Anybody know anything about adding an overdrive to an older truck? Mine is a 1979 F250 4x4 , 351m, c6 tranny. Is it possible to add an overdrive to this or is it a waste of time and money, or most important, will it damage my truck?

 

it is possible? yes... waste of time and money? maybee. depends on why you want overdrive. if the reason you want overdive is to save on gas, then yes it is a waste. buy a honda. if the reason you want overdrive is for the driving pleasure and as an added bonus you get better mpgs, then no its not a waste. will it damage your truck? i dont think so, provided you get a quality unit made by a quality company. www.gearvendors.com should have eveything you need. but be warned, they are expensive. more than some people paid for their whole truck.

 

He could just build an AOD.. There's a few members that have done this as well.

 

but then you have a POS tranny...
yes this is MY opinion, but I think it is shared by a few others around here - one of them being NumberDummy - who saw many a part for these heat pigs go put the door. Maybe if he reads this thread he'll chime in on what a jewel of a trans the AOD is.

Yes the gear vendors is pricy, but is it the right way to get OD on an older truck like ours - many think so. I think a gear vendors would cost more than paying someone to swap an AOD into your truck, but it wouldn't cost much more. Plus you still have a stronger tranny with less heat problems AND the ability to split gears, etc.

 

I agree with Chase. The AOD is a P-O-S. It is O.K. in light duty but our trucks are big and heavy. The gear venders would be the best choice. Very strong and not too difficult to install. One word of advise: Check clearances first before you buy it if your truck has a mid-ship fuel tank inside the frame rail. I tried to put one on a previous 2-wd truck with a C-6 and the gear venders unit did not clear the fuel tank. I ended up selling the truck before I made any modifications.

 

AOD's hardly hold up behind smaller motors. When I had the supercharged 3.8L (out of 90's T-bird) in my ranger it ate a fresh AOD within 3 months. IF you MUST run an AOD then get the biggest cooler you can find (mine looked like a mini radiator!) and check/change the fluid a lot.

As for the gearvendors. I have seen used ones for $800 or so. Plus they have an adapter exchange program which lets you trade in the adapter for another, so if you find one for a TH400 or something you can trade that adapter for the c6 one...

 

i didnt know that...


the only question i'd have about the gear vendors unit is, if it bolts to the back of the trans, or x-fer case, then would you need to shorten your driveshaft? and wouldnt that cause more extreme angles?

 

yes, and yes/no.
4wd trucks it's between the tranny and T-case seeing as Fords are divorced in these years. 2wd trucks I think the 2 piece drive shaft takes care of the angles.

I haven't put one of these on a 70's ford, I may have to depending on what i go with tranny wise on my crew.

 

If you have a married transfercase/tranny then it attaches to the back of the transfer case. If you have a divorced transfercase/tranny then you can attach it either to the tranny or transfercase. As far as the adapter swap goes, you have to pay for each adapter but Gearvenders will store it for you as they will only let you have one adapter per unit at a time. If you get one with the wrong adapter for your application, you will have to send them the wrong one and pay for the new one. If you ever want to change back to the oner you sent them, they will trade you for the one you have at just the cost of shipping. You never have to but an adapter twice. If you ask Gearvenders, they do not make a version to mount between a married transfercase/tranny.

 

I guess fellow member Danny Cabral has the 1 in a million that works.. Build an AOD right and I feel it would work.

 

im guessing that an aod is an auto over drive. my dads f-350 has an auto with an od coupled with a 7.3 diesel. its gone out once in 150,000 mi.

 

The 7.3s use a different transmission alltogether however.

 

Does anybody know if the GV OD unit will be a width issue to the side mount gas tank in a 4x4?

Mine is a 79 4x4 Supercab, with a C6 and a married NP205. From what I've read, the GV unit bolts directly to the rear output of the transfer case, and I'd just have to get a new one piece driveline, and do away with the two piece...that's my theory, anyway. As for room for the GV unit, I'm curious with my configuration if there will be clearance issues. I'm guessing I might luck out due to the longer cab, the GV unit might miss the side tank, but that's speculation at this point.

 

Ok, here is my take on an AOD.

I have looked into it at great length and I have to say that everyone so far is right on with their comments.

In a nutshell the AOD is a great thing.. You have a couple of choices for rebuilt units that have had the weak parts replaced with stronger ones. The add on units, like the Gear Venders drive is about the same price... and just as much work to install.

Bottom line it will cost about $3500-$5000 to put one of these things in your truck and if it is a 4x4 then it will not be as strong as a C6. Oh, and how much gas can you buy for $5000??

That equals about 20000+ miles !! I wanted to put an AOD in my 4x4 truck but after a lot of research I concluded that it wasn't worth it..

Regards,

 

THe first thing NOT mentioned is the AOD was only available behind a 302/(351?) so it wont bolt up to a 351M without some expensive modificatinos. The 460 E4OD will bolt up, however it will not work unless you convert to a full manual valve body, or purchase an expensive stand alone computer, plus modify your rig for the various sensors it needs to run. I am not sure what torque converter you would need to run, or what modifications are needed. At the end of the day, and each every other day, you will be miles ahead, and happier with a gear vendors.