GT22-8 Modifying GT14 to 8 speed and 22hp Predator

[Aldon 4,826]

I figured I would go ahead and start a thread that will capture some of one of my distinct projects. The plan I started with is a GT14 as starting point, a 22hp Predator, Electric PTO, Independent Hydraulic lift and 3 point for tiller etc.

 

At the big show I had the luxury of hanging out with @stevasaurus and we discussed transmissions at length. I have wanted to add an 8 Speed to a GT14 for a good while and I picked Steve's brain quite a bit. In addition to this, Kyle aka @fast88pu dropped by and as we discussed GT14's with loaders and Hydros and my want to do a 8 speed, he flagged me to the GT14-8 with loader in one of the buildings and off we went to visually inspect it.

 

One shortcoming of the straight swap which was easy to note upon viewing said modified tractor is that the axles are too short and do not come flush with the end of the hub when tires are fitted to appropriate clearance. I needed the visual to understand as Kyle already knew this as he had a similarly modified GT14 he had picked up from @scotty.

 

So my project appeared dead in its tracks until I went out to Cody's in Scranton PA area and he told me that the axles in the Hydro Transaxles could be swapped into the 8-speed directly. Kyle was riding shotgun with me just by chance. So at some point in this day trip Kyle and I agreed to a deal where I took home a 8-speed he had on hand with 1 1/8" axles.

 

Steve helped me out with all the bearings I needed as well as mentoring me on a few of the challenges I encountered. This particular 8-speed is one of few with slightly unique main bearings,,,,,,but I managed to source all the replacement bearings and get prepared for the project, then Winter came along to seriously slow things down.

 

It should be noted that in many of the GT14 transaxles, if not most, the axles are different from one side to the other. one side is 14 1/8" and one side is 14 3/4".

 

  One of my axles was beyond redemption. Could not get two good sets from 2 parts transaxles. On hold until @ztnoo came to my assistance here and I now had two good 14 3/4" axles. Along the way it was suggested I should make use of the Limited Slip differentials from the Hydro transaxles if I could. I spent several hours over the holidays trying different combinations but could not figure a way to make it work. It is plausible that there is a different Limited slip set up or parts that would make this easy. Or, if I had access to machine shop I could do it. But with a bench and what parts I have on hand, I am moving forward with normal diff with only real change being that I am installing longer axles. One of the pics below shows the 3 different axle lengths. In the pics below, it may be difficult to read the tape measure but the width of the modified set up is 29 1/2. Additionally I have a couple pics of the limited Slip Diff Side pieces that hold the axle to the assembly. Note they are not same and both are different from the 8-speeds. Lastly a sketch drawn to scale as much as I could determine. I am not a draftsman but it should be close. I want to end up with (29x12.5-15 ags) I have decided to use D Series Hubs. Rim wise I will need custom back spacing and I have sourced the necessary rims and inserts from Miller Tire. Thats where I am at until I can remove a very stubborn hitch pin from one tranny half after which I can start rebuild using new bearings and will post pic when I reach that point. eta a few weeks:) I dont do well in the cold. 

 

Edited January 17, 2017 by Aldon

[bmsgaffer 2,043]

I am following this one! It sounds awesome and I look forward to your progress!

[WHX?? 48,813]

I've seen your work Aldon, I'm in as well!

[953 nut 55,155]

   Been looking forward to this one. The six speed Transaxle from a 1057 or 1267 (5060) is a limited slip and they work great, I have one in one of my 953s. You may be able to pick up the center section from one of our parts vendors.

[Aldon 4,826]

1 minute ago, 953 nut said:

   Been looking forward to this one. The six speed Transaxle from a 1057 or 1267 (5060) is a limited slip and they work great, I have one in one of my 953s. You may be able to pick up the center section from one of our parts vendors.

What diameter axles are one those?

[953 nut 55,155]

5 minutes ago, Aldon said:

diameter axles

1 1/8

'

[Aldon 4,826]

Hmmmm. Well if I run across a parts tranny from 953 or 1054 before I start mocking things up, then there is still a chance this could end up with a limited slip.

 

Otherwise, I plan to try and mount Go-Kart disc brakes to the backside of the D-series Hubs as they have 4 tapped holes conveniently located on backside. Spaced 2 3/8" inches apart. I am not absolutely certain this will work until I mock it up and custom set wheel backspace. But it works in my head! LOL

 

The brakes, essentially turning brakes, can be my poor mans limited slip.

Edited January 17, 2017 by Aldon

[WHX?? 48,813]

We kinda had this discussion about the 5060 and it's pros/cons for a plow tractor transmission the other day when I visited @Shynon's. Not that you might plow with it Aldon but anyway it was brought up if that 50 yo spring were to break in there... yikes. Another con is the aluminum side plates that holds all those pinions in ther might not hold up to the rigors of plowing. Mike @prondzy actually showed me a side plate that was cracked due to overtorquing the differential bolts. Probably not huge concerns pending what you might use this machine for. We are just plowing fruitcakes and looking for the strongest unit for doing that. Either way double  for what you have in your head! 

[953 nut 55,155]

1 hour ago, Aldon said:

run across a parts tranny from 953 or 1054

   1067 or 1267, I transplanted one into a 953, the stock 953 is an open differential and not known for their strength.

[Aldon 4,826]

Lol. 

 

I heard you that time:-)

[WHX?? 48,813]

I got it the first time Aldon....Richard that has got to one brutal 953 in the rear then!

[mmmmmdonuts 274]

Definitely very interested in this thread. Just out of curiosity which 8 speed tranny do you actually have model wise? The 8 speed / 8 pinion would be the strongest but I don't think it has limited slip. My Raider also has the 5060, which is the 10 pinion limited slip with the 1-1/8 axles. I also read in a different post about modifying a 10 pinion it to an 8 pinion (albeit with some grinding). 

[Aldon 4,826]

The tranny is a 8 speed 8 pinion. But the blessed maker likes to challenge me. So somehow I ended up gettting one of the few 8 speeds that they ran out of 1533 bearings for and used a unique bearing on. @Racinbob and @stevasaurus identified as a 111199 if I recall.

 Some pics of the state it was in when I got it....it's not obvious but the hi-lo shift fork was broken. I have new parts ready to install as it goes back together. Also a pic of the unique bearing. 

 

I have been been unable to locate new bearings to replace. If anyone knows of a source, send me a note. Thanks

[bmsgaffer 2,043]

When they stopped using the 1533 they used the 111199, same as in the hydro transmissions I believe. They are still available here: https://www.rcpw.com/toro-parts/genuine/111199.html

[Aldon 4,826]

Thanks. Much appreciated.

 

I think I spent all my time trying to find the bearing elsewhere using the  S875B part number on the bearing. ***** I just ordered a pair ! *****

 

For those interested, here are some pics of the bearing comparisons, along with what I was able to measure them.....disclaimer "I am not a machinest" as such, take that into account. also a couple pics of the broken shift fork and the NOS parts. I will capture tractor stuff in the next post for those concerned that this thread is too Tranny heavy LOL

 

Pics of GT14 Hydro Diff vs 8 speed 8 Pinion Diff before modification.

 

 

Edited January 18, 2017 by Aldon

[stevasaurus 22,713]

Aldon, do you mind if I throw out a few facts about these transmissions?  This may help some to understand what you are trying to do, or what you have run across. 

1.  Only 10 pinion transmissions are Limited Slip

2.  All 10 pinion transmissions are Limited Slip

3.  Not one 8 pinion transmission built by Wheel Horse has Limited Slip

4.  All 10 pinion differentials have one axle shorter then the other...and so one end plate is shorter then the other...1 part # for left and a different part # for right

5.  All 8 pinion differentials have axles that are the same length...1 part number for both axles

6.  If a hydro has the 10 pinion differential or the 8 pinion differential...all of the above applies

7.  Only the #5060 10 pinion LS differential (1968) had aluminum end plates...1969 and up have steel end plates

8.  Service Bulletin #252 explains the conversion of limited slip differential to 8 pinion differential

9.  If you have 4 pinions, you have 1" axles

10. If you have 8 or 10 pinions, you have 1 1/8" axles

11.  All 1 1/8" axles from Wheel Horse transmissions "should" be able to interchange

 

OK...what does all this mean?  If Aldon has 2 axles the same length and they are the length he wants (so his tires fit), he will be putting them into an 8 pinion differential and he will not have limited slip.  If he wants to modify (cut one axle shorter then the other), so as to have the same distance sticking out past the frame, then he could use a 10 pinion LS differential.  Hope all that makes since. 

[Aldon 4,826]

Excellent feedback Steve! In fact, read your PM:-)

 

Once I have consulted with the swami again, I may yet go with limited slip. It would save a whole lot  hassle with developing turning brakes.

 

So as mentioned previously, to get the ball rolling on non-tranny stuff.

Just prior to winter I made a parts tractor run with @fast88pu so as they sat on the trailer when I returned and dismantled waiting for spring thaw to get started.

Tentative - waiting on @Shuboxlover - swept axle, reduced steering set up. Highly probably this will be part of this build.

3 point procured from fellow member here who is selling reproductions on Ebay. Not sure if he is set up as vendor on the square.

22HP Predator procured.

Plan is currently to use 29x12.5-15 AG tires on rear. 

For a couple reasons I decided to go with D series Hubs. 1, easier to do turning brake using go kart disc if I go that route, 2, more importantly, easier to build wheel to custom spec due to insert availability. Both the blank and insert available from miller tire. Shout out to Kyle who has helped me with this stuff quite a bit.

Now the pics:

 

[WHX?? 48,813]

4 hours ago, stevasaurus said:

(1968) had aluminum end plates...1969 and up have steel end plates

Not to steal your thunder or thread  Aldon but @stevasaurus my 67 had AL plates and can the steel end plates be used on earlier units? Do you think WH knew the AL plates were a weak spot and went to steel?

Those bearings are awfully close in dims Aldon but Lowell's won't work??

Edited January 18, 2017 by WHX9

[Aldon 4,826]

Actually I was comfortable using the 1533's if I could not locate the correct ones. I had planned on using the green loctite and using a punch to deform the edge as I expect new bearings to far outlast my needs. However since I was directed to correct bearings, Ill use them and save a potential future owner the hassle of having to heat the bearings and extra effort to remove the punch areas.

This is the product I had planned on using but will not require now.

Edited January 18, 2017 by Aldon

[WHX?? 48,813]

Yes that's a good product to have on the bench anyway. Hope you don't give up on the dual brakes idea tho!

[stevasaurus 22,713]

OK...the 5060 trans had aluminum plates...the 5071 and 5073 had steel plates.    and yes you can interchange them.  Actually, the #5060 I rebuilt had one of each...tells me someone else has been in there.  

[dclarke 4,032]

Pretty interesting build, Aldon. I'll be following this also. 

[19richie66 17,500]

I am along for the ride.

[Aldon 4,826]

It may be a while before I post anything of significance although I'll respond to questions. 

 

As of tonight I finally cleared the latest significant hurdle. And I am embarrassed to say how happy I was to accomplish such a simple feat.

 

I have wrestled on and off for weeks and tonight I finally managed to break that danged hitch pin loose from the larger half of the tranny case. I was concerned I was going to crack the casting but it finally gave up!!!!! 

 

And since it seems silly to post such a minor event, I'll post a couple pics of the D-series hub for those not familiar with them. The 4 threaded holes on the backside are where I am considering mounting a go-kart disc brake set up to act as turning brake and assist as a poor mans limited slip diff. 

[fast88pu 3,324]

See you got the pin out