using an h42 as a rox bock (1 Viewer)

[lowtideride]

using an h42 as a rock box

I'm wondering how hard it would be to run dual h42's and use the second one as a rox bock. You would only need one adapter plate. I would also think you would have to change an out put shaft so that where the adapter plate is the out put shafts have the same spline count. I have seen some adapters have a coupling to attach the shafts. Its out of my hand to be able to make a coupling for this but not the adapter plate itself.

Any ideas on how this could be done? I know with enough time and money anything is possible but am I just having a pipe dream on keeping the budget for this under 800?

-Al

 

[lowtideride]

ooo its late, ya can tell by the title.

 

[cruiser ken]

If you put them both in reverse do you go forward?

 

[Mace]

actually, yes

very doable Al, but the machine work would be a PITA..

 

[lowtideride]

Well I posted up and someone broughtt one to a wheeling trip this weekend, looks like I gotta do it now. Its an 85 with the extention....Which might help. Ill have to call up marlin and see what out put shafts they have for it.

 

[rusty_tlc]

If you put them both in reverse do you go forward?

At that gear ratio (4.27X4.27=18.23) "go forward" would be a relative concept.

 

[bustanutley]

I'm thinking that a cruiser tranny may not be up to the task, but what do I know...

 

[lowtideride]

I think a 60 series tranny would hold up...its not last in line to take the torque which will help it, (although its not first either)...I think the R&P/ axle shafts would/will go first..


I could be wrong though...wont be the first time.

 

[lowtideride]

Alrighty,

I Picked up a late h42(with the spacer) with about 100k on the clock. Ive been studying the FSM and started to tear into it. I also have an H41 shifter plate for the top of it which moves the shifter forward and might be enough to save the glove box, but really thats the least of my worries.

I have scratched my noodle and thought of a few ways to attach them together...

and here is my best plan so far... Please point out flaws in my logic because i'm sure there is a few. This idea on attaching it might be a crap shoot, but at least I will know how not to attach it.

I was thinking of cutting the output shaft off right up to the gears and then getting the gears machined in the center to accept the input shaft for the t-case. Would this be a doable idea?

 

[lowtideride]

I was also thinking instead of using the output you could use third gear, thats if the gears would mesh up correctly and completely get rid of out put shaft pictured above. Then you could have an underdrive and I could swap back to 3.73s or 4.11s....


So, you would end up with 3rd as high and 1st as low...

 

[FLYINGLOW]

I was also thinking instead of using the output you could use third gear, thats if the gears would mesh up correctly and completely get rid of out put shaft pictured above. Then you could have an underdrive and I could swap back to 3.73s or 4.11s....


So, you would end up with 3rd as high and 1st as low...

Do you mean input pictured above?

If the gears mesh correctly it would work, you would just need a sleeve to make use of the input bearing.

If you did cut off the stub on the input though, is there not a recess on the back side? Is the dia of the recess smaller than the dia of the valleys of the splines on the output shaft?

Just throwing some ideas to you. I think I might have to go down and dig out my exploded view of a tranny.

 

[lowtideride]

Do you mean input pictured above?

If the gears mesh correctly it would work, you would just need a sleeve to make use of the input bearing.

If you did cut off the stub on the input though, is there not a recess on the back side? Is the dia of the recess smaller than the dia of the valleys of the splines on the output shaft?

Just throwing some ideas to you. I think I might have to go down and dig out my exploded view of a tranny.

Yes the input pictured above...I was talking about getting rid of that all together and using 3rd gear in its place. Because I believe it is the right spline count already...and then just use a spacer where 3rd use to be. Thatssss all if the gears meshed correctly but I doubt they would.



As for the input pictured above what I was talking about getting rid off the shaft and maching the centers to accept the output that is suppose to go into the t-case. So, you would then would have to cut the output to lengh...but Im not sure how you would retain the gear to make sure it would not move. You would also have to find a new size bearing, agian though prob. the least of the problems...

thanks for the insight man... when I get my own machine I will post an exploded view of the tranny.

 

[lowtideride]

Alright scratch the 3rd gear idea off the list....heres why.


3rd gear is larger so that would move the whole second tranny downward which would be a major nono. It would have to move down to make room for the larger gear. also you would have to relocate the bearing in the side of the case which would be a PITA...


So, back to changing the input shaft to be able to accept the output shaft, by maching the center...

 

[FLYINGLOW]

I think you also need preload on the output shaft, like the nut that goes on the end. I don't think SM420s have this problem though.

 

[lowtideride]

hmm, how much of a problem could that be?

 

[lowtideride]

wait, I don't think you do...If you have read or seen how the toybox is installed. I does not use pre-load at all.

 

[fng55]

lowtide, how deep can you spline the inside of the input gear before you run into the race for the rollerbearings that tie it to the output shaft?
more machine work but would it be easier to cut that input shorter and respline with an adaptor sleave to fit a cut down output shaft?
keep us posted, carl

 

[lowtideride]

lowtide, how deep can you spline the inside of the input gear before you run into the race for the rollerbearings that tie it to the output shaft?
more machine work but would it be easier to cut that input shorter and respline with an adaptor sleave to fit a cut down output shaft?
keep us posted, carl

I've thought of that too. I think if I did that it would make the adapter wider. With the idea now the adapter is only around a .5 inch. And with using the h41 top on the second case the shifter is only 8inches from the first shifter, which makes everything fit about perfectly.

Also I wanted to keep the shaft bigger because of the torque load...albeit that shaft at most is seeing 4.8 to one where the axle shafts will be seeing at times up to 232 to one...I just wanted to keep it as strong as possible. Thanks for the response though and Ill will keep ya posted...

 

[FLYINGLOW]

wait, I don't think you do...If you have read or seen how the toybox is installed. I does not use pre-load at all.

Ok, I see now. I thought the output used the tcase as some sort of support, but I must have been wrong.

 

[lowtideride]

Ok, I see now. I thought the output used the tcase as some sort of support, but I must have been wrong.

The later trannies do, from 85 and up. the earlier trannies just use a spacer and the bearing is retained in the tranny itself.