28 replies to this topic

[FTodaro]

I am looking for a how to manual to do a step by step rebuild of the 1999 trans. I found Rod Graingers book that covers the 94-97 but nothing for the 1999. are the transmission guts on the 1997 the same lay out as the 1999?

Any other suggestions on a how too manual.

[FTodaro]

I started the tear down of the transmission. I finally received Graninger's manual which does have a pretty comprehensive step by step process with pictures. I also have the Mazda transmission supplement manual to work off of. My problem is difficulty shifting into revers. all foreword gears work fine. The tranny has 90,000 miles and one season of racing.

I pulled the case apart and just have the gear set now sitting on the bench. Just looking at the gears they look fine no signs of abuse. I am going to next take some measurements before I dismantle it and see if I can find anything out of spec.

My plan if I cannot find any obvious problem is to replace the recommended parts in a rebuild which include: detent balls and all springs, bearings, shift forks, syncros, shift rod ends, all roll pins and lock washers, and I think I may also add the 5th reverse clutch hub.

I noticed that it will not shift in reverse even when its not running so I wonder if I have a bent rod vs a syncro issue.

If I can figure out how to post pictures I will try to post a few if I find an explanation for my problem.

[ChrisA]

I started the tear down of the transmission. I finally received Graninger's manual which does have a pretty comprehensive step by step process with pictures. I also have the Mazda transmission supplement manual to work off of. My problem is difficulty shifting into revers. all foreword gears work fine. The tranny has 90,000 miles and one season of racing.

I pulled the case apart and just have the gear set now sitting on the bench. Just looking at the gears they look fine no signs of abuse. I am going to next take some measurements before I dismantle it and see if I can find anything out of spec.

My plan if I cannot find any obvious problem is to replace the recommended parts in a rebuild which include: detent balls and all springs, bearings, shift forks, syncros, shift rod ends, all roll pins and lock washers, and I think I may also add the 5th reverse clutch hub.

I noticed that it will not shift in reverse even when its not running so I wonder if I have a bent rod vs a syncro issue.

If I can figure out how to post pictures I will try to post a few if I find an explanation for my problem.

Frank, keep me posted on this and plan on me picking your brain about the job. My original Tranny is sitting in the storage unit waiting to be rebuilt.

[Ken Wilkinson]

Chris, If you do a rebuild let me know because I wouldn't mind doing the one out of the donor car we took the ecu out of...can 2 be done for almost the price of 1!?!
Ken

[FTodaro]

Ok I got the process of posting pictures figured out so rebuilding this transmission should be a breeze. The first part of the process is splitting the case and getting the Gears exposed


Now that I have the Gears on the bench, have taken another close look and do see wear on the 1/2 clutch hub and the Reverse 5th hub is worse. the spline on the 5/r hub looks as if it was heated some as well as signs of wear.


I started taking it apart. I need to fashion a bearing pulling to pull the first bearing off the main shaft then I will post again.

[FTodaro]

I finally finally got the transmission apart. Thanks to Karl Zimmermann of Applied Racing Technology who lent me a few tools. I found my problem. As I pulled the case apart I noticed that the 5/reverse clutch hub showed signs of heating it had discolored. As I pulled the clutch hub apart I found two pieces of the synco in places it was not supposed to be.

These piece came out two.

This clearly was why I was having problems getting it into reveres. Now that I have it apart I am going to replace the fifth reverse cluctch hub, all the syncos and the normal rebuild stuff, shift rods, forks springs. I also note that some guys who rebuild do not always do the main shaft bearings. I noted that the rear most bearing felt like it was loose so I am going to replace the main shaft bearings.

Lets hope I can get it back together. I will post again when I start the re assembly.

[Jeff Lyon]

Frank,

this is a great post. I have 5 transmissions sitting in the shop that all need synchros. Thanks for taking the leap and sharing!!

[FTodaro]

I will start posting some pictures of the assembly. I received my parts from MS. After looking at the transmission I was selective in what parts I replaced. I can tell you i ended up replacing parts that had no wear at all but did it as a precaution. Generally i replaced the following.
1. all three shift forks- probably not necessary as they were in spec
2. shift rod ends, they are soft and had wear
3. all syncros only 5/R had issues I replaced 3/4 as they are used the most in racing but they were undamaged
4. the springs in the 3 hubs this is an important step. there are 3 hubs 1/2 3/4 and 5/R that the shift fork pushes the hub between the two gears, inside the hub on each side is a wire spring that keeps the hub clicked in it gear. this is a fragile part and they have a 45 degree hook that secures the spring in the hub. Mine were broke at the 45 degree bend. a 50 cent part that can cause damage
5. springs, and detent balls, likely not needed but for the few bucks I did it, this is the spring system that the shift rods lock into its gears. various snap rings and roll pins holding on the shift rods, there cheap and is a security issue.
6. The most expensive part was replacing the 5/R hub assembly, this was the main problem as my syncos came apart and damages the hub, rather than try to save some of it, for the 42.00 I replaced the hub. I spent about 150.00 in parts.
Things I did not replace were oil seals and all the bearings. I was going to do this but after looking carefully at the bearings the races looked good and they did not make any noise when i cleaned them and rolled them. So I ended up only replacing the rear most bearing because out of all of them it had the most play. again not needed but I just did it.

Will post pictures this weekend when I get after it. As a repeat. If you are going to do this project you need to get the enthusiasts manual I reference in the first post. you need to take pictures as you tear down the transmission, as some of the parts particulally the hubs have a certain orientation that you have to recall when you are putting it back together. When I dissemble the parts I put them on a dowel in the same order and orientation as I took them off the two shafts. As I am putting it back together I am referring to the pictures also as sometimes things get turned around when you clean them.

One more point, I cannot speak about the 1.6 transmission but the transmission on the 94 to 97 1.8 is vary close to the 1999 so the items I am discussing are relevant to the those transmissions. Again while I do not know for sure I think that all the transmission are vary close if not exact so if you have 2001 and up this should also help you.

[ChrisA]

I think I've done #2 a few times.

[Cy Peake]

What "special tools" are needed to make this happen and are they readily available or do they only come from Mazda?

[FTodaro]

What "special tools" are needed to make this happen and are they readily available or do they only come from Mazda?

Yes there are some special tools that make the job easy but not 100% necessary. the Enthusiast manual gives you options on how to fabricate a long bearing puller that is needed to remove the rear most bearing off the main shaft. You can fabricate that. I was able to talk Karl from ART to rent me his special tools

There is a nut that has to be removed from the main shaft Karl has built a tube wrench that will take it off. The manual shows you how to do it with a drift (round punch) . Again the tube wrench makes it easy.

You need a few various sizes of Drifts to knock out roll pins, a pair of C clip pliers to remove the c clips. A hard plastic hammer that is about it.

its good to have caliper and feeler gauge to take some measurements once you open up the box.

I did not look into it but Mazda has part numbers on the special tools they discuss in the workshop manual.

[Glenn]

Great series! Thanks, I have always been reluctant to open up on of these "boxes full of black magic" but may over come that fear now!

[FTodaro]

I think I've done #2 a few times.

You know it was a long night last night but thanks to you I changed Shit rods to shift rods.
Just keeping me humble.

[FTodaro]

I had to delete some of the prior photos due to the limit on downloads.
The next pic is of the guts of the transmission before I started to dissemble. You can see the main shaft and the counter shaft. there are 3 shift forks that fit over the synco hub the one on the far left is the 3/4 middle 1/2 and the right is R/5 hub.

This is the special tools i used. also need snap ring pliers, a few drifts and an hollow tube to drive gears back onto the shaft.  Garage fun 035 (Medium).jpg   46.19KB   82 downloads

This is a view of the reverse/5th syncro hub. you can see a wire spring on the inside that hold 3 little locking pins in the hub. these should be replaced.

This last picture is of the Reverse syncro that whet bad. it was really the only true failure I found other than the springs in the hubs, but a pice of the syncro broke off in the hub and was preventing me from shifting it into reverse. But since I am in the box I am replacing a few wear items.


I was hoping to get this back together today but I am a few parts short so my next weekend we will be putting it back in the car.

[Sphinx]

the parts list at the bck of the SM constructor's manual I think comes out to $600 or so. You skipped seals and bearings; is that the difference?

[FTodaro]

the parts list at the bck of the SM constructor's manual I think comes out to $600 or so. You skipped seals and bearings; is that the difference?

Yes its a big difference. I am not sure what is up at Mazda speed right now but when I would go on line to order parts the price listed in "red" the discount price, is not what the ultimately charged me when i called in the order. I even asked the price on a few parts and it came shipped at a lower price. Say a part was 20.00 the billed amount to me was about 1/2 or 10.00 so the parts were cheaper than what they list on line. Not sure why. Maybe its because over the last year or so I have spent a small fortune, between rebuilding the front end, new motor and now a trans. Anyway, the cost of parts was reasonable .

To your point, rather than just go through and replace all the parts on this list I looked carefully and inspected the parts. Bearings. I did not have bearing noise to start with, but I pulled the bearing dust covers off, cleaned them out and then rolled them, if the race was smooth and and did not make noise i did not replace them I looked at the shift forks for wear and measured the clearance. I ended up replacing them but I think I could have reused them. the shift rod ends, are soft metal they had to go. the snyros looked perfect except for my 5/R which was what was wrong. I replaced 3/4 only and you hardly use 1/2 in racing and they looked good.

It did not leak oil so I did not replace all the seals only the front fiber one in the bell housing as I ripped it coming off. I did replace all the spring keepers on the shift hubs. the are fragile, I did replace the springs and detent balls on the shift rods, but that was not needed, they are cheap. I did replace the rear main shaft bearing, likely not needed. I did replace most of the roll pins and c clips, but the were cheap.

My point, i think you can go in and pinpoint the problem or the warn parts by taking a few measurements and a careful inspection and be good. Your you can spend 600.00 in parts to just replace them.

I will be posting the conclusion soon as soon as I get the parts i need from MS.

[Caveman-kwebb99]

Yes its a big difference. I am not sure what is up at Mazda speed right now but when I would go on line to order parts the price listed in "red" the discount price, is not what the ultimately charged me when i called in the order. I even asked the price on a few parts and it came shipped at a lower price. Say a part was 20.00 the billed amount to me was about 1/2 or 10.00 so the parts were cheaper than what they list on line. Not sure why. Maybe its because over the last year or so I have spent a small fortune, between rebuilding the front end, new motor and now a trans. Anyway, the cost of parts was reasonable .

To your point, rather than just go through and replace all the parts on this list I looked carefully and inspected the parts. Bearings. I did not have bearing noise to start with, but I pulled the bearing dust covers off, cleaned them out and then rolled them, if the race was smooth and and did not make noise i did not replace them I looked at the shift forks for wear and measured the clearance. I ended up replacing them but I think I could have reused them. the shift rod ends, are soft metal they had to go. the snyros looked perfect except for my 5/R which was what was wrong. I replaced 3/4 only and you hardly use 1/2 in racing and they looked good.

It did not leak oil so I did not replace all the seals only the front fiber one in the bell housing as I ripped it coming off. I did replace all the spring keepers on the shift hubs. the are fragile, I did replace the springs and detent balls on the shift rods, but that was not needed, they are cheap. I did replace the rear main shaft bearing, likely not needed. I did replace most of the roll pins and c clips, but the were cheap.

My point, i think you can go in and pinpoint the problem or the warn parts by taking a few measurements and a careful inspection and be good. Your you can spend 600.00 in parts to just replace them.

I will be posting the conclusion soon as soon as I get the parts i need from MS.

You want to rebuild my old tranny next?

[davew]

Having rebuilt a few hundred of these transmissions, let me point out a couple things.

Front seals get hard and aften tear on reassembly even though they look poerfectly good. They make a big mess when they leak. Please don't ask how I know this.

Roll pins that have hundreds of heat cycles on them get week. Upon reassembly the may fall out!!! Don't ask ;-(((

About 10% of the shift forks are reusable. ANY wear will make a sloppy trans.

Detent springs get weak, shift rod notches round off.

Second gear syncros take the most abuse on a street car, that is why Mazda redisgned them in 1994.

The purpose of rebuilding is to make the trans like new again. Why go through all the work, to make it "almost" like new.

Just my experiences
Dave

[joe varble]

Having rebuilt a few hundred of these transmissions, let me point out a couple things.

Front seals get hard and aften tear on reassembly even though they look poerfectly good. They make a big mess when they leak. Please don't ask how I know this.

Roll pins that have hundreds of heat cycles on them get week. Upon reassembly the may fall out!!! Don't ask ;-(((

About 10% of the shift forks are reusable. ANY wear will make a sloppy trans.

Detent springs get weak, shift rod notches round off.

Second gear syncros take the most abuse on a street car, that is why Mazda redisgned them in 1994.

The purpose of rebuilding is to make the trans like new again. Why go through all the work, to make it "almost" like new.

Just my experiences
Dave

Times "2" on what Dave said. Plus a good many drivers nick reverse on down shift's 5th to 4th which is what kills 5th/reverse clutch hub sliders.

[FTodaro]

Having rebuilt a few hundred of these transmissions, let me point out a couple things.

Front seals get hard and aften tear on reassembly even though they look poerfectly good. They make a big mess when they leak. Please don't ask how I know this.

Roll pins that have hundreds of heat cycles on them get week. Upon reassembly the may fall out!!! Don't ask ;-(((

About 10% of the shift forks are reusable. ANY wear will make a sloppy trans.

Detent springs get weak, shift rod notches round off.

Second gear syncros take the most abuse on a street car, that is why Mazda redisgned them in 1994.

The purpose of rebuilding is to make the trans like new again. Why go through all the work, to make it "almost" like new.

Just my experiences
Dave

I do not disagree with most of what you said as I replaced the forks, shift rod ends, roll pins,c clips, front oil seal, front gasket, all detent ball and springs, syncos3/4 5/r,syncro springs, in my case the R/5 clutch hub, I did not replace the shift rods, I could not find any detectable wear. I think one of the considerations in this decsion is why are your rebuilding it in the first place. In my case it was a narrow problem with Reverse the transmission 1-5 shifted fine. I am not doubting the logic of replacing things while you are in there, but I guess I do not agree that you have to do things like the bearings for example if they are with in spec. And Mazda has specs on almost all of the springs for example if they are within spec I would argue they do not need replaced. but as you say, if you are there and the cost is not significant why tempt fate.

I do stand by the decision on the 1/2 syncro, could not find any detectable wear or damage. Maybe i will regret it, we will see.

Gives me something to do during our long Ohio winters.