overdrive
 

I bought a 1965 chevy inline six truck to add to my stable. It gets along with my 69. The guy I bought it off of had installed a early sixties 3 speed standard tranny with a manual overdrive, but the overdrive linkage was never hooked up. I have put a manual cable on the overdrive and have switched it back and forth going down the road, but I do not notice any rpm change. The only thing I notice is the tranny "free wheels" when you let off of the throttle when it is in overdrive. If its not in overdrive then you can hear the load on the motor when you let off of the throttle. I do not have the electric solonoid hooked up on it yet. Does anyone have knowledge of how these overdrives are supposed to be hooked up or react. You would think that you would hear a rpm change.

Thanks

From what little I understand of these trannys - the manual cable engages the flywheel and the solinoid kickes it into overdrive. I have been looking for info on these too so if you find out more - let us know!

Try this site:
http://www.classictruckshop.com/club...over/drive.htm

can i get that overdrive unit to bolt to my truck? that sounds relly interesting, and is cheaper than a modern unit....i would only need it for freeway usage, and then i would also not need to regear my rear axle...


anyone know where i can find one and if it will bolt up to an NP435

Sounds like you need to wire up an electrical switch to provide 12 volts to the solenoid on the overdrive unit.

Thanks for the help guys. I will go to the web site provided and see if I can find out the ins and outs of the T-85N overdrive tranny. For starters I guess I better see if I can find a ID plate on the tranny to see what it really is and what year. Does anyone know how to identify this tranny? If there is any T-85N guru's out there, let me know.

Thanks

let me know if there's any interest in these.

I have four of them. One hooked to a Dana 20 4x4 t-case. Still located at my buddy's house in Cameron Park, CA.

:metal:

Yes! What condition are the T85's in? Do you rebuild these things? I would
be interested in one.

I have two that are in great shape. I bought them off of ebay about five years ago, without pictures. Was sold as "4 Jeep Overdrives". When I got them, I was a wee bit shocked, as I was expecting Warn overdrives.

Apparently these were also an option in the Willy's Wagons and pick ups.

If I were to run one of these, (which I can't due to BBC) I'd replace bearings and seals and go. They're not tough to assemble/dissasemble and all the bearings are common at any bearing store worth it's salt. The planetaries are solid and the housing is complete with all the switches.

I don't want to thread highjack anymore than I have. Throw me a PM if interested.

if they bolt up to a my NP 4sp, i would be very interested , especially if it was a decent price...

I've seen them hooked to an SM420 and a SM465.

What is a stock manual 3 speed called? I have a 3 on the tree.

i have a NP435, so if it is found that it can hook up to this, i would def be interested. also, how much would you want for one in good condition?

any takers on the NP bolting to this?

I had one of those in a '49 Willys truck. Yup... all you need to do is pull the freewheel cable and put 12 volts to the solenoid. Mine also had a momentary disconnect switch under the gas pedal so that when you floored it, it would kick out of overdrive and act like a passing gear!

same here

see above...

I may be able to ad a bit of insite on the tranny questions... The T85 is a Borg Warner "side cover" 3 speed with came both standard and overdrive.. the overdrive shoud be a Borg Warner "R10".. they came alot in Jeeps, Ramblers, Studebakers, Chevrolets.. I haven't seen many in Chev's Most of the Chevs in the early to mid sixtes had either The "chev 3spd" which is a weak little one.. or the 3spd Saginaws.. Most 67 72's I have seen only came with the Saginaw overdrive but doesnt mean that they all were that way... One neat trick that I have done years ago is take the Saginaw 4spd out of a Vega or 70's Camaro and take a truck Saginaw 3spd overdrive and mate the two.. Violia.. 4 speed overdrive.. but that a whole other topic...
The T85 is a strong trans.. The manual cable is for the lockout and release of the planetary gear providing the gear reduction.. which will "freewheel" opon release.. the electric solinoid locks it in overdrive.. originally it had a relay and a "wide open"throttle switch to kick out the overdrive upon hitting the gas... the original electric configuration had power to one side of the solienoid all the time the terminal was hooked to a little switch on the trans which in turn hooked to ground completing the circuit when the ign was on and the cable pushed in...
There are a couple of ways to wire it for manual operation.. one is run power to a "toggle switch" on the dash.. the other wire to one side of the soleniod.. and the other side of the soleniod to ground... to use.. get up to cruise speed.. flip the switch... push in the cable and back off the gas a bit... and it shoud lock into overdrive..... To take it back out... flip the switch and hit the gas... you should feel it kick out.. "kinda like passing gear" ... you can use overdrive in any gear.. 1st.. 1st/over etc.. when you play with it enough you can actually make it shift like a 6spd..
Sorry for such a long post but all the talk about those overdrives brought up some fond memories of the late 70's for me... if anyone has any questions about either the T85's or Saginaws feel free to PM or email... I have had many of them apart on the bench over the years...
Livrat

Liverat or anyone, does anyone know what the procedure was to engage the overdrive? I have the original cable so I understand that you push in the cable to put it in freewheel.......but how did they switch the soloniod to 12 volts? Was there a toggle switch on the dash or what? Also did they originally place a momentary disconnect switch on the throttle for passing?

One other question...does it hurt the tranny by running the cable in freewheel without the solonoid kicked in?

Sorry one more...Was there a was to keep the cable from binding when placing it in and out of overdrive? I bought a new heavy cable and I have been having trouble getting it into a good position so that the cable moves freely back and forth. I've thought about using a 12 volt accuator instead of the cable. Any thoughts?

originally there was a relay mounted somewhere that took 12 volts from the coil and routed it to the solenoid.. there was also a switch on the throttle linkage to disengage the solenoid during wide open throttle.. there should also be a switch on the overdrive itself which prevented the solenoid from functioning while the cable was in the lockout position.. You can just hook up a toggle switch to the solenoid and work it manually or try and find an originall schematic diagram and relay to make it work like the factory intended.. I prefered the manual method...

It will not hurt the trans to have it freewheel without the solenoid kicked in..

the original cable assembly had a special bracket to align it with the lockout lever.. Never tried an actuator.. but dont see why it would not work as long as you have the correct throw to properly engage and disengage the overdrive....