Jump to content
gwest_ca

Transmission locked in 2 gears at once

Recommended Posts

With both shift rails in neutral there is 1/4" clearance between the ball-pin-ball so either rail can be moved to a new position because the balls are in both rail neutral grooves.

 

If the 1st and rev rail gets magically moved into a gear position without the shifter the 1/4" clearance is once again restored by the 1st or rev gear groove and the neutral groove on the 2nd and 3rd rail.

 

Now the shifter can place the 2nd and 3rd rail in another gear with no abnormal effort.

 

What I don't get is why the 2nd and 3rd rail can't be returned to neutral just as easy using the shifter. A long screw driver will do it.

 

Garry

 

  • Like 1

Share this post


Link to post
Share on other sites

have you taken this apart a checked the détente spring? if you have not owned this tractor since new any thing goes may have broken or wrong spring

spring needs to be long and stiff enough to hold balls in détente grooves when in neutral or gear positions

 

Brian

Edited by buckrancher
  • Like 1

Share this post


Link to post
Share on other sites

That’s true Brian. Many times service bulletins were issues for just the reasons you stated. But also, many times for engineering changes to improve performance or correct an issue. Wheel horse was a fledgling company 50-55 years ago when this was going on and they were working with their own design. Again, engineering on the go. My reference to tolerances was only to simplify figuring the proper length of the stop pin. But let’s face it. Just about the only tight tolerances on a Wheel Horse are in the engine that they didn’t build. Theoretically, if all the tolerances were tight enough the original 3515/16 shift rails would have been fine. But they were having issues on new tractors. The reason……excessive tolerances. Then wear stepped in to increase those tolerances. Initially they corrected it with the 5615/16 shift rails (left rail post #2) and the 5614 stop pin. Per the service bulletin:

If it becomes necessary to replace one of the earlier shift rails, we recommend that both new shift rails (Parts No, 5615 and 5616) together with the new Part No, 5614 Shift Stop Pin be installed. The additional cost to the customer is negligible and will definitely eliminate the possibility of the transmission locking in two gears.

So, there you have it. Issued for too much tolerance? A design that didn’t take all the factors in account? Or some of both? Ya gotta love it.

The old 3615/16 rails migrated from the 3-piece cases to the early 2-piece. No thought was given to the fact that now the rail was being inserted into a blind hole. Thus, the suction/pressure issue. Very real. Sure, grinding a flat was the simple fix. It didn’t even have to be opposite the detents. Just provide a release. But they didn’t do it. Not until the public had them in their hands for ‘testing’. :huh: And they revealed the problem.

I was definitely  :confusion-confused: about the groove all the way around and only speculated that it may have been to incorporate the shift stop parts. I’m liking your idea on the milling thing. I hear that quite a bit in many applications.

I doubt that anybody 50 years ago could have imagined that their tractors would still be going strong this long. I have strong memories of driving these tractors when they were new, then building my own herd when married in 1975. I never gave any thought to it. My ‘oldies’ were only 10-15 years old. It was usually an abused machine that had the common issues we see today. Believe me, there were plenty of them but not nearly like what is almost normal now. All of us today are battling a different war than the Wheel Horse engineers were. Other issues are causing the same, as well as new problems. Yes, all the things you mentioned are valid. I wasn’t trying to address those issues, just discussing is more like it was 1965 instead of 2015. :)

 

  • Like 3

Share this post


Link to post
Share on other sites
59 minutes ago, stevasaurus said:

Notice how I am just lurking here?? 

HI STEVE:greetings-wavegreen:

 

You may remember the story of Elmer telling his employees to build them like they were making it for themselves as wheel horse really had no inspection dept. at that time the problem with that is my idea of what's good can be very different than yours and it shows up in places

like transmissions

 

Brian

  • Like 1

Share this post


Link to post
Share on other sites

I just happen to have a #5025 transmission apart in the garage.  I am thinking I will grind a flat down the shafts on this trans.  The week before Thanksgiving, when we got that 9" of wet snow, I was out there pushing snow around with the 702.  I had rebuilt this trans with "all" new bearings and seals a couple of years ago...all the gears were good.  I noticed the shifter was a little loose, but knew it would be OK if I took it easy.  Sure enough, right at the end, I lock it in 2 gears, and I am out by the curb.  I did manage to play with the shifter enough, and managed to get the 702 out of gear, but the forks were still not right.  I pushed it back to the garage, pulled the shifter, used a screw driver to position the forks back to neutral, replaced the shifter and took the slop out of it.  Back in business and it only took about 15 minutes.  The forks are not worn, the shifter is not worn...I just cut the "H" pattern enough to clear the one fork and slide into the other.  I don't know if it was suction, could be, but I did not get the one fork all the way into neutral when I slipped into the other fork, and the 1st fork slipped back into gear...and now the shifter is in the other fork.  Only one way out now...pull the shifter out and use the screw driver.  :)

  • Like 3

Share this post


Link to post
Share on other sites

565f3a5fb9d12_LurkingSnoopy.jpg.f783e1e5

 

We couldn't see you, we couldn't hear you but we could feel it...................something was out there...........:)

  • Like 4

Share this post


Link to post
Share on other sites

:ROTF:way too funny.  This is great back and forth...excellent to read.  This will go into the reference section when it is done.  :)

  • Like 3

Share this post


Link to post
Share on other sites
20 hours ago, buckrancher said:

have you taken this apart a checked the détente spring? if you have not owned this tractor since new any thing goes may have broken or wrong spring

spring needs to be long and stiff enough to hold balls in détente grooves when in neutral or gear positions

 

Brian

Model 701 tractor was not new - only new to me in about 1974.

The dealer at the time was an hour away and could not figure it out.

In the end everything was replaced but unfortunately the shift rails were the old style without the flats.

The only new part that was not replaced was the donut because the new shifter came with one on it.

The last thing I tried was making my own pin which is still in it. I replaced the spring with a bushing to keep the pin centered on the balls and kept shortening the pin until the 2nd rail could be inserted. Then the bushing was replaced by the spring. That was teardown number 6.

Number 7 was when I discovered the oil was sealing the rail to bore clearance. I just installed it back in the tractor and have been holding the shift rail in the neutral position until the pressure or vacuum dissipates to test my theory. It works.

 

Wish we had this wonderfull resource back then. Perhaps I would have received rails with flats instead of NOS rails and problem would have been resolved. I know what I'm doing to it the next time it comes out.

 

All the 1964 model transmissions got a new model number in 1965 and suspect that was a result of the new rails with flats being used.

The photo of the rails with flats posted above is the first time I have seen them.

 

Garry

  • Like 2

Share this post


Link to post
Share on other sites

So true about having this resource way back then. Yes, it was the 65 models. I don't know for sure but I believe that was just the change to the deeper neutral detent as in post #2 and not the flat. That was one of the 5615/16 rails I found for my 5010 and it didn't have the flat but it doesn't matter in the 5007/5010 transmissions. I've been trying to find out, with no success, when they started the flat.

Share this post


Link to post
Share on other sites

the deeper neutral détente scalp was kind of backward thinking the deeper the scalp the more chance of slop in the setup all the scalps need to be the same depth

 

Brian

  • Like 1

Share this post


Link to post
Share on other sites

I don't know Brian, could be. I suspect their thought process was to make the neutral detent deeper allowing a longer stop pin with hopes of it being a bit more forgiving to tolerances elsewhere. Again, they didn't want the ability for one of the shift rails to move unless the stop ball was in the opposite neutral detent and they were engineering on the go. :)

Share this post


Link to post
Share on other sites

I would have thought you could achieve the same thing with a stiffer spring the problem with making the neutral scalps deeper is you are limited in the stop pin length

the stop pin should be measured from the bottom of the scalp radius to the full diam. side of the opposing shift rod less .005 for clearance and the diam. of the detente balls you don't gain anything at neutral

you end up with less spring tension on the detente balls another way to look at it is the stop pin length is proportional to the scalp depth the ratio does not change just the spring tension

by what Garry has said he is not getting or keeping the balls of the detente in the neutral scalp position before he try's to shift to a different gear causing the hang up. Grinding or milling a flat on the shift rods will help this if the cause is drift  from vacuum and pressure in shift shaft bores that are a little to tight I would also think a stiffer detente spring could also fix the problem

 

 

Brian

  • Like 1

Share this post


Link to post
Share on other sites
On 12/2/2015, 1:26:20, stevasaurus said:

I just happen to have a #5025 transmission apart in the garage.  I am thinking I will grind a flat down the shafts on this trans.  The week before Thanksgiving, when we got that 9" of wet snow, I was out there pushing snow around with the 702.  I had rebuilt this trans with "all" new bearings and seals a couple of years ago...all the gears were good.  I noticed the shifter was a little loose, but knew it would be OK if I took it easy.  Sure enough, right at the end, I lock it in 2 gears, and I am out by the curb.  I did manage to play with the shifter enough, and managed to get the 702 out of gear, but the forks were still not right.  I pushed it back to the garage, pulled the shifter, used a screw driver to position the forks back to neutral, replaced the shifter and took the slop out of it.  Back in business and it only took about 15 minutes.  The forks are not worn, the shifter is not worn...I just cut the "H" pattern enough to clear the one fork and slide into the other.  I don't know if it was suction, could be, but I did not get the one fork all the way into neutral when I slipped into the other fork, and the 1st fork slipped back into gear...and now the shifter is in the other fork.  Only one way out now...pull the shifter out and use the screw driver. 

Steve I have had old transmissions do this and if everything inside is right you should not be able to get the shift lever out of one fork and in to the other without the transmission being in neutral

if you tear this down really look at these parts

shift lever check ball diam. should be around .500 be sure there are no flats on the sides of the ball also look at hole for set screw pin in collar to be round and not hogged out and collar tight to shaft

shift forks check for radius grooves in slot where shift lever ball contacts sides

also check all detente parts

 

Brian

  • Like 2

Share this post


Link to post
Share on other sites

This is interesting stuff.

A stiffer spring could possibly likely help but it still wouldn’t provide a positive ‘lock-out’ that they were seeking. With this design that’s not possible with all the détents the same depth. Something was needed to provide an interlock necessitating that one of the balls was in a neutral detent before the other could move.  You’re figuring the stop pin exactly as I mentioned only using .005” for tolerance where I left that out for the sake of discussion and I'll continue to do so. The .005” does sound pretty good in this application. But, the measurement needs to be taken from a deeper neutral detent. That is the only way to be positive one of the rails is in the neutral position or it can’t move. Bottom of deeper neutral détent to the opposite rail side minus ½” (2 shift balls assuming exactly 1/4" each) = X. Bottom of any of the other four détents to the opposite rail side minus 1/2" =…..something less than X.  Therefore one ball must be in a neutral détent in order for the opposite ball to roll up to the outside diameter of the rail.

Steve and I discussed his issue a couple days ago on Skype. Unless they’ve been changed, his 702 has the old 3515/16 rails with the three identical détents. The 5615/16 rails probably wouldn’t have stopped it from locking up with what happened. Even with a relatively simple set-up like this there were multiple little bugs to iron out. Remember, these guys didn’t have the advantage of going to the future and looking back at the evolution and be an armchair quarterback. If I’m understanding him correctly he was pulling one rail back to the neutral position and slipped the shifter ball into the other fork just as he got there. But the fork/rail the shifter came from was pulled back due to suction. He also felt it when he had the shifter pulled and tried to slide the rail back to the correct position. Don’t underestimate the suction/pressure thing. It’s the only way a syringe works. Try capping the end and moving the plunger. Then cut a slot in the side of the plunger and try again. I don’t know just how much forgiveness there is as far as this being allowed to happen but you’re right, it shouldn’t. Clearly, it’s a 53 year old machine and there’s wear and tear so undoubtedly that played a part. I also know that you’ll find it. After all, you’re one of the transmission gurus here. But I’d also lay odds that, if the rails had the flat to release the suction, it wouldn’t have. Steve, I’m looking forward to your findings. We can share dimensions if you’d like as I have some excellent extra forks here. I wish I had some extra later style rails but the only pair I have will be going in the 500 Special that will be my snow pusher when we move back up there.

:)

 

  • Like 1

Share this post


Link to post
Share on other sites

we are pretty much on the same page with this I did not state to measure from the deepest scalp but that what I was thinking the problem with the deeper neutral scalps is you lose spring pressure in neutral position as both rods have deeper neutral scalps

and you are stuck with a stop pin that only takes in count one of them for length so in neutral the détente balls will be in there farthest position with the lest amount of pressure on them from the spring

 

HI STEVE:greetings-wavegreen:

 

Brian

  • Like 2

Share this post


Link to post
Share on other sites

very true. But it shouldn't take much to keep in in neutral or in any gear for that matter. Oh wait, the infamous chewed 3523 gear :ranting: maybe the engineers should have worked on that a bit more. Brian, is it you that I heard did gunsmithing?

Share this post


Link to post
Share on other sites

My trans was rebuilt like 4 years ago...my 1st transmission rebuild.  All bearings and seals were replaced with new, including the #1533.  I put in new detente balls also.  All of the gears, shafts, spring, stop were not replaced.  Here is the only picture I have of the fork shafts...I do not see a lot of wear.

 

When I locked it up 2 weeks ago, I was pushing snow forward in 2nd gear.  I pushed in the clutch and started raising the blade (HY-2), brought the shifter toward neutral and did not do the sharp "H" pattern I was doing before.  I was in neutral enough to be able to move the shifter into the other fork, I may have still been rolling forward a very little, and I ended up still being in 2nd gear with the shifter now stuck in the 1st/rev fork.  To me, it had to be suction...this is a new trans with clean oil.  When I pulled out the shifter, and here is the thing, the 2nd/3rd gear fork was totally positioned into the 2nd gear slot on the shaft.  Something pulled that shaft back into gear...and they were not little green and yellow gremlins.

 

I remember driving my 1964 Ford one time when I locked up the gears in that.  That was a 3 speed on the column, and I knew you had to do a sharp "H" pattern or that would happen.  A pry bar under the hood on the linkage would fix that.  :)

 

I have a #5025 apart in the garage, maybe take some measurements and pictures this weekend.

  • Like 4

Share this post


Link to post
Share on other sites

Hmm..  just finally read through this thread since my last post and got to thinking....   

 

The whole purpose of the deeper neutral grooves and slightly longer interlocking pin are to ensure that one shifter rail cannot move if the other is in gear.  Try this on a transmission with the old style rails; pull the shifter and using a screwdriver move one rail into gear, then try moving the other rail into gear.  With all the grooves equal depth the second shifter SHOULD move normally into either gear even though the first rail is already in gear.  

 

With the newer rails and pin this will NOT be possible.  The older pin ONLY prevented one from moving BOTH rails from NEUTRAL at the same time!  The new pin prevents the second rail moving UNLESS the first is in neutral.  

 

Now here is a problem...  this longer pin still DOES NOT fix the vacuum issue!  The vacuum will suck the first rail back into gear immediately when the shifter ball moves to the second rail.  At that instant the second rail is still in neutral, allowing the first rail to move into gear without the shifter.  The addition of the flat is what corrected the vacuum issue.  

 

To those experiencing the vacuum sucking it into 2 gears I propose a (somewhat) simple fix (WARNING: TEARDOWN AHEAD!)

 

You can easily modify your existing rails to relieve the vacuum issue after tearing down the transmission and removing the forks from the rails.  Using a grinder or even better a belt sander, grind a flat on the backside of the rail (opposite the detente balls) and reassemble the transmission.  

  • Like 1

Share this post


Link to post
Share on other sites

jrc0528...you are basically correct all the way through, except ,(maybe) for this...and I am not sure about this.  I am just going to talk about being it 2 gears at the same time.  The options are this...be in 2nd and 1st or rev at the same time or be in 3rd and 1st or rev at the same time.  The cluster gear is a one piece unit with 3 gears on it from top to bottom...or from side to side as it sits in the trans.  The left end is 2nd gear, the middle gear engages the reverse idler all the time, and the right gear would be 1st...the fork gears slide between these gears.  I am not sure that, while you are in 2nd gear, you could even get the 1st/rev fork gear to line up on the cluster gear and engage in either 1st or reverse.  3rd gear is a different matter...3rd gear would ride on the input shaft which turns independent of the cluster gear shaft, it engages a pinion gear which turns the 11/44 toothed gear.  I think it is possible to be in 3rd gear and maybe slide the 1st/rev fork gear into an engagement with the teeth of the cluster gear.  In the 1st scenario, I would think you would grind gears trying.  In the 2nd scenario, the transmission would actually be in 2 gears at the same time and would be locked...hopefully killing the engine before tearing the transmission apart. 

      In my case, I was locked in 2nd gear...the tractor would move forward even though the shifter was locked in the other fork.  My problem, going forward would put me out in the highway...not an option.  I had to be able to roll the horse backward or pull the horse backward.  :)

     

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for saving me the typing Steve. I know your gears are cranking (pun intended) and will let us know. One more thing jrc, with the old rails with shallow detents of course the other rail can be moved while one it in gear providing the gears will allow it. All it required was that one on the detent balls be in any detent since they were all the same. All that stopped it was the fact that the shifter ball is with the rail it just moved and there was nothing to physically move the other rail. :)

  • Like 2

Share this post


Link to post
Share on other sites

need a stiffer detente spring

 

Brian

Edited by buckrancher
  • Like 1

Share this post


Link to post
Share on other sites

:occasion-xmas:  Hi Brian  I'm behind the tree.  :)

I think..."Experiments on video" is in order...but Baby it's cold outside.  :eusa-think:  I think I can lift one side of a transmission case with one fork shaft pushed in with some oil in the hole.  Lift it up by the fork...question is...how long before it falls.  What do ya think?? 

  • Like 1

Share this post


Link to post
Share on other sites

Being one that is always doodling I have always admired the parts illustrations. The attention to detail is outstanding.

Take a look at the shift rails in this 1966-1969 parts list

It shows a notched rail and flats.

What took me here was the fact the same rails are used in the 6-speeds and have never heard of them being a problem.

 

Garry

  • Like 2

Share this post


Link to post
Share on other sites
40 minutes ago, stevasaurus said:

:occasion-xmas:  Hi Brian  I'm behind the tree. 

I think..."Experiments on video" is in order...but Baby it's cold outside.    I think I can lift one side of a transmission case with one fork shaft pushed in with some oil in the hole.  Lift it up by the fork...question is...how long before it falls.  What do ya think?? 

you guy's that plow snow in the winter with the early gear tractors when the oil is the thickest must have most of this problem never had it happen to me I use a hydro:D

 

Brian

  • Like 3

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×