Re: [DML] Re: Fw: tricky -tranny

["content22207" <brobertson@xxxx>]

Exactly what I said -- "hydraulic couplings". 

As for "opening the filter", assume you're talking about DeLo
automatic. Most traditional filters simply overlay pump inlet. Like
miniature furnace filters -- nothing to open.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "David Teitelbaum" <jtrealty@xxxx> wrote:
> The friction plates (clutch discs) in an automatic transmission aren't
> all that much different then a manual "wet" clutch. Most people are
> familiar with the "dry" type as in most cars but "wet" ones are in
> heavy equipment like trucks. In an automatic transmission the plates
> are cooled and lubricated by the trans fluid. The trans fluid also is
> used in the cltch pack pistons to apply pressure to the plates to
> engage them. Without enough pressure the clutches slip. In an
> automatic the plates are not meant to be slipped anywhere near as much
> as in a manual transmission. The torque converter is there for that.
> In an automatic the clutches are really more like on-off devices
> leaving the torque converter to match the engine speed with the
> transmission, not the clutch packs. In any case the amount of friction
> materiel that is in the pan is a function of mileage, if there is a
> lot at low mileage you are in trouble. Also if there is any
> significant amount of metal that is bad news, especially if it is
> magnetic. As the trans wears inside you will get brass-bronze from the
> bearings and thrust washers but you should not see cast iron,
> alumiunum, or steel from the case or the gears. This is why it is
> important to open the filter and actually see what is going on inside.
> As for the fluid, if it smells burnt it has lost it's lubricating
> properties from being overheated. This happens when the clutches slip
> and burden the fluid with particles of friction materiel and break
> down the fluid from the heat. It won't lose it's capability as a
> hydralic fluid, ie: it is still incompressable, but it can't lubricate
> the bearing surfaces properly so now you start a cascading failure
> ruining the "hard parts" like gears and housings. An external sign is
> leaking seals. When the fluid is overburdened with particles it is
> like grit and that grit eats out the seals resulting in fluid leaks.
> When you see this it is already too late. Replacing the seals now is
> like rearranging the deck chairs on the Titanic. The bottom line is
> NEVER DRIVE AN AUTOMATIC TRANSMISSION THAT SLIPS. You will cause MAJOR
> (read expensive) internal damage. This advice is good for any
> automatic transmission, not only in Deloreans.
> David Teitelbaum
> vin 10757
> 
> 
> 
> --- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> wrote:
> > Clutch discs in automatic transmission totally different than friction
> > plate in manual. Are not supposed to touch anything. Transmission
> > fluid itself forms coupling. That's why it's so important to keep
> > clean, unburned (like brake fluid, once you overheat it loses
> > hydraulic properties), not foamy (don't overfill), etc. If you lose
> > hydraulic coupling, discs will wear out very quickly. Don't know about
> > DeLo tranny, but nearly all of its contemporaries can drop pan and
> > look for collecting disc debris. If it's there, get ready to rebuild.
> > 
> > Bill Robertson
> > #5939