• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


Lsd install recommened bolts to replace

CSM

1000 Post Club
Messages
1,530
Likes
1,623
Location
Cleveland, OH, USA
#24
I just finished this project, picked up my car from my local Ford dealer last Friday, see this entire list of things you need. You will need to buy all the different shim sizes but will likely only need 1 or 2 of them but is better to have all just in case. I bought all my parts excluding differential shims from Tasca Ford. Would recommend buying new drain plugs for the transmission as the stock ones didn't seem to want to seal properly, just got that fixed today with some aftermarket drain plugs with washer. I bought the input/output bearing kit which was $67usd and comes with new bolts (6) for input/output shafts. I never rebuilt the entire transmission but only replaced the input/output shaft bearings as its pretty easy to do that part and generally the input/output shaft bearings are the typical items in the FiST transmission to fail. I bought the differential kit from mountune for $215usd. All of the items on the list as per the Ford service manual is what they recommend to replace and not re-use, the diagrams show pitching most of the bolts in the garbage due to being a torque yield style of bolt.
This is a pretty exhaustive list.

Probably tackling this later this summer. Thanks for sharing this information! very helpful
 


Messages
203
Likes
54
Location
Prince George, BC, Canada
#25
This is a pretty exhaustive list.

Probably tackling this later this summer. Thanks for sharing this information! very helpful
No problem glad to help out anyone whom is looking to do this job, also have all the Ford service manual bits for this job, can share too. Got these from a guy whom had a blog online but I think it got taken down due to copyright issues. PM me your email and can forward if you would like those as well.
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#26
Just a reminder that the shims are only necessary for certain types of LSD to set the pre-load on the differential (clutch type differentials). I've installed three MFactory LSDs without adding any kind of shim to the case and all three are just fine.
Me and my dad kinda boogered the factory shim that was in there so we just took it out. Installed everything and the trans is making a rotating whirring noise now under load. Assuming that factory shim needs to be in there so I ordered another one.

Assuming you didn't remove any shims that were already in there as well a not add any?
 


MagnetiseST

1000 Post Club
Premium Account
Messages
1,311
Likes
1,153
Location
Dania Beach
#27
Me and my dad kinda boogered the factory shim that was in there so we just took it out. Installed everything and the trans is making a rotating whirring noise now under load. Assuming that factory shim needs to be in there so I ordered another one.

Assuming you didn't remove any shims that were already in there as well a not add any?
You absolutely need at least that shim, I did not remove or add any. To your credit, I DID remove the stock shim the first time because I thought it was part of the race. I did not put one back in, and it clunked like a mofo until I did.
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#28
You absolutely need at least that shim, I did not remove or add any. To your credit, I DID remove the stock shim the first time because I thought it was part of the race. I did not put one back in, and it clunked like a mofo until I did.
Gotcha. Mine doesn't clunk per say but it's like the whirring sounds I described. Hopefully adding it back gets rid of it. Amazing how a small ass shim prevents this.

OEM shim I took out measures 0.45mm should I get a 0.40mm or 0.50mm? They don't make a 0.45mm
 


MagnetiseST

1000 Post Club
Premium Account
Messages
1,311
Likes
1,153
Location
Dania Beach
#29
Gotcha. Mine doesn't clunk per say but it's like the whirring sounds I described. Hopefully adding it back gets rid of it. Amazing how a small ass shim prevents this.

OEM shim I took out measures 0.45mm should I get a 0.40mm or 0.50mm? They don't make a 0.45mm
the stock shims are .50mm, if its smaller its from being compressed. Grab another .50mm, stuff that sucker in there and hopefully your whirring goes away. Its likely from a poor engagement of the final drive to the main shaft.
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#30
the stock shims are .50mm, if its smaller its from being compressed. Grab another .50mm, stuff that sucker in there and hopefully your whirring goes away. Its likely from a poor engagement of the final drive to the main shaft.
Probably didn't help either that I was quart low on fluid by my own ton foolery
 


MagnetiseST

1000 Post Club
Premium Account
Messages
1,311
Likes
1,153
Location
Dania Beach
#33
Got my shim today. Its completely flat, where as the one that was in the transmission had a lip(assuming thats because of it being pressed in. How do you go about pressing it in?
i believe there is a tool for it, probably like a bearing installer or something. I'm not really sure. I happened to have a spare transmission case with the OE shim in it when I needed to replace mine.
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#34
Got the shim in last night. It just drops in there and is held in place by the bearing race. Going to finish it up this evening
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#35
the stock shims are .50mm, if its smaller its from being compressed. Grab another .50mm, stuff that sucker in there and hopefully your whirring goes away. Its likely from a poor engagement of the final drive to the main shaft.
Still makes the noise with a 0.5mm shim in there. Going to just take it out for the 3rd time and properly measure for shims this time.

I really don't think its any trans bearings because before the LSD install it never made a sound
 


Quisp

1000 Post Club
Messages
1,118
Likes
404
Location
Davenport
#36
Still makes the noise with a 0.5mm shim in there. Going to just take it out for the 3rd time and properly measure for shims this time.

I really don't think its any trans bearings because before the LSD install it never made a sound
Does it make noise all the time or only coasting off throttle?

Sent from my SM-A205U1 using Tapatalk
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#37
Does it make noise all the time or only coasting off throttle?

Sent from my SM-A205U1 using Tapatalk
It only makes the noise when on throttle in gear. I can be on throttle in neutral and nothing happens. Only when I'm in gear AND on throttle. Its like a whirring bearing noise. Hard to really describe. My dad said it could be just how it is since its a mechanical diff and its the gear whine I'm hearing but everyone else whos installed the mFactory doesn't have noise so thats why I don't believe that.
It not that loud but loud enough to where you can hear it with windows up and sometimes windows down.

Something to note, it doesn't make the noise when going 70+mph. Little things like this is why I don't deal with transmissions lol, too fidley.

I just don't believe not shimming it is whats making that noise happen. But then again I don't know much about trannys
 


TDavis

1000 Post Club
Messages
1,435
Likes
1,149
Location
Columbia
#38
Contacted the people at mFactory. Nice people. They said with the Helical there will be some noise because it has alot more gears in the diff then stock. Said break in period for the diff is 500-1000 miles so it should dampen from there but never go away.
 


Last edited:

Quisp

1000 Post Club
Messages
1,118
Likes
404
Location
Davenport
#39
It only makes the noise when on throttle in gear. I can be on throttle in neutral and nothing happens. Only when I'm in gear AND on throttle. Its like a whirring bearing noise. Hard to really describe. My dad said it could be just how it is since its a mechanical diff and its the gear whine I'm hearing but everyone else whos installed the mFactory doesn't have noise so thats why I don't believe that.
It not that loud but loud enough to where you can hear it with windows up and sometimes windows down.

Something to note, it doesn't make the noise when going 70+mph. Little things like this is why I don't deal with transmissions lol, too fidley.

I just don't believe not shimming it is whats making that noise happen. But then again I don't know much about trannys
I went from Ravenol to Motul 300 and it cut the noise down. Mine only does on coasting.

Sent from my SM-A205U1 using Tapatalk
 




Top