towing lubrication

[Pete Lewis]

here's a shot of a single rail mainshaft which shows signs of lack of lubrication on the first gear journal  due to amounts of towing

 

many dont realise when being towed with the engine off the  mainshaft has to turn inside stationery gear sets 

 

there is no splash lubrication which  most boxes  rely and partial seizure is quite common and can happen very quickly

 

so if towing any car a    even a short distance  it needs the engine idling or the clutch held down and in  a gear  to get some lubrication

 

splashed around .

 

Pete

[dave.vitesse]

Good point Pete, The five speed TR7 is worst as this gearbox has an integral oil pump driven off the input shaft. If you tow the gears go around but there's no oil circulating.

 

Dave. 

[Unkel Kunkel]

Very interesting , Pete.

I for one, was not aware of this - presumably this applies to other vehicles too?

Is there a distance for which it is reasonble to tow?

So, I suppose could remove the prop shaft or raise rear wheels?

[Pete Lewis]

One reason why recoverd cars are on spectacle lifts or trucks on suspended tow

Many of our trucks had a tap in the clutch hydraulics to lock the clutch down , engage a gear before any tow,. It amazes me when you see cars on a A frame tow behind camper vans that thinngs dont seize up

they tow for miles

 

If you keep rotating a shaft inside static gear bushes or bearing they will ultimately run them dry

 

automatics with a input driven oil pump could be a right disaster

 

some have oil pumps on the output which would be ok

 

but any box splash feed is asking for trouble as there is no splash when towing

 

if that helps

 

pete

[rogerguzzi]

One reason why recoverd cars are on spectacle lifts or trucks on suspended tow

Many of our trucks had a tap in the clutch hydraulics to lock the clutch down , engage a gear before any tow,. It amazes me when you see cars on a A frame tow behind camper vans that thinngs dont seize up

they tow for miles

 

If you keep rotating a shaft inside static gear bushes or bearing they will ultimately run them dry

 

automatics with a input driven oil pump could be a right disaster

 

some have oil pumps on the output which would be ok

 

but any box splash feed is asking for trouble as there is no splash when towing

 

if that helps

 

pete

Hello Pete

                But not a problem with MOST moderns (front wheel drive?)

 

Roger

[Pete Lewis]

The problems within the gearbox apply whatever end does the driving

 

unless the engine is turning the input shaft or the things in gear turning the inards

you still have a dry mainshaft running inside stationary gear sets

Once the oil is spun out .. its got no lubrication

 

pete

[rogerguzzi]

Hello Pete

Me being thick again and reading post correctly! I was thinking of the spectacle type not A frame (must remember to engage brain before opening mouth etc!)

 

Roger

 

Ps my excuse is had an annual hair cut today and I am like Sampson only in the head?

[Pete Lewis]

Delilah is out on the loose watch out

 

pete