Transmission Trouble

A '73 has a Dana 20. A divorced overdrive is impractical/impossible in this application. The rear driveshaft is too short already.

See my response above. What's your axle ratio? What is your tire height? With 31s and 4.27 axles, you're turning 3008 RPM. This is fine - your 258 will run at this speed indefinitely, with no ill effects. Get some quieter tires, insulate your floors, fit a quieter exhaust, and drive it. Be proud. You have a great looking Jeep with an excellent and desirable drivetrain.

It's fine for highway driving. I drove my '73 with 4.27s all over southern and central California (easily 500-1000 miles in a weekend), to the Grand Canyon and back a few times (500 miles each way), and to work each day; no problem. Drive it and be proud.

Taller tires are also an option.

 

Man i wish i had your trans... I have the crappy 3 speed in my cj6. Let me know if you switch it, I may be interested in your 4 speed!

 

timgr the tire height is 31's and I'm not sure about the axle ratio. After talking to my mechanic I've got two options in front of me left. They are to either rebuild the current t-18 in it now or try to find an older model cj 5-speed transmission. I thought that the later model cj transmissions wouldn't fit??? Any info about that one guys?

Thanks

 

The CJ-5 only came with one 5-speed transmission that I know of ... The T-5. It's a light-duty passenger car transmission, but would hold up behind the 258 ok, depending on your driving habits. It is not compatible with your transfer case, so you'd have to swap to the later Dana 300 transfer case too.

The Wrangler used a few additional 5 and 6-speed transmissions, but the Wrangler has a 10" longer wheelbase compared to your CJ-5. Unlikely they will fit easily.

What did your mechanic recommend? Does this mechanic know anything about trucks and Jeeps? This really really really seems more like a clutch problem than a transmission problem. At a full stop, you should be able to put the transmission into reverse without a lot of gear clash. That you can't indicates that the transmission does not stop spinning at a full stop with the clutch in. This is not a problem with the transmission.

Take it somewhere else, seek out some experienced help locally ... something. Be resourceful - your current resources are not serving you well.