Do you like your overdrive?

[aboyandhisdog]

I'm wondering if any of you have an overdrive...are you happy with it?  Has your MPG increased at all?  Are there any down-sides to an overdrive to watch out for?  I've been on Herm's site and it looks pretty interesting, just wondering what you guys think.  Thanks.

[Chasm]

Tom:

I have driven CJ3A's with overdrive and without. At first, I thought I had to have one in mine, but I have changed my mind on that!

My 3A cruises along very nicely at 45mph. She will go 50 when I need her to. I am running non-directional 6 ply tires with 9" brake drums, and there is no roll bar or safety equipment, save the seat belts I installed. If I get the overdrive, I seriously think it would be kind of scary since I would most likely drive it faster.

If my CJ3A was a commuter / daily driver, I would consider the overdrive if I upgraded the brakes, tires, and added a roll bar. Otherwise, I am happy to be the guy who backs up traffic on some of the local roads!

Just my 2 cents!

Mike

[3aJeeper]

Interesting feedback as I have thought about an overdrive too. Mine is still a long way from being driven �- let alone street legal ;-) - but I wonder what others think? 45mph is about all I'd need given how I intend to use it.

Hadn't thought thru that ovedrive = faster and might require additional safety equipment. I don't want a roll bar so it may be safer to keep it stock and have the designed limitation act as a 'governor' so-to-speak.

If I wanted fast I wouldn't have a CJ3a - amirite? �;D

[aboyandhisdog]

I appreciate your input!  I thought maybe more folks had OD's but maybe not.  My Willys must be geared a little lower than some others because when I go 45mph I'm turning 2600rpm (I have a tach).  That seems like plenty of revs for my engine.  I don't necessarily want to go faster...I would like to turn fewer revs at the speeds I normally drive.  My engine just purrs at 2000rpm so I figure, if I could turn 2000rpm at 45mph with an overdrive, that would be much less stress on my engine and drivetrain.    

Chasm, you're right on about the safety concerns of more speed.  I do have 11 inch brakes and new radial tires and am only driving rural, low traffic roads.  Every once in a while though I need to get on a highway for short distances.

[Gunslinger]

I've struggled with the same question, I've got the same set up as you, 5:38 gears in the rear end, and at 3000 rpm I'm doing a little over 45 mph.  I can get her up to about 52 if I let it wind up, but its clearly out of the torque curve, and it gets squirrly.  I thought "lets put on an overdrive and reduce the rpm by 25% at the same speed, and have about 25% more speed when I need it".  Good idea, not so sure; its still squirrly, I did put the roll bar on mine, took it out of a wrecked wrangler, took some mods to make it fit but it looks good and gives me a place to hang the bikini top, which is  a slightly modified Smitty built top for a cj7.  At the end of the day I just don't think the old girl really want to go that fast, its too much work to drive it that fast so I'm thinking 45 is good enough.

[Chasm]

Well, I felt like I was going real fast this evening!

I took off the canvas and top bows, laid the windshield down, and went cruising around. With the windshield down and the air flowing over my freshly shaven head, I was able to cruise around 50 mph! �8-)

BTW: If you want a roll bar that fits nicely in the back of your CJ3A, look for one from an early CJ5. It will fit nicely on top of the rear wheel wells. It's a 2 man job to put it in, because you have to lift one side and tilt it to get the angle iron foot under the lip of the tub. After you get it in, threre's at least 1/4" of space between the roll bar tubes and the lip of the tub.