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diff coast side contact pattern


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that looks fine too. shinest bit is just above center,

on drive, its just below

 

see hoo the pattern es shifted alot wid load,, quite alot

shift pin deeper in, drive goes doon

pin shallower, coast goes

t,me that fine, as drive will lower it whenst ont car.

 

if it runs quiet ok

if it aint, try a 2-3 shim t,move cw away frae pin

as on other post aboot 1,ish, i said same, still think it noo,

....even thou there seems t,be moer blue on inside of teeth, its wot showed up wid nee load, that telling me this,

but patterns alot sharper wid load,no seeing the run off into tooth.

can ye see what im on aboot here !!!

 

but if ye aint moved owt frae earlier, then this why im saying move it 2 thou, an try agen

its v v time consuming aint it,

wee tip. elctric drill, a /9/16th socket in a holder speeds  up bearing cups tek,n em on /off

 

NOTE, if yer shift,n shims aboot, then all measurements and patterns MUST be done wid same pree loadings on side bearings,

if its done wid less, , even if its same amout either side left oot,so it goes in /oot easier,

it,ll show a diff pattern up, as CW will be shift,n aboot in the bearings,

when ye add load t,it

 

 

M

 

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Another wee tip, see sec pic,

see the small thrust bed, its wuff wuff , ridges init.

whenst putt,n the side thrusts in, mek em as tight  as ye can get,

by this i mean actually really good hard  tap,n em in wid a punch.

 

they gotta be this tight, cos in a few miles { corners t,be moer accurate }

the thrusts will be just right, as they will ev bedded into the grooves in carrier.

 

mek em just a nice fit, so ye can turn halfshafts will result in them being slacker than a Laydee of the nights  money mek,n bit, !!!

 

M

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When I first stripped the diff there was a lot of backlash in the spider gears causing clunking on take off.The thrusts were stamped 62 one side 64 the other side but only measured approx. 54thou, and the sun gear shims that should be 48thou measured 44thou.I couldn't at the time get any metal sun gear shims, Rimmers and Moss only had fibre ones so had to put the original ones back in, and put 66 thou thrust shims in.This resulted in the spider gears being quite tight but really notchy to turn.

I`ve now managed to get some brass shims for the sun gears from Chris Wittor and have ordered some 64thou thrusts to see how that feels.When the spider gears are back together should they feel notchy to turn,feels as though they were not meshing properly.

Dave

 

 

 

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Rightio Marcus,

I`ll put the spider gears back together with the 48thou brass sun gear shims and the 66 thou thrusts and see how that feels.

Whilst the carriers out I`ll move a 2thou shim from the cwheel side to the other side  to increase the backlash, It is quite tight at the moment at between 3.5 to 6 thou .It was approx. 10 thou when I first stripped the diff.

cheers Dave

 

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Dave,

If I were you I'd leave the backlash where it is, it will open out under use.  From memory, in the article on the TR Technicalities CD, Pete Cox recommends using a backlash of 3 to 6 thou.

Rgds Ian

PS I'm totally with Marcus on the planetary gears.  on my 3.7 axle I had to virtually force them in and they were very notchy (it was the only shims I had) but when I stripped it, they were as smooth as silk.

Edited by Ian Vincent
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Ian/Marcus

Rebuilt spider gears today, tapped thrust shims in as they were that tight, and  now needs socket and bar on each output shaft to turn the gears which are very notchy.

Moved 2th shim from c/wheel side to other side and backlash has now increased from 3.5 -7 th  to 5.5 - 9 th.

took photo of increased backlash contact pattern with load on drive side, not sure what its telling me, whether its improved or not, needs a more experienced eye to interpret.

1st pic shows spider gears and thicker shims

2nd pic shows contact pattern on drive with increased backlash

cheers Dave

48th +66 th shims.JPG

backlash + 2th 2.JPG

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Ian, 

Only changes I have made since it howled is to increase the pinion pre load and to move a 2thou shim from c/wheel side to other side to increase the backlash and reshim the spider gears

With c/wheel carrier  bolted in place it now takes a strong 20 inch /lb to spin the pinion.Feels nice and smooth but it did before.

I just hope now that, with the increased backlash, it doesn't clunk on take off as the backlash now is almost the same as when I first stripped the diff,and that was one of the reasons I did it ,but I think that was down to the worn spider gear shims.

Maybe its now time to box it back up fill it with oil and try running it with my electric drill, but the diff only howled above 30mph, don't know if my drill goes that fast.!

 

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3.5 to 6 thou .It was approx. 10 thou when I first stripped the diff.

says Dave, 

so what did ye shift, CW only, pin only, or byath!!

Answer=

 

 

ye say

the increased backlash, it doesn't clunk on take off as the backlash now is almost the same as when I first stripped the diff

So is this wid just CW shift, Pin shift,or both,

Answer =

 

Nee need t, put it all t,githa for running int drill,

the oil will quieten the  diff noises.

 

run it as it is, as bit of oil int bearings, an meb,e a wee bit on Pin, as it,ll distribute along the CW teeth.

 

if yer dril goes 3,000 rpms, then thats 60 ish + in  direct top gear 1-1 ratio int box

 

...Pete Cox recommends using a backlash of 3 to 6 thou ,

 

this is good info, BUTT,  but ev said it befoer,

it all depends on what the diff needs,

if its noisey at 4-6, an quiet at 12-14, then its gotta be the latter.

 

the patterns , look t,me spot on, try it  wid yer drill beofre fully assembling.

 

re side thrusts,

If its hard t,turn, then this is fine, it wont be efta a wee while.

butt, lock side shafts, an turn frae pin end, it,ll be easier.

 

 

{ Wee tip, Half shafts bolts, a thin 1/4 drive ex bar  will fit thru  the wols int stub axle,

this can then ev socket attached, and can then be tightened wid a T bar or ratchet,

this way its faster than a spanner,

ring spanna for last nip up only,!!  }

 

NOTE the edges oft teeth noo, they are dark all way up teeth,

nee shiney edges as like on yer original pics,

I did ask, but ye wer,nt s,sure aboot wot i was on aboot.

look at 2 nd pic, see shiney bits on extreem edges,  

esp on yan near the yella spot ont case.

re yella spot tooth, see ho the shiney bit is up the tooth,

this me tinks is cos it just wer,nt sit,n in a worn in spot,

thats a high point.

 

and this,n, see the shiney edges,

If it does wine a wee bit, its meb,e the best it can be got,

if it howls, then it just shows hoo hard it is t,get a quiet diff,

yer talking a few thou diff t,either mek it quiet, or noisey.

 

Gud luk

rgds M

 

 

 

 

 

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Hi Marcus

Reinstalled pinion with same size shim that was found when I first stripped the diff, I think it was 40thou standard size, the preload was then set and the pinion left at that .

All adjustments since have been made on the c/wheel shims.

I understand what you mean about the backlash, 4-6 thou is the ideal figure, but on a worn diff may be noisy, whilst an increased backlash may make it quieter, who knows.

Now I`ve got the contact pattern about right I`ll squirt a bit of oil in it and give it a run with my drill.

cheers Dave

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