preloading the lsd ohhh boy!!!!

[Dan-The-Glanza-Man]

preloading the diff one these vids looks a bit tricky whos done this them selfs???

 

[weeJohn]

I have done it to test the locking torque on one, is this for setting up?

I cut the splined bit off an old CV joint and welded a big nut to the cut end. Then I could fit the spline in the diff, hold the diff in a vice and using a torque wrench turn the nut and see what torque the diff locked at.

 

[Dan-The-Glanza-Man]

yeah setting up mate thats still hard for me to get lol have you got this bit then i thought you fit it and then tighton one of the bearing side to push the diff closer to the other bearing to make it have less play thats what im thinking im proberly rong lol

 

[weeJohn]

I think we are talking about different things, I am talking about the ammount of friction between the plates inside the diff as some diffs allow you to swap them around to adjust the locking force point of the diff.

I think you are worried about the ammount of play you will have between the 2 support bearings of the diff, the tapered roller bearings at each end of it. I just dry fitted it then once the casing was tightened measured the end to end play by lifting the diff.

 

[Dan-The-Glanza-Man]

get what you mean but confused.com still the diffs brand new 1.5 way cant see why it needs addjustin and didnt no you could lock it even more i thought a lsd was a lsd and depending on what make you have depends on how good it is lol, but i thought as you say preload i thought was the side to side play between each bearing once fitted as ive noticed on the speedo side of the casing on the bearing cup theres teeth on it as if you put a tool on it and wind it in or out depending on the play you have on the diff

 

[weeJohn]

Usuaslly need to fit different shims between the taper bearing and the shoulder of the shaft to take up the play. I have never noticed the bit you are talking about mate, might be worth a go to see if thats what it does.

Some diffs need to see about 50ft/lbs of torque difference between the 2 wheels before they lock up. Our trackcars diff is a 1 way and was able to be adjusted by moving the plates round so it locked up at 35ft/lbs difference, good figure for a FWD car.

 

[Dan-The-Glanza-Man]

hmmm dont have any idea what the 1.5 way trd locks up at lol

 

[weeJohn]

Its a helical diff yes?

I dont know if they are adjustable as there is no friction plates. Probably a wedge slotted in somewhere that the profile off sets the torque difference, blows my mind a bit how they work at all lol, but they are good!

 

[Dan-The-Glanza-Man]

i think so i got it cheap brand new and the trd papers all in jap lol and i cant read jap im not fussed about how much to lock it any lsd is better then a standard diff i was spinning in 5th gear with 17s last summer not good so this should sort it out loads, all im worried about is side to side moment i thought preloading was that when u fit the diff after you put the box togethert you need to check the play between the diff bearings i thought it was that do i still need to do this or just put it in and bolt it up lol

 

[Sheldon]

spinning in 5th qith 17s?

 

[Dan-The-Glanza-Man]

yessssss!!!!! with out a lsd aint hard lol

 

[Dan-The-Glanza-Man]

boys gettin fustraighted now , finally got the right bearings from toyota and just knocked the old bearing cups out the casing and theres big shims behind them so gessin you cant reshim it when its back together as the as the shims go behind the cups and then the casing holds it then you put the seals on the outside,


has any one had any trouble with reshimming or has any one done it when fitted there diff

fitting my trd and im gessing its going to need shimming as its a different diff and it could be longer or shorter and if it aint right will fuck the bearings up

rep giving for help thanks dan

 

[weeJohn]

Contact Chris@CCM, I know he had to shim one before.

 

[Dan-The-Glanza-Man]

ill pm him lol i fitted it but aint bolted it yet or sealed it up and took a driveshaft end off and taped the casings together and left the shims it came with both sides and there anit no play when i just moving the diff but it could be to tight for all i know so i want advise

wil do that thanks weejohn repped

 

[Texx]

You need a gauge type torque wrench to be able to check if the shims have preloaded the bearings enough or not. You should expect to apply 1 - 1.5Nm of torque before the diff begins to rotate. Any less than 1Nm or any more than 1.5Nm and you should fit a thicker or thinner shim then try again.

 

[hardcoreep]

On a clutch type the locking percentage or preload is determined by the plate number and plate arrangement. I have heard of Japanese racers adding 1 or 2 more plates to get what they want. On a helical the preload is controlled by a spring mechanism. It comes set from factor for whatever application its being used for. I don't know anyone that's been able to change that setting, but I was told that can also be done, just not as easy as the clutch type.

 

[Texx]

I'm assuming we are talking about preloading the diff carrier tapered bearings? and not the locking mechanism inside the LSD itself?

 

[bumblebee]

..seems like this thread is way too advanced for me lol

 

[Texx]

 

[Dan-The-Glanza-Man]

yeah texx thats what im on about thats fantastic help thank you ever so much so i gess its got to be in netural to check this i need to get a gauge wrench then lol only got the other tyre, also to clear this am i bolting it down with out sealant then checking to torque or can i just put the casings together as i dotn want to have to split it all again if the shimming aint right

so happy you can help thank you