M5OD Problem

[ajmiller]

About a year and 2 months ago I put in a remanufactured M5OD from a tranny shop in Portland. The thing has worked perfect until about a month ago. Whenever I shift down, and even sometimes when I shift up it makes a nasty grinding noise only when i let the clutch out. For some reason it only did it when i used the clutch. I would shift without the clutch and it wouldnt do it. The guy at the tranny shop said it was the reverse sink gear, apparently they are notorius for going out in this style of tranny. The tranny had a 1 yr warranty but it was already 2 months late but i called anyways. They decited to give me another rebuilt one exchange for the other one. We did that and the new one does the same thing! We called and they had already taken apart mine and said nothing was wrong...He said it could be the slave cylinder or even the clutch. I had just put a new clutch in 7 or 8 months ago along with a slave cylinder. My bro in-law who is the mechanic said the new tranny the guy gave me was from a newer explorer and was stronger than mine, both the mazda style out of an explorer. The only thing im concerned about is if the 2 slave cylinders are the same from the 2 different mazda m5od trannys, because i put the one from my old tranny in the new one. Anyone else had this problem? Any help would be awesome.

Thanks

 

[Explorin94]

If it does it while only the clutch is pushed in then it should be the throwout bearing.

 

[ajmiller]

It only does it when I release the clutch.

 

[PlumCrazy]

Sounds like a throw out bearing to me. Might as well throw a new slave on while you have the trans out. There is now an upgraded design made by Perfection than is metal instead of plastic and is less pone to blowing out.

 

[Explorin94]

It only does it when I release the clutch.

Sorry miread your foirst post....but my diagnosis stands with the t-bearing

 

[ajmiller]

The bad trans is still in the truck, ill pull it and try a new slave and see what happens. If it was a throwout bearing wouldnt it grind all the time? Because the first time i took it to my bro in-law to have him test drive it, it wasnt doing it until i drove home.

 

[BRUTUS_T_HOG]

sticky pilot bearing? did you change it when you did the clutch?

 

[kukaepe]

I agree with Brutus, if you hear no noise when shifting without the clutch I would sure suspect the pilot bearing in the end of the crankshaft. When the crank and the transmission input shaft are at different speeds the pilot bearing comes into play...they are always at the same speed when you shift without the clutch....just a thought...

 

[pcollins]

The bad trans is still in the truck, ill pull it and try a new slave and see what happens. If it was a throwout bearing wouldnt it grind all the time? Because the first time i took it to my bro in-law to have him test drive it, it wasnt doing it until i drove home.

The T/O bearing isn't constantly spinning i'm pretty sure.

 

[gw33gp]

I had something similar before I changed my clutch. I would not call it a grinding sound but was sort of an odd squeal that could be interpreted as a grinding sound. It would do it as the clutch started to engage and continue until fully engaged. I thought it was the clutch.

When I got it apart, I found the clutch was in very good condition as well as the pilot bearing. The throw out bearing appeared to be good but was kind of loose on the slave cylinder guide. Upon closer inspection I found the inner diameter of the throw out bearing was worn out. There are many small vanes that are kind of flexible and ride on the slave cylinder guide. They were either worn or permanently deflected allowing play between the TO bearing housing and slave guide.

This play would result in a vibration under certain conditions causing this odd sound. Since I had it apart and had all the new parts, I did a complete clutch job. I did a slight mod to the ID (vanes) of the throw out bearing to help reduce wear/deflection in hopes that it would last longer.

I just realized you have an 89 2.9L engine and the design is different than my 2002 4.0L. So, my experience may not apply. I did change the clutch twice in my 89 2.9L Ranger but it was the clutch that was worn out. I don't remember if the TO bearing was worn.

The clutch looked like it would have lasted another 100,000 miles so maybe I can reach 300,000 miles before another clutch job is needed. I am not sure the slave cylinder will go that long.