sgi02

After picking up my FD everything was butter , but about 1/2 way home I started to get a whine in 1st , 2nd , and 3rd gear. 4th and 5th seemed to be fine.

Everything was cool until tonight , while I was out driving ( Normal , not spirited beat to oblivion driving. ) I noticed first gear became super loud , like literally if the transmission was right next to your ear while shifting gears , this is what it sounded like. The remainder of the gears seemed to be unaffected. The car still drives fine , clutch doesn't slip , just a bad noise in 1st ( Not grinding. )

The transmission was supposed to have been rebuilt , with a new 5th gear syncro , before I purchaced the car , but I am starting to begin to doubt that lol. As far as I know the car should also have a relitivley new Mazda Flywheel , and ACT Clutch & B&M Short Throw Shifter.

Any idea's where I should begin to look on this one , or should I just start looking for a new transmission?

Thanks in advance for the help!

sereneseven

first check to make sure there oil in it

if it gets noticibly quieter in 4th but a little louder in 5th chances are its the snout bearing in between the input and output shafts

if its quiet in both 4th and 5th its most likely the countershaft end bearings

I would reccomend you start looking for a new one or look into having it rebuilt....a word of caution most of your generic transmission rebuild places use cheap parts and tend to do half assed work so don't expect an AAMCO to last for long.

DamonB

This is also the same bearing that growls in neutral with the clutch out.

Replacing this bearing requires tearing the ENTIRE gear stack apart. On the other hand fifth gear, the front input shaft bearing, the rear output shaft bearing and both bearings on the counter shaft can be replaced without the work and special socket required to take the gear stack apart. Because of this I bet there's an awful lot of "rebuilt" transmissions out there that are really nothing more than new 5th gear synchros and perhaps new countershaft bearings and main bearings on the input and output shafts. That requires only about half the work but unfortunately doesn't replace the needle bearing between the input and output shafts that's most likely to be failing.

dgeesaman

iTrader: (7)

Another factor is that this particular needle bearing uses the nose of the mainshaft as the inner race and the bore of the input shaft as the outer race. So even if the rebuilder decided to replace this bearing, they would probably need to replace *both* of the shafts. And I don't know any rebuilders who would put $500 of new shafts into a budget rebuild.

But I'm not sure that this noise is bearing related. Sometimes a used gear can get chipped due to poor axial alignment and then continue to whine like a spur gear. This tends to be concentrated on that one gear, and more noisy on either acceleration or coast down.

But again, it requires fully pulling apart the tranny, so whether it's that small captured roller bearing they ^ are talking about or a damaged gear is pretty irrelevant.

Dave

White94RX

First check the fluid, and maybe change it to a better fluid if it's full. If not, you've got either the gears whining or bearings going bad.

If it was rebuilt, they may not have all the clearences/tolerances just right.

DamonB

Gear noise is a high pitched whine. Bearing noise is more like growling. Gear noise often causes a vibration as well since the problem is at one particular point on the gear as opposed to a bad bearing which has a problem everywhere.

If the needle bearing between the input and output shafts is bad it will make noise anytime those shafts turn at differing speeds and the larger the speed differential the louder it will be. That means it's loudest in neutral and the lower gears. IIRC fourth gear is 1:1 so the input and output shafts turn at the same speed and this bearing would be silent.

sgi02

Thanks a lot for all of the input guys! I have some new Neo 75W 90 that I will try to freshen it up with to get a little more life out of it.

From what you guys are saying it definatley sounds like a bearing in 1st , and then gear whine in 2nd and 3rd.

Couple quick questions if I may..

1.) Whats the going rate on a used transmission or a rebuild? What would be the better choice?

2.) Is it a bad idea to try to change the gear oil in the transmission using jack stands or should I find a lift.

Thanks again as usual guys , you help is always appricated!

DamonB

This is tough IMO. Anything cheap enough is worth it. I bought a spare tranny sight unseen because I got it for so cheap it was worth the price even if everything inside was garbage. IMO any transmission for these cars is old and has some mileage so the safe thing to do if you have tranny issues is to rebuild it.

Changing the tranny and diff lube is no different than changing the oil. You remove a plug and it runs out. Replace plug and refill. Stands are perfectly fine. You just need the car high enough to get under it.

dgeesaman

iTrader: (7)

Changing the gear oil in your garage is no big deal. You just remove the bottom plug and watch it drain; doesn't much matter how high the car is.

Pouring in new gear oil is a minor hassle, but I took the fill plug and my funnel to the hardware store and bought some clear plastic tubing that fit over the funnel and still fit inside the fill hole. Then I ran it up through the engine bay so the funnel was beside the throttle elbow.

Definitely only try pouring warm oil. If it's anywhere below room temperature, it will be thick and take a really long time. It might be worth filling a sink with hot water and setting the bottles in there first. (I'm talking about getting the oil to maybe 100F - no serious heating). Or set them on the hood of your FD after driving it, haha.

Rebuild vs. used tranny - both have risks. The ideal situation is a new tranny. I'm not sure if Mazda still has any, but if so they will be a few grand. A good rebuilt or good used tranny will be virtually the same as new. A rebuild from a competent rebuilder will not be cheap, but it will be a sure thing and maybe if it's a rotary shop they will cut you a decent deal by having used hard parts available. Otherwise, a rebuild by a regular tranny shop will either get you broke because they replaced everything they should have, and they bought the new parts from Mazda, or get you only another 50k miles because they didn't replace everything they should have.

A used tranny such as the low-mileage JDM trannys can be a tremendous bargain, IF the previous owner knew how to drive and didn't flog it. Ditto with any used tranny from a US-spec car. The downer is that you pretty much have to have a competent tranny rebuilder open it up and inspect it before you pay, or be able to return it cheaply. The JDMs all seem to be imported to Florida or Cali, so that doesn't help either of us.

Dave

ronarndt

I just had mine rebuilt about 6 months ago because of similar symptoms. Paid about $2500, including replacing the clutch disc (only) and release bearing. Job required replacing not just bearings, but a gear that had developed an uneven wear pattern.

sereneseven

^ ouch I had mine rebuilt about a year ago and the guy charged me about $400 @ that time mazda only wanted $2200 for a brand new one. my box is still **** all the guy did was replace syncro's so i am thinking about getting a new and just being done with it I'll post up the $ when i get it

DamonB

I did some research when sourcing parts to rebuild my transmission.

I found both www.transupply.com and www.drivetrain.com nice to talk to and both can supply all the bearings, seals, synchros and gears (if required) to rebuild an FD tranny.

In the end I found it was cheapest for me to buy the bearings and seals from one of the companies above and to buy the synchros direct from Mazda Motorsports. This allowed me to replace every bearing, seal and synchro inside the tranny for about $325 in parts.

sereneseven

^ do have a good cheap source for the x long puller reguired ??

DamonB

^ You make it. Cheaply and easily done.

The only special tools you'll need are the extended reach puller, the extended reach 41mm socket required to remove and disassemble the gear stack and a nice set of snap ring pliers. An engine stand is handy to hang the tranny off of when working on it but a workbench will do.

dgeesaman has nice write ups on rebuilding the transmission including pics of the tools:

http://www.davidgeesaman.com/

The FSM and dgeesaman's info tell you everything you need to know.