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Lsd install recommened bolts to replace

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#1
I'm gona be doing a lsd install and wanted any input from anyone who's done it about what bolts or parts are recommended to be replaced so far I have this list
subframe bolts
-axle nuts
-lower control arm ball joint nut and bolt
-sway bar end link nut
-transmission case bolts
If you can help me with part numbers for the case bolts and subframe bolts it be great I can't seem to find them on diagrams
 


Erick_V

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maestromaestro

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If you look in the shop manual (you should be able to find a link to d/l on this forum) for transmission removal, it will tell you which bolts are reusable and which need to be replaced. There a a few of those. There’s also a fabulous thread on transmission rebuild with all sorts of useful information.
 


MagnetiseST

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from personal experience, I've only ever actually replaced the bolts on the ring gear. Haven't had an issue. It is recommended to replace:
-Strut / knuckle bolts
-Pinch bolt for the ball joint
-Ring gear bolts
-Axle nut
-Control arm bolts

Also replace the clutch slave cylinder while you're in there (and clutch if you feel its necessary). I've never seen to replace the case bolts, they arent TTY.
 


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#5
If I take my car to a shop to have them install my lsd, is it likely they will know what bolts to replace?
 


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#6
I'm gona be doing a lsd install and wanted any input from anyone who's done it about what bolts or parts are recommended to be replaced so far I have this list
subframe bolts
-axle nuts
-lower control arm ball joint nut and bolt
-sway bar end link nut
-transmission case bolts
If you can help me with part numbers for the case bolts and subframe bolts it be great I can't seem to find them on diagrams
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.
 


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#8
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.
Edit: The Quaife LSD is helical gear style, the instructions from Ford Racing for the Quaife does not talk about the pre-load with shims. Are you saying for clutch type differentials you don’t need to pre-load this don’t need the shims.


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MagnetiseST

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#9
The Quaife LSD is helical gear style. Are you saying for clutch type differentials you don’t need to pre-load this don’t need the shims.


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Nope for a clutch type you should need to. For helical you shouldn't, but every case is different, and every LSD make is different. One of the three is a dedicated track car and it doesn't have any issue.


Edit:

Check the link for the Ford Racing instructions for installing a Quaife. Absolutely 0 mention of shimming the differential.

https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-4026-FA.PDF
 


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#10
Nope for a clutch type you should need to. For helical you shouldn't, but every case is different, and every LSD make is different. One of the three is a dedicated track car and it doesn't have any issue.


Edit:

Check the link for the Ford Racing instructions for installing a Quaife. Absolutely 0 mention of shimming the differential.

https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-4026-FA.PDF
Ok well crap, my mechanic at Ford installed the 0.5mm shim I believe to preload it for Quaife LSD. Is this bad?

Edit:
I talked to Ford Performance via the chat and asked whether shimming is required with the Quaife LSD and he said the following:
"new bearings or a new Diff could need shimming"

So basically you have to measure the tolerance to determine if you need any shims, otherwise you could have too much play within the transmission.
I'm no expert learning as I go along here, but from what I've read online other people doing LSD on the FiST have installed new shim base on the pre-loading required.

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MagnetiseST

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Ok well crap, my mechanic at Ford installed the 0.5mm shim I believe to preload it for Quaife LSD. Is this bad?

Edit:
I talked to Ford Performance via the chat and asked whether shimming is required with the Quaife LSD and he said the following:
"new bearings or a new Diff could need shimming"

So basically you have to measure the tolerance to determine if you need any shims, otherwise you could have too much play within the transmission.
I'm no expert learning as I go along here, but from what I've read online other people doing LSD on the FiST have installed new shim base on the pre-loading required.

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Too many shims could bind it, but its likely fine. You are supposed to measure however the tools to properly do that are not usually something that a DIY guy would have (a dial gauge to measure run out), the dealer might have the tool but no one to use it properly. I think that Ford would've put it in the guide if it were absolutely necessary, but they didn't which leads me to believe that the tolerances are pretty good from factory.
 


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#12
Too many shims could bind it, but its likely fine. You are supposed to measure however the tools to properly do that are not usually something that a DIY guy would have (a dial gauge to measure run out), the dealer might have the tool but no one to use it properly. I think that Ford would've put it in the guide if it were absolutely necessary, but they didn't which leads me to believe that the tolerances are pretty good from factory.
I think the bottom line here is that you need to make that measurement to determine whether you need shims or not. Too much play is bad but so is being too tight if you put too many shims in. Not too sure why the instructions don't indicate this step with regards to measurement, maybe they don't expect very many DIY's to do this job. My mechanic at my Ford dealer whom is Ford certified to work on transmissions and engines said the pre-load bearing measurement procedure is absolutely necessary and so did the contact at Ford Performance. With my install the 0.5mm shim was used.

In my opinion it is very bad advise to tell someone they don't need shims as part of this install just because the instruction don't say so, one should make the necessary measurement then determine if they need shims or not.

I sent an email to Quaife and this was there response below:
1588173401421.png
 


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MagnetiseST

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#13
I think the bottom line here is that you need to make that measurement to determine whether you need shims or not. Too much play is bad but so is being too tight if you put too many shims in. Not too sure why the instructions don't indicate this step with regards to measurement, maybe they don't expect very many DIY's to do this job. My mechanic at my Ford dealer whom is Ford certified to work on transmissions and engines said the pre-load bearing measurement procedure is absolutely necessary and so did the contact at Ford Performance. With my install the 0.5mm shim was used.

In my opinion it is very bad advise to tell someone they don't need shims as part of this install just because the instruction don't say so, one should make the necessary measurement then determine if they need shims or not.
I never said you were wrong or that you didn't need it. If someone measured it and found that it was necessary... great. Not everyone can afford to pay someone to install the differential, some people like to do their own work, etc.

Yes they should be measured, you should also replace all of those throw away bolts, should not tune the car, should not install a short shift adapter, should not do a million things that we do. Also its a Ford Racing installation guide, if they assumed that a Ford Technician was doing the job and they would know to shim it or that it indeed needed to be, they would have referenced the necessary step in the FSM.

It comes down to how willing you are to replace the part again sooner rather than later, or if you are capable of having the car down while you repair it. Being that we do our own work and have 2 spare cars, if any of the transmissions blow up from not being shimmed, so be it. If it were bad enough (the pre-load), it would make awful noise as the bearings failed while we drove it.

I'm not saying you should or should not do it, I did not. I do not believe it is necessary on mechanical diffs, the transmission tech at our shop agreed and has done more than a few Focus / Fiesta LSD installs. Some need it, some don't. Makes you wonder why they aren't shimmed stock though.... (though I've heard some are).
 


MagnetiseST

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#15
Interestingly enough, I have a spare case and it has a shim on the bellhousing side, this is factory. It had never been touched. So there are definitely cases where shims are required.
 


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#16
I have the Ford hardware/sealant kit... and as I assemble the cases... the sealant provided looks more like red loctite... double checked both the package and the tube... am I crazy?

AA715474-3E1B-4270-8F6A-EB47A2B14524.jpeg
 


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#17
I have the Ford hardware/sealant kit... and as I assemble the cases... the sealant provided looks more like red loctite... double checked both the package and the tube... am I crazy?

View attachment 30728
Is this part of the differential kit from mountune? If so it isn’t locktight


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#18
I have the Ford hardware/sealant kit... and as I assemble the cases... the sealant provided looks more like red loctite... double checked both the package and the tube... am I crazy?

View attachment 30728

This is what my install looked like, was done at my local Ford dealer by a friend of mine.


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#19

This is what my install looked like, was done at my local Ford dealer by a friend of mine.
Looks like the same raspberry jam in a tube... although I didn’t spread it on as thick. I guess it’s similar to the blue Hylomar they make, it never really dries but leaves a thin layer of goo that the oil doesn’t wash off. I use a small piece of fine scotchbrite to even it out a bit. Thanks for the vote of confidence. BTW the Ford Performance Kit (not Montune but they sell the same) shows flipping the tranny the other way when assembling, and I would say I prefer the Ford Performance instructions if anyone is contemplating this job, it’s a lot easier to stack everything up the way they show it, your friend followed the instructions in the service manual. Thanks again.
 


Quisp

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#20
Looks like the same raspberry jam in a tube... although I didn’t spread it on as thick. I guess it’s similar to the blue Hylomar they make, it never really dries but leaves a thin layer of goo that the oil doesn’t wash off. I use a small piece of fine scotchbrite to even it out a bit. Thanks for the vote of confidence. BTW the Ford Performance Kit (not Montune but they sell the same) shows flipping the tranny the other way when assembling, and I would say I prefer the Ford Performance instructions if anyone is contemplating this job, it’s a lot easier to stack everything up the way they show it, your friend followed the instructions in the service manual. Thanks again.
I would leave the "Bead" Like the one above .
 




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