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ZF/M50D conversion noise with clutch out

jspurl3

Sr. Member
Joined
Dec 30, 2008
Messages
818
Loc.
Baton Rouge, LA
I just rebuilt my motor and did the bc bronco zf conversion kit with an M50D trans. It runs great but makes a whining noise when I let my foot off the clutch and gets louder as I accelerate. New Luk clutch, flywheel, and all the components of the bc kit. I bled the master cylinder for a while and believe I got all the air out but that was my first time messing with a hydraulic clutch assembly. Any suggestions would be great. Thanks!
 

Bronco73

Bronco Guru
Joined
May 29, 2003
Messages
2,989
Loc.
Cape Coral, FL
I would think you have an issue with the trans. Was it a used trans? My guess is high mileage or a well used trans is the cause. Fluid level? What did or does the old fluid look like?
 
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jspurl3

jspurl3

Sr. Member
Joined
Dec 30, 2008
Messages
818
Loc.
Baton Rouge, LA
Good point I was thinking I did something wrong in the clutch install. It was used. The fluid looked fine. It makes the whine in neutral too but I don't think it was as loud.
 

bigmuddy

Contributor
Bronco Guru
Joined
Dec 28, 2004
Messages
7,001
Loc.
Marthasville Missouri
I tried to use the starter from my auto tranny and it would start it. However it you could hear it riding the the flywheel at all times, it would change slightly when I pushed the clutch in.
 

00gyrhed

Bronco Guru
Joined
Aug 3, 2006
Messages
2,428
ZFs are noisier than almost any light truck transmission. It might just be normal. Find someone with one in a bronco with no carpet or undercoating and get in the cab and roll up the windows. It will probably sound just like yours.

Is the noise there when you cruise in 4th (not OD)? How about in coast in second or third.
 
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jspurl3

jspurl3

Sr. Member
Joined
Dec 30, 2008
Messages
818
Loc.
Baton Rouge, LA
Yes it's a M50D not a ZF just mentioned the ZF because that is the conversion used. Are the M50D known for being noisy as well? I really mind it and I still have a hole in the floor to patch that will quite it down. I just didn't want to drive it much if something is wrong.
 

Bronco73

Bronco Guru
Joined
May 29, 2003
Messages
2,989
Loc.
Cape Coral, FL
My father has the 4x2 model M5OD and he has I think around 500k miles on it. His has developed a little noise at idle in neutral but it shifts and drives fine. He changes his fluid about twice a year.

If it shifts and drives fine I would just drive it until you develop a shifting or vibration problem. Did you use the correct fluid?
 

Bronco73

Bronco Guru
Joined
May 29, 2003
Messages
2,989
Loc.
Cape Coral, FL
I figured you used the correct fluid.

In a few months I hope to be installing a 99 model M5OD trans myself. It's sitting in the garage until I can afford the rest of the parts to swap it in.
 
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jspurl3

jspurl3

Sr. Member
Joined
Dec 30, 2008
Messages
818
Loc.
Baton Rouge, LA
Well I will let you know of the noise goes away other than that I am a big fan of the way it fits and shifts. I didn't have to do any shifter modification or any body lift
 

WorkerBee

Full Member
Joined
Aug 22, 2011
Messages
224
Loc.
Northern CA
I just installed the m5od and it's pretty quiet. I don't have any sort of noise at all. I think I just got lucky because it was a pick n pull trans that I took a gamble on. I have the same clutch and flywheel as you. So far very happy with it. Good luck and let us know what you find.
 

Bronco73

Bronco Guru
Joined
May 29, 2003
Messages
2,989
Loc.
Cape Coral, FL
Well I will let you know of the noise goes away other than that I am a big fan of the way it fits and shifts. I didn't have to do any shifter modification or any body lift


Good to hear. I have had the ZF and never installed it and even have the mountaineer auto trans too, never installed it. I have been back and fourth on which tranny I wanted to go with and I made my mind up I hope for the last time.
 
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