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Transaxle Problems On The 850 - Help, Please!

bolens 850 transaxle transmission

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#1 MailmAn OFFLINE  

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Posted September 12, 2012 - 06:33 PM

Like I need any MORE problems than I already have. I was out playing around with my new toy and trying to get the chute from my new Trac-Vac to mount to my 850's mowing deck. (But more on that later once I get this problem taken care of!) However, I was riding around on my 850 when I had some transaxle problems. It seems my tractor is now stuck in 1st gear and I cannot get it to shift into any other gears. It won't go in Reverse and if I try to shift it into 2nd or 3rd gear, the engine bogs way down and almost stalls and the tractor doesn't go anywhere. It only seems to move when it is supposed to be in neutral. I tried playing around with it some and it only goes ahead in 1st when it is in neutral or in teh positions for Reverse or 1st. Anything else doesn't work. Did I break a pin off on the R/1st shifter shaft inside the transmission or something? How do I take it all apart to check on it and see what the problem is? IDK what caused this or why it just suddenly broke on me, but I'm dead in the water if I can't get it to drive properly!!

Any help would be greatly appreciated!! It is kinda stuck where it is though esp. with no Reverse gear and I can only push it around with the free wheel pin out (or drive it forward in 1st, obviously... but I kinda don't even want to do that if the transaxle is broken...)

Thanks in advance!

#2 Bolens 1000 ONLINE  

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Posted September 12, 2012 - 06:55 PM

Sounds to me like you are stuck in 2 gears at one time.
Either one of the detent springs in the transmission let go and the shifter arms were allowed to slide freely or your shift lever was too loose and slid out of place.
Can you get some pics of your shifter and the underside?

#3 8tyman8 OFFLINE  

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Posted September 12, 2012 - 07:25 PM

Sounds to me like you are stuck in 2 gears at one time.
Either one of the detent springs in the transmission let go and the shifter arms were allowed to slide freely or your shift lever was too loose and slid out of place.
Can you get some pics of your shifter and the underside?

shift fork is broke one broke on my 750 and i had to replace it i broke a belt as well
here is the video of replacing the fork

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#4 Bolens 1000 ONLINE  

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Posted September 12, 2012 - 07:51 PM

:ditto:

That could be your problem as well. I have seen a few of the forks break before, but I would check your shifter out first.

#5 fonz3482 OFFLINE  

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Posted September 12, 2012 - 07:56 PM

I had my shifter somehow come out of place once and do the samething. Hopefully its that simple. Just lay under the tractor and check out the end of the shifter itself and how it lies in the shifter forks that come out of the trans. The bogging is most likely what brian said, the trans is being placed in 2 gears at one time.I beleive the forks shouldn't both move when shifting, the shifter should only move one at a time. Kinda hard to explain, so I'll quit babbling. Get everything aligned right, and you should be good. I believe someone had a picture of the proper placement for the shifter fork to shifter end. Good luck

#6 MailmAn OFFLINE  

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Posted September 12, 2012 - 08:47 PM

shift fork is broke one broke on my 750 and i had to replace it i broke a belt as well
here is the video of replacing the fork


Thanks for the video. I really HOPE that is not the issue, but I will check. The great thing about your video is I now know how to get access to the transaxle without having to pull half the tractor apart to actually remove the rear axle from the tube frame! At least Bolens thought ahead about how to service these things! Now I just have to see what the problem is. I really HOPE it is not the whole shift fork broke off like that and I might get "lucky" in that only the roll pin that holds it on broke off? How did you get your broken shift fork out, may I ask? I'd hope that those roll pins might come out a bit easier since they are enclosed and greased all the time unlike some of the roll pins on the outside of the tractor that were a witch to get out - like the ones that hold the brake shoes on!

If the fork itself is indeed broken, I don't happen to have a spare parts tractor lying around like you do. Does anyone know where I can get one ASAP (like yesterday)? No clue how much they will cost, but I'd imagine they can't be cheap since nothing else for these tractors seems to be anyways...

Sounds to me like you are stuck in 2 gears at one time.
Either one of the detent springs in the transmission let go and the shifter arms were allowed to slide freely or your shift lever was too loose and slid out of place.
Can you get some pics of your shifter and the underside?


I don't THINK this is the problem. I think the issue is inside the transmission. I did take a quick look underneath the tractor as I was concerned that maybe I was stuck in two gears at the same time, but I don't think that is the case. I'm only stuck in 1st gear at the moment. The shifter shafts seem to slide freely and I can shift into 2nd and 3rd fine, its just the tractor doesn't want to move when I do so. If I leave it in neutral, it moves forward in 1st gear. If I put it into Reverse, it is going in 1st gear as well. So, that makes me think that the shift fork roll pin broke off while it was in 1st gear or something and now the gears are stuck engaged in 1st. I can move the shifter so that it slides the R/1st shaft in and out but it doesn't seem to change anything inside the transaxle. If I try to put it in Reverse, the shaft does slide out all the way until it hits the parking brake shaft, which I'm pretty sure it is not supposed to do.

I think the job for to-morrow will be to pull the deck off of it and try to get a look at the insides of the transaxle if I can to see what has happened. I HOPE it is not that involved of a fix, but I'm worried it will be! I was always curious though because it seemed like I always had a hard time shifting this tractor into gears and I didn't think it should be that much of a problem to shift it into gear. Reverse was always notorious for being hard to shift into at times without grinding gears or having to have the clutch pedal half let out to barely spin the driveshaft so I could force it into gear. Are these always that hard to shift or is it something bolloxed up in my transaxle causing problems? I suppose it was beaten up a lot by a previous owner?

Edited by MailmAn, September 12, 2012 - 08:51 PM.


#7 Bolens 1000 ONLINE  

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Posted September 13, 2012 - 05:43 AM

I'd pull the top cover off and see what was going on. It shouldn't be that hard to shift into gear, Having a loose shift lever can also make shifting difficult.
In the future If the gears do not mesh go back into neutral and let your foot off the clutch and then press the petal down and try again if you keep grinding the gears into place you're going to have some major problems later on.

#8 MailmAn OFFLINE  

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Posted September 13, 2012 - 10:24 AM

If I don't have major problems already, Doc! I know what you mean and I have tried that, but sometimes it just seems like the gears won't line up. I don't know if it is from the driveshaft stopping too abruptly and the rear axle keeps turning or something and it locks a gear into place or what. I'm pretty sure there is no syncho in this transaxle (it's not a car after all) so shifting can be tricky sometimes if everything isn't all nicely lined up. A good example is if you watch the end of the movie where I tried to adjust the points (badly, according to Bruce! :smilewink: ). As I try to line it up to back it off of the truck, it doesn't want to go into Reverse at all and I end up grinding the gears to force it in. I HATE doing that!! :mad2: But after letting the clutch out a couple of times and reapplying it, the transaxle still didn't want to go into Reverse, so I ended up having to force it. I'm sure moves like that are not good for my shift fork either!

Well, I'm in the middle of tearing it apart right now and filming the process, so we'll see what is the matter with it later on today, hopefully!


Oh, and thanks a lot, Farmerall, if you do have a shift fork that I can use if indeed mine is toast! :thumbs:

#9 Bolens 1000 ONLINE  

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Posted September 13, 2012 - 01:33 PM

If I don't have major problems already, Doc! I know what you mean and I have tried that, but sometimes it just seems like the gears won't line up. I don't know if it is from the driveshaft stopping too abruptly and the rear axle keeps turning or something and it locks a gear into place or what. I'm pretty sure there is no syncho in this transaxle (it's not a car after all) so shifting can be tricky sometimes if everything isn't all nicely lined up. A good example is if you watch the end of the movie where I tried to adjust the points (badly, according to Bruce! :smilewink: ). As I try to line it up to back it off of the truck, it doesn't want to go into Reverse at all and I end up grinding the gears to force it in. I HATE doing that!! :mad2: But after letting the clutch out a couple of times and reapplying it, the transaxle still didn't want to go into Reverse, so I ended up having to force it. I'm sure moves like that are not good for my shift fork either!


Its just the way those transmissions were designed. I believe it states in the manual, if you cant shift into gear the first time, just let off the petal and try it again until the gears are aligned. It happens to me periodically but not as often as you are describing.....Never shift until the driveshaft has completely stopped.

I'm attaching some pics showing how everything should be when in neutral.
Does your shift lever ball look like in the picture or is it sitting lower in the collar?


Well, I'm in the middle of tearing it apart right now and filming the process, so we'll see what is the matter with it later on today, hopefully!


Looking forward to hearing the update

Attached Thumbnails

  • trans pic 004.JPG
  • trans pic 005.JPG
  • trans pic 007.JPG

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#10 EricFromPa ONLINE  

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Posted September 13, 2012 - 02:04 PM

If it's stuck in a gear and the shifter dropped below the grooves in the shift rod because of a worn bottom shifter plate,it won't go into reverse.If it does it will most likely snap your belts or rip a gear or 2 up.

Can you stick it in Neutral and crawl under the thing and snap a couple pics of the bottom end of the shifter and shift rods?

They're just in front of the transaxle underneith.Some one else here had to re do they're shifter but I can't find the post it was from around last fall.It had good pics and info in it.
My 1050 got stuck in 2nd and I ended up getting another shifter ball cup for the bottom.the old one was rust pitted and worn to the point that the shifter would drop out of the groove in the shift rods.

#11 Bolens 1000 ONLINE  

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Posted September 13, 2012 - 02:08 PM

I found some images I saved of 1st,2nd,3rd Gear.

Attached Thumbnails

  • 1 Gear.JPG
  • 2nd gear 002.JPG
  • 3rd gear largesize 002.JPG


#12 MailmAn OFFLINE  

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Posted September 13, 2012 - 10:58 PM

.
.
Well, I finally got it apart today and, more importantly, FINALLY got the video edited and uploaded!! (Of course, it only takes a couple of hours to tear the whole tractor apart and film it, but it then takes 6-8 hours to edit that footage, re-encode it, upload it to YouTube, and wait for YouTube to process the uploaded movie so it is available for viewing!! [Phew!] I mean, I like making videos, but they are time consuming and can suck!!) But in any event, enjoy the fruits of my labor:




http://www.youtube.com/watch?v=zWgX13c4I5E

(There's even a hidden surprise in the video since I'm wacky and crazy like that...)



So, it's not looking good for my transaxle right now. :mecry: :( Not sure how it got that way - from me grinding gears with it a couple of times over the past few months, or more likely from years of abuse by a previous owner which made it hard to shift into gear in the first place? Either way, I'm not sure the best course of action from here. Can I throw a new shift fork into it and be okay, or can the transaxle be rebuilt or is the cheaper and easier way to just replace the whole unit with a good used one? Where can I find parts for it and how expensive will each repair be and how likely is each one to last me for?

Oh, and sorry in advance for the length of this video. I could have edited it down further probably to make it more concise, but again, that's more time in editing and it still wouldn't be up then if I took the extra time to edit it any further. As it is, I probably spent WAY too much time on it for what it is, lol...


.
.

(EDIT - Want a fun drinking game to play with your buddies? Have a drink whenever you hear me say, "So, that's what I'm looking at" in the video!! lol. Just noticed it. I hate it when stuff like that happens!!)


.

Edited by MailmAn, September 13, 2012 - 11:29 PM.


#13 Bolens 1000 ONLINE  

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Posted September 14, 2012 - 07:10 AM

I wrote down some notes while watching the video so I'm going to make some bullet points on the issues
  • Shifter Is Way too loose! (This could be one of the causes of difficult shifting since the shifter is allowed to bounce around and not hitting the areas it should when trying to go in gear)
  • You did alot more work than you had to! Hate to tell you this, but you really didnt have to remove that dash panel to get that cover off. If you are careful you can pick up the end of the cover and slowly ease it back out.
  • The gear oil Looks like its got water in it. I would change it with fresh 90wt Gear oil. Be sure not to get the new synthetic oil as it will eat away at the brass parts in the transmission! The oil Level looks ok. It only should be filled to the top of the fill plug in the rear. When running the gears will bring up the oil from the bottom and splash coat the ones on top.
  • The gears actually dont look too bad (I have seen worse) If you get a new shift fork I would say you would be all set for a while. I would imagine you can get a used fork for around $10 +- and NOS would probably around $20

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#14 MailmAn OFFLINE  

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Posted September 14, 2012 - 09:29 AM

  • Shifter Is Way too loose! (This could be one of the causes of difficult shifting since the shifter is allowed to bounce around and not hitting the areas it should when trying to go in gear)
  • You did alot more work than you had to! Hate to tell you this, but you really didnt have to remove that dash panel to get that cover off. If you are careful you can pick up the end of the cover and slowly ease it back out.
  • The gear oil Looks like its got water in it. I would change it with fresh 90wt Gear oil. Be sure not to get the new synthetic oil as it will eat away at the brass parts in the transmission! The oil Level looks ok. It only should be filled to the top of the fill plug in the rear. When running the gears will bring up the oil from the bottom and splash coat the ones on top.
  • The gears actually dont look too bad (I have seen worse) If you get a new shift fork I would say you would be all set for a while. I would imagine you can get a used fork for around $10 +- and NOS would probably around $20


I always knew the shifter was lose, but didn't think that it would cause the gears to bind up or cause other problems inside the transmission? I tried tightening the bolts underneath, but they always seemed to rattle loose again. When I put it back together, I'm going to use new hardware (as I have been replacing all the old hardware whenever I disassemble something on the tractor) with some of the nylon locknuts on it to see if that will keep it from rattling loose again. Hopefully it will keep it all tight. When I took it apart, it looks like it was just held on underneath by a normal nut with no washers.

I actually took everything apart like I did to make it easier (and so I can hopefully do some more painting while it is all apart as well :smilewink: ) However, I DID try to shortcut it by trying to lift up on the front cowl to get that lower cover off, but I couldn't get enough clearance to get over the PTO handle, so I said the heck with it and took everything apart. The worst part seems to be that steering column as the paint on that looks really bad. I'm sure I'm using the WRONG color brown (as all of the browns I have seen look lighter than the original color Bolens used on my tractor), but since I've already painted everything else on the tractor with the same color Rust-Oleum Dark Brown, might as well keep with the theme... (At least this brown looks darker than the Leather Brown Rust-Oleum that Tom from Farmersville used to paint all of the parts he sold me...)

I did think that the gear oil looked milky like there was water in it. I just topped the level off with new stuff, I never drained it. I'm going to do that after I fix it. If it got water in it though, where did it leak from? Was there just a leak in the top gasket that allowed water to get in or could I have a small crack in the case? Where can I get a new gasket for the top cover to seal it up or do I just put some RTV on it and call it a day? It is good to know about the Synthetic gear oil, but it has me worried now as well. I'd have to check, but I'm PRETTY sure I didn't buy synthetic grease to grease all of the fittings on the tractor, but I do think I bought top-of-the-line synthetic 80W90 gear oil to top off the transaxle with as well as to put in the mower deck gearbox. I didn't know that synthetic oil was hard on the bronze/brass components. I figured I was doing better by putting the synthetic in!! :( I put synthetic gear oil in the differentials of my truck and my 1975 Plymouth as well. The truck is newer and probably okay, but IDK if they used any components in the older diffs like the one in my old Plymouth that could be damaged by synthetic oil...

REALLY??? The gears don't look that bad? :confuse: IDK how they could be much worse if you ask me!! Especially that little first gear one that the faces of the teeth are ground right down on. I'll admit that most of the other gears look okay, so you could probably get away with only replacing two gears really - the small 1st gear and the larger sliding gear that engages either 1st or Reverse. But I'm not really sure where you would GET new gears for this and, even if I could, how to install them. How do you remove the shafts that the gears ride on and then remove the gears themselves? I'm kind of worried that maybe all three gears on that input shaft are incorporated into one piece and you'd have to replace the whole thing and can't just replace the individual gears on it. I'd have to look at the parts manual to get a better idea. Has anyone ever attempted to rebuild a gearbox on one of these before?

Also, are both the shift forks identical or do I need a different fork for the 1st/R side than the 2nd/3rd side? How hard are they to replace? I noticed in 8tyman8's video that he put some kind of a rod through the back shift rod support to hold something in there that allows the shift rods to "click" into position or something? I'm worried about taking it apart and screwing something up that will be a witch to fix. Where can I get a rod to slide in there to try and keep it all together? Is there anything else I need to look out for inside there? I've never rebuilt a Bolens gearbox/transaxle before... Although I have seen the insides of a GM automatic transmission before. At least I have to say that this isn't quite THAT complicated, lol!

Edited by MailmAn, September 14, 2012 - 09:35 AM.


#15 Bruce Dorsi ONLINE  

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Posted September 14, 2012 - 10:35 AM

Kevin:

In addition to what Brian has already mentioned:

(1) Those bits and pieces of the worn gears have been distributed around the entire transaxle. ......A thorough cleaning is necessary to remove all those nasty bits! ....Some of that metallic grit may have gotten into the bearings!

(2) When you replace the shift fork, you will slide the shift rod forward. .....You may, or may not, be able to move it far enough forward without sliding the the transaxle rearward on the frame tubes. .....You do not have to undo the clutch shaft or rubber coupling, as the cast-iron flange just slides off the transmission input shaft.

(3) When you slide the shift rod forward, you will lose the detent ball, and possibly its spring, from its position. .....To prevent this, you can slide a 1/2" bolt into place from the rear, as you slide the shift rod forward. .....If you do drop the ball and/or spring, you have to remove the setscrew from the side of the housing to re-install them without difficulty. (Look at the parts manual to see these parts.)

(4) If it were me, I would go further. ....Since you are already this far, I'd suggest taking the gears out of the trans case to de-burr them with a file. .....The missing part of the teeth will not present a problem, but the burrs on the gear teeth will hinder proper shifting, and will eventually break off, and contaminate the gear lube again.

(5) Swapping a complete transaxle does not preclude future problems, especially if the used transaxle has unknown problems.
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