gear advice

New here to to forum, but an old cj5 owner. Just bought another '74 CJ5, 232 6 cylinder. For some reason the guy had 16 inch tires on it and it's killed what little power the engine had. I'm looking to change the gearing, was thinking 4.56 I mostly ease around on old dirt roads, not much highway driving...My question, is this too low of a gear?? thanks for any advice

 

I presume it has 3.73s now? The factory ratios were 3.73 and 4.27. The 4.27 ratio was fine for highway travel, but the 232 isn't a powerhouse ... you can go from 100 to 112 hp by replacing the 232 with a 258. 258s are cheap and plentiful, but a 232 should be free - very little demand. A very durable and reliable engine though.

With 28" or 29" tall tires, you'd be at about 3500 rpm with 4.56s at 65 mph. That's fine for the engine, but a little noisy. 4.27s might be better. You may be able to find '72-75 4.27 axles, which would probably be cheaper than changing the gears.

I presume this is a 3-speed transmission? The T-14 has a huge gap between 2nd and 3rd (3.10, 2.61, 1.0, 3.1R) which is a bad match to the 3.73s IMO. The passing gear isn't really usable - you end up slowing down to 35 or 40 if you have to downshift. If you can find a T-15 from a V8 CJ5, it has a usable passing gear (3.0, 1.83, 1.0, 3.0R) which will help with drivability.

Welcome from Boston!

 

Thanks for the advice. I'm assuming it has 3.73's now. It does have the stock 3 speed tranny with Dana 44 rear and Dana 30 front axles. The guy claimed the 232 was just rebuilt, and from what I can tell so far they did an alright job. Doesn't run hot or burn oil. The old engine starts and runs great, but if I could happen upon a 258, I'd probably jump on it. It's been a few years since I was in the Jeep market, had a '72 a '75 a '76 and now the '74...I remember now what I once said "JEEP"...Just Empty Every Pocket

 

For what you are talking about the 4.56 should be fine but probalby a little lower then you think. I run 35" MTRs with 4.56 gears. I set it up this way because it was just slightly lower (numerically higher) then stock gearing (3.73) with that tire size. That gives me a little bit more for off-road use. @60 MPH I run about 2800 RPM.

Depending on your overall tire size you may consider 4.10s.

 

I was going to suggest 4.1 also.
Very happy with them.
up to a 33's you should be fine and a little more middle of the road.

 

I have a Cj5 stock 1971 with Dana 27a Front end, and I think Dana 44 rear.
It came with 265x 7515 tires....I don't know much yet.
Are these tires an OK size for this Jeep.

Mostly it will be used for climbing a 3 mile long ...very steep hill in the winter so I can get home. It's a dirt road, and everyone here has 4x4 and most of the time need chains and 4x4 to get up the road.