Any one else want a .52 over drive? Less than a grand?!

[hot rod deuce]

Ok so in my quest for more gears and free power, I have been looking at trannys. Some of you may remember my RTO-613 plans. Well a 613 is more like a 15 speed with overlaping gears. They DO NOT split like a normal 13. Plus they are very weak and every one I talked to said a hot 5.9 would eat it.

SO I went for an evening walk in my junk, oops I mean stuff yard. I found an RTO-913. It is about 120 pounds heavier than a 613 and splits like a normal 13. The problem was that the OD was in the back box. The splitter to be exact, its direct and about 12% over. This is the box that splits the top 4. The other box, or ranger is a direct and about 4:1 reduction.

The 12% OD is not enough for a guy that wants to run 100 mph. SO in to the front box I went. After close inspection I found the two front gears can be swaped. This offers .62 OD. Put this all together and you have about 50% OD.

The best part is these trannys are cheap. The problem is they are out dated and every one is scraping them. They are the same as NEW truck trannys but todays trucks run much more TQ. I have an 1,800 FT LB 18 speed laying on the floor and most people would never tell the 913 from the 18 speed.

Mine has a #2 bell that will bolt right up to my new 5.9 and use a double 14" clutch. Im not completely sure the #2 would bolt up to the LDS. However I do think there are #3 bells made for the fuller box that was used behind Chevy 427 truck motors. So if you did some looking and were creative its a sweet box.

Any way, I hope some one can use the info! Im going to go stick my head back in the gear box.

 

[rhyne6262]

I have a few questions, I own a M35 and want to convert the tires to the large Michelins. What parts are needed to run singles in the rear? Then is it possible to use the existing rims? How big of a tire would fit the truck without lifting and causing any rubbing in the truck?
Regards
Adam

 

[gimpyrobb]

6262, do a search for flipping hubs. You shouold try to not butt in to a thread with off topic questions. The search is to the right. <---

 

[Stretch44875]

just so ya know right is --->, LEFT is <----

LOL!!!!

 

[gimpyrobb]

Yes, sometimes I am truly dumb. LEFT!

 

[m-35tom]

hr are you saying that with the 12% in the rear box the total od is near 50%? as in .66? count the teeth and figure what the total really is. .66 or more would require some serious power, as in something other than a multifuel.

 

[gimpyrobb]

Tom, I'm pretty sure he has a hot 5.9 Cummins installed.

 

[hot rod deuce]

its 62 in the front box and and .86 or so in the rear box, my notes are all in the shop. it comes out to just a hair under 50%

It will take power but the huge splits make the truck seem like a dog. My first OD will be about like the factory one, my second will be .62 and the shird will be the .52 one.

he is right it will take a load of power. I should be fine for power, Im around 330 HP and 600+ ft lbs now but I found an after cooler from a higher HP 5.9 that I am going to swap in as soon as I can get some lights in the bumper and ditch the ones in the grill to make room. So i will have more room to go with the parts I have. The multi is 134 hp and 300 (or 330) Ft Lbs acording to the books I have from Boyce. My thoughts were that the axles can handle the multi with the transfer case in low (2:1) with a saftey factor. SO if I double the TQ it should be a safe range with the T case in high. I can just be careful withthe case in low.

The idea here is to get my crusing RPM down to where the 5.9 actualy makes some power.
1800 will be 64 MPH figuring on a 52" tire with the axle 26" from the ground, I think it will be a little less because of tire squat. I never actualy mesured the axe center to ground. Before it was flat on the governer at 2300 to get 64. Plus friction, wind drag and all that good stuff.

I have not played with the RPM governer end of the pump yet but I will be puting a 3,000K gov. kit in as soon as I get to it. That will give me 100 MPH acording to my math.

 

[hot rod deuce]

Just cought another part of tom's question. The fuller tranny is really two boxes in one. one is the stick and the other is the air switches. The front box, what we would think as the tranny, gets me .62. Then the power goes the the next box. this is what get you the "high/low" and the option to split the top four gears. This box gets another OD about about .86. So you actualy have 2 gears that OD but you can run any one of them alone. or combine them. so you actualy have three OD gears.

This box also gives you three reverse gears.

 

[Trango]

Hi HRD,

So Spicergear and I have been brainstorming about this very subject, and I've been also doing heaps of research on these trannies.

Now, which gears are you swapping? My research also shows that these twin countershaft trannies are twin for redundancy, essentially. I mean to say that the countershafts are identical, right?

So, you have the input shaft coming in, and engaging the drive gear on the mainshaft. This splits the torque to the countershafts. The countershafts, in turn, drive all of the other gears on the mainshaft, which selects gears like any normal tranny, by basically coupling the gear to the mainshaft.

Now, this mainshaft travels down, past the "firewall" between gears and range box, which is where the range is selected (and airshifted for you).

Just to follow you, it sounds like you are swapping the gears that drive the countershafts off the input shaft, possibly with one of the "3rd" or "4th" gears that you'd normally be selecting with the gearshift? Am I guessing this correctly? I'd guess that you are basically going to shift the whole front part to a faster countershaft speed, by cannibalizing one of the shifted gears, such as "2nd gear", "3rd gear", and then put the original countershaft drive gears farther down the countershaft, in the space of one of the original gears....

am I reading you correctly?

Thanks
Bob

 

[hot rod deuce]

Yes, your on the right track. I swapped the gear that is on the input shaft, this is the one driving the countershafts and put it on the 3rd gear spot. It is giving up your 3rd gear and making it an OD. So what is happening is, you SPEED UP your counter shafts making ALL of the gears a touch higher. Then since the gear you took OFF of the input shaft is on the main shaft it becomes DRIVEN rather than the DRIVER, so makes the main shaft go faster. the "3rd gear" cluster is now the "power" to the counter shafts. so it works backwards too because rather than the OUTER gears (or counter shafts) driving it it is driven by the input shaft.

I *THINK* if you buy the kit to make an RTOO you get some new gears because the kit gives you less OD im pretty sure. I think the factory kit tries to avoid making the counter shafts go faster because it will mess up all of the other gears, making them faster. plus I think the splits would be smaller.

I am wondering about buying a parts tranny and just getting rid of the gears I put on the input shaft to drive the counter shafts and put "stock size" gears back on the input shaft. This would give you LESS OD but would not mess up all of your other shifts. I it would be about 5% less OD. I know it would make the stuff last longer but I would rather have the extra OD because I will never wear it out. None the less its something for you guy to consider.


So yes you are right. I can snap some pics and see if I can post them. The box is taken apart right now but I think I can show evey one else.

The counter shafts are the same EXCEPT the lower one has 47 teeth on the PTO gear and the upper has 44. (dont quote me on the tooth count but its along those lines) Bottom line is the lower PTO gear is bigger than the upper PTO gear. So if you put the lower CS on top the cover will not fit on.

Dont forget you need to time these trannys, make sure you get the Keys on the counter shafts in time with the key on the main shaft or it will grenade its self with time. This has to do with the tooth count on the shafts. its kinda hard to explain but they will vibrate a ton.

 

[Trango]

Ok, that is EXACTLY the stuff I need - thanks! I most likely have a source for extra gear clusters, so I can probably do this without screwing up the splits (not that this is a big problem either, since you just have so many gears in these trannies).

Fantastic work, again. I was thinking I'd have to do something really complicated to the range box - glad to hear it's alot simpler than that!!!!!

Ok, time to track down the parts catalogs for my 13609B and figure out some tooth counts.

 

[m-35tom]

don't forget that you will have problems with the transfer when you turn it that fast. over 65 mph or so you will need to go to 50 wt oil. when i ran mine at 70 + the 90 wt would foam and come out all the seals (new) i was turning the drive shafts at 4600 rpm

 

[hot rod deuce]

Oh yeah thats a good call! thanks for sharing. Do you think synthetic gear oil would not foam?

 

[hot rod deuce]

Trango, be care full, when you swap gear clusters make sure the timing isues work out. If you dont mess up the splits you will have to give up a little bit of OD on the top...So you are goona use a nine? The 13 is only about 4 or 6 inches longer plus you get a bigger OD. With a nine I think you will get about .62 over all. Do the nine speed rangers go from UNDER to DIRECT or from UNDER to OD?

Not trying to yell at you with caps, just making it stand out so I can understand it too.

 

[m-35tom]

hrd, will either of those trans fit in place of a stock transmission?? i thought they were huge in comparison.

 

[Trango]

Hi Tom,

They indeed are HUGE trannies - about the size of a Chevy V6 motor, to be honest, with a nearly commensurate weight.

Without going to so far as to speak for HRD, I'd say that this type of option really only suits a repower, where you're already messing around with mounts and tcases etc.

It's weird, but I was just thinking about this, again, cleaning up the house, and I was thinking that for a standard deuce with the LDT465, your re-gear option for the 3053 is probably the best thing running. But, if you already have to futz with the mounts, or if you have a very short engine and have the space to shoehorn this in the place of the tranny, this is one possible good way to go.

Ahh, look at me - I haven't even done it yet and I'm saying it's a good idea. Soon, though.

Happy new year,
Bob

 

[hot rod deuce]

Trango, do you have a body lift yours? I have 3 inches and will need a hair more to make this clear the floor boards unless I start chopping. I dont think a 12609 is any bigger than a 913 height wise but its goona be TIGHT even with 3 inches of body lift. I have too much work done to the insides to cut the floor up. My T-case needs to go back about a foot and a half too. Then I will probably need a 2 part front drive shaft with a hanger. The clutch and brake system needs to move. They will probably wind up on the fire wall with a hydo clutch and maybe hydroboost brakes.

Its not for the faint of heart but if you want some thing small there is a SWEET spicer 7 speed, about the same size as a stock trany. its a couple inches longer but you get two more gears and anO D around .70 or so.

But this would still requre a lot of doing, moving the transfer back and the like. Plus you had better be handy with adapters and bell housings.

The best big OD is tom's gear swap if you dont have a shop and ton of old trucks laying around for parts or know where to get the parts. it sounds like bolt on parts where any one can take out the box and swap some gears out. I would comepare it to putting in a locker or the like.

Hmmm....Just did some math, if I can spin my drive shaft 4600 I will be going over 100 MPH! Did you do this with your .70 OD?

 

[sermis]

" if you want some thing small there is a SWEET spicer 7 speed, about the same size as a stock trany. its a couple inches longer but you get two more gears and anO D around .70 or so."

Do you know the model number? What did they come in? I am thinking of putting the 3053A from my parts truck into my M725 to have an OD. I would like more than 0.85 OD. Was also thinking of a browne after the t-case to help too but all I can find right now is the D? with only have 0.84 OD

 

[hot rod deuce]

95-ish Ford 650-750 with a 190 HP 5.9