D200 Transaxle Parking Brake Pawl

[BMW1 42]

We are putting this transaxle back together and noticed the parking brake pawl seems to be in bad shape.

The part is NLA but someone said it could be mig welded and filed.

 

I have never seen what it should look like. Is there supposed to be a "notch" in the pawls or should the weld be built up and then filed so there is no "notch"?

 

[daveoman1966 3,752]

This is what happens when the parking brake is engaged when the tractor is still moving.  This part is also NLA from Toro/WH.  Take it to a PROFESSIONAL welder and build up the 3 teeth,, restoring them to original shape.  NOTE... the metal filings from the Parkling Pawl have, no doubt, found their way into the hydro oil and throughout the system.  Those tiny filings will scratch / scar the soft BRASS components of the Hydro pump and other internals...not just of the Hyd Pump, but also of the Hyd Motor that is bolted to the transaxle.   I would HIGHLY urge you to pull and inspect the HYDRO MOTOR, particularly the 9 soft brass PISTON SLIPPERS.  If you see that they look like these, you have a lot more to do than just refurbishing this parking pawl.  If the 9 brass faces of these piston slippers are smooth...without nicks or gouges, you are LUCKY.  Note...if these are damaged, the Hyd Pump like-kind components will also be damaged.   These parts can be saved....I've rebuilt a couple dozen of them.

[BMW1 42]

What is the original shape of the pawl?  Are the "notches" supposed to be there or should it be continuous metal with no notch?

 

We found most of the metal pieces in or near the strainer.  Why wouldn't the filter catch any other filings?

 

We got this tractor from someone else knowing there were transaxle problems.

 

I will look at the slippers.  If they are scratched, how does one fix them? are new ones available or do you use 400 grit sandpaper on a piece of glass?

[Sarge 3,463]

No, those notches in the pawl teeth do not belong that way - they need to be welded up and reground. Not an easy job and the welder must select the correct filler metal. I prefer to TIG weld them and use ER80SD2 on those - it is a lot tougher than 70 series filler and blends very well with the base material. Very fine particles can get through that screen and damage the slippers in both the pump and hydro motors - as well as the charge pump side of the main pump behind the engine. That pickup screen is generally not all that tight against it's sealing ring - some even fall off. These issues lead to a weak pump and motor - or total failure.  There are limits and specs about how much can be taken off those slippers facings by a total length limit - after that point, they need to be replaced as an assembly. There are suppliers out there that have the parts to fix the Sundstrand, totally worth the effort in my opinion due to its brute strength. Yes, you can face them off with a piece of glass and 320, then 400 grit and higher - the smoother the surface, the better. The matching faces in the pump and motor must also be faced - this has been outlined by Dave and others several times - do a search.

 

LJ Fluid Power in Michigan has a lot of the parts to fit this series pump in stock as well as gaskets.

 

Sarge

[daveoman1966 3,752]

Here are pics of the internal of the Sundstrand Hyd MOTOR.  Examine all of these and use a surface plate with 220  400  800 grit paper progressively ...by hand, in a wax-on-wax-off pattern to achieve a near-mirror finish removing as little material as possible. Also ensure the integrity of the bearing and O-ring seal. 

NOTE... the components here are near identical to the Hyd PUMP and it will probably need attention as well.  I havfe pics of the pump internals...before and after...if wanted.