Overdrive: Is It Worth It?

So I finally decided to break down and get an overdrive from Advance Adapters based on the feedback from this forum and discussion.

Here’s the link Fireball provided during this initial post discussion as a source for purchasing the OD.

And here’s a comment Fino posted regarding the possibility of needing a different fit

how do I determine what I need before I order?

just for reference, I’m running the V6 with T14/Dana18, 4:88 axels, and 31x10.50s on a 1970 cj5.

any help or suggestions would be greatly appreciated!

thanks in advance.

 

T14/D18 should be 10 spline 29 teeth. The problem is, if you ever plan a transmission upgrade, pretty much everything else is 6 spline. You really need to think about what your plans are for the jeep before spending $ on an overdrive for the oddball T14.

 

And if you take care to keep the oil level up, a used overdrive sells pretty quickly around here if you ever do an upgrade where it isn't usable.

I agree that you probably would need the 29 Tooth 10 spine, IF your transfer case is original to the CJ5, but since things like transmissions and transfer cases are often swapped out over the years, I highly recommend pulling the PTO cover and verifying tooth count on your gear. Older D18s required a 26 tooth gear, and there was an oddball military TC that used something else.

 

When you pull the cover to check the tooth count it's a good time to make sure you have a socket to fit the nut holding that gear on. I don't recall the size but it's a larger nut that standard sets cover. When I did mine I had to stop work to make a run to the store.

 

thank you. I’ll pull the cover and do the count and post what I find.

Just a quick question though….

when installing one of these things, would I need to worry about dislodging any needle bearings or anything?

 

X 10,000

 

This is the best description of what driving an old CJ feels like yet

That being said, the OD in my ‘57 CJ5 exponentially increases its road worthiness even on suburban roads in my area. I kinda couldn’t imagine driving around without it.

 

I like mine. Gives me an additional 15-20 mph overall. Without, I'm usually pegged at 45-50. With, I can hop on the highway and cruise over 60. I don't drive far on the freeway much otherwise it still wouldn't be good enough with people passing me at 80, but it gets me out to some local spots a lot easier.

I wouldn't want to drive mine much over 60 anyways.