Overdrive Q,s

[aaron1976]

Does anyone have an aftermarket overdrive unit on their truck?

I have an 87 f250 4 spd standard and was told it has on overdrive that didn't work.
I don't see anything in the drive trane that would equal an overdrive. Wondering if someone could give me some info. Are they located at the rear axle/diff or at the out put of the transfer case? Mine is electric or it is wired in the cab but I see cut wires underneath.

I am sure it has been taken off but I may look into putting another one on.
The truck runs at 2800 rpm or so at 65 mph. Seems high, what to you all run for rpm:mph?

Any real reason to put another OD on the truck, better fuel mileage?

 

[DragRag]

Sounds like you may have had a gearvendor O.D. or some other brand at one time. I have one on my van, and love it, yes they do return better mpg. I think only about 1.5 though, they are pricey, and it takes time to amortize them if you are buying for savings. They also reduce engine wear to though, mine drops about 500 rpm when it kicks in. I think they are worth it on a non overdrive truck.

 

[aaron1976]

Where are the overdrives located? I have some wires running to my transfer case that come from the switch/relay but I have never seen one in the T case. I haven't seen all that much though so nothing new.

 

[aaron1976]

Thinking about it I have seen over drives at the output shaft of a transmission. I guess it would figure that it would be there as well on a t case

 

[crashnzuk]

Here's a pic of the one on my dad's 86 crew. Hangs off of the back half of the t-case. The rear half of the t-case and the adapter part are both from, and say, Gear Vendor on them.
Travis..

You must be registered for see images attach

 

[aaron1976]

I don't have that on my truck.
I will have to start looking for a unit. The local junkyard has a lot of IDI and older gas trucks. They also are dirt cheap. I have pulled a lot of parts for my truck there and have spent $30 or so.

Thanks for the info

 

[franklin2]

I don't have that on my truck.
I will have to start looking for a unit. The local junkyard has a lot of IDI and older gas trucks. They also are dirt cheap. I have pulled a lot of parts for my truck there and have spent $30 or so.

Thanks for the info

A overdrive unit in the junkyard, and for around $30? You must really believe in the power of positive thinking.

 

[aaron1976]

A overdrive unit in the junkyard, and for around $30? You must really believe in the power of positive thinking.

You have to know the guys at the place I go to. They are not the crispiest fries in the basket but they do have some teeth left... not many though.

I bet I that if I do find one I could get it for $200 or so.

 

[Diesel JD]

I've actually heard of a few people to find a GV or DNE2 overdrive in the junkyard, but I'd guess they are rare-ish out in junkyards. The GV is 2700 brand new. There was a guy selling a knockoff of the GV for around 1500 who posted here once r twice. If you find a Doug Nash box, make sure you know it's an OD, I had a DNE box but it turned out to be a GM underdrive unit. The Ford and GM adapters are the same but the UD and OD boxes look very similar, and they cannot be switched around to make an UD an OD or vice versa.

 

[aaron1976]

I guess a guy could spin the input side one turn and see what the output side does. There are a lot of trucks of same vintage there at the junk yard. Should be one on one of them but there probably isn't. It has been too cold to go pull anything this winter so I thought I would just wait till it warmed up. Bought warm enough now.

 

[Diesel JD]

Hey another option is a brownie box (aka Spicer Brown-Lipe auxillary) not quite as easy as a GV but many times tougher. There probably were a lot of them in Wyoming back in the day with all your mountains and so forth.

 

[RLDSL]

if going for a boneyard gv unit, try to find one from a vehicle same as yours, otherwise getting an adapter is going to cost you. Last time I contacted GV about that when I was contemplating going that route, their price was around $700 PLUS you have to trade in the old adapter piece, and if you do not have an old adapter piece to trade in, they flat will not sell you one, because they don't want folks running around grabbing OD units off old 740 volvos and using their adapter housings to make their own OD units

 

[jperecko]

It is also possible to have a ranger OD... they are not too thick and go between the trans and t-case I believe...

 

[The Warden]

It is also possible to have a ranger OD... they are not too thick and go between the trans and t-case I believe...

Those are shifted manually, though, unless a previous owner did something like Ziggster did and made it into an air-shift unit.

Shame you can't use a Ranger with a ZF

BTW, Aaron, if you by chance come across a U.S. Gear/Doug Nash overdrive unit for a Ford 4x4, if you could grab it for me, I'd really appreciate it Also, if you have 4.10 gears, your cruising RPM's sound about right...even with a ZF in my truck, I'd like to get my freeway RPM's down further...

 

[Diesel JD]

What RL said is something I hate about GV. They act too much like entities I don't like, the government, a big bank, a street gang, with their anti competitive practices. I sure was pulling for that dude here with the knockoff units to sell a bunch of them and not to get sued out of existence, i guess I should have supported him by buying one of his units but 1500 still seemed like a lot of money for me, then I am cheap. The Ranger III overdrive goes between the engine and bellhousing I'm pretty sure. They look like a pretty cool unit, I personally wouldn't mind the manual shifting, contributes to making the truck unique and a conversation piece and probably reduces the amount of people that want to borrow it. Tim are you sure you can't use a Ranger in front of a ZF5? Also if you find a DNE2 or someone else does, make sure it's from behind another ZF5 or a C6 as the 4 speeds have a different spline count and you would not be able to adapt them together.