312 Hydro

[ep103 0]

Hello: I am new to the forum, I am working on a 312 Hydro that has been sitting for a few years, I think the fluid has leaked from the hydro unit, because when the lever is moved to the forward position the tractor will leap and buck, ( kinda makes me think of bull riding ). Is the hydro pump seperate from the transaxle, or does the oil in the transaxle also supply the hydro pump, the transaxle is showing full on the dipstci, and I have the rear cover off, and I see no way to add oil to the hydro pump..Thanks in advance for all your help.. Ed

[oldredrider 2,547]

First, is your tractor a 312H or 312A. They have different transmissions.

[ep103 0]

I am not sure how to tell, it says Toro Wheel Horse Classic, the tail end of the Id. number is missing, but what I have is 3112KE0, thank you for the reply..

[daveoman1966 3,611]

Toro shows it as a 312-H.  If the dipstick reads 'full', why would you want to add fluid?

 

Model Number 31-12KE01 Model Year 1990 Serial # None-None Product Name 312-H Garden Tractor Product Brand Wheel Horse Product Type Riding Products Product Series Garden Tractor, 3/4/500, C, GT Chassis Type N/A Swath Deck Optional Discharge Deck Optional Safety System N/A Engine/Motor Manufacturer Kohler Engine/Motor Model # M12S-471527 Engine/Motor Size 12 hp Engine/Motor Type 4 Cycle Engine Starter Electric Traction Type N/A Transmission Manufacturer Eaton Transmission Model # 1100-032 Transmission Speed Infinitely Variable Transmission Type Hydrostatic

[312Hydro 473]

Hi Ed. If you move the lever gradually, does it start out slowly? Speed is dependent on how far forward the lever is moved.You might check the cam and linkage to to be sure it is adjusted properly.Also check the filter to be sure it does not have a check valve in it. Some automotive replacement filters do. Just a few items to get you started. The manuals are in the files section too.

[gwest_ca-(File Mod) 10,499]

Here is the operator manual

 

Garry

[ep103 0]

Dave L, this is the question, I am asking because, I have read on other sites, the hydro pump is seperate from the transaxle, and the fluids are not the same, they said hydro will hold 3/4 of a quart and 20 weight is what is recommended, whereas the transaxle will use 10W30 oil. Again my question on this unit if the dipstick for the transaxle is ok, then am I to assume this also means the hydro is Ok, and Rich even easing the shift lever forward it will jump and pull a wheelie. The reason I suspected the hydro pump being seperate and possibly low on oil is I had a John Deere 317 that did the same thing then I relized the vlave was turned to allow for pushing, after the valve was opened up and fluid running again it did fine. But I am at a total loss here, and respect all your opinions..

[can whlvr 991]

I have a 90 312-h,it is a good tractor,check the area where the frame bolts to the rear end,check for a cracked plate,them id look at the linkage and make sure its operating smooth,maybe someone tightened the slider too much

[daveoman1966 3,611]

If the motion lever moves very easily, there MAY be a broken part of the control mechanism.  This is a common ailment of C series Sundstrand autos and the failure part is similar to the 312-H.  Looking at item #13 in this schematic, there is a samll tab on the end of it with a hole in it. Part 14 is a small bolt that secures the tab to the side of the hoodstand to keep the #13 shaft from turning. 

 

If that tab is broken (common), the shaft will have absolutely no resistance and allow the motion lever to almost slop around at will.  This MAY be the problem and is at least worth looking at.   

 

I don't have a pic of the 312-H, but here is a pic of a C-160 showing the location of the possible culprit.    

[daveoman1966 3,611]

The 312-H s/b equipped with an Eaton 1100-32 hydro trans.  It uses 10w30 or 10w40 oil...5 qts to refill.  The hydro pump supplies power to the trans and the hyd lift.  

A someone else mentioned...change the oil and filter,.  Not just any filter off the shelf either...get the OEM filter from Toro and dot it right the 1st time for only a few bucks more. 

[ep103 0]

Ok guys, I really appreciate the imput, I will check out and do all the things you have suggested, and I will report back on my findings..many thanks.. Ed

[can whlvr 991]

the linkage from a Sundstrand and an eaton are completely different,i have both,and the tab and the cam plate have failed on both my sundstrands,but this doesn't apply to an eaton,most likely you have worn parts in the linkage,shut off the tractor,remove any body parts like fender pan,etc and move the control back and forth,watch for slop in the linkage,it may need adjustment or a new part,dont forget to check the frame to tranny too

Edited June 1, 2014 by can whlvr

[ep103 0]

Everything checks out except the frame to tranny it looks to be broken up a bit, I will see if I can get it welded back again.. Thanks and I will keep checking in for more suggestions, and will post after the welding ..

[daveoman1966 3,611]

This is how I repaired the cracked frame plate on my 520H.  The 300 400 500 series frames are the same, as are most earlier years.

No welding required and the repair is probably stronger than original mfg line production.

[ep103 0]

Dave that is pretty clever, I haven't got the farme done yet, but did change the filter, as many of you suggested, and that did smooth it right out, thank you so much for helping me on this, it is much nicer to ride now..

[daveoman1966 3,611]

If you note, in the last of those 3 pics, where the wood block is positioned under the 8 sp trans case, as it sits atop a cement block.  In this position, the fulcrum is at the frame end plate and actually forces the plate back into original position, holding tension on it while the repair is made.  DON'T take all 4 bolts trans mount bolts out as the tractor MAY break in half.  Instead, remove only 2 bolts on Lt or RT side and fix that side first.  When it is all repaired, then do the other side.  Another hint...use the Nylok nuts on the 3/8' bolts so they stay tight.       

[ep103 0]

Good point Dave, thank you for the heads up..looks good and solid..

[jeffcraddoc@yahoo.com 2]

I have a 416h that blew the onan, with repair parts very limited I want to put a kohler in its place. the tractor will not be used for mowing, its new job will be pushing dirt and snow and pulling my wagon. So I am not really concerned about the HP loss. I am not in the position to drop 1500 on a kohler motor. My 312 has 390 hours and is much easier to rebuild when the time comes. I am a 100% disabled vet, 11 knee surgeries and upper body injuries I need as much assistance as possible.. the Hydraulics and auto trans makes my work as easy as possible. how hard is it to transfer motors. also does the onan 16 hp have any value for all the peripheral parts for spares.

[kpinnc 10,733]

On 5/31/2014 at 9:06 PM, ep103 said:

I have read on other sites, the hydro pump is seperate from the transaxle, and the fluids are not the same, they said hydro will hold 3/4 of a quart and 20 weight is what is recommended, whereas the transaxle will use 10W30 oil.

 

If you had a 312-A, instead of a 312-H, this would be correct. The "A" used an Eaton 700 transmission, while the "H" uses the Eaton 1100. The gearboxes are the same (Toro referred to them as Transaxles in the manual), but the transmission (or "pump" they are sometimes called, though that is incorrect) is very different. The 1100 used a coaxial charge pump for hydraulic lift and oil filtration, and has external plumbing to the gearbox which doubles as a sump. It shares 30w oil with the gearbox.

 

The 700 series had a plastic resivior on top of the transmission and did not share fluid with the gearbox. It also did not provide hydraulic lift, and used 20w oil in the tranny and 30w in the gearbox.

 

The 1100 series transmissions (312-H) also have nearly three times the output torque as compared to the 700 (312-A).

Edited September 27, 2021 by kpinnc

[lynnmor 6,779]

On 9/25/2021 at 10:48 PM, jeffcraddoc@yahoo.com said:

I have a 416h that blew the onan, with repair parts very limited I want to put a kohler in its place. the tractor will not be used for mowing, its new job will be pushing dirt and snow and pulling my wagon. So I am not really concerned about the HP loss. I am not in the position to drop 1500 on a kohler motor. My 312 has 390 hours and is much easier to rebuild when the time comes. I am a 100% disabled vet, 11 knee surgeries and upper body injuries I need as much assistance as possible.. the Hydraulics and auto trans makes my work as easy as possible. how hard is it to transfer motors. also does the onan 16 hp have any value for all the peripheral parts for spares.

 

The engine swap would not be difficult, you may need some PTO hardware and an engine mounting plate. You will need to do some wiring and the engine will need a muffler fitted.  Hopefully someone on here did the actual swap and will chime in.

 

The Onan does have some value if you want to part it out.  When you said "blew" what exactly does that mean?  What parts are damaged?

[Handy Don 10,600]

On 9/25/2021 at 10:48 PM, jeffcraddoc@yahoo.com said:

I have a 416h that blew the onan, with repair parts very limited I want to put a kohler in its place. the tractor will not be used for mowing, its new job will be pushing dirt and snow and pulling my wagon. So I am not really concerned about the HP loss. I am not in the position to drop 1500 on a kohler motor. My 312 has 390 hours and is much easier to rebuild when the time comes. I am a 100% disabled vet, 11 knee surgeries and upper body injuries I need as much assistance as possible.. the Hydraulics and auto trans makes my work as easy as possible. how hard is it to transfer motors. also does the onan 16 hp have any value for all the peripheral parts for spares.

 

Are you planning to take the 312's engine to put into the 416 or acquire another 12 hp Kohler?

 

As @lynnmor noted, an engine swap itself is not mechanically hard, though the P216 uses a different engine mounting plate and will have some different wiring, the degree of difference depends a lot on the tractors' respective years--get and consult the manuals for wiring diagrams.

 

The P216 engine is heavy--upwards of 125 lbs.--but it does have hooks for lifting. The Kohler 12 is not a lightweight either. You'll need help or a safe lift/hoist.

 

You won't need a PTO if you'll not be connecting a blower or mower or tiller so you could either remove it or just leave it.

 

You will need a correctly-sized drive pulley. If your 312 is an H, the outer diameter may already be correct since both the 416H and the 312H use Eaton 1100 hydros. With the correct pulleys, the existing drive belt will probably be ok.