Differentail Issue

[JochemsTR]

Hello,

after just 100 km....going from nearly 0 play to this.....any thoughts?

 

 

Jochem

Edited April 5, 2018 by JochemsTR

[graeme]

Jochem,

 

There are two thrust washers in the diff which can reduce this play, they may have broken up. Was the diff rebuilt 100km ago?

 

Thrust washers are Item 49 on this diagram. Different part no's depending on thickness.

 

https://www.moss-europe.co.uk/shop-by-model/triumph/tr5-6/clutch-transmission-drivetrain/axles-differentials/rear-axle-tr5-6.html

 

Cheers

Graeme

[JochemsTR]

Graeme,

yes the diff was rebuild in 2017...drove about 3.000 km....and all was fine.....this winter I changed the rear hubs (Dennis Vessey) and axles....checked play occasionally but after my two test drives I suddenly noticed this.

Since I am planning a big tour thru the frenchs alps in June, I do not want to assume any risk and I very likely have the diff inspected prior to this....

Jochem

[TriumphV8]

Besides No 49 there is also 47 that can cause play.

47 often is made from reinforced paper what I

immedeately swap to brass (CuSn12).

To be honest I also do that because I do not have all

different sizes from No 49 at hand and want to point

the play in direction that I can set it with the No 49s I have.

 

So it might be possible during overhaul the paper rings had

been changed, the proper copper rings 49 had not been availiable

and they did the best they could do with what they had at hand and

now the paper rings seated a little bit and the copper rings never had

been from perfect size.

 

The third position where play occurs is the CWP area

leading to a breaking after some time. The reason is a wrong setting.

 

Last area is the play between 53 and 46.

 

In most cases the play especially in the range shown above

does no harm but you have to decide.

 

I would drive and check from time to time.

[JochemsTR]

Hello Andreas,

since this play occurred so suddenly, I would want to open up the diff and find out whether trust washers and other rings are still ok. especially with the tour ahead. I would hate to call the towing company for something that could have been avoided easily. I know pos 47 reinforced paper was replaced with brass already.

Jochem

[RogerH]

Hi Folks,

I'm not a diff expert but wouldn't there normally be a small amount of play in this area.?

 

Perhaps after the rebuild it has free'd up from being a little tight.

 

Roger

[JochemsTR]

Hello Roger,

I agree, but this play is about 5-6mm versus 0-1mm in only 100 km....

Jochem

[BlueTR3A-5EKT]

Beware - There was a batch of soft yellow brass thrust washers in the market a while back - the 'customer wants metal' brigade failed to spot that soft yellow brass wears alarmingly quickly compared to the orig bronze or fibre items. Then again your issue may be elsewhere.

 

The fibre items I have found quite durable, if not as good as the orig bronze items.

PM me if you want some, I will see what I have in my differential rebuild stocks. I am downsizing all my rebuild spares stocks.

Peter W

[JochemsTR]

Hello Peter,

I appreciate the offer and I may take you up on it.

Hopefully the cause can be identified.

Jochem

[poolboy]

I notice the same thing following 2 rebuilds...practically zero backlash on the bench which increases within a few thousand miles to a certain amount then stops.

I could be wrong but I believe it can be attributed to the convex/concave or "dished" shape of the thrust washers finally conforming to the convex shape of the planet gears and concave housing.

Anyway, once it reaches that point of confirmation, if that what it is, the backlash seems to stabilize.

Edited April 5, 2018 by poolboy

[MostEasterlySteve]

Hi Folks,

I'm not a diff expert but wouldn't there normally be a small amount of play in this area.?

 

Perhaps after the rebuild it has free'd up from being a little tight.

 

Roger

 

I notice the same thing following 2 rebuilds...practically zero backlash on the bench which increases within a few thousand miles to a certain amount then stops.

I could be wrong but I believe it can be attributed to the convex/concave or "dished" shape of the thrust washers finally conforming to the convex shape of the planet gears and concave housing.

Anyway, once it reaches that point of confirmation, if that what it is, the backlash seems to stabilize.

 

I'm no expert either but at this stage I don't see anything to be too concerned about. Some backlash is normal from my (admittedly limited) experience. New mechanical components have to bed down after renewal or overhaul and changes do occur. I'd just drive it as much as possible before the big tour and keep an eye on it.

[GT6M]

a cupple of thingys t,consider

 

the cup weshers need t,be as TAF whenst new,or even 2nd hand if re used wid thicker side thrusts,

actually tap em in wid a wee punch, NOT just push em in.

reason, the diff case / carrier is no smoothe, its got wee ridges init.

so put em in t,spec, an in a few hundred miles they are as slack as owt, like yer showing us

 

{ think of a saws teeth, an put a bit of wood across it,

wood is only resting on high bits,

run it up,n doon the saw, an the teeth ev gone into the wood,}

 

this is wot happens wid yer cup weshers, they bed in, become slack, hence the play

a wee tip, put wee wols / indents int cups in 4-6 spots, this helps hold oil,

bit like yer thrusts in the G Box

 

use a really good oil, an change it every year,

crap oil, cheapo stuff, { an some expensive stuff } wear oot too fast if used for long times at high speed / loads

an get a magnet or 2 in thea, sump an fill plug { fill plug,n will collect moer sheite that the bottom one }

Oil is cheaper than diffs,!!!

 

M

[John L]

Is this a job that can be done with the unit still in the car, if you take the back cover off, can you get the pin out that holds the planet pin/shaft in place? Do you need to take the drive flanges off either side as well?

John

[poolboy]

I'm thinking it may be possible on a TR6 to do the job of replacing the TW's with the differential case still suspended by the front 2 mounts...but you will need to disconnect both the inner axle assemblies in order to remove the carrier for the planet gears.

 

Edited April 6, 2018 by poolboy

[dingle]

Is this a job that can be done with the unit still in the car, if you take the back cover off, can you get the pin out that holds the planet pin/shaft in place? Do you need to take the drive flanges off either side as well?

John

I don't think you can replace the thrust washers with the diff in the car. The pin that holds the planet pin in place is "trapped"by the ring gear, which must be removed. Even removing the rear cover with the diff in place would be challenging or impossible.

Of course, I have been known to be wrong.

Berry

[John McCormack]

I have recently noticed a bit of backlash in the diff evidenced by a light click when taking off and changing gears. It isn't too noticeable and can e easily missed.

 

I was under the car on Friday to check it and it has similar, maybe slightly more, movement as yours.

 

The backlash may have been there for awhile but it became noticeable when I fitted CV half shafts that removed all the other clunks and noises from the rear end.

 

My Triumph mechanic, an excellent tradesman who was Triumph trained and been a Triumph mechanic since the 60s, took it for a drive for the annual registration check and said it wasn't an issue. I rang my diff/gearbox people and they said not to worry about it unless the light click annoys me.

 

The mechanic is going to weld up a cracked diff mount later this month so while the diff is out I probably will get it attended to. A few hours job I am told.

Edited April 7, 2018 by John McCormack

[GT6M]

John a wee click is not good news,

generally its a pointer that a tooth or 2 es come adrift,

cos of the helix on the pinnion, it,ll easily cover one tooth off,even 2, but 3 it wont,

an 2 it generally will click

 

had it loadsa times, on me own and sent in items.

 

if it es, its a disaster waiting to happen,

 

get yer self a snake cam of flea bay or some other spot

bung it in , see wots wot inside for piece of mind , IF ye got a drain plug all the better, but fill hole will suffice