dip stick dysfunction

[Sarge 3,463]

Wow , one is a fluke , but breaking 3 warrants splitting that case - something has to be amiss . I'd seriously wonder if the dipstick tube is bent or something odd like that - there has to be a cause .

Sarge

[tommyg 152]

Technically, it's been two. But it will be the third dipstick I've had in there. The first was a case of a bent filler tube. So I figured it was an obvious reason. But the second has no good reason that I can see.

[gwest_ca-(File Mod) 11,102]

Is it possible the dipstick could vibrate enough for the end to catch on one of the differential bolts? Lots of room for it to do that.

Since the stick is already short I would add some zig-jags (-'\/\/\/'-) just shy of the tube diameter to what is left of it to keep bottom of the stick centered. Then add a piece to the bottom to restore the original length. Nothing to lose.

 

Garry

 

 

[tommyg 152]

I don't think I want to risk adding anything to the dipstick. The furthest it can deflect would be determined by the diameter of the filler pipe that secures it. But one thought I had was to find a pipe maybe an inch or so longer than the stock pipe and thread it so that it seats an inch or so deeper into the transmission case. That way, the dipstick could not be deflected quite so much and might be all I need to keep this from happening again. In the meantime, I'm still trying to retrieve the piece inside. Unfortunately, the inspection camera can only be manipulated so far, so much of the case is out of camera view. I'm going to pick up a flexible magnetic retriever tool this evening and hope I luck out. I can go in through the filler tube as well as the drain hole. 

[pfrederi 17,895]

Tommy:  I was thinking 9Always dangerous)   Why not bend the dip stick away from the handle side and then insert it with the handle pointing to the center of the tranny (Narrow edge forward bend towards the outside of the case.  There is nothing moving out there.  assuming the rubber gasket at the top of the stick is in good shape and seats tight I doubt the dipstick wiggles around that much that it would hit anything.  The break on you stick looks like it was clean and hit on the wide side.

[tommyg 152]

Taking a close look at the broken dipstick, the slight curve near the break would suggest that it was broken when I was in reverse. I'm thinking I would have had the hadle pointed toward the wheel. Are you suggesting pointing the handle the other direction or more with the centerline of the tractor? I'm not sure I'm a fan of bending it at all in case it was ever inserted in a different direction. But I get what you're saying. I might try and rig up a way to insert the inspection camera the exact depth the dipstick would extend. Then actually start it up and move a few revolutions forward and backward to see if there's anything else I'm missing. I can disconnect the viewing screen from the camera itself and just place it in my lap since it's wireless. At very least, it might be the first view of what happens inside your hydro when in operation!

[pfrederi 17,895]

Mine was a "not tear it apart" fix and yes you would have to ensure the dipstick was always inserted the right way so that the bend would move it away from the differential.

[tommyg 152]

After about 20  minutes of "searching" with a flexible magnetic retriever tool, I caught a glimpse of the broken dipstick with the inspection camera. Took me another 5 minutes or so to fish it out, but it's out. Looking at the break, I'd guess that thing got snatched up in the differential somehow. It was a clean "snap". Probably bent it 90 degrees before it broke. Scratched my head on a solution so that it never happens again and came up with a simple one in the third pic. Whenever I need to check the transmission oil, I'll just unscrew the cap off the pipe, grab the dipstick and dip it in, then replace the cap. I might see if I can find a way to stow the dipstick on the tractor itself so it's always handy. You guys don't think there's a pressure issue with the cap screwed on do you?

 

 

 

 

Edited March 15, 2017 by tommyg

[WHX?? 49,189]

Good idea Tommy, would still be nice to know but beats running the broken off piece through  a diff. Nice camera work!

[Sarge 3,463]

The dipstick acts also as a vent - it may pressurize the housing as it heats up when working and possibly cause leaks or a blown seal .

Sarge

[tommyg 152]

That's what I was worried about. Perhaps if I drilled a small hole in the cap? Of course, I don't want dirt to get inside. 

[oldredrider 2,549]

Just snip the broken dip stick off and use the upper portion to plug the fill pipe.

[tommyg 152]

2 hours ago, oldredrider said:

Just snip the broken dip stick off and use the upper portion to plug the fill pipe.

 

Someone put their thinking cap on. Thanks.

[pfrederi 17,895]

The cap seals pretty tight.  Think about the other older sundstrands...they had the dipstick as part of a pipe plug the screwed in tight.  that isn't venting.  There is a lot of air space in the transaxle to handle any expansion contraction of the fluid

 

I was looking at an 8 speed that i just opened up it has a hard plastic sleeve to encase the dipstick it sticks down about 3 inches into the transaxle   (#45)

Edited March 15, 2017 by pfrederi

[evanloock 221]

There is a small sintered metal piece that is part of the square head of the threaded dipstick used on the Sundstrand trans.  I assume this allows some venting, but it couldn't be much.  I pushed one of these sintered pieces out of a spare dipstick I had and it was the size/shape of a Zippo flint.  Can't think of any other function it would have other than allowing for pressure to escape w/o allowing contaminants into the trans case.

[tommyg 152]

8 hours ago, pfrederi said:

I was looking at an 8 speed that i just opened up it has a hard plastic sleeve to encase the dipstick it sticks down about 3 inches into the transaxle   (#45)

 

 

Actually, I kind of made a prototype of that design using the original tube. I inserted a 1/2" piece of plastic "Pex" tubing into the end of the metal dipstick tube which extended down past the differential. The only problem was that it also narrowed the tube to the point where I could not get oil into the transmission without some sort of air escape. Perhaps I over compensated for the length of the tube, though. Might try that idea again with a shorter piece of plastic.

 

[jrc0528 20]

Tommy,

 

Try drilling a 3/16 or 1/4 hole through the side of the PEX just under the metal tube.  This should allow the air to vent from the case back into the tube so you can fill normally.

[tommyg 152]

Well, here's what I ended up with. The plastic tube extends past the end of the dipstick by about an inch. I drilled a 1/4" hole hoping that will act as a vent when it comes time to fill it. Keeping my fingers crossed that this resolves the issue.