Replacing centering spring in manual trans
 

The shift selector in my 87 no longer returns to center. The only thing I can guess is that the spring broke. I have a new spring but need to know if I can change it with the trans still in the car. It looks like there is an access cover on the right side of the shifter tower on the trans. Will removing this give me enough room to get the return to center spring replaced in the car? Will I have enough room to drive the roll pin out of the selector and are there any tricks to getting in in and out?

Thanks

Steve

i think you have to take the tail housing off.

pull the heat shields, pull the shift lever, pull the retaining nut from tail housing, the detent ball and spring--or whats left of it will fall out, replace and reverse. It is in the stick drawings of the tranny in the FSM. But you don't have to remove or dismount the tranny at all--I did mine recently.

Thank you! Now I have to go look up where the retaining nut is in my FSM

Steve

Hey,

Just read through your first threat again. The nut you're looking for is on the opposite side of the cover you saw, or maybe its the one on the back, anyway, you're in the right place, just the other side

Steve,
Just to clairify with what the factory manual calls these parts:

1) The Check ball - This is the large bolt at the back of the shifter housing.
2) The lower shifter lockout mechanism - note the orientation of the plunger.

Once those two things are out, you can remove the 4 bolts that hold the access cover.

At this point you're in the shifter housing looking at the shift actuator and the roll pin that holds it to the shift rod. (Make sure the transmission is in neutral.) You'll need to find a drift to tap the roll pin out. I had to loosen the trany cross member to get a good angle on the roll pin.

Once the pin is out, you need to rotate the shift actuator rod 180 degrees. Once rotated, you'll be able to push the rod forward into the transmission, giving you enough room to slide the shift actuator end off the back of the rod.

With the actuator finally out, you can wrap the spring around it. The orientation has the "Hook" part centered above the socket for the shifter. The other end of the spring wraps around the actuator and rests on the indentation on the right side.

The only tricky part now is reinstalling the actuator piece on the rod. You still have the actuator rod turned 180 degrees... You need to replace the actuator on the rod, slide the rod back, turn the rod 180 degrees till it’s in the normal position, then reinstall the roll pin.

Good luck! This job can be done with the tranny in the car, but it's easier with the transmission on the floor.
Jeff

Thank you for the detailed explanations Ted and Jeff! I have had manual transmissions apart before but am very new to the RX7 platform so I need all the help I can get. I will print this thread out and bring it with me.

Steve

Ok I was able to remove everything to get the shift selector block out of the transmission, with the trans still in the car, and without having to tilt the trans down. I saw several posts where people were suggesting taking the whole trans out - that is a little extreme. All I had to do was remove the one center nut that bolts the trans to the cross member and jack the trans up until it hit the floor pan. That allows enough room to drive the roll pin out and slide the block out.

I installed the centering spring but I need someone to take a look and verify I have it in correctly. I hooked one end around the flat on the right side of the selector block, but then the loop end looks like it just sits there and presses against the left side of the shifter? Is that correct?

http://farm3.static.flickr.com/2735/...6b060ebe_b.jpg

http://farm3.static.flickr.com/2712/...2955b28b_b.jpg

http://farm3.static.flickr.com/2563/...755bd905_b.jpg

^That turned out to be the correct orientation and what a huge difference it makes with the centering spring installed. The shifter stays in the 3/4 gate now like it's supposed to and it is much easier to tell what gear you are in. This project was very worthwhile, I couldn't stand driving the car with the centering spring broken. Total time was about 5 hours, including me having a hard time getting the roll pin out (I did have enough room to drive it straight through, barely), having a hard time getting the shift selector in and out, having to cut a new roll pin from longer stock, having to file down the new lower shifter bushing to fit, and installing the reverse lockout wrong and having to take it apart a couple times to get it right. I did most everything from the interior of the car. Having the centering spring also eliminated the short shifter vibration.

Nice pictures. Good information.

Thank you, bondospecial! I been wondering how I was going to fix mine as well. Just found out that my car never had one.

Good info my 1234 is really floppy and annoying have check back on this thread when I do mine!

Also going to be doing this soon. Thanks.

I have a few more good quality pictures of the process of removing the roll pin and selector block, I will post them up shortly if it will be helpful to others.

Steve

This thread has been very informative, but I do have a question. Is the spring layout in the pictures the same as a long shifter? Long story short, I just finished replacing the clutch on my 84 GS, and that spring is being a ***** to me. When I thought I had it hooked up around the shifter, I closed everything up, put it in gear, and...it sprung off. Any suggestions for getting a deviant spring to work? A little more info would be that the spring is more of an angle than a curve. Should I replace it?

The spring is the same layout as a stock shifter. The spring should stay to the left of the shifter, just touching against it. It does not hook AROUND the shifter. All you do is pop the shifter in to the right of the spring and into the cup and the spring just rides against it. That "hook" on the end of the spring was just made so it does not catch on anything, the hook does not hook on anything. If you tried to hook the shifter into the spring you probably over stretched it.

That doesn't sound good, lol. But thank you for the advice! Now I'll go use this remedy on my poor Arisu!

Just ordered my spring on Mazdatrix, be here shortly. Does anyone else have any pictures or a movie perhaps because wozzoom kind of scared me.

I will upload more pics tonight, sorry for the delay

Anymore anyone? MY spring comes in today!!!!

Thanks for the information, I have tranny parts coming in soon and this will help out!

Woops forgot about the pics. Well they weren't much different from what you saw above. Here is my version of the instructions

Step 1. Put wheel chocks behind the rear wheels and put the front end of the car up on jackstands. Get it high enough in the air that you will be comfortable working under it.

Step 2. Remove the heat shield screwed to the body over the driveshaft, that is under the transmission.

Step 3 (could be done before steps 1 and 2, does not matter). Remove the plastic piece in the console that has the leather shift boot in it. Remove the 2 piece rubber shift boots. Then remove the bolted down plate that holds the shifter stick in. Remove shifter stick. Remove the entire console from the car. Remove the 4 bolts holding the metal ring that retains the final lower boot that seals the pass compartment from the outside above the trans and remove that boot.

Step 4. Remove the single nut that holds the trans center stud mount to the cross member

Step 5. Put a hefty (3+ ton) floor jack under the transmission and jack it up until it hits the floor pan.

Step 6. Put a small piece of 2x4 under the rear of the plastic surrounding the shifter hole.

Step 7. Push the shift selector into 3rd gear

Step 8. Remove the 5/reverse lockout mechanism (plate on the drivers side bottom of the tail housing held on w/ 2 bolts) and remove the nut from the back of the tail housing that has a spring and check ball in it

Step 9. Use an appropriately size pin punch to drive the roll pin out of the shift selector. Do not use a nail or something improvised, you need a real pin punch. The piece of 2x4 you put under the rear of the plastic surround will allow you to insert the pin punch straight at the roll pin, in between the plastic dash surround and the floor pan.

Step 10. Using a small pry bar, manipulate the selector block to a 45 degree angle and it will just barely roll out of the case.

Step 11. install the spring as shown in my pics above.

Step 12+ installation is the reverse of disassembly

Total time about 3 hours if you take your time and clean everything.

I'm stuck on step 8 and 9. This not simple, fuck you guys! Can someone come to my house and help me? A somatic would be useful. Haynes book is no help.

according to the FSM, the fastest way is to do it while the tranny is out of the car. all you have to take off is the extension housing and 4 bolts. you can do it in 30 minutes if you do it properly.
WHILE THE TRANNY IS OUT
1) drain tranny
2) remove 4 bolts extension housings
3) remove blind cover (4 bolts)
4) knock out roll pin (use pin punch)
5) rock the inner shift lever downward
6) rock the extension housing upwards

at this point, you should be able to slide the extension housing outward enough to remove the inner shift lever off of the shaft
at this point, align the shift spring on the inner shift lever, then simply install in reverse order. ALWAYS replace the roll pin, as well as any gaskets or sealing areas

its VERY difficult to replace while in the car. i would not recommend it unless its your only option.
always be sure to fill the tranny and check the level. dont just assume that the level is good. replace the fluid with proper weight gear oil.

Lloyd

I must be super smart? I really didn't find this to be that big of a deal in the car, thanks to the info the guys gave me earlier in the thread about removing the 5/reverse lockout mechanism. The hardest part was getting the selector block out, there was barely enough room with the transmission shift shaft pushed as far into a gear as it would go, but if I turned the block to a 45 degree angle after the pin was out it did pop out and then back in. I got a nice set of hardened, Made in USA pin punches at Lowe's for about $25. Having a properly sized pin punch made driving the roll pin straight through easy. It doesn't seem like there is enough room to drive the roll pin straight through but there is.

well, the pin is half way of being out and looks like that's the best I'm going to be able to do. should had just taken the whole tranny out.

What you can try doing, I found this made the pin come out easier, is put the shift selector into neutral, find some sort of long metal dowel that fits in the selector cup (I had a bolt about a foot long that was very large diameter), make sure you have driven the roll pin as far as it will go, and once you have the roll pin driven until it seems to stop, use the dowel/pipe/long bolt, whatever, to rock the shift selector side to side slightly - you will have to use some leverage. It will put a curve on the end of the roll pin and allow you to more easily drive it out all the way through. The roll pin should go more than 1/2 way through without stopping though. If you are getting hung up at the halfway point (this happened to me at first) it means your pin punch is hitting the selector shaft itself and hanging up on it. A properly sized pin punch and making sure I was driving straight through popped the pin past the 1/2 way point

If you do it in neutral next to 5th and reverse the pin has no where to go. It will get stuck in those gears. I believe 3rd gear is prime to getting the pin fully out but thanks to a friend who doesn't listen...

??

Like i said if you drive the pin as far as it will go then put a dowel, socket extension, something long that fits pretty snugly in the cup where the shifter ball end would have gone, and pry side to side, you will put a slight bend in the free end of the dowel pin, such that when you smack it again with your pin punch it will curve when it hits the side of the trans instead of jamming, and it will come out. I had never done this before and had never worked on an rx7 before, I just did what I had to get the pin out without breaking anything. I'd give you a hand if i were local

okay well im trying to remove the pin right now and its stuck halfway, so my question is should i stick something is the selector cup and rock it left and right until the pin bend????? any advice would be greatly appreciated. and thnx to anyone in advance

The shifter block should of been tilted at an angle before removing the pin or else you will get it stuck at the "wall" inside that hole. See signature.

If the transmission is still in the car this is going to be a pain in the ass. The other side of the rectangular opening (other side of tail-housing) has more access covers you can remove and play around with. With the transmission still in the car its probably going to be very difficult, if not, impossible to get to that. You need to tilt the shifter block at the appropriate angle so the pin has room to come out.

thanks for getting back to me and the transmission is out of the car and i believe that the pin is hitting the wall is there still a way to get out the pin?

You will have to remove the covers for the detent balls on the other side of the opening you are trying to remove the pin from. Remove all those covers on the other side of the tail-housing. You should be able to play with the pin on the other side and hopefully slide it in enough to let you tilt the shifter block the approriate angle to let the pin out.

Otherwise, you can try putting the shifter in there and slamming the pin against the wall as a last resort. Hopefully it will give you room by pushing the pin back in.

If the pin is hitting the wall right now, there is no other way to go but pushing it back in and doing it at the right angle.

I'm bumping this thread to provide a little more information.

The pin punch you should use to drive the pin out is a 3/8" pin punch. Don't try to use anything bigger (7/32" is too big). Don't try to use anything smaller or it could just get stuck inside the roll pin.

I did this with the transmission out. Had to remove it to split the rear case from the main case due to a leak. I can imagine this would be really difficult with the trans in the car. Personally, I wouldn't bother - it's so easy to remove the transmission, just pull it out. Gives you a chance to check the clutch, replace seals, etc.

Hope this helps.
JV

well got call from mazda that some parts i ordered where ready for pick up.

I ordered
shifter return spring
shifter bushing

clutch bolts and lock washers


The FC transmission i picked up the return spring was broken. So while I had the trans out of the car I decided to change it and the bushing for the shifter.

It was my 1st time to change out a the spring and bushing. not very hard to do. took about 30 minutes. but now I know how to do it maybe 10 ~ 15 minutes. the hardest part was finding a punch the right size to push out the 2 pins

http://infini-fc3s.cyberosity.com/ga...icture+123.jpg
http://infini-fc3s.cyberosity.com/ga...icture+120.jpg

this black stuff is rubbery im not sure how it got in there. part of the spring is still there but I could not find the other part of the spring that broke off. lol where did it go?
http://infini-fc3s.cyberosity.com/ga...icture+124.jpg

old vs new
http://infini-fc3s.cyberosity.com/ga...icture+127.jpg

cleaned out and installed
http://infini-fc3s.cyberosity.com/ga...icture+129.jpg
http://infini-fc3s.cyberosity.com/ga...icture+130.jpg

1st thing I did was remove the side cover with 4 bolts
then the bolt on the back that has the spring and ball
the 2 bolt cover with spring and black insert
punched out the pin you can see on the outside and removed it and the insert ( pay attion to the orientation of that insert. LOL you can install it 180 deg out and then you wont be able to shift into reverse. LOL yes I put mine in wrong the 1st time lucky I check it with a shifter before I installed it in the car)
next I put the shifter in 2nd gear and punched out pin. I though it would hit and get stuck but it popped out no problems.
removed the 4 bolts that hold the shifter on the tail shaft.
used small pry bar to lift the up that plate off the 2 alignment pins
hammered the shifter housing so it slides back and I could remove the old spring and bushing
installed the spring bushing
hammered the shifter house to slide it forward
replaced the 4 bolts
fixed the spring around bushing
put the shifter in 4th gear and reinstalled the pin



I dont know how you guys did it with trans still in the car. It was very easy doing it with the tranny on the bench

You did too much work. There was no need to separate the tail shaft from the gearbox. Once the pin is off, you spin the whole bushing block 90 degrees and the big shifter shaft that goes into the bushing block falls down into the gear box allowing you to remove the bushing block.

oh man I had a feeling when I was doing it there had to be a easy way. Oh well next time.

spring
 

Bumping this up from the dead. I just changed the shifter spring in my transmission yesterday. Worst job ever. I'd say if it doesn't spring back to just leave it unless you have the tranny out. It was very hard to get a good angle on the pin, hard to get the block out, I also had to file the block to get it back in. No walk in the park. Im also very mechanically inclined incase you are wondering. Not trying to be a buzz killington here just giving a heads up if you plan on tackling this job. You will get angry on many levels.

there is just so many things that you can tackle before you go "no freakin way"!
My solution is instead of buying the broken part..buy ALL the Parts around a GOOD Part..lol!
I had a broken spring..tried to do it..NOPE..got a Trans shop to do it..NOPE..(btw they suck!) ..
so..solution?...used trans..YAY!
Don't screw with me Mazda..I'll keep buying shit!..lol!

Hello All,

Jeff, I read your post and it seems quite clear, but if you are still watching this space, I have a couple questions for you or anyone else who has experience doing this...

I am asking these questions to be sure I understand before proceeding...

1. The 4 bolts are removed to get access to the roll pin.
2. The tail of the transmission is lifted up about an inch so the pin is above (or high enough over) the transmission tunnel sheet metal and can be drifted out. Will the console have to be removed for additional clearance? I am guessing the roll pin is a type of Spring Pin and will not be so tight that mighty blows of a hammer are needed to move it?
3. Once pushed toward the driver side, will the pin fall into a safe area of the transmission for easy retrieval or is there any chance it can fall into a void and be lost if not caught before it is fully pushed out of the shaft?
4. The shaft is then pushed into the transmission to get the old spring remnant free and to install the new one. Question? How do you get the shaft that was pushed into the transmission back out? Vise grips and a towel?
5. After the new spring is installed on the rod, and the control rod end replaced, the roll pin is press (drifted) back into place in the same direction it was pushed out.

Did I miss anything? Is this essentially it?

I am also assuming there is nowhere near enough clearance to get a tool like this in place...

This is my first reply, so here goes. My spring broke within two years of driving and have been shifting without it for the remaining 28 years. Bought a new spring when I installed a short throw shifter, found out it is not an easy install. Anyway I have pondered what caused the spring to break, you know that nice sharp edge where the spring comes up and over? It must rub against the spring while using the shifter causing a score line that in time breaks the centering spring. It would be a good idea to radius that sharp edge when installing the replacement spring.

Where did you buy your replacement pins? And how many need to be replaced?

https://cimg2.ibsrv.net/gimg/www.rx7...d4b12d4561.jpg
https://cimg3.ibsrv.net/gimg/www.rx7...a247048088.jpg
https://cimg4.ibsrv.net/gimg/www.rx7...ca84f0e6aa.jpg
Ok, here we go!
I finally got my hands on a transmission and removed the control rod end with an intact centering spring!

The three pictures show what I believe to be the root cause of the spring failure.
I painted white out on all the areas of contact between the spring and the control rod end.
The engineers did round off one corner on the square area that meets the spring, but the top edge I have indicated on the control rod end was left a sharp 90 degree edge!
Under the white out there is a thin shiny wear line where the spring rubs against as it moves back and forth while shifting.
This hard edge is what I believe causes the spring to be scored against and over time breaks!
So my fix is to access this edge and round it off and smooth it to a fine polish, Also smooth off the other contact area while you have access.

We are supposed to fill this control rod area with manual transmission oil, is there another type of fluid that is more slippery, like maybe silicon oil? Or would something slicker cause the transmission to slip out of gear? I know this is not the smoothest shifting tranny there is but every little bit helps.

I went at the edge with small files and sandpaper until the edge was slightly rounded over about 1/64". Touched up all the other surfaces and reinstalled the spring. The area on the spring that made contact with that edge showed pitting after a light sanding of that spring area that proved to me to be where the spring fails!

Just to rub it in, there was no rolled pin holding the control rod end onto the rod! It has a bolt and lock washer that goes into a partway threaded rod hole. Much easier to deal with. Why did they change that in the FC transmissions?

Remember when " I blew a tranny!" meant something else!

Centering spring could definitely be part of it, but make sure to do your shifter bushings as well if you haven't. They're super cheap from your rotary distributor of choice and like to disintegrate. If the shifter is actually sloppy, odds are it's the bushings, and those are a way easier job. Mine were so bad I couldn't even find most of the broken pieces. Took me like 30 minutes and shifter is super crisp and precise. Mind you, the centering spring is probably still broken (as mine is), but it'd be a shame to tear apart the shifter just to find you needed to order new bushings too.

i was reading this thread before doing my return spring. and found that instead of driving the pin out with a punch and possible getting stuck against the housing. i just screwed a screw into the roll pin with a slide hammer attachment and used a slide hammer to pull it out. much easier to do than punch it out. hope this helps some one in the future. ps did this with the trans out of car. could possibly work while still in the car.

Here is a brief write-up on replacing the centering spring. I rebuild all Mazda RWD 4-5 speeds. Feel free to contact me if you have any transmission related questions.

https://cimg3.ibsrv.net/gimg/www.rx7...c72a58afe4.jpg

When I looked at my original transmission, the centering spring broke about 1/8th inch above the control rod end! Right where the 90 degree bend is. So it did not fail because of contact with the sharp edge!

Perhaps the spring steel was too brittle, causing it to snap at a random spot. That would account for all the broken springs, manufacturing defect!

What do you think?

My spring was broken when I bought this JDM S4 T2 trans years ago from JapantoLA, I also was confused and thought the S4 needed a bushing, couple that was a shitty mis sized S5/Miata Ebay short shifter with disintegrated buhings and the shifting just got worse and worse over the years. Finally working out the niggles left in my build and the shifter is on the list. I ordered the Mazdatrix bushing kit with shifter cover boot and the Atkins replacement centering spring. I am attempting to do it with the trans in the car, really wish I would have done it when I did the last engine refresh and new clutch etc, oh well, going to give it the old college try and see if I cant get it or else I will drop the trans, probably almost certainly faster to drop the trans but my garage isnt heated and i dont have a lift, its just not ideal at the moment but i recently did two transmission swaps on my Cummins and my Volvo 240 so if I need to do it I will. I bought a fresh set of long pin punches, going to try the 3/16 one and hope for good results. I made a slide hammer type tool to try as I really liked that idea but I cant get a screw to thread into the pin, shitty screws no doubt, a nice shard thin stainless screw would be better. Also had a moment when I pulled the lockout 19mm bolt and didn't see any ball bearing, but lo and behold it was sitting up in the trans still and I was very relieved to find it as I thought it had dropped and rolled away. Biggest challenge is that the trans only comes up so far before it bottoms out on the tunnel, I have my dash in the car and am fearful to pry on the console surround too much, its in the way of the pin, and given that you are supposed to drive the pin at an upwards angle I am having trouble getting to it.

https://i.ibb.co/cvC8LhN/IMG-20240103-143732376-HDR.jpg

https://i.ibb.co/jMS58B1/IMG-20240108-123016057-HDR.jpg

https://i.ibb.co/cgGWxsF/IMG-20240109-103441537.jpg

Slide hammer made from large nail, two sockets and a screw, and a welder lol. Might try again but try Tigging a SS screw on there for better bite.
https://i.ibb.co/F8F5yYm/IMG-20240108-122709371.jpg

https://i.ibb.co/VCVjJYW/IMG-20240108-122717853-HDR.jpg

Rebuilt Transmission with new centering spring.
 

I found someone who rebuilds RX-7 transmissions on eBay and sent him my centering spring for the rebuild.

I am going to fill the shifter reservoir with synthetic transmission oil and hope for the best!

If the centering spring breaks again in a few years like the original spring did i will let you all know.