Orion: still popping out of gear! Lets form a club!!!

[treerootCO]

I'll add my name to the list....need to keep an eye on these threads.....

Detent Ball = 90360-10003
High-low shift sleeve = 36235-60011
Gasket kit = 04362-60030
Input seal = 90311-42014

lots more info over on https://forum.ih8mud.com/showthread.php?t=25753&page=7&pp=30

too much to retype

 

[treerootCO]

Yes Brett, please elaborate on this.


Thanks!

This is from the Marlin board. The gears in the Orion have the non taper mentioned in this post. Poser brought up the point, that if this was the case, all the cases would be popping into neutral. At first, I figured that was true. Now, I am starting to believe this is the real problem. The little things we have all done have helped but have not fixed the problem. If anyone on this board knows Marlin, give him a call and find out from the source if all of his first generation gearsets had a neutral problem.

http://board.marlincrawler.com/index.php?topic=2436.msg19917#msg19917

Quote:

"The problem with your transfercase is internal. The 4.70:1 gear set that you purchased through Advanced Adapters is using our old discontinued 4.70:1 gear set made by their gear cutter. I know this because he was our gear cutter for about 3 years and as soon as we left him to make better gears, A/A immediately began retailing 4.70:1 gear sets (both A/A and Marlin used the same gear cutter). The problem is that his machinery lacks the ability to cut those old gear sets (originally designed in 1997) the way the manufacture Toyota did -- And this is one of the reasons why we left him.

Our new 4.70:1 Gear Sets are cut by none other then Toyota©'s Gear Cutter in Japan. We went straight to the source and our New Gears are manufactured by the same company that made the gears in everyone's pickup on this board.

The above picture is a shot of the shift hub teeth on the Input gear. The factory 2.28:1 gear sets used a 2° taper that was tapered into the gear - forcing the shift hub to stay in place. Our old discontinued gear sets (now A/A's) does not have this 2° taper and therefore the shift hub can "float" up or down those teeth depending on coast, drive, and load.

This was a HUGE problem with our gears when we used to sale those. Customers all over the place would complain about it popping out of gear, it would even happen to Marlin. So to counter this problem, the only thing we could do was try to strengthen the detent ball spring pressure and hope that the fork could keep the shift hub in place, but we found that this was only a 50/50 chance of working. Some units would stay in gear while others would still pop out. It may have been due to some shift hubs with higher mileage that had wear on them but we were unsure.

So we demanded for our gears to have the same 2° taper as the factory gears but our old gear cutter lacked the ability to cut any taper to those teeth. So we were left with no choice but to leave him and find a better gear cutter and that's when we hired Toyota's gear cutter. Now Marlin could design his gears the way he had wanted to..."

 

[Pin_Head]

The tapered teeth are a good thing. Toyota wouldn't go to the trouble of the extra machining if a single straight cut would do the job.

The tapered teeth compensate for the gear and shift collar tilting on the shaft so that the tilt doesn't create any force to slide the shift collar back to neutral. Even with a tiny tilt of 1 degree, this creates a lof of force against the shift fork when you have 400 ft pounds of torque or more acting on the gear.

 

[peesalot]

ding , ding , ding , ding , ding , ding
the taper issue combined with poser's spacer for the hi/lo gears is the solution.
can not fix taper but mine has settled down and seems to work well.

 

[cruiseroutfit]

...Without seeing the parts firsthand, my impression may be overly simplistic, but if there is an engagement issue, could it not be addressed by re-notching the detent positions on the hi-lo shift fork shaft slightly outboard of their current position? ...

On track thinking... in talking with Randy (AA's Orion dude), this is exactly what they are doing to solve the problem.

 

[Advent]

I will probably be installing a Toy box in front of it within the year. The 4:1 low range is nice, but the jump between low and high is not to my liking. A 2.28:1 intermediate low should round it out nicely. But that means that the 2F will have to come out of this rig in favor of a 350 TBI, because of the length concerns. Oh wll,... If I have to...

You know Mark, it would be cheaper to build a centered rear diff, and do a 203/205 combo...Then you could sell me the Orion

 

[TOMSRYD]

Thought mine was O.K. ...... Ran the Rubicon for the Marlin Crawler Round-up with no problems ... Thought my popping out of gear days were done.............Then I ran a short trail at surf-n-turf; about 2.5 miles, Out it's popping again........ Guess I'm in the club

 

[Poser]

On track thinking... in talking with Randy (AA's Orion dude), this is exactly what they are doing to solve the problem.

By making a new high/low shift shaft.

 

[cruiserbrett]

Sorry for forgetting to post, but treeroot's borrowed picture sums up exactly what I meant about the tapered teeth where the dog clutch engages. Even old 3 speed cases have the tapered tooth design, and theres a reason for it. It essentially pulls the dog clutch towards the gear under load(which is both acceleration and deceleration BTW)

I am sure you can mitigate alot of the symptoms with a tighter detent ball tension, and a new dog clutch, etc. but its kinda avoiding the problem.

BTW, Mark A., the wear you talk about is actually helping them from popping out of gear. In fact, if you look at the dog teeth on the gear, they are manufactured in varying thicknesses as well as witht eh abovementioned/pictured taper. The varying thickness teeth prevent all teeth from engaging the dog clutch slider, and it will allow the dog clutch to wear in sooner.

 

[Mark W]

You know Mark, it would be cheaper to build a centered rear diff, and do a 203/205 combo...Then you could sell me the Orion

Let's see... Longer, heavier, less gearing, more expensive... Yeah that sounds like a good idea.

Better order your own Orion.


Mark...

 

[peesalot]

the new shaft or repositioning the detents don't cut it sorry people. why don't the A/A guys read tree's original thread , it would save time.

Moving the position of fork only lowers the # of times it pops out. You see , the collar and fork wear make a significant change , if they are worn or even each piece being somewhat worn it will negate some of or all the moving over of the shift fork.

Here's how I know : when assembling mine we had the tab that holds shift rail in backwards , this caused the collar to drag on the dogteeth when in neutral. we noticed this as we were spinning it to set output tension.
To solve this we ran a little test :
we spaced the shift rail retainer out til the dogteeth were clicking when in neutral( it twernt much beyond where we were already) , then we lost the shim and flipped the retainer tab around which shoved the shift rail into case about an 1/8 in. farther than the other way and it was perfect for dogteeth clearance but put edge of collar way close to gear.

This is why I say the new shift rail position aint the answer , it is a waste of time , simply playing with the retaining tab will find a suitable shift rail position.

The problem that I can not solve is :

a) no taper on dogteeth ( any tranny builder will tell you this is what causes sm420's to pop outa 3 rd.) already a tested and proven problem area


b) even positioning collar at best location just lessens occurance , you must IMO , machine shift collar down or use poser's spacer idea . I think even just using the thinner shift collars and proper position of collar may solve issue.

 

[cruiseroutfit]

By making a new high/low shift shaft.

In the future... but now they are machining (EDM) the existing ones as per Randy. I've got one I am working on now, if it needs be, I might have to toss it on the Robofil.

 

[cpg]

OH no dont put it on a charmilles it will pop out much more. Have someone with a Mits burn it.

Check the clearance of the thrust washers. I made some special ones to bring the clearance to .004" (was around .025") Also reshaping the detent for the ball to match perfectly. This with the new under cut gear has eliminated the transfer case from popping out.

 

[cruiseroutfit]

OH no dont put it on a charmilles it will pop out much more. Have someone with a Mits burn it....

Ford versus Chevy battle there...

Neither of them are a Toyota...

 

[65swb45]

Sorry for forgetting to post, but treeroot's borrowed picture sums up exactly what I meant about the tapered teeth where the dog clutch engages. Even old 3 speed cases have the tapered tooth design, and theres a reason for it. It essentially pulls the dog clutch towards the gear under load(which is both acceleration and deceleration BTW)

I am sure you can mitigate alot of the symptoms with a tighter detent ball tension, and a new dog clutch, etc. but its kinda avoiding the problem.

BTW, Mark A., the wear you talk about is actually helping them from popping out of gear. In fact, if you look at the dog teeth on the gear, they are manufactured in varying thicknesses as well as witht eh abovementioned/pictured taper. The varying thickness teeth prevent all teeth from engaging the dog clutch slider, and it will allow the dog clutch to wear in sooner.

Brett, by way of observation of the situation only, and by NO MEANS to be taken personally, it seems to me that what you are saying proves exactly the opposite of what you mean.

If the hi lo shift sleeve and the dog teeth on the output gears share the same ramp angle, it would be EASIER for them to slide past one another, while a non-ramped dog tooth would actually begin to 'bite' into the hi-lo sleeve sooner than a ramped one.

Nonetheless, it is disconcerting to hear about this ramping issue. I had not considered this possiblility before.

 

[Poser]

Check the clearance of the thrust washers. I made some special ones to bring the clearance to .004" (was around .025") Also reshaping the detent for the ball to match perfectly. This with the new under cut gear has eliminated the transfer case from popping out.

How many miles do you have on your case with .004 clearance?


What oil are you using in the case?



Thanks!


-Steve

 

[Pin_Head]

Brett, by way of observation of the situation only, and by NO MEANS to be taken personally, it seems to me that what you are saying proves exactly the opposite of what you mean.

If the hi lo shift sleeve and the dog teeth on the output gears share the same ramp angle, it would be EASIER for them to slide past one another, while a non-ramped dog tooth would actually begin to 'bite' into the hi-lo sleeve sooner than a ramped one.

Nonetheless, it is disconcerting to hear about this ramping issue. I had not considered this possiblility before.

The issue is not so much the gear teeth "biting" into the clutch sleeve. The issue is that by cutting the teeth straight, you create a force that tends to push the clutch sleeve back to the N position when the gear teeth mesh with the sleeve splines. The force arises from the fact that even new parts have some clearance and can tilt slightly on the shaft so that the gear ans spline surfaces are not absolutely parallel to the shaft axis. Even a fraction of a degree will create enough force to overcome the detent ball spring.

Eventually, the trapezoid teeth will wear a matching surface in the sleeve and this will serve to positively retain the sleeve.

 

[1Fine40]

By making a new high/low shift shaft.

So is AA going to provide the owners with this new shift shaft as a matter of course, or do we have to bug Randy to get one? (I'm sort of hoping they will re-cut the Hi/Low gears w/ a taper and have us exchange our original straight cut ones for the tapered units....) Prolly a pipe dream....on that one

Cheers!

 

[tequilalover]

This is all friggin great. I ordered my Orion not too long ago - It's still in the box at the mechanics shop about to go in. So what should I do now?

 

[cruiserbrett]

If the hi lo shift sleeve and the dog teeth on the output gears share the same ramp angle, it would be EASIER for them to slide past one another, while a non-ramped dog tooth would actually begin to 'bite' into the hi-lo sleeve sooner than a ramped one.
.

I agree that the angle will make them slide easier, but if you look at the direction of the taper in relation to the direction needed for the collar to "pop out of gear" you'll notice that the load of the tapered teeth will pull the collar towards the gear(not the output shaft.) Kinda like the thrust loading created by helical cut gears, except that since the other side of the tooth is tapered in the opposite direction, it will also pull the collar towards the gear when opposite thrust loading is imparted on the gear/collar, when transitioning from acceleration to deceleration...