H4Inf

I started to notice some transmission noise a week ago... Today It's much louder... and I'm guessing its going to keep getting louder and louder until ....

In first, second and third gear I can hear it, or in neutral, with the clutch pedal up. Surprisingly 4th gear is lovely and silent... I'm guessing this has something to do with the 1:1 ratio here?

Anyway I'm just wondering about how many miles/km's i'll be able to get out of this... I'll stick to low rpm under 4000.

Cheers,

Paul.

Edit: If you've ever played GTA it reminded me of the sound just before your car blows up :P

64mgb

iTrader: (1)

I don't know if it'll help your situation, but I've heard stories about people switching to synthetic fluid and eliminating noisy transmissions.

H4Inf

I don't think its just noisy, something is getting worse, and from what I've read its the input bearing... Just needa know if I can drive it and for how long!

lovintha7

That's typical for noise in every gear except 4th when the bearings are going bad. Rebuild time. www.drivetrain.com has decent prices on new bearings and synchros.

Here's Mazdatrix's website explaining trans noise:

http://www.mazdatrix.com/g2.htm

check out the 5th block. That should sum it up for you.

H4Inf

Still wondering how long I should be able to drive on it for.... First I need to get home from where I am now (30 mins), then I need to get it to a shop (40 minutes).

And will it just get worse and worse untill..... what happens when it gets to the point where the bearing has had enough?

Aaaand should I just drive ni 4th gear if possible?

lovintha7

It'll go for awhile and then some. I drove mine for 2 months like that before I found a used tranny. I'd say I put 5k miles on it, and it was making noise long before I bought it.

Edit: Those were not EASY miles by any means.

PS, Did you go to the F1 race 2 weeks ago?

hammmy

I have a balky synchro for 2nd gear in my '82. I'm going to try using $40 worth of Red Line MT-90 synthetic manual tranny fluid to see if that will cure the problem.

Than again, you could probably get a decent 12A tranny for $100 or less.

Edit: After consulting my new '82 factory manual, I see that I will need 2.1 quarts, so about $20 assuming I buy 2 quarts of Red Line.

lovintha7

Bought mine for 70 bucks plus shipping. Still going strong. And I've tried Red Line MTL, and Lucas Trans Oil, but they won't touch H4Inf's noise. It'll just be as noisy. He needs a rebuild, or a new trans.

H4Inf

Hmm. I just drove home and it is quite noisy - I've been keeping revs under about 2000rpm where possible and just taking ages to get up to speed... shifting to 4th gear at about 40km/h (24mph)... In 4th gear I can't hear any noticable sounds.

My exhaust is 120+ dB so that isnt helping... but yes I can hear it loud in all other gears apart from 4th. It sounds like the stock fuel pump off the 82.

It's like a ticking sound that increases with engine rpm.

skrewloose78

my 83 had the same symptoms, a roaring noise in every gear but 4th.the countershaft bearings were about to go out, it was actually bad enough that it shoved the shaft thru the retainer in the front of the tranny.i was able to drive it 800 miles from houston to bama(where all of my spare parts are) using mainly 4th gear and taking it easy in the rest.the next morning when i went out to work on it i had no reverse or 1st and barely had 2nd.

H4Inf

I'm about to record the sound, from a number of different places so we can possibly narrow the problem down, or at least let people know what it sounds like.. I'll record from in teh car, on the gearstick, under the car on the xmission (maybe different areas), and ill try from in the engine bay on bellhousing...

H4Inf

This is the recording from under the car, right below the transmission drain plug.

The recording starts with my foot off the clutch (making the sound) then i push my foot in a couple times. (The second time in the long version/first time in short one i do the clutch as slow as possible so you can hear it pick up)

Long version (700k)
http://twiztid.ausgamers.com/paul/kar/transsound.mp3

Short version (150k)
http://twiztid.ausgamers.com/paul/ka...ound_short.mp3

Thoughts?

Cheers.

H4Inf

b u m p ;-) - sound files of my noisy transmission above

MosesX605

Yuck!

Was the tranny in gear when you tried this?

Rogue_Wulff

Many years ago, I had a ford badged mazda truck that made a very similar noise. It was louder in 1st than 2nd, and even quieter in third. by the time I hit 4th, pure silence. It was only a 4 speed, so I drove it 4th as much as possible until I could pull it out to rebuild. Turned out to be nothing more than the bearing at the back of the input shaft/ front of the main shaft. Less than $5 in parts to repair, but required a whole day to do the job.
I will say this much, that was the simplest tranny I have ever had the pleasure of working on.

H4Inf

This sound occurs in neutral, 1st, 2nd, 3rd and reverse. It probably occurs in 5th but I didnt make it to there. I stuck to 4th because it makes no noise at all.... which as I said before I think may be because the ratio here is 1:1 so it must put less stress on bearings perhaps?

lovintha7

Like I said earlier, I have a tranny that does exactly that. You need a new tranny.

H4Inf

Alrighty then. New tranny time :-)

Should I replace it with another one the same, or should I look at something a bit stronger perhaps?

I breifly recall someone saying something about fitting trannys made for other cars, that were perhaps a bit stronger... any ideas?

Being in Australia, there arent as many cheap 7 parts around as you guys have in USA...

Cheers

H4Inf

I've been thinking for days and since heard another RX7 that makes this sound....

I'm thinking it could be broken teeth on the shaft which has 1 2 3 and 5 and something to do with reverse on it....

There is no sound at all in 4th, which is 1:1 ratio, so it probably bypasses this shaft. (I have never seen inside a gearbox so im not sure, just guessing)...

I'm guessing I broke a far few teeth on the input shaft gear.. See I have already removed one tooth from the box... at that stage I couldnt hear anything... then I thrashed the car around with the loud exhaust on for a few weeks and I could just hear the sound over the exhaust..

then i raced an rx8 and the volume of the sound stepped up a bit more... hmm. the last 2 times i dropped the clutch from about 3-4000rpm from a dead stop. im guessing that each time i did this, i broke another tooth off this shaft? The noise isnt slowly getting louder, it just suddenly jumps up when i drop it in, as my theory goes im breaking teeth... I guess once you break one, the ones around that will weaken, until they break... and so on.

Im going to drain the tranny tomorrow and see what I find! Hopefully some teeth :-)

Another things which adds to my reasoning is I recently had a look at another RX7 for sale and it made the same (but quiet) noise mine did. The owner said it had been doing that for the last 7000km... so maybe a broken tooth..

Any thoughts?

Cheers!

Paul.

.::evil inside::.

what a crapheap aye paul, you'll have to buy my tranny off me and do a swap or salvage the bits for a rebuild your car is weak, sif break a box! lol

H4Inf

I'll give you $5 for the tranny, and youll throw in a free rear-view mirror and perhaps some other goodies as well ;-) Looking forward to your new parts car

H4Inf

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/blown-transmission-whats-wrong-248038/

That is what im hoping is my problem!

Not that it's good, but the fact that I may have worked it out before opening it up :P

Manntis

when mine made noise, putting in new bearings solved the problem. Far cheaper than getting a new tranny, too :