1965 F100, Custom Cab, Styletside Longbed.
300 cubic inch I6
T18 4 speed
3.50:1 rear end
96k miles

Completed the install of the Gear Vendors Overdrive a few weeks ago(Wednesday evening), 1 1/2 days before our annual family camping(skiing) trip to Lake Shasta.
1st test drive was about 5 miles up the freeway to pick up our trailer for the trip. A lot quieter and 65mph was a breeze.
Then pulled the '62 Shasta Astroflyte home and it towed great with the OD. 60 mph was right in the sweet spot.
Friday morning drove 267 miles to the campground. No issues. Back home a week later no issues.
Wish the OD had been in for the 2,500+ miles we did in April with the trailer on our Southwest trip.
The Gear Vendors install really only took a couple of days. It was a longer job as I took the drivetrain all the way down to the back of the crankshaft to check the clutch and change the oil pan gasket.
Cleaning a ton of grease off every thing from the years of oil leaks took a ton of time too, but I think I just saved back all the weight I added with the new sound deadening.
MPG results are better but I'll need more miles and trips with and without towing to get more conclusive results. It was about 2.5 MPG better on this trip(almost 14 mpg) then the Southwest trip, and I drove faster and the truck bed was packed full compared to basically empty on the Southwest trip. Also Southwest trip was mild temperatures and the Shasta trip was over 100 for about 2/3 of the drive.
I originally bought the whole Gear Vendors setup from and old craigslist ad I had printed over 1 1/2 years before I bought it. Guy still had new in the box every thing to put it in a Fox Body Mustang and was setup to go behind a 4L60(AOD). I figured why not call the number, if he still had it he might let it got cheap. $1,000 bought it all. Found a T18 adapter for $300 on Ebay. $300 to get a new 1 piece driveshaft built. About $600 for the T18 specific parts I needed from Gear Vendors, speedo stuff, control box, switch for shifter ****, and some wires they sold me that I probably didn't need(could have used what was with the 4L60 stuff). So less than the $3,000-3,500 to get a whole new setup from GV.
Now I just need to sell all the 4L60 specific parts to bring the total cost back down a little.
Bottom line: I like it. Quieter, faster in traffic and towing, speedo is dead on.
**Just posted a couple more pics, switch on shift know and control box under dash.**



All the additional stuff I needed from GV. Probably could have used some of the wires from the 4L60 kit and saved a few bucks. MOst expensive parts were the deep sump pan and the control box (under the green box which was a new seal for the adapter.


Better pic of control box. Purple gear is the speedo gear housing that goes in the tail of the GV.


The whole thing bolted together, adapter on the right. Before the deep sump was installed.


The greasy beast before pulled. This is after lots of oven cleaner, degreaser, carb cleaner and a trip to the quarter car wash.


Who ever had put the new clutch in put only 2 out of 4 bolts in the cross member and 1 of the bolt holes had cracked clean through. So no wonder it drivetrain hopped when reversing.


This is the tail piece that come off the T18.


How to mount your T18 on an engine stand when you need to get to the input shaft.


Deep sump. A lot more fluid capacity, recommended for towing. Dex III or Lucas Syn.


The T18 adapter in place. The coupler connects the T18 output shaft to the GV input shaft and is shimmed with the wafer looknig things in the first pic.


The whole unit in place.


Open hole is for the speedo gear housing. Left below that is the solenoid that engages and disengages the OD.


Carrier bearing support bracket form original 2 piece driveshaft that I removed for clearance for the new 3" 1 piece driveshaft.


Driveshaft in.


Driveshaft clearance.


Speedo adapter parts. The original cable goes into the coupler on the left. The middle unit sends signal to the control box to shut the OD off under 30 mph if you forget.


How I measured to know how much to cut off the little square cable connector to fit it all together correctly.


OD switch on shifter ****. Wire spirals down the shifter cane and into the boot. Might change it to running straight down the cane and cover it with shrink tubing. In the background are the 3 wires, 1 to the ****, 1 to the solenoid, 1 to the speedo sending unit to the control box.


The control box. Right now just zip tied under the dash to part of the original loom. I'll probably make a bracket to mount it off an existing hole or bracket. I have a motto of when ever possible "no new holes and no zip ties" when working on our classics so zip ties were the lesser of the evils for now.



Made it there no problem. Set for a week at our annual campground, that may actually be on fire right now.


The big $ wakeboard boat the ran aground one night at 11pm. He almost wiped out our 1967 Astro Marine Starflite 18, that I learned to ski behind 40 years ago on the same lake, on a ski my Brother-In-Law(best friend) made in wood shop in 1971. The boat was bought new by my BIL's parents. I need to build the burned '66 shortbed for my wife to tow the boat to the lake while I tow the Shasta trailer.

 

That's awesome! Great work. What rpm do you think 60mph is getting you?

D

 

Looks great nice write up.

 

Not sure. I want to find a vintage, or vintage looking, tach to install in the truck. Probably one that only goes to 4 or 5k.
When I do that I'll update this post with MPH/RPM numbers and more MPG numbers too.

 

I found these on Ebay. I think they were made by Automatic Instruments

 

Nice write up.
Did you try splitting the gears and if so what gears and what did you think of that?
Some day once my truck is on the road I would love to get one or the Range Splitter from Advance Adaptor.
Dave ----

 

Yes. I used 3rd OD a couple of times. Not a whole lot of hills on I5 so didn't get a lot of chance to do splitting. It was perfect for between factory 3rd and 4th. If the GV had been in on our Southwest trip in April I would have done a lot of 3rd OD. I think I can use it in 2nd also but really didn't need to. I know I can't use it in the Non-Syc granny 1st. I'll probably call GV first before using it in 2nd because I think I remember reading conflicting info that said it was ok in any gear on a T18 except 1st, but recall info that also said 3rd and 4th only.

 

Don't you have to be going 30 or 35 mph before the box will let it shift?
If so that could be why you can't use 1st or 2nd gear.
thanks for the feed back.
Dave - - - -

 

Yes, have to be above 30mph. I would think you could be over 30 in 2nd OD but it would be winding it out a little to get there as I almost never use 1st. The good old I6 300 pulls so good I can be in 4th going 30.
Down the road I might consider even using a taller rear gear like 3.25.

 

I'd like to as the OP about some wires on his GV stick shift setup. I started a thread with my specific questions over in the main drivetrain section.nice job, and I totally agree on the no new holes and absolute minimal zipties too.

 

Got to say love the write up on the GV install
Did I miss what rear gear ratio you have it your truck?
I know you said something about maybe going to 3.25 gear?

I got a little up date of my own.
I pulled the trigger on the Advance Adaptor's OD unit only because of the coast, under $1700 to GV $3000+
I can also split any gear at any speed if need be.
I did this just before this virus hit and should have been here but with everything shut down who knows when it will show up?

Nov 2019 I got my truck on the road, 81 F100 flare side 300 / T18 / 2.75 rear gear.
I also don't use first gear other than if in a parking lot as it is not really useful if not pulling a heavy load.
I do have a tach and I am shifting before 2000 rpm from 2nd to 3rd and at about 2000 RPM 3rd to 4th.
The 300 pulls from like 1000 RPM to just over 3000 the few times I have run it up that high but there is no need all the power in at low RPM.
On the high way at 65 MPH it is turning about 2300, speed limit is 70 MPH here but the MPG goes down.
I want to get the RPM down to about 1800 RPM @ 70 MPH where the RPM would be at at 55 MPH back when the max speed limit was 55 MPH.
Dave ----

 

Sent you a PM to help make contact to answer your questions.

 

I saw your reply in thread that said you'd sent a PM.
1) my inbox shows a warning of 90% full but, isn't allowing me to delete in mobile mode now.
2) no message has shown up from you yet, unless you can see my email Addy then I'll go look in "that inbox"..... Unfortunately mobile version won't let me see which email Addy I have set up for this forum /facepalm

Thanks for the fact that your still active and willing to answer legit questions.

 

I had the same full inbox issue. I cleaned mine up and have room now. Also tried sending a message to your email through FTE, couldn't see you EM addy.