I've been told the '99 5th gear was changed to a shorter gear. I cant find the link to the specs at the moment, but im sure someone on here has the info im looking for.

Secondly, I was reading that the 99 Power steering was dialed back by 20%, and a check valve was added. I'm wondering if anyone has any info on this as well. I would speculate that mazda being mazda, they just added a patch such as a pressure reducer in the line. That would be the easiest way to dial back the PS force I would think. Anyone with info on the PS reduction in '99 I would be interested to hear some more about it.

-Heath

 

JDM Series 7-8 5th gear is 0.762

Our US 5th gear is 0.719

 

hmm after some searching I found the 95-2002 5th gear listed @ .806 (US 5th gear was listed at .719 as well though so I'm not sure which is accurate now).

 

JDM models came with either 0.762 or 0.806 depending on version

 

^^^basically determined by wheel diameter.

Not sure there is any difference in the castings (depth?), the P/S pump appears to have had the pressure relief mechanism removed and then the screw on cap and washer replaced.

 

My car has the 0.806:1 5th installed. I think these are the part numbers I used:

counter gear r50417308
fifth gear r50417610a

Count the teeth when you get it to calculate your ratio.

Keep in mind if memory serves, there is an internal snap ring or something inside your stock 5th. I just bought a new one - but be VERY careful if you start rebuilding the trans - many small parts and it will blow up if you don't have it put back together right.

 

If you have a 99 spec car in front of you, would you be willing to snap a few pics of the differences you just mentioned. I would also be interested in knowing what the size of the PS wheel is. If youre willing, would you measure the wheel so we can compare to the US model. Many people delete the PS, but for the street most of of would like to keep it. Simply lowering its effect may be a nice upgrade.
Thanks, Heath

 

Do you happen to know if that is a US part number? I have a hunch that the RS model may have had the .76 gear and the RZ/Spirit R had the .806 cause they obviously did something to make them faster than the RS but the power output was the same (IIRC). Could you tell me your speed @ say 2000RPM or 4500RPM etc (something easily divisible for our tachs). I'm wondering what the speed difference is. What do you think of the shorter 5th? I'd love to hear your thoughts on it.

Also now im wondering about the ring gear size on the diff. I seem to recall reading that they changed it as well for 99 but i may be remembering incorrectly.

 

According to the japan EPC these are the p/n for the different gears(see attached image).

Regarding the p/s check valve i am interested too,but the 99 spec parts have the same p/n as the 93 parts,so i am stuck too..A picture would help a lot,so i can see for what to look..

 

..

 

Pulley diameter was maintained throughout the production run with no change. You'll have to compare with the US parts catalogue...only important change I can see, is the pressure relief....whether there's something else done in the body of the pump, that's the mystery....it is a "B" revision, which implies nothing much.



RS, RZ and spirit R, all were the same power - and because they came with 17" wheels standard, came with a 4.3 rear end, which was fitted several years earlier than 99 too. Somewhere on here, I've listed the four gear part #'s if you wanted to try something other than the pair fitted in Nth America and export markets.

 

i wonder if its something in the actual rack that is different? could be check valve related i suppose (or line pressure reducer or something), but if the pully part number is the same that is out. BTW is that a 99 spec parts catalogue??? If so, I would KILL to get my hands on a copy of that (or a scanned version). Infact.... I'm sure a number of people including myself would be willing to start a LARGE.... LARGE donation pool for anyone willing to scan and email it wink wink

 

Might be something to do with the rack, can't access the 92~98 Au disc to compare because of a laptop fault, but the newer one goes by F138-32-110A. That prefix should indicate some later change iirc, how you'd incorporate that into a LHD unit is the Q. Manual is version V, not mine, but have various out of focus shots of pertinent pages.