transmission rebuild
#1
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transmission rebuild
so my tranny makes a fairly loud grinding noise in every gear at certain points in the rpm range specific to every gear(i think every gear).....should i rebuild my tranny along with putting in a new clutch(that was planned already)........ive never even touched a transmission, do you think i could rebuild mine in a weekend? i dont even know how, is there a kit to buy? is it better to just have it looked at or buy a new tranny? i feel like im losing )not a ton) some power too, it feels like there is more available than what is transferred to the ground, hard to explain...i just need educated tranny help please
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i dont think im going to rebuild it, it doesnt sound that easy or inexpensive at all, plus i searched and some people said that just changing out the fluid(something thicker and better) and flushing the tranny works well....the car only has 92,000 original miles, ive had it for two years and i never did the fluid and IT IS TIME FOR A NEW CLUTCH and i read that can cause some grinding too, plus my hydraulics are out of wack....ok i will just try all these i guess before getting a new trany....it sucks that this is happening cause im prob. getting new wheels this week...thanks for the input guys
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just helped my buddy rebuild my 5 speed and we needed no special tools, just a good assortment. After taking it apart and putting it back together twice ( stuck syncro ) I have all the confidence in the world in rebuilding my own next time. The only think you will need is a couple bearings pressed with a press. If you have any mechanical skills and are organized you should be able to do it with no problem. It is realy quite simple how Mazda put these together. You don't need to worry about tolerances like you do the rear end cuz everything goes in set areas. I would recommend the use of a digital camera though for reference. My buddy charged me 400 but said anyone else it would cost about 900 - 1100 to do.
Jim
Jim
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well i dont think its my tranny(hoping at least) my clutch is worn and i think that is it....when the car is running somewhat cool i can hear a little of the grinding in neutral but not after its warm...i replaced the fluid today, it needed it bad and it feels quicker(shifting) and smoother but still grinds..............i tried to do mt rear end but i fudged up the fill plug(checking level first) a little(it is really tight(darn mechanics of past years i guess) so i am leaving it for now....i noticed today that i might be leaking brake fluid so i am making that priority!!!!!! but i will get a new clutch put in after that and hopefully all will be well....also, for the most part our trannies with a non ported or turbo motor should last well over 150000 miles without needing a rebuild anyway right?
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Originally Posted by rOtAryIsbEttEr
Seldawg,
where did you get the new parts to rebuild it?
where did you get the new parts to rebuild it?
#10
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a lot of times, a worn clutch will not cause grinding, just slipping. a bad release bearing(throwout bearing) will cause grinding and tough shifting. if its really easy to grind the gears with or without the clutch while driving and or the shifter feels kinda weak, its probably chunked up or worn synchros.
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the symptoms you described for the throw out bearing sound more like my car..........well see i guess, im going to ask for some help from rotary guys here in vegas
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Originally Posted by boog
the symptoms you described for the throw out bearing sound more like my car..........well see i guess, im going to ask for some help from rotary guys here in vegas
jim
#14
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Yeah, get your hydraulic system tightened up first. Chances are that will fix your issues. The noise in nuetral is your throwout bearing, but they can make a lot of noise for a very long time before they will actually cause any issues.
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I put the Centerforce II in the 7 and it feels great. No change in pedal feel at all, feels just like stock. Grabs harder than ever though. Would recommend it to anyone. Also put the Centerforce pressure plate as well.
#17
I bet it's your throw out bearing.
I bet it's your throw out bearing. Since your going to change the clutch anyway, the transmission will be out and you can just open the cover and take a look at it. If you bring it to a machine shop, they'll take a look at it for a few bucks, or maybe free. Since you say it makes noise in all gears at a certain RPM the only thing in the transmission that I can think of that might do that is the bearings at the end of the main shaft. Every transmission problem I've had only show up when you shift. Not when your just driving aong.
#20
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I haven't worked on a Mazda tranny yet, but on all others you did not have to remove any covers to reach the throwout bearing (if I recall correctly). I think it should be plainly visible once the tranny is out, and replacement should be a breeze. As long as you are replacing the clutch anyway, go ahead and swap it out.
However, based on the information in your second post I believe that your issue is not your clutch, but rather your hydraulic system. My guess would be that you also need to replace your slave cylinder (relatively cheap and easy to do).
One other thing. When you refill your tranny, you might want to consider using a 50/50 mix of gear lube and ATF. This is recommended by the Datsun racing guys for all Jap trannys. The ATF provides plenty of lubrication, but also has a lot of detergents which are good for cleaning the gunk out of the synchros and to keep them clean. I have found that you get much faster, crisper shifting with this solution than with straight gear lube. This info comes from the book titled "How to hotrod and race your Datsun". Good luck with your maintenance adventure!
However, based on the information in your second post I believe that your issue is not your clutch, but rather your hydraulic system. My guess would be that you also need to replace your slave cylinder (relatively cheap and easy to do).
One other thing. When you refill your tranny, you might want to consider using a 50/50 mix of gear lube and ATF. This is recommended by the Datsun racing guys for all Jap trannys. The ATF provides plenty of lubrication, but also has a lot of detergents which are good for cleaning the gunk out of the synchros and to keep them clean. I have found that you get much faster, crisper shifting with this solution than with straight gear lube. This info comes from the book titled "How to hotrod and race your Datsun". Good luck with your maintenance adventure!
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Beyond the obvious TO bearing and pilot bearing, I'd suspect the transmission input shaft bearing, which I've found wornout on previous cars (tho I've not disassembled a 7 trans yet). They are subjected to unusual stress. If the noise changes with roadspeed instead of motorspeed it's probably a UJoint, or, more rarely, a rear wheel bearing, but usually those have a peculiar cyclic sound, in my experience. Any car can have a worn UJoint after 100k+.
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