Solid Pinion Spacer (to replace crush sleeve)
 

Does anyone know of any solid pinion spacers? Looking for one for my FD to use with a TII differential.

Weir Performance makes one for the miata and older rx7, but not for the FD.

I've contacted a few people that sell them in hopes of getting one, but would be curious if anyone knew of any available.

Thanks!

Ones I've seen have always been ground to size, for each application. Are the off-the-shelf items you mention shimmed rather than a direct fit?

Yes, the weir miata one comes with a shim pack.

Why do you need that? Just put in the TII lsd, replace all the bearings, seals, shim it, and set the back lash per the factory service manual.

I have a TurboII diff in it now, all new bearings, etc.

Every time I make a couple good launches (on the torsen), the diff starts getting a coast whine (happened to 2 diffs so far, the first one it happened to is the one being rebuilt with new bearings and the TII diff).

I want to make sure it doesnt happen again.

In progress pic for fun:
http://i60.tinypic.com/2aexn2t.jpg

Was hoping to find a used one to get a ballpark length - but forgot I threw it in the garbage! New unused crush tube is nominal 45mm long, 30ID at the small end, 40 at the large...maybe you could ask if the miata one is a similar dimension? I know the earlier rx7 pinions are quite a bit smaller, so they're unlikely to fit. Hope the shims are hardened stock too.

Interesting, the distance I have between the front and rear pinion bearings going by the witness marks (3.9 cwp) is around 46mm, so not quite sure what's happening with the crush.

I have taken some measurements from a new OEM crush sleeve, and the used one pulled from my differential.

New Crush Sleeve:
Big end: 1.590
Small End: 1.210
Length: 1.880

Used Crush Sleeve:
Big End: 1.590
Small End: 1.210
Length: 1.720

I think it is important to note that I believe the problem i was having with the diff was a loss of pinion bearing preload due to the crush sleeve collapsing on hard launches.

Are you running a Torsen or an early TII clutchpack?

The torsen cannot withstand much shock. What you are probably doing is chipping the spider gears so it becomes noisy.

I've inspected the torsen, and it appears to be in good shape I will also inspect the spare that is currently in the car (check the bearing preload when i remove it, replace the crush sleeve, and reset the pinion bearing preload). The problem that arises is a coast whine. Usually associated with a loose pinion bearing preload.

I have previously run the torsens, and am now switching to a clutchpack from a S4 TII.

Weir Performance makes one for the 94-05 Miata and older RX7's.

I got in contact with them regarding it, and I sent him one of my used crush sleeves and a brand new one. Hopefully he can make one work out for us.

He should get them Monday, so I'll post when I hear back from him.

SPS is good idea

Heard back from Spence at Weir.

He needed a couple more measurements from me, which I got to him today. He's gonna send me a couple sample spacers, and I'll have one more set of info to get him, before he can provide them to anyone who would like such a product.

The spacer was 1.700" long, and i used one (.012") shim to get the preload correct, for anyone interested.

Solid FD pinion spacer
 

I know this is an old thread but I also need a solid pinion spacer for an FD. Did Weir ever offer them after you had yours made?

I don't think they ever offered them officially. I recently emailed them again to see if they offer them still, based on the measurements we took. The one-off ones (well, I got two, so... two-off?) I got were perfect.

I contacted Spence at Weir. He does still have all of the dimensions and shim packs. He doesn't turn the FD spacer on the CNC lathe because the demand isn't there. He's going to turn one out for me in the next week or two.

https://cimg0.ibsrv.net/gimg/www.rx7...747331f040.jpg
Just picked up my spacer from Spence.

What's the benefit over the stock piece here? Minimizes play in the rear end?

Under harsh use (hard launches, hard decel) the original crush sleeve can continue to crush and cause a loss of preload on the pinion bearings. A solid spacer takes more time to properly adjust the bearing preload but cannot move.

Digging up oldies again did you manage to get this solid one working in car ?

I used this spacer in my FD with OS Giken diff at the mechanics suggestion and it works well. ~20k miles on it so far.

Nice where can I get 1 from ? UK ?

wondering if he can make one to not only fit the early Mazda 8.8 35mm pinion, but also with a 35x40 integral spacer for the larger FD pinion bearing? 🤔

that would make more sense to me than the bearing spacer with OE crush sleeve.

Here’s the thread link for anyone who isn’t picking up on what it is I’m referring to:

https://www.rx7club.com/3rd-generati...rs-fds-688203/
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