Sundstrand Motion Control Issue

[pfrederi 17,893]

I have overhauled a hydro gear...resurfaced the slippers and the base of the piston block (hydrogears do not have a replaceable valve plate..also hope I didn't take too much off the base of the piston block).  Hooked it up to an electric motor for a test and it worked OK but i had a leak around the swash plate shaft.  I need to get in there to replace the  O ring. To do that you have to pull the cam arm follower #53.  Drove out the roll pin but the arm will not come off the shaft.  Soaked it with various juices, no joy.  There isn't enough room to use a flange puller and even my smallest 2 jaw puller hooks won't fit under it.  Thought I could pull it off in one step with the housing (#49).  Problem, these are early hydro gears, they used  three 12pt bolts and you can't get a socket wrench on one as it is behind the arm.  I have a parts hydro gear and of course the arm slide right off.  I am getting ready to use a carbide cutter and break the one that is stuck...but I hate to break things that aren't around any more.

 

Any Ideas /tips???

Edited January 19, 2018 by pfrederi

[Ed Kennell 38,703]

I'm guessing it's the top bolt that is covered by the arm.    Can you get in there and file flats on the head and use an open end wrench?

Edited January 19, 2018 by Ed Kennell

[pfrederi 17,893]

Bolt head sits in a recess with out much clearance around it

[Jerry77 1,218]

Dremel or very fine  small burr  ?  drill out and easy out?? you would own new bolts from the junk one  - I am probably not looking at it right..........hope you get it.....

[953 nut 55,860]

I'm sure this seemed so simple to the Engineers who designed it five decades ago. Perhaps @meadowfield or @daveoman1966 has a solution, they seem to be the Hydro Gear experts here.

[Aldon 4,827]

I had this happen and used a steel chisel to get the cam started. 

 

Let me knwo now if you need. Any spare parts as I have a couple sitting in pieces on my basement bench.

[Jerry77 1,218]

Ok, one more dumb comment:  don't know anything about hydros, but looks like a pinpoint tip for your brazing troch turned low and slightly heat the cam arm follower would allow it to come off  the shaft - shouldn't take much heat, but again I don't know what that would do to the surrounding stuff....

[Ed Kennell 38,703]

1 hour ago, Aldon said:

 used a steel chisel to get the cam started

   I like that idea.  Maybe two chisels or custom made wedges. One driven tight on each side of the lever, then tap on the end of the shaft.

[JoeM 7,874]

Propane torch a little heat may be the trick.

If I remember, the cam housing is aluminum, careful on how much you pry on it, I cracked one once removing a rear end.

[Sarge 3,463]

The last time I pulled one apart to replace the seal and try to service the piston block I had the same problem - that arm was stuck tight and basically rust welded to the shaft. I ended up having to use a welding tip on the torch and some paraffin wax to help get it apart. It's tricky not to heat that aluminum casting and that part is very brittle, broke two of them in the past just trying to knock out the roll pin in the arm. I just heated the whole bottom portion of the arm just enough to swell it a bit, applied the wax at the joint and allowed it to cool for about 30 seconds - arm slid right off. Heating it did cook out the o-ring completely - it came out as dust but it was getting replaced anyway.

 

If I remember right, didn't someone come up with a better way of sealing this portion with an oil seal instead of the o-ring ??

 

Sarge

[pfrederi 17,893]

Thank you all for the ideas.  i have tried the propane torch.  May give the oxy / acetylene a go.  Also tried the chisel but chickened out as i didn't want to break the surrounding housing. I can see why WH switched to allen head bolts later.  At least with a ball end allen wrench I could probably get the bolts out and then try a flange puller to get the whole unit pulled off.    Also figured out I don't have the 12pt 1/4" socket I need.  Have one coming...just when you think you have about all the wrenches and stuff you need....

[Sarge 3,463]

There are some box ended ignition wrenches that the 12pt end will fit behind that arm since they are thinner - but most aren't strong enough to break the bolt loose. I got 2 out of 3 on the last one and that's when the torch came out - at that point it irritated me enough to get what it deserved. After all the aggravation with that pump - upon further inspection the stupid swash plate ring and whole piston block was cracked somehow - never did figure out how the heck that happened but the pump was toast at that point - it destroyed the housing as well. That was the original rear axle/pump on the 1277, ended up swapping in the whole assembly from an 876 auto that still lives today - strong enough to break the frame more than once, too.

 

Sarge

[R. L. Addison 299]

I think the last one I had like that there was enough room on the shaft to drive the "rooted" arm in toward the diecast housing and broke it loose after cleaning the shaft as well as I could. If it will move at all, it can be worked a little bit and then light taps should move the shaft in the arm, without damaging the case. Best I remember there was not much room, so it required all the patience I could muster.

[pfrederi 17,893]

SUCCESS!!!!  The arm was about  1/16" out on the shaft.  Used r.l. Addison's idea and wacked it in.  moved back flush. Nothing really exposed enough to clean up but used more bug juice and a chisel to move it back to where i started.. and there it stopped..  About 45 minutes of differing wedges that moved it out a tad, driving it back and repeat.  Damn thing held on until it had come out over  2/3rds of the way off!!  Finally got an old battery clamp puller to fit in and victory!!!

 

 

Thank you all!!!

[Ed Kennell 38,703]

    

[953 nut 55,860]

                                    

[Sarge 3,463]

I forgot - the last one I had to pull was done with a small, 2-jaw puller that my Dad had in his old tool box. It looks to be a very heavy duty version of the battery puller but I suspect it's one designed for wiper arms on older cars that used those infernal tapered/splined shafts - the arms always got very stuck on those things and it was easy to break the drive shafts off. That puller has tiny arms that will fit into the worst places - I've used it quite a lot and have yet to break it. I'll have to dig it out again and see if there's any brand marking or part number - it may be an original Mopar tool since Dad worked for Chrysler for so many years.

 

That shaft/arm has about a .005" clearance - you'd think the dumb thing would come off easier but they sure don't, glad you won the battle without breaking the housing.

 

Sarge

[pfrederi 17,893]

Set up a test system.  So far so good no leaks.  Really can't evaluate power I don't have a larger pulley for my electric motor.  Probably tuning the pump at only 1000 rpm.  This is really a spare unit to have if one of my workers has a problem.  The slippers and piston block seemed to clean up nicely so hope she works in real life.

 

see movie after picture

 

Again appreciate all the help in getting the control arm off.. 

 

 

 

MVI_0160.AVI

Edited January 25, 2018 by pfrederi

[Sarge 3,463]

That's a great idea there, I've wanted to set up a test stand of sorts to test dead tractors and the Sundstrand pumps since most were neglected to an early death - just like to build a plate that can bolt to the trans, spring loaded tension arm and an electric motor...just at least enough to spin them up to rpm's and test for full function/pressure/noises. I've tried before to use a drill motor to spin those pumps, but none will give it enough rpm's and torque to fully test the pumps - it does take a fair amount of horsepower to even think of turning that Sundstrand unit. Thought I was going to fry my 36v Bosch industrial drill in high gear testing the D's pump system and priming before I put the engine back in place last time...not to mention it about broke both wrists when that thing finally primed itself.

 

Sarge

[Ed Kennell 38,703]

22 hours ago, pfrederi said:

  Really can't evaluate power

MVI_0160.AVI

 

It wouldn't take much to make your test rig a true dyno Paul.      I tested a Sundstrand once by ratchet strapping it to  a 6x6 support and driving it with another tractor PTO.

 

With the hubs in place, I locked one axle with an arm to the beam and measured the torque with a spring scale on a torque arm bolted to the other hub.

Sorry I never got a pic of that rig.