3 on the Tree Truck
 

Happy Thanksgiving everyone, just have a quick question.

My 65 is a 3 on the tree truck and I will never get rid of the three, I love it! But what I hate is only going 55mph, so the highways out here are off limits. I was curious what rear end gears others are running to allow more of a highway driveability.

Thanks, everyone.

Re: 3 on the Tree Truck
 

You actually have 2 options to keep the 3OTT.

1) Switch your rear gears to something like a 3.08 or something around there

2) Swap the regular 3OTT for a 3OTT with Overdrive. It shifts the same as a straight drive trans, but there is a borg-warner electronically controlled overdrive that takes place of the regular tail shaft

My truck originally had the overdrive trans, but the previous owner removed it many years ago. I like having a 3.73 rear, so I'm going to go with an overdrive trans

Re: 3 on the Tree Truck
 

Chances of finding a 30TT OD is really rare from my research but I guess it's worth digging into again. I did recently look at a 3.08 rear end but it was out of a 70's and a 5 lug, so didn't want to hassle.

Anyone running a 3.08 with a 3 on the tree? Just curious how sluggish it is from 2nd to 3rd, and the cruising RPM on the highway.

Re: 3 on the Tree Truck
 

What would the transmission be worth 3 speed with over drive?

Re: 3 on the Tree Truck
 

I wonder if a truck is different? - https://www.ebay.com/itm/Manual-Tran...IDX:rk:16:pf:0

Re: 3 on the Tree Truck
 

The worth depends on what the owner is willing to sell it for and what the buyer is willing to pay. I've seen them go anywhere from 200 to 500 bucks. I have only seen 1 of these in person though.

You also have to factor in the other components such as the kickdown switch and relay and wiring if you want it to operate as GM intended

Re: 3 on the Tree Truck
 

That's good to know..I saw one yesterday that had supposedly been rebuilt along with the linkage...But didn't think to write down any numbers etc and crazy me forgot to take a picture....The man who had it didn't know what it was worth and neither did I, but Im thinking he probably wants over 500.00 for it...

Re: 3 on the Tree Truck
 

So that trans is just a regular sm318

Here is a sm319 (has overdrive)
https://www.ebay.com/itm/1955-thru-6...mZR1:rk:2:pf:0

As far as I know, the only difference between the cars and the trucks are how the shift arms connect. The earlier year transmissions do not have a tailshaft mount cast in, but the later years do. For our trucks, you could get either year range trans

Re: 3 on the Tree Truck
 

Yeah, I would not doubt that he might want over 500 for a rebuilt one. Keep in mind also that many of the electrical components are not repoped which means you need to find either good, used ones, or NOS ones. You might end up paying just as much for all the additional components as you did for the transmission itself

Re: 3 on the Tree Truck
 

this is the one I saw yesterday..I remember thinking that it looked like it had an il filler neck on the side...Wasn't really interested as I put a 700R4 in my truck but when I saw this thread it made me wonder.

Re: 3 on the Tree Truck
 

I have a longbed with a stock 283 and 3 on the tree w/3.08's. I find it to be a great all around set up. I don't know if the old 3 speeds came with different gear ratios or not, but it would be worth researching before doing an axle swap. Once you know what you have to work with, you can then use various online calculators to determine your launch ratio and what your rpms would be as you "row thru the gears"

Re: 3 on the Tree Truck
 

I am - previous owner had them swapped in. I added Electronic ignition and 2 bbl carb -- they help but you can feel the difference. Going uphill especially. I can go 65-70 on the highway and I avg just over 18mpg. I have a 3spd OD going in -- then back to the 3.73's.

I found mine on ebay that was rebuilt and has the electronics and an old harness. $700

search this site. A few guys have made their own harness on the cheap and newer parts.

Re: 3 on the Tree Truck
 

Back in the early 80s a bud of mine asked me to help him install a Saganaw 4 speed in his truck. It was 3 on the tree also. Weren't no problem, popped right in & all we had to do was change the yoke & a little linkage mod.
The trans didn't come with a shifter, the old trans was jumping 3rd & he couldn't afford to buy a shifter so that's why the column shift 4 sd!
It was during these linkage mods that it occurred to us that there was no provision on the column shift for reverse!:lol:
But it was late & he drove it home shifting on the column.
He later either used a pull in solenoid or a cable for reverse, can't remember.
But anyway the trans had such a low 1st gear it almost was like an Sm465 taking off in low!
3.11 I think...
Later we installed a rear axle assy from a later truck with 2.73 gears. That trans pulled the 2.73s just fine & the little 283 had no problem clipping along at 75! It did it so well that he got NUMEROUS tickets in that old 67!

Re: 3 on the Tree Truck
 

That's exactly the tranny in my 66 shortbed. It sure does have a wide 'ol gearspread. I run with a warmed up 283 and a 2.76. Sometimes though in the mountains, it's just too much with that gear and a small motor. I did try dropping to a 3.08 but then 1st gear was a joke. I could take off in 2nd or start in first and skip 2nd. Either way, it was like having a 3 speed again. The 2.76 went right back in ... better to just climb hills in 3rd. Edit: for identication purposes in case anybody stumbles upon one... that type of Saginaw 4 speed with that particular spread has 3 rings etched into the input shaft.

Re: 3 on the Tree Truck
 

You can wire the overdrive trans up not needing engagement cable or foot switch. My installation in 63 C10 went like this:

Used side plate (4-bolt) and shift arms off original three speed. This allowed the use of stock shift linkage arms.

Wired with toggle cut off / cut on switch for solenoid. Now when I want overdrive, flip the switch to on, accelerate to about 30MPH, let off gas and she shifts into OD.

There is a thread with lots of information and pictures. I tried to copy thread below but not sure I did it right but you can search on "3 Speed Overdrive" and the post you want is "3 Speed Overdrive, Now about getting it it"

http://67-72chevytrucks.com/vboard/s...d.php?t=313886

Re: 3 on the Tree Truck
 

Here’s one for sale (Not Mine):

https://classifieds.ksl.com/listing/53993496

Re: 3 on the Tree Truck
 

Have you looked at Gear Vendors Overdrive? They aren't cheap, but if you're hell bent on keeping the 3OTT they might be another option. I never cared for the 3OTT, especially if it didn't have a syncro for first, but it's definitely got a certain amount of cool factor.