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Gavin you did a excellent job. So good that it influenced me to get in on the bulk buy. I have disassembled a tranny to familarize myself prior to recieving the unit. If I have any questions I hope you will help answer. Thanks and again good job.
 

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Discussion Starter #64
Finally got a couple apportunities to run the car in anger at an autocross school and a regular autocross event.


its good....its real good :)

Gavin
 

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Sorry to jump in so late on the game..

Excellent writeup! There's something I'd like to comment on the bearing issue though... It's a good thing you didn't go for the ball bearings. They won't handle the axial forces like tapered roller bearings do, and while there is a 23mm wide ball bearing in the SKF catalog, it has the same contact area between the balls and bearing surfaces, ergo not one bit tougher! Angular contact ball bearing is much better at handling axial loads, but those aren't available in 45x75 sizes at least from SKF.

the 45x75x20 tapered roller bearing is rated at 80kn of static and 58.3kN of dynamic load. The respective numbers for 45x75x23 ball bearing are 14.6kN and 20.8kN. The nearest matching tapered roller bearing (45x85x19) is rated at 28kN and 38kN. Furthermore, the numbers for ball bearings are reduced with axial loads. Most likely, your bearings would've failed at the first launch.
 

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Discussion Starter #66 (Edited)
just a bit late, but not too too late :)

At the behest of sleepcounter I looked into ball bearings and while I found numbers similar to what you have posted(albeit in imperial measurements) the end result was....I couldnt find ball bearings in the size that would fit the dimensions of the differential anyway. In other words, it was a dead end.

I used the stock shim as a template and simply cut my own shims using a pair of scissors.


The shim that was in the diff already was .20mm. After a bit of trial and error(uninstall races, install races) getting the tension right I settled on an additional .10mm and .06mm shims for a total thickness of .36mm.

Notes. Brass is a softish metal. It was easy to work with and easy to trim. There may be a chance that over time it could compress by a certain degree with the heating and expansion of the transmission. How likely this is I am not sure. I did lean towards the higher side of the torque range of the bearing tension just in case. Still I wonder if brass was a poor choice instead of (the slightly less easy to work with)aluminum or steel. Time will tell.
I have had to pull the diff and reshim it. Although I had set things as per the manual (well...sorta. More shims than recomended) things seem to have shifted back to below spec. I developed a "clunking" in the transmission and believed it to be the diff tension. Upon checking the diff, the breakaway torque was much much lower than the minimum spec. Clearly the soft brass shims had compressed too much. I have now reshimmed the diff to an over-spec tightness(22in/lbs) using stock shims(thanks Rami!) with the assumption that after a few drives things will loosen up a bit and things will fall back into spec. Ill see how this goes.

Gavin
 

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While my 626 isn't a daily driver I have put a good 8k miles or so on the PG. In fact I went though a spurt in the past year or so where I was using the 626 as a DD for a few months, logging approx 100miles a day.
 

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Discussion Starter #70
The white car has been relegated to autocross duty only. No daily driving whatsoever.

Currently the car is up on jackstands(again) awaiting new axles, new struts and a new clutch.

Gavin
 

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From my understanding, unless you go though mazdaspeed (race) the 5 speed transmissions are not available new anymore
We have some brand new 5-speeds here in canada. They cost the dealer about 3400$ though. I guess they want to keep them or something, thats an insane price. The client would have to pay like 4500 for one. Crazy.
 

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Hey Gavin, by the looks of it the pics went down on the write up. Any way you could put them back up? Thanks

Nick
 

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Not that it really matters now but through Ford-

Shim selection gauge:T88C-77000-CH2
The sleeve as well as collars are kit: T87C-77000-J

I also have part numbers for shims through Ford which are the same part numbers for their 3.0's as well. I'm thinking they may still be available. Either way, the closest to .36 is your .35 which is E92Z4067-AL. I can also cross referebce the Ford numbers for Mazda and let you know those too.
 

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Discussion Starter #76
and that is actually.....really helpful :)

It doesnt matter to me at the moment as I was able to get some factory shims for the reshim of the diff, but is anyone else is brave enough(or stupid enough) to do this...the info is there(provided that ford actually still has the parts).

Gavin
 

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Discussion Starter #79
No problem.

Id forgotten that I did in fact have an addendum to shimming the diff, but it was a bit buried in here. Figured it was worth it to add it to the main post.

Gavin
 

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I meant to add this in here when i first figured it out, but that was 9 months ago and i guess i forgot till now! Lucky you guys bumped it to remind me.

It seems that mazda has speced an odd sized bearing to use to suspend the diff (75mm OD, 45mm ID and 21mm thick)
The bearing size is actually 75mm OD, 45mm ID and 20mm thick.

I read your guide Gavin, and went and bought the right bearings. But, after seeing they needed to be 21mm thick, i added a 1mm shim underneath each bearing. Only to reassemble the gearbox, and find the case would not close. It had a 2mm gap. Destroyed the bearings pulling them back off the diff, so a new set later and they went in perfect!

The bearings I got are Koyo brand, made in Japan. And i just got them from a bearing wholesaler. Part no. is 32009JRYA1

On the off chance that anyone else uses this guide, you may want to update it!
 
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