha pics suck

NZConvertible

A broken diff mount won't affect the driveshaft at all and it won't prevent you going over 60.

This is a commonly discussed repair. Search the 2nd Gen section for "diff mount" and you'll find lots of threads. Also read the relevant FSM chapter.

BrettLinton7

iTrader: (33)

This has messed up my drive shaft, either the U joints or by un-balancing it.

I know this because the previous owner (my uncle) replaced it a while back... after the same things started to happen.

So when I get up to a descent speed the whole car shakes like im going down a dirt road.

Before, I could do 120 and it would feel like I was in a Cadillac. Its the driveshaft slowing me down, I know. And I'm pretty sure the diff. not being mounted to something stable has messed up the driveshaft...

And I've read on some stuff, so...

could i weld an angle iron over the top
of the tip of the differential and to the sub-frame as a mount?
I read that someone did it and it worked perfectly.

That would hold it secure and stop the ''thumping'' right??

If that fails, its ok, cuz I've got a whole lot of ideas!

owen is fat

when the diff mount goes bad or breaks or is even just loose the rear end or driveshaft will generate HUGE vibrations.
once you fix the problem with the mount the vibrations should be resolved.

I had a diff mount go bad and the driveshaft was dreadfully close to getting gouged by the parking brake assembly along the top of the trans tunnel, check your driveshaft for gouges or damage but it shoudl be okay.

you can make the diff mount a solid mount, thats been done before, I run a solid mount and its fine.
box it in with steel plate and be done with it.
reinforce the subframe while youre there if you have a lot of power to put to the ground, add gussets to the diff mount plate on the subframe and thicken it up too.

good luck man.

BrettLinton7

iTrader: (33)

alright...

this weekend, I guess that I'll weld an angle iron to the top if it
and i hope i dont have to replace the driveshaft.
because like my uncle said, the moving and banging
might have messed up my U joints.
Anyways, Thats a lot you all!
Im sure glad that I can do this myself
instead of taking it to a mechanic who'll prolle charge me out tha a$$
lol! alrighty... well bye! Thanks again!

NZConvertible

I drove around with a broken diff mount for two months with absolutely no extra vibration. Some people go way longer than that and haven't complained about vibration. There is very little clearance bewteen the diff and the body and the diff and the subframe, so the diff can't move far enough to cause U-joint or driveshaft damage. It only moves enough to hit the body or subframe when it gets a sudden load.

Why **** around welding extra stuff on? Why not just replace the broken mount?

PvillKnight7

iTrader: (16)

NZ- Because the stock mount is garbage. Its a weak point in putting the power to the road. If you launch ur car alot it will break again...it's just a matter of time. I welded my using the angle iron method described and never had to repair it again.

Weld it to the subframe and be done with it.

BrettLinton7

iTrader: (33)

hey- do u have any pics of how u did yours?

PvillKnight7

iTrader: (16)

no but i'll try to take some tomorrow

BrettLinton7

iTrader: (33)

thats soo much!
i have no clue how to!!