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Setting Differential Preload.

Sekred

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#1
I am in the process of assembling the transmission that failed recently and up to the point of setting the diff preload. This maybe helpful if you are installing a LSD yourself.

This image is what you will see when you have removed the bellhousing end of the trans case.

IMG_3141.JPG

Here I have remove the differential and the reverse pinion so I can changeout the bearing as part of the rebuild. Removal of the reverse pinion is not necessary to change the differential.
Sorry about the 2 images here.

IMG_3141.JPG IMG_3127.JPG

I need to remove the bearing cup from the front or the bellhousing side of the trans case. I have decided to pull it out using a socket and threaded bar. Removal is easy using this method and it does not damage the shim. To reinstall the bearing cup I used a hammer and punch. I installed the bearing cup without the shim. The bearing cup is not a tight fit in the housing. I did not bother freezing the cup or heating the housing. I used the same method to replace the bearing cup in the other side the transmission housing.

IMG_3130.JPG

IMG_3132.JPG

IMG_3134.JPG

I have reinstalled the bearing cup without the shim, reinstalled the diff and front of the transmission case. I am changing out the diff, removing the Quaife LSD and refitting the OEM diff. I have installed the diff without the ring gear fitted. It needs to be swapped over anyway and it allows me to measure end float without drag from the ring gear against the reverse pinion and the output shaft pinion. Before I measure end float I need to rotate the diff a few times so the rollers of the bearing seat properly in the cups. Rotating the differential and moving it to measure end float are done by hand because there is no drag to overcome with the ring gear removed from the diff housing. I am using a dial indicator and magnetic base. I Must get a consistent reading measuring 3 or 4 times. Don't rotate the shaft during end float measurement.

IMG_3135.JPG

Once I was happy with the end float measurement, I removed the front housing, removed and reinstalled the bearing cup with the correct shim and finished the assembly of the transmission.
Just to note, I did not have to change shim size in this case.
 


Last edited:

haste

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#2
Why did you remove the quaife lsd and go to the open diff?
 


OP
Sekred

Sekred

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Thread Starter #3
Why did you remove the quaife lsd and go to the open diff?
Returning the car back to stock and may sell it towards the end of year. I was not going to remove the quaife until the trans shit itself. Out of interest I stripped the quaife to have a look. Still perfect after 25,000ks running a BT.
 


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#4
What is end float? I ask because I have never set up a Fiesta transaxle. All the ring and pinion setups I have done measure preload in torque unit (usually inch pounds)
 


haste

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#5
What is end float? I ask because I have never set up a Fiesta transaxle. All the ring and pinion setups I have done measure preload in torque unit (usually inch pounds)
Think of the differential bearings loose inside of the transmission housing. End float is a measurement of this movement. You can literally push and pull the differential to one side or the other when it has float. Measurement is taken from this movement and the correct shim installed to remove the float and preload the bearings.

The preload gives the bearings tension inside the transmission and keeps it from being loose.
 


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