GT 14 with 90-2070 Hydrogear

[BurtB 100]

Tractor is MN: 1-0502 7 SN: 878267. Engine is MN: K321S Spec: 60149c, SN: 4050020. Transmission is MN: 90-2070 SN: 01-LA 32074. See nameplate picture for the trans.

 

I see an old thread with a GT 14, same model number, that had this Hydrogear. https://www.wheelhorseforum.com/topic/70887-gt-14-transaxle-questions-and-hello/

 

So either not all GT 14s came with 90-2062  or we both had replacements that were the same the model. I've searched on 90-2070 but not finding much. Does anyone know anything about this transmission?

 

Per @953 nut , made a dolly to remove the whole thing safely. I can get better pics if needed.

 

I have pulled all the bolts to separate the pump from the gearbox. There are two long bolts at the top that are still in it with the nuts on by a few threads. There is what looks like a dowel pin that connects the gear box to the motor housing (green arrow in picture points to it, you can just see it).

 

I've tried gentle smacks with a mallet, including under the pump with an oak stick against the back of the motor housing casting. I've also tried a little prying near where the dowel pin is. I haven't gotten it to budge. Dowel pin lacks threaded hole for a slide hammer. I don't see a threaded hole for a jack screw. Any recommendations for getting this loose without damage?

[953 nut 61,650]

Though the GT-14s all are listed as having the 90-2062 Sundstrand hydro and Charger, Electro, and Bronco are listed as leaving the factory with the Sundstrand 90-2046. The difference between these two models is the number of teeth on the output gear of the hydraulic motor that is coupled to the Wheel Horse transaxle. Other manufacturers also used Sundstrand transmissions which all used the same pump/transmission (the part in the finned aluminum housing) and that was probably the source of the 90-2070 pump/transmission which bolts directly to the Wheel Horse configuration.

 

You shouldn.t have to separate the hydraulic motor as shown in your second photo, just remove the casting it bolts to unless you feel a need to take "EVERYTHING" apart. If you do go in there be very clean and cautious. The mating surfaces are machined to tight tolerances and any scratches or other marks will ruin it. If you open it this is all you would see.

@daveoman1966 has a lot of good information in the thread you linked to, he is the Sundstrand Go To man on this site.

Edited October 6 by 953 nut

[BurtB 100]

I've read Dave's writeup on reworking these, have it printed out, and am following it. Truly helpful and awesome  But, I may have misunderstood.

 

I thought the motor housing had to come off as well as the finned pump housing.

 

(Still don't understand how these things really work.) My limited understanding is that the aluminum finned pump produces hydraulic pressure. Pressure turns a hydraulic motor in the casting that connects the pump to the transaxle gear box. That same connecting casting has ports to power the lift cylinder and accessories. The motor control is on the front of the finned housing.

 

You're saying I only need to remove the four bolts that hold the finned aluminum housing to the cast motor housing?

[pfrederi 18,866]

No.. Have you looked at page 52 and 53 of the Sunstrand manual it tells in detail how to remove the hydro assembly from the transsaxle.  There should be no need to separate the pump and the motor.

\

3 bolts and two nuts...

 

Edited October 6 by pfrederi

[BurtB 100]

I'd only skimmed it and clearly didn't read closely enough. I'll be digging into that manual tomorrow. Thank you much!

[daveoman1966 3,854]

To be clear---   The Sundstrand Piston-to-Piston models--90-1136, 1137 ,1140, 1173 have a Hyd MOTOR attached to the end cap of the Hyd PUMP. The hyd pump and motor have nearly identical internals with a cylinder block with 9 pistons each.  If you overhaul the hyd PUMP, I highly recommend doing the same for the Hyd MOTOR as they share circulating fluid.

Conversely, the Sundstrand Hydrogear is a much different configuration having a cylinder4 block and 9 pistons ONLY in the Hy PUMP.  I have made available .pdf files to refurb both styles...the Hydrogear format and the Pistons-to-Piston style.  Here are a couple pics showing the differences. First pic is Piston-to-Piston---  Second is a Hudrogear.  

[BurtB 100]

@pfrederi and @daveoman1966

 

I'm officially cornfuzzled.

 

Per page 53 of the above manual: "Remove three cap screws and two nuts which secure the Hydrogear to the transaxle (Fig. 94). Slide the Hydrogear rearward to disengage the cam block and lift the assembly off the transaxle (Fig. 95)." 

 

I've got the bolts out and the nuts off with the bolts they're on also loose and removable. It's not sliding or lifting. I've got the nuts back on by a few threads right now to keep it from falling should it magically come loose.

 

I've tried sliding, pulling, tapping with brass and rawhide hammer, tapping the back of the casting with mallet and wood, pry bar, cussing, and mean looks. I haven't smacked it super hard. I do have a black cat and can use her and some candles if necessary.

 

There is what looks like the end of a dowel pin in the lower casting below the motor, I don't think it's a locating spot face. I can't find it in the exploded drawing. Pic attched, blue arrow pointing at it.

 

What am I doing wrong or do I just need to hit it harder?

[pfrederi 18,866]

I think that is just something in the casting.  Here is a pic of the Hydro gear on My GT14.  I think I see some signs of a casting thing about where yours is .  it is not an aligning pin .  you have the three bolts out and the nuts off the 2 bolts that go through the transaxle case.  There is nothing else...except there is a big gasket with a lot of surface area that has been clamped on her for 50 years.  I have used a chisel in the past to free up the motor and also split the trans axle case.  

 

 

[daveoman1966 3,854]

I'm with pfrederi on this---there is no 'alignment pin'---  just the old gasket super-stuck.  I like the black cat idea, but a flat putty knife blade might work better.  Find a convenient spot and tap the end of it into the gap to split it apart.  NOTE---  I have that gasket on Ebay--  OEM # 5955.  $20   eBay item number:136504776861

 

[BurtB 100]

That's more surface area on the gasket than I realized. I haven't hit or pried hard enough to pop a petrified gasket that large loose. (Probably mar the casting pretty bad if I did, might even crack it.)

 

I'll be tapping in a putty knife tomorrow and hopefully get it loose.

 

I'm guessing what I thought was a dowel actually is a spot face. Might be from cleaning up a sprue given the lump present on pfrederi's. It might be a plug used to save a casting if there was a void at the sprue. I'll take pics when I get it off.

 

Better safe than sorry, I guess. I tend not to go all gorrilla on something mechanical until I know what I'm doing.

 

Thank y'all very much for the advice!

[953 nut 61,650]

1 hour ago, BurtB said:

putty knife tomorrow and hopefully get it loose.

A couple of old sacrificial wood chisels tapped in at the widest opening you can find will get it going. Be prepared to move them around a bit to pop it loose.

[BurtB 100]

Okay, got it off. Thank y'all for the help! Putty knife wasn't enough and had to use wood chisels per @953 nut. I've got some small mars that will have to be stoned off but no biggie. That gasket was really on there, I had to smack the snot out of it to get it to pop.

 

So the weird spot I've been looking at is a spot face, there's nothing on the other side of the casting. Pictures attached.

 

Looking inside the transaxle, I can see a little light wear on the gears but nothing I'm worried about. When I spin the axle by hand, I can feel an expected amount of cogging. I've got the transaxle opening covered with a rag and am going to leave it alone other than cleaning the magnet filter basket.

 

Next up, I'll start opening ports, replacing orings, dissect the pump, get my surface plate out and emery paper. 

 

I'll take pics of surface plate and emery paper and how I figure eight resurface the pistons. Used to run and maintain a waterjet with a servopump that did 66,000 psi (fluids actually do compress if you get pressure high enough).

 

Magnet basket has filings but I don't see any chunks. It's about what I expect for gears this old. Have a closeup of it, please let me know if y'all don't like the filings.

 

 

[953 nut 61,650]

2 hours ago, BurtB said:

So the weird spot I've been looking at is a spot face, there's nothing on the other side of the casting. Pictures attached.

2 hours ago, BurtB said:

got it off.                                            

 

That is your debris filter, pull it out and clean it for reuse.

2 hours ago, BurtB said:

 

Magnet basket has filings

Those are likely the remains of the parking brake, tractor has to be at a full stop to apply the brake. It can be repaired by welding several passes on the old one and smoothing it out with a file.