10 speed eaton fuller or road ranger behind a 7.3 IDI has it been done

GOOSE

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If you are looking for something to get MPG's out of...this isn't it. If you are looking for a major cool factor, and the ability to pull almost anything way more easily that a straight 5 speed truck wouldn't dream of pulling...than this is your route.

But I SERIOUSLY doubt you will gain ANY MPG's with this conversion. Just my .02 cents.

Well said, unless you pull heavy all the time, then the added gears would still help you out. You will have to go the brownie route or a US Gear/Gearvendors set up to get a double overdrive and reduce your cruising rpm's. 3:55 gears and an RTO6610 would probably be a real good combo to give you pulling power and good highway abilities.
 

88IDImattman

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thats the tire size i have now the 235/85r16 and i turn right at 2300 rpm .......... as far as the RTO6610 ..i have wanted to do something like this since i got my CDL i love the thought of it plus having the ability to tow anything is AWSOME .....i just figured it also might pull a few extra mpg on the hwy ..im not expecting some miracle mpg's just something better than the 19ish i get now ........and honestly throwing a flip switch when shifting is just somthing that gets in your blood i guess because i love driving them
 

Mulochico

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........and honestly throwing a flip switch when shifting is just somthing that gets in your blood i guess because i love driving them

Kinda like a twin stick to me!!! 1st big truck I ever took on the street was a 5X4. 200 different possible gear transitions. :eek:. Definitely didn't get bored with that one. :sly I would still love to drive one of those old girls. ;Sweet;Sweet
 

Goofyexponent

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thats the tire size i have now the 235/85r16 and i turn right at 2300 rpm .......... as far as the RTO6610 ..i have wanted to do something like this since i got my CDL i love the thought of it plus having the ability to tow anything is AWSOME .....i just figured it also might pull a few extra mpg on the hwy ..im not expecting some miracle mpg's just something better than the 19ish i get now ........and honestly throwing a flip switch when shifting is just somthing that gets in your blood i guess because i love driving them

What transmission do you currently have? E4OD? ZF? C6, T19?
 

Goofyexponent

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most of the smaller tanssy's were put on smaller engines. The engines in that category (dt466, cat 3116, cummins 8.3, etc) have an RPM redline similar to that of an IDI.

So long as the engine isn't cranking upto 4000 RPM (let's not get into that debate again!!!) the I forsee no real problems.

Even some of the gasser trucks (firetrucks and the like) had 427 chevy's and 532 Ford's and they also had the single counterchaft boxes. They could spin 4500 RPM safely and not harm themselves or the gearboxes.
 

RLDSL

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ok so i spent some time looking at the gear vendor page tonight seems pretty kool is less of a job to install got to remember the 5000 mile fluid change on it an all then i got tot the price WOW !!! ...........thats alot for that small a unit isnt it ????................

also i am wondering if anyone can figure out what the RPM's would be if i did the RTO6610 with my 410 rear at say 60 mph running a 19.5" rim size ....currently my truck runs 2300 RPM at 60mph ...........so what would it be with the 10 speed ??? .....Im really looking at all options as i try an make a decision about the project ...i know i ask alot of questions but knowledge is power an when i set to doing this i want to do it correct not half ass it
If you do any kind of heavy towing, bear in mind that the original Laycock Overdrive unit that Gearvendors used that GV claimed a 16k GCVW , was designed for a triumph 2 seater, and the one that they currently use was designed for a Volvo 740 passenger car ( although the ones in the Volvos actually have a stronger cone clutch in them due to current manufacturing restrictions that no longer allow them to produce that cone clutch )
I used to have a shop specializing in those vehicles, and I personally have had to rebuild more of those things than I can count, and they are not as strong as people would like to think. THey do fabulous in their original application , generally going about 200k before hydrahlic rebuild and a tad linger before anything mechanical, but if someone times a shift wrong or leaves them engaged when they shouldnt, its all over. Mind you , this is on a 3300 pound vehicle. Do the math. THen search the internet for horror stories from retiries who have had brand new GV units under warranty fold on them away from home and have had to pay insane amounts of money to be towed to the nearest GV authorized repair center many states away, while ma waits in the 5th wheel stuck in one state and pa sits in a motel racking up bills waiting on parts to be shipped in. There are tons of these, more than you can count.

There is a very good reason I went with a Brownie, it wasnt just to be cool, I wanted something I could depend on, and even then being captain overkill, I never trust anything, so I left the original center support bearing crossmember in place, and I carry my factory driveshafts when travelling, and I installed my brownie in a way that if it EVER somehow failed ( how I could blow a box designed to pull 43, 280 pounds +*( EDIT make that 73, 280 pounds, dang wobbly fingers LOL, I'm not sure , but, still, I like to be prepared) I installed it to where we could be towed into ANY idiots shop out on the road and I could point to what needs to be done and in a maximum of 2 hours labour for the biggest idiot in the world, the brownie could be removed and thrown in the bed, and the factory driveshaft could be popped back in its original location and we'd be back on the road
Luck favours the prepared
 
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RLDSL

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RLDSL

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Ont thing any of you guys have to remember if considering one of these boxes, is you HAVE to get a single countershaft box. A dual countershaft box would eat up your HP in friction losses, not to mention being insanely heavy.
Most newer big truck boxes are dual countershaft, they have a habit of overspecing since trucks can be used for many different things over their life. A dual countershaft is really for heavy hauling, so you have no need for it ( A dual countershaft 4 speed air shift brownie is the coolest thing on earth, but HEAVY, they go very nicely behind any seriously heavy box.
 

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