Planet gear shimming

[Tonyw]

Hi All,

I am rebuilding my diff unit as I had a clonk!! There was loads of play on the planet gears. The back lash on the crown and pinion is within spec and running in the right position.

The planet gears are very worn and as the bros have them on offer cheap I have bought new ones. I have also bought new thrust washers for the sun gears. My problem is that the shims I need for the planet gears to remove the back lash is about 28 thou and the smallest shims are about 40 thou!! How do I get around this? If I fit the old gears with 50 thou shims I have about 10 thou gap but it is a lot better than it was.

Does anyone know how I can get around the shim size problems??

Many thanks

Tony

[GT6 M]

thats cos ther a diff between Stag planet gears an TR / Salloons type
Stag type are slightly thinner, hence yer probs.

I hope ye no got the fibre type, if so, bin it, honest.

re shims, If ye can, fit the bigger thrusts if ye still got,m to the side gears,
and fit the biggest cup thrust ye can get into the smaller ones.

I mek me own up, but CW sells a good selectionee.

NOTE, wen putting new cups in, then get em as TAF, actually tap em into spot wid a wee drift.
Put em in, frae top,n bottom sides, tap em in a bit at atime, try an move the gear too wid a brass punch
this moves gear roond, so cup can be tapped in a bit moer

{ MEK sure that the side gears line up wid the holes on shaft before ye get the shims in, or ye,ll ev to tek em oot agen. }

reason, the diff cup bearing bits are no smoothe, they got wee ridges in em
thee,s wee ridges are high bits
they eat into a new cup thrust, so wot ye think is tight,ish at first, soon becomes v v slak

bung em ii TAF and then they wear to diff carrier wid in a few hundred miles
and come just right

ALL diff carriers have diff wear grooves, I got 3 olde cariers for patterns, all give diff wear ridges wen blued up


Wee tip,
get yer thrusts, byath types, and a 1/8th drill, and drill a wee indent into em,
not all the way thru, just enough t,cacth oil as a resovoir, bit like a gear box thrust bearing ont laygears.
doo this on byath sides and at diff angles to each side, so they no come thru, follow,!!

Ohh, use 80/140 gear oil, much better than the 80/90 stuff
AND, bung a drain plug init,wid a magnet
a magnet on filler plug too
it,ll catch moer sheite than the drain plug will

IMPORTANT, fill first wid a cheep oil, engine oil will doo,
and run fora while, bench run wid a drill will suffice
BUTT, alternat locking one side shaft wid some bolts

this will get the diff gears moving, /bedd,n in, so any bronze comes off, will get changed oot when ye drain it off

As bronze wont stik to yer magnets
be suprised wot come oot
can doo it int car, as they doo soon wear in

M

[flying farmer]

Rimmers do shims up to 70 thou in 2 thou increments for the planet gears.

I have found that sometimes the sun gear thrusts are ok, and it is just the planet thrusts that need replacing.

[Tonyw]

Thanks Neil, I checked rimmers and they start at 50 thou and I only need about 28 ? Unless they have some not listed which I doubt. Thanks for the response.

Tony

[robbo]

Give Chris Witor a ring. www.chriswitor.com I recently changed the thrusts in my diff and he supplied me with the sizes I needed genuin BL planet thrusts as well.
Cheers
Rob.

[Tonyw]

Give Chris Witor a ring. www.chriswitor.com I recently changed the thrusts in my diff and he supplied me with the sizes I needed genuin BL planet thrusts as well.
Cheers
Rob.

Hi Rob,

Thanks for the advice, I have spoken to Chris and we have sorted the problem. The new gears I have bought from the bros don't have the groove machined in them and you can't mix grooved and non grooved gears. This is why they won't set up correctly. He has advised me to shim the old gears up.

Thanks again.

Tony