Dr. Rotary

So last Summer I bought a 1991 Mazda RX-7 FC N/A in LA for $5,800. It looked like it was in pretty good condition with 79,000 miles on it and a clean interior and engine bay but i'm pretty terrible at buying used cars and it looks like this one has a transmission problem.

The shop that does most of the work on my car was fixing an issue with the slave cylinder that was causing all the oil to leak when they noticed a kind of low-whirring noise that is audible when the clutch is NOT engaged. They told me that either the input bearing or the counter shaft bearing is broken and that if I don't have it fixed sometime soon the transmission could die. They told me they could rebuild the transmission with parts and labor totaling roughly $2000. My problem is that I am almost broke and that I am actually looking to sell the car in the near future. I've already spent around $2600 on this car and I feel like I've already gone way above its actual worth.

So the question is should I leave it as such? I was told I could look into alternatives such as buying an already used transmission and just having that put into the car but as I have no tools or knowledge currently, i'd still have to have the shop do it which is something like $900 in labor. however another friend of mine more acquainted with cars said something about the bearing only being like a 10 dollar part and that I should put it in myself however I feel like I would only break more things rather than fix them.

lduley

iTrader: (1)

if it were me, I'd have them drain and replace the fluid in the trans, and drive it. Unless the car has been BEAT on, I'm sure the trans is fine

Dr. Rotary

The car itself doesn't look or feel very beat up. The guy I bought it from was said it was a Sunday driver of his. Though now that I figured out what that noise is when the clutch is disengaged I remember it has sounded like that since I bought it. The guys at the shop said it's only going to get worse the hotter it gets in the trans. And so just a fluid change should help out a bit?

KansasCityREPU

iTrader: (9)

These car are old and require maintenance. Replacing the slave cylinder or changing trans fluid are pretty easy things to do. To keep cost in-check, us RX-7 owners need to do most of the fixes on these cars.

Dr. Rotary

Yeah I understand that. I'm in the process of learning. The slave cylinder is already done but i'll look into doing the trans fluid change myself.

misterstyx69

iTrader: (142)

sounds like a throw out bearing.
When you get into replacing that you may as well do the pilot bearing too.
The cost of both is less than 60 bucks in parts.
The only "big job" really is getting the old pilot bearing out of the back of the eshaft and tapping the new one in.
The throw out bearing just slides off and on.

Dr. Rotary

Forgive me but i'm pretty new to this. Correct me if I am wrong. The pilot bearing is attached to the flywheel and it connects it to the engine whereas the Throw out bearing is on the other side of the flywheel behind the pressure plate. I would have to take out the transmission to be able to replace the both bearings? Also where is the eshaft exactly?

lduley

iTrader: (1)

The pilot bearing ***** inside the eshaft (or crankshaft if you will) and its where the input shaft of the trans going into to help its stop slapping around inside the eshaft hole, and allow it to freespin
The throwout bearing is what pushes against the pressure plate, which in turns disengages your clutch

In all honesty, i wouldn't let it worry me until it becomes REALLY loud, chances of an internal bearing in the trans just seizing up are SLIM unless your hogging on it, especially with fresh fluid, which MAY quiet it down

misterstyx69

iTrader: (142)

well ya..since the bearings are in between the trans and engine the only way to replace them is pull the trans.
Eshaft or Eccentric shaft as it is called is the "rotary term" for Crankshaft.(since it is not a piston engine they had to call it something!..eccentric..lol!)
The pilot bearing sits in a little hole at the back of the engine's shaft so the input shaft of the trans can slip in there and align the 2 shafts.
IF that bearing goes then the most noticeable symptom would be that you can't put the car in gear when it is running,but when the car is off the trans would be able to work it's gears since the trans was not spinning.
The Throw out sits on a Fork and pushes the Splines of the clutch's pressure plate so the plate goes loose and you can switch gears.Then when you have the car in gear and the pedal is up it gets out of the way.
It can still spin and give you that whirrr noise and eventually it can let go.
I've had them last a long time and then again replaced one to replace it again as it was bad.

Your fluid change would have nothing to do with those bearings as they sit between the engine and trans and have no lubricating parts other than the dab of grease that they were touched with.They do not see any oil or gear oil(manual trans "lubricant").

RotaryEvolution

iTrader: (30)

i'd replace the throwout and the input shaft bearing while the transmission is out. the input shaft bearing does not require the transmission to be rebuilt.

the whole job should cost less than $500, i'd charge about $450 for a job like that which includes the cost of the parts.

Sgtblue

iTrader: (16)

Just to clarify...If the noise is heard when the clutch is NOT engaged (i.e. pedal depressed) it's NOT the input shaft bearing. That's only heard when the clutch is engaged. Usually sounds like a low growl. It also tends to disappear after 2nd or 3rd gear as the input shaft speed decreases and nominal noise increases going down the road.

Dr. Rotary

Ok I used a poor choice of words. I meant that the noise is audible when the Clutch Pedal is disengaged. Here is a link to what the noise sounds like and what position the clutch pedal is in when the it is heard:
I'm not sure if that helps pinpoint exactly which bearing is the issue. A lot of people have told me to not worry about it. I will be looking to sell this car either here on these forums or locally and thus am wondering if that would hurt its value/repel someone who might be looking to buy it.

Sgtblue

iTrader: (16)

Sounds like an input shaft bearing IMO. As mentioned above, I think it can be changed from the front of the transmission without a teardown. If ignored it can gall the input shaft.

Dr. Rotary

Good to know. On a similar note yesterday I had a strange issue pop up whilst trying to start the car. As I turned the key to position 3 to turn on the vehicle I could hear it trying to start but it was sputtering and having a hard time. It wasn't until the third time that after around 3 seconds of struggling it was able to finally start properly. Does this have anything to do with the bearings we've discussed? I thought it sounded more like a starter issue but I just got a new starter roughly 200 miles ago.

Also are the pilot bearing and input shaft bearing the same thing?

TheRealBruceWayne

I had the same sound on an old Nissan Laurel I owned.
When the clutch was not depressed it was noisy, as soon as I depressed clutch the sound disappeared.
If it is what I have said above, it is a bearing inside the trans making the noise. When you press in clutch the flywheel disengages from the trans and noise should stop.

My issue was the 3rd motion bearing. This is a major job on a gearbox as you need to pull the whole damn thing apart.

Try driving the vehicle and listening for the sound. If you can hear it when driving, try putting trans into 4th gear, if the noise is alot quieter or gone altogether it will be that 3rd motion bearing.
(4th gear is the only one which this will go quiet with as it has a 1:1 ratio.

If it is the same issue as i had, a reconditioned or 2nd hand gearbox may be a cheaper route to take.

TLDR:
Clutch pushed in and noisy = input shaft bearing
Clutch not pushed in and noisy = bearing inside transmission itself (major job)

Sgtblue

iTrader: (16)

I seriously doubt it since your clutch pedal was depressed and clutch disengaged in order to start the car. And no, they are not the same.