[Dieselchessy]

I've owned a JD 170 for several years now. The previous owner (PO) ran it hard and put it away wet. It also had the failing powder coat and rust on the fender deck. A few weeks back I started fixing it up so it would last several more years. That's when I came across another 170 on craigslist described as "bad transaxle, no forward gears". I went and bought it to have for a parts tractor. But.... its in better shape than mine except for the tranny so I started researching the transaxle and looked through the Tecumseh repair manual you can find online. The transaxle looked simple enough to me.
http://www.smallenginesuppliers.com...eh/Tecumseh_Transaxle_Service_Information.pdf


My other JD 170 has this transaxle:


The symptoms:
The tractor drives in reverse fine. No noises, grinding, ect.... In any forward gear it would grind. Shifting felt a little sloppy, but you could still feel the separation between gears.
So I removed the fender deck and looked over the shift linkage. The bolt holding the shift arm on the tranny was loose causing a little slop in the linkage. I knew it wasn't the entire problem but I tightened it up and did some further investigating.
The tranny would now shift into every gear, and you could run it by hand with the rear wheels off the ground and it worked fine. But if you held the wheel and tried to turn the input pulley then after a bit of pressure the tranny would pop and slip of sorts. Not knowing how this thing ticked, I was thinking maybe it was jumping gear teeth.

So I removed the tranny from the tractor. Right off I found the input shaft had a little too much up and down play. I removed the pulley and found the clip ring and its washer had ground away some of the tranny case and the input pulley. I'm still thinking through how I'll repair this. Ideas are just a simple shim washer or maybe a thrust bearing, or ???


I pulled the top off the transaxle and found the grease had separated and some of the oily component was on the gears, but the solids were all caked in the bottom of the housing. All the gears, bushings, bearings, ect... looked good. So I played with it for a bit learning how it works. (Yes that red stuff is my blood. Don't try and shift these with your fingers, the keyway edges are sharp):00000061:

Then I pulled it apart to look at the shift forks (this one has 4). There I found the issue. The tips of the shift forks are rounded off.

This is the shift keys and an axle end bearing. Looking at the manual, this it the "heavy duty" version of 4 possible axle bearing setups.

Seeing how these forks interact with the keyways in the gears I pulled all the gears and look them over. All are pristine except for 3rd. It has the inside corners of the keyways ground up a bit. I'll likely not replace 3rd gear. I do most of my mowing in second, and the damage is minimal and not where they shift keys should contact if you don't shift on the fly. I suspect the PO did most of his mowing in 3rd and either had the clutch adjusted wrong, or did some shifting on the move.

Having pulled this thing apart and playing with it I now understand the quirks of these things, why forward gears fail, and why reverse doesn't.

The shift keys ride in keyways on the gear shaft. They are bent so they have a spring action on the tips for the forward gears. The forward gears lock in by the little triangle tips of the shift keys. As you move from gear to gear the spring tips get compressed into the shaft keyway and then spring out to engage the keyway of the selected gear. If the edges of these tips get worn down then the force of the gear turning just pushes them back down into the axle keyway and the gear spins. The grinding you hear is the shift keys grabbing each keyway in the gear and then getting compressed back down and popping over to the next keyway as the gear spins.
The reverse gear uses the back of the keys that are square and not spring action. That explains why I sometimes have to let the clutch out a little to get into reverse. There is no ramps. You have to spin the shaft till the keys line up with the slots in the gear. Reverse doesn't break because the keys fully fill the shaft keyway and the gear keyway. The reverse gear/key/shaft engagement is much stronger than the forward gear setup.

So I'm looking for a source for Peerless parts. Shift keys and bushings primarily. I see Sears lists lots of parts, but prices seem rather steep and the description for the keys doesn't say if its a 2 key set, or just a single.

I'll put new keys, new bushings (these have a little play), and new axle bearings (just because) in this. I'll likely not replace the 3rd shift gear unless I find it for a good price. I'll fill this with a blend of Bentonite grease and Lucas oil stabilizer.

After I get this one back together I'll pull apart my other Transaxle and do an R&R on it. Its the same age so I suspect the grease is in similar condition.

 

[turbodave]

I was able to get shift keys and bearings from my JD dealer for the last two 180 transmissions I've gone through. The exploded view of the trans and part numbers are on JD's site: http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt.

The shift key is part# M82826 and comes as a set of two. I think it was about $25 last time I bought a pair.

 

[Dieselchessy]

Thanks, I'll look online through JD, or search the JD part numbers. The Sears part numbers don't lead anywhere. Sears is asking $23 something, but doesn't even hint as to what you get other than "shift key".

 

[JDSTX38]

The pulley on the input shaft on My STX Peerless 920 017 did the same thing as yours and dug into the case a little, but also my needle bearing were shot. I ended up replacing the input shaft, needle bearings, pulley, thrust washers, grease seal, C clips, woodrof key. The parts cost about $110.00, and as far as the top case, I just bought a couple extra thrust washers, and shimmed it up ( don't use regular washers) and has been fine for three years.

 

[Dieselchessy]

The pulley on the input shaft on My STX Peerless 920 017 did the same thing as yours and dug into the case a little, but also my needle bearing were shot. I ended up replacing the input shaft, needle bearings, pulley, thrust washers, grease seal, C clips, woodrof key. The parts cost about $110.00, and as far as the top case, I just bought a couple extra thrust washers, and shimmed it up ( don't use regular washers) and has been fine for three years.

The thrust bearing JD9835 and its two washers M46676 only run about $5 for all. My input shaft has this setup on the inside of the case. I'll just level off the top of the case boss and put the same setup on top. It will be easy enough to service the upper thrust bearing once a season by removing the pulley. I'll grease it with marine axle grease.

The needle bearings in mine are fine. Very minimal side to side play, still well greased, none look damaged.

By time I get axle bearings, bushings, shift keys, seals, grease, ect.... I'll have about $100 into this tranny. Could be worse.

 

[JDSTX38]

It seems all the thrust force on the input shaft is the bevel gear pushing the input shaft up not down. IMHO putting a none sealed greased bearing exposed on the top of the input shaft is going to be a grit and dirt collector with no real benefit, but I could be wrong.

 

[Dieselchessy]

It seems all the thrust force on the input shaft is the bevel gear pushing the input shaft up not down. IMHO putting a none sealed greased bearing exposed on the top of the input shaft is going to be a grit and dirt collector with no real benefit, but I could be wrong.

I had the same thought on the thrust force. But then that leaves me wondering when it had time to grind the case. Maybe when the motors running but not in gear so there isn't enough force to push the shaft up?

Maybe the bearing will be a gunk trap, but not anymore than the current system was. This thing had nothing but a washer for sealing. The o-ring is down inside just above the inside thrust bearing. Its $5 so not much to lose. The bearing will be tucked up under the pulley and on top of the boss so should be little issue with water. Maybe I'll put a piece of rubber hose over the boss and pulley hub to act as a dust seal.

 

[JDSTX38]

I think the reason the case got ground down was because the C clip that holds the pulley from dropping down onto the case failed so the pulley was riding on the top of the case. With both the upper and lower C clips holding the pulley in place nothing should be riding on top of the case because the input bevel gear riding on the large bevel gear will prevent the shaft from dropping.

 

[JDSTX38]

If your pulley is chewed up and has any wobble on the shaft then the pulley and or input shaft need replaced. The two C Clips {AKA snap rings) should hold the pulley tight with no wobble or any sliding up and down on the shaft between the Snap rings.

 

[Dieselchessy]

If your pulley is chewed up and has any wobble on the shaft then the pulley and or input shaft need replaced. The two C Clips {AKA snap rings) should hold the pulley tight with no wobble or any sliding up and down on the shaft between the Snap rings.

I don't believe mine is set up to have the 2 snap rings fix the pulley, maybe. My lower snap ring was in sorry shape but I believe that was from the rubbing. My pulley was tight on the shaft up against the top snap ring. I had to PB blaster it and tap with a hammer to remove it.
It wasn't the pulley that moved. The entire shaft would move.
Lateral play is minimal. All my bearings look fine and everything on the main gear shaft looked fine. I'm thinking I need to investigate the beveled main gear and its thrust washers ect. to see if it is moving and allowing the input gear to move down its face too far.
I hadn't considered the beveled gears for acting to controll gear shaft position. I'm more used to set ups where shaft thrust is controlled by hardware other than the gears themselves so that backlash and such can be adjusted and fixed.

This tranny seems to use thrust washers and bearings for such.

 

[JDSTX38]

Another possibility is maybe the transaxle was serviced in the past, and the needle bearing and input shaft have been previously replaced, what you maybe seeing is old damage. :dunno: The grease in the needle bearings looks to fresh to be original, and the grease in the case looks different from bentinite grease, or maybe the grease is contaminated? I will be curious as to what you finely fined out what the problem was.

 

[Dieselchessy]

Another possibility is maybe the transaxle was serviced in the past, and the needle bearing and input shaft have been previously replaced, what you maybe seeing is old damage. :dunno: The grease in the needle bearings looks to fresh to be original, and the grease in the case looks different from bentinite grease, or maybe the grease is contaminated? I will be curious as to what you finely fined out what the problem was.

Tranny having been serviced is a good possibility. The axle bearings say "china" on the seals. Was Tecumseh using "china" bearings in 89? I have no idea what Bentonite grease looks like, though I imagine it would be a tan kind of clay color?? It seems to look that color in the online pics of the Tecumseh grease bottles.
This transaxle has the same black/grey grease everywhere. You cant tell a difference between the grease in the needle bearings and the grease in the housing.
None of the bronze is corroded, so I'm guessing they used suitable type of grease.
That might explain the 4 shift keys, and the good condition of this unit after 24 years of use.
This transaxle was quiet in reverse (only gear that worked) compared to my other JD180 tranny. My other tranny has a bit of gear whine like is a bit dry.

I'm holding on ordering parts till I pull my other tranny and look in it. If its easily repairable I'll fix both, but if it has major issues, I'll combine parts to build 1 good one, and one machine will graduate to "pats rig" status.

 

[Dieselchessy]

I pulled my other transaxle apart. It was much different. The grease is black tar. The axles were rusted into the rims. Bearings rusted onto the axles. NSK Japan bearings. Had to sand the rust off the shifter shaft to get it out of the case. Broke aff 4 bolts in the case.
The first unit must have been serviced. It's grease looks to be a black moly type grease. All bolts came out nice and axles were greased inside the hubs. Only 2 shift keys.
I ordered all the parts I'm replacing for both. When they come in I'll grease them with cornhead and maybe some Lucas and put them back together.

 

[littletractorguy]

Looking forward to seeing the end product... I have to dive into the 801 I liberated from a parts 160 yet this summer (in my copious amounts of spare time), so thanks for the information and the pics!

 

[Dieselchessy]

If you have questions when you get into it just ask.

When I get these cleaned up ill take pics of the differences between my 801-038B and 840A. The 038B has the better bearings in places and four shift key slots. From the looks of my 2 cases you could upgrade to the better bearings. But the 840A only has 2 shift key slots. The peerless manual makes mention of serviced units having four slots, but to just use 2 keys, same as original. I'm thinking 4 is better myself. But then the 4 key unit was stripped out and my 2 key unit still holding. Go figure. I suspect 4 keys will be harder to shift than just 2.

One other little detail. I pulled one of the axles out of the spider gear (diff) because its stuck in the rim. The end of the axles had 2 clip rings each. Both in the same groove. Didn't see the second in all the tar and took me a few to realize why the axle would move, but not pull free.
I'll attempt cleaning this stuff with kerosene. I'll let you know how that works out.

I ordered my bearings from ultimate industrial solutions on E bay. Chinese, but decent quality, cheaper than NSK and way cheaper than deere. Got my deck spindle bearings there also. NSK would be my first choice for quality, but then I work on NSK robot axis every day, so biased. Chinese will work for a mower. All other parts coming from Green parts Store. They had most everything.

 

[littletractorguy]

Thanks! Good to know! I will definitely be asking, I'm sure! I'm figuring I'll do a whole pictorial teardown, both cuz these guys all like pics, AND cuz I do kinda want to be able to put it back together the same way! :sidelaugh

 

[austinado16]

You'll probably want to repack that with Bentonite Grease.

I had Toro 13-38XL with that stupid shift on the fly system, and it's shift keys and the 5th gear were all blown out like yours. I also found a differential spider gear that was the wrong part and just wallowed around on the cross shaft in the diff. Man, did that transmission make some noise

 

[Dieselchessy]

Thanks! Good to know! I will definitely be asking, I'm sure! I'm figuring I'll do a whole pictorial teardown, both cuz these guys all like pics, AND cuz I do kinda want to be able to put it back together the same way! :sidelaugh

Download the Peerless service manual. It has it all laid out with pictures. I would be more into a photo documentary, but with the Peerless manual and all the U-tube vids, it would just be repeating what's already out there. I just took a few pics to document and make the thread more interesting.

 

[Dieselchessy]

You'll probably want to repack that with Bentonite Grease.

I had Toro 13-38XL with that stupid shift on the fly system, and it's shift keys and the 5th gear were all blown out like yours. I also found a differential spider gear that was the wrong part and just wallowed around on the cross shaft in the diff. Man, did that transmission make some noise

Bentonite grease is a bit of a conundrum for me.

On the one hand:
Its lasted 24 years pretty well.
Its manufacturer recommended.

On the other hand:
If it was such a miracle lube why does no one use it except for extreme high temp applications (this tranny don't get hot)?
Its 3x the cost of other lubes.
In the last 25 years they've made some decent improvements in greases.

My gearbox that's in the best shape with the best looking lube looks to have a moly type chassis grease. Yes it was likely serviced, but obviously quite a few years ago, and it was still quiet, decently lubed, and shows very little if any gear tooth wear.

My gearbox with the tar (Bentonite?) was in much worse shape, noisy, and the grease was no longer being picked up by the main beveled gear so the 2 input beveled gears are pretty worn with some pitting on the gear teeth.

My belief is that Tecumseh uses Bentonite so they can build a low price, unsealed, never needs serviced tranny that will outlast the expected service life of the machine. I don't believe they use it cause its the very best gear, bearing, and bushing grease ever created.

For me Bigfoot grease is one of the very best I've seen at surviving water, being sticky, and staying in place. We lube our outboard prop shafts with the stuff and after a season of saltwater fishing the stuff is still there, still sticky, and still working. Its a staple product around here for lube on heavy equipment, farm equipment, ect..

I have an E-mail out to LSC to see if its suitable for bronze bushings. If it is, I'll likely use Bigfoot in the gear boxes. If not, then I plan on using Corn Head grease. Either way, I expect the grease to outlast the remaining life in these 2 machines. If they start to get noisy down the road I can always service them.

How's that for trying to out think a tranny design engineer?:sidelaugh

 

[Dieselchessy]

Just a little update on my progress.

I cleaned up unit #2 with the Kerosene. It worked great, melted the grease right off. Used a toothbrush and chip brush for scrubbing.

But....I found after cleaning that the sleeve for the needle bearing at the pinion gear end of the countershaft was cracked and expanded a bit. The needle bearing was still functioning but all the needles fell out once the shaft wasn't in there to keep them in position.
This looks to be a bit of a weak point in the design. The way the housing is milled for multiple bearing choices it leaves the better part of this sleeve unsupported. A quick internet search found a few of these same failures. And JD/Peerless fixed this setup on later models.

I looked into upgrading to the ball bearing but the countershaft for the ball bearing setup is turned down on the end to fit into the inner race of the ball bearing. A replacement shaft runs $80 and the bearing is $30. I don't have access to a lathe to turn this down and machine shop time is $100+ and hour around here.

I found the sleeve/needle bearing set for ~$50 shipped.

This tranny has some pretty good wear on the spider gears and bevel gears. It looks to have run with dried out grease for some time. It had some gear whine the entire time I've owned it (7-8 years). I should have dealt with it years ago. To make it "like new" would be several hundred dollars worth of parts, but for $50 for this bearing I can make it "serviceable" and suspect it will give several more years service.

So sleeve and bearing are on order and the lawn is growing fast.

Sorry no pics, I'll add them later. Neighbors wife came over about 8pm to get water. Wife told me she had also got water yesterday. So I stepped away from the tranny build and wandered over and spent an hour or so fixing their cistern pump electrical so they could have water again. Country living.