My first vehicle! 1956 CJ5

[Catlewis]

Couple thoughts on your current issues,,,,,, regarding the oil leak, how old is the oil (when was it last changed), and what weight oil do you have in the crank case? Manufacturing tolerances on these old engines require thicker lubricants than modern vehicles. I'm using Castrol 20-50 in mine right now. It also leaks a little at the rear main. Plan is to continue driving and monitor oil level.
The trans noises you mentioned,,,,,,, before digging into the trans, first make certain your mounts are good + carefully inspect all mechanical linkages that pass through the floor or firewall to verify none are missing grommets or contacting the body (resting or under acceleration or deceleration). Sometimes the natural torque / twisting of the engine and or trans under acceleration or deceleration results in linkage contacting the body and resonating thru the sheet metal producing all kinds of "OMG" noises.

[bmorgil]

Wow hard to diagnose noise when you have to describe it sometimes. I think Cat has you on a good start. Make sue it isn't something vibrating when you let off the throttle. Resonance is hard to find. Also take a look at the heat riser under the carb. Make sure it isn't loose and rattling. gm is eluding to gear whine. As he is saying, when things wear you can start to loose position on the gear pattern in the axle. Axles have some distinct noise characteristics. Whine is one of them. a high frequency whine that is constant and increases with speed is usually pinion related. Deeper growling that has a rhythm that goes with wheel speed is usually the carrier bearings or Ring Gear related.

[56willys]

Couple thoughts on your current issues,,,,,, regarding the oil leak, how old is the oil (when was it last changed), and what weight oil do you have in the crank case? Manufacturing tolerances on these old engines require thicker lubricants than modern vehicles. I'm using Castrol 20-50 in mine right now. It also leaks a little at the rear main. Plan is to continue driving and monitor oil level.
The trans noises you mentioned,,,,,,, before digging into the trans, first make certain your mounts are good + carefully inspect all mechanical linkages that pass through the floor or firewall to verify none are missing grommets or contacting the body (resting or under acceleration or deceleration). Sometimes the natural torque / twisting of the engine and or trans under acceleration or deceleration results in linkage contacting the body and resonating thru the sheet metal producing all kinds of "OMG" noises.

Im running just straight 30 weight oil in the engine. If my understanding is correct, 20-50 will be thicker when hot? As for the linkages making noise, All i can say is there is a lot of moving stuff and not much rubber/grommets etc.

[56willys]

Wow hard to diagnose noise when you have to describe it sometimes. I think Cat has you on a good start. Make sue it isn't something vibrating when you let off the throttle. Resonance is hard to find. Also take a look at the heat riser under the carb. Make sure it isn't loose and rattling. gm is eluding to gear whine. As he is saying, when things wear you can start to loose position on the gear pattern in the axle. Axles have some distinct noise characteristics. Whine is one of them. a high frequency whine that is constant and increases with speed is usually pinion related. Deeper growling that has a rhythm that goes with wheel speed is usually the carrier bearings or Ring Gear related.

I hadnt really thought of it being rear axle noise. But it could be, it sounds like its coming from the tranny but with a loud exhaust, top down, and every single noise resonating under the tub it is hard to pinpoint exactly where noises are coming from.
I just got th rear diff drained and im starting to put fresh oil in it. Ive never changed axle fluids yet, so maybe some fresh lube will help it.

Ill try to get it out on the road and get a video of it running so you guys can hear what the sound is. I have no idea how to explain it better.

[56willys]

Im planning on ordering a rear main seal pretty soon, Then if i dont get it installed before Bantam ill do it right after. Can i do a rope seal with the crank in place? Anything ive seen says you have to pack the seal in, looks like it might be a pain to pack it in with the crank inplace. So ill probably get rubber. Any thoughts on where to get the seal from? KW has a USA made one https://www.kaiserwillys.com/product...-4-134-engine/ Or is there a better brand out there to get?

As always thank you guys!!!

[bmorgil]

Rope seals are installed by packing them in to the block. The crank needs to be out. I have the KW seal in mine.

[Catlewis]

You've done a ton of work to this Jeep, and I didn't take the time to look back thru your post to see if you ever had the rear drums pulled, however these rears have typical tapered conical wheel bearings similar to what's commonly found on a front spindle. These require manual packing as they're not lubricated by the rear diff oil. If you haven't had those apart and re-packed, that could be some of your noise??? Body isolators are also marginal. Replaced all of mine and they're nothing more than a strip of 1/4" rubber.

[bmorgil]

I agree Cat, he has a ton of work on this baby!

I see he fabricated some body mounts. On the rear wheel bearings, they are greased with a zerk in the axle tube. You apply grease until it purges from a tiny hole on the top of the axle tube right above the bearings.

[Catlewis]

Yep, and thanks for reminding me! I forgot all about those zerks........ (which I actually like!) Point of the advice was to inform (if he didn't already know) they're not lubricated by diff oil as commonly found on most conventional rear designs.

[56willys]

Yes, I made body mounts out of some heavy ¼ inch rubber. I did grease the rear bearings through the zerk fitting. I did when I first got the jeep and again last week. Although I didn't know about the hole in the top. I was even wondering how I would know when it's full. Having the zerk fitting is super slick, makes me wish the front hubs had them also.