Looking at some overdrive units for my TH400.. But $2600+ is just out of the question. The thing is I just need a simple in or out manually unit for on the highway etc... But the Gear Vendors OD unit has all kinds of computer controls and shift controls to do gear splitting etc etc... Does anyone just make a unit that would be a simple manually controlled overdrive that would work?

 

Raise (numerically lower) the rear gear and increase the tire size. It's honestly the cheapest option, the other choice is switch to a OD transmission. If a TH-400 will work, then you should be able to use either a 200-4R or a 700-R4.

Here's a good calc I use:
http://www.summitracing.com/expertadvice/storydetail/calcsandtools/Gear-Ratio-Calculator/

 

Right now I have 2.73's in it. Which work out pretty good for the most part. It would just be nice to be able to have a 3.55-3.73 gear in the back and then just flip on OD when needed.

Also this is a TH400 behind a ford motor. So the trans would also need to be behind a ford motor. So making Chevy stuff fit gets a little complicated sometimes. Plus it needs to take 1000 to the tires or more...

 

Built AOD, AODE, 4R70W. Lentech rates their piece @ 1500hp.

 

4L80E. Plenty of them behind fords. IMO, overdrive is only half of the equation. Lockup is the other half. In my car 70 mph is (26" tall tires and 3.00 gears) 3rd unlocked (same as a th400) is about 2700-2800 rpm, overdrive is about 2300, and locked up with OD is an even 2000. Also a HUGE difference in transmission temp.

 

I just might have to think about putting in the 4L80. The parts are going to be going into another car in the next few years. Might just wait untill then and do the whole switch over at that time.. Any good recommendations for a Trans shop that does the switch over for the bell housing or where I can buy the trans built etc? I would probably be able to use the flexplate and adapter from my 400 I would think.

 

Jakes Performance builds a killer 4L80E transmission (and he can put an aftermarket reid bell on them). Also he has a couple of different in house transbrakes.

 

OD conversions always seem expensive I think until you add up the conversion. The build of the transmission and other parts to go with 2600 start to seem cheap if you already have a good transmission

 

Yeah the trans and converter are great that I have now (the TH400), rev manual valve body, brake, good for 1500HP+ all day long. So I hate to sacrifice that. Did the whole switch from a manual for about $3200 for everything new. I probably should have just went with the 80E from the get go but the 400's were a lot more popular to do the switch.

 

Yeah, you'll probably spend a bit more than that on a swap with OD. Subract from that what you get for your 400 which will be pennies on the damn dollar. OD unit might be cheaper in the long run. They are right down the street from me,too. Iirc their base model is rated to 1200hp.

 

Looks like it would be $4350-4850 for just the trans ($l80E) to do something that would take the power I intend on running through it.. Wooowwww lol. Prob not bad for what it is though. But I do agree, $2600 isn't as bad as it originally looked like!

 

I'll have to call and see what they can do. I just wonder if they have a more "simple" version for what i'm looking to do with it.

 

You might be able to opt of of the 45 mph OD on automatically. That may save something. But it's not a real complicated install.

 

Before you make a decision look into the controllers for any of the electronic trans. Of the ones I have seen the controllers alone are in the $ 1000 dolla range.

Im thinking by the time you are all said and done with an overdrive trans and all the components you will be above what a gear vendors cost is.

Good luck.

 

all I need is an on/off switch and I would be happy lol

 

GV has one of those lol. It has a switch that will OD come on at 45 if you let it. Or a head light switch for when you want to manually up shift to OD.

 

A three speed auto is so clean I would hate to see someone go a different route. Do you have the wide ratio gearing with the lower first gear?

 

Some OD trannies can be setup for full manual. Also US Shift makes controllers for under $600.

 

I believe it's just the standard 1st in the car

 

Looks like i'll need to give them a ring. Few years out though of needing one.. Although it would be nice having one now in the current car...