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David Lacey
Frequent User
Username: dlacey

Post Number: 64
Registered: 11-2010
Posted on Saturday, 10 October, 2015 - 08:15 pm:   Edit PostDelete PostView Post/Check IP

Hi All,
I started a family trip to Thailand today, a 500km drive in SRH 4452, one of the last 4speed shadows. Last night I checked the fluids, gbox was clear reddish as always.

The journey went fine, cruising 60-70mph, no issues. Last 500m was a challenging ascent on an unmade road. The shadow climbed it ok, revving somewhat (no rev counter but I guess 2000rpm max).

After cooling I checked the fluids and the gearbox oil is black...Very black....not Brown. In the past when I have encountered burnt auto boxes the fluid is Brown.

So why would it go from clear/red to black in one day? Is black colour a normal failure mode?? Could it be contaminated with engine oil on the steep incline??
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David Gore
Moderator
Username: david_gore

Post Number: 1756
Registered: 4-2003
Posted on Saturday, 10 October, 2015 - 09:30 pm:   Edit PostDelete PostView Post/Check IP

David,

What does the oil smell like? AT fluid, engine oil or burnt.

If you put a couple of drops of the fluid from the dipstick onto a clean white paper towel, do you see any evidence of solid particles in the stains from the oil?

My guess is either overheating of the fluid due to a blocked/ineffective oil cooler or contamination from one or more disintegrating transmission clutch plates.

If there was engine oil contamination through the rear engine oil seal, I would have expected evidence of engine oil dripping from the bell housing between the engine and transmission.
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David Lacey
Frequent User
Username: dlacey

Post Number: 65
Registered: 11-2010
Posted on Saturday, 10 October, 2015 - 09:35 pm:   Edit PostDelete PostView Post/Check IP

All,
Now it's cooler and clearer, I can see my panic is overstated....Yes the fluid is black, but ony on the dipstick! There's something tar-like in the dipstick tube, which when hot is contaminating the stick (also the gbox to some extent)..didn't see it when the engine not realky hot...
I see now the stick is black but the fluid itself still clear....
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richard george yeaman
Grand Master
Username: richyrich

Post Number: 363
Registered: 4-2012
Posted on Sunday, 11 October, 2015 - 12:13 am:   Edit PostDelete PostView Post/Check IP

Hi go and get a cold beer and have a good holiday and enjoy yourself.

Richard.
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David Lacey
Frequent User
Username: dlacey

Post Number: 66
Registered: 11-2010
Posted on Sunday, 11 October, 2015 - 08:15 pm:   Edit PostDelete PostView Post/Check IP

Hi Guys,

Today with it cold I took a close look. There's something coating the inside of the filler tube, when cold it's hard, doesn't scrape off...but I guess yesterday it got very hot n started softening. The fluid is clear...not sure what that black is...I will keep a close eye and work out what to do when I get home. Thanks for the advice.

The beer certainly worked...
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gordon le feuvre
Frequent User
Username: triumph

Post Number: 88
Registered: 7-2012
Posted on Monday, 12 October, 2015 - 02:28 am:   Edit PostDelete PostView Post/Check IP

As David Gore says burnt fluid has a very strong smell far above normal oil smell. There is NO mechanical connection between engine oil and transmission. Do not stress, all Shadows came with vented Taurus cover as Clouds used to overheat in traffic, and venting the cover was a service bulletin fix carried over to Shadow as standard